1WTNT41 KNHC 292058 2TCDAT1 3TROPICAL STORM TOMAS DISCUSSION NUMBER 1 4NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 5500 PM AST FRI OCT 29 2010 6 7AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT INVESTIGATING THE 8VIGOROUS TROPICAL WAVE LOCATED SOUTHEAST OF THE WINDWARD ISLANDS 9FOUND A CLOSED SURFACE CIRCULATION...ALONG WITH FLIGHT-LEVEL WINDS 10AND UNCONTAMINATED SFMR SURFACE WINDS THAT SUPPORT A 35-KT TROPICAL 11STORM. AS A RESULT...ADVISORIES HAVE BEEN INITIATED ON TROPICAL 12STORM TOMAS...THE NINETEENTH NAMED STORM OF THE 2010 SEASON. 13 14THE INITIAL MOTION IS AN UNCERTAIN 295/15...DUE TO THE POSSIBILITY 15OF REFORMATION OF THE LOW-LEVEL CENTER WITHIN THE CENTRAL DEEP 16CONVECTION. TOMAS IS EXPECTED TO CONTINUE MOVING WEST-NORTHWESTWARD 17FOR THE NEXT 48 HOURS...PASSING THROUGH THE WINDWARD ISLANDS IN 18ABOUT 24 HOURS OR SO. AFTER THAT...THE BROAD TROUGH THAT IS LOCATED 19OFF THE U.S. EAST COAST AND THE BAHAMAS IS FORECAST TO LIFT OUT TO 20THE NORTHEAST...WHICH ALLOWS A RIDGE TO BUILD TO THE NORTH OF TOMAS 21ACROSS THE GREATER ANTILLES...THE BAHAMAS...AND FLORIDA. THE 22EASTERLY FLOW ON THE SOUTH SIDE OF THE RIDGE SHOULD FORCE TOMAS ON 23MORE OF A WESTERLY TRACK THROUGH 96 HOURS. BY DAY 5...A SECOND MUCH 24DEEPER TROUGH IS EXPECTED TO DIG SOUTHWARD INTO THE SOUTHERN PLAINS 25AND SOUTHEASTERN U.S. AND CAUSE THE RIDGE AND ASSOCIATED STEERING 26CURRENTS TO WEAKEN. THE RESULT SHOULD BE A SHARP DECREASE IN 27FORWARD SPEED BY 120 HOURS. THE NHC MODEL GUIDANCE IS IN GOOD 28AGREEMENT ON THIS DEVELOPING SCENARIO...EXCEPT FOR THE GFDL AND 29HWRF MODELS...WHICH ARE CONSIDERED TO BE OUTLIERS AT THIS TIME. 30THE OFFICIAL FORECAST TRACK IS ALONG THE SOUTHERN EDGE OF THE 31GUIDANCE ENVELOPE...BUT NOT AS FAR SOUTH AND WEST AS THE GFS... 32ECMWF...AND UKMET MODELS...WHICH ARE DEPICTING A MUCH WEAKER AND 33SMALLER TROPICAL CYCLONE THAN IS EXPECTED. 34 35RECON AND SATELLITE DATA INDICATE THE LOW-LEVEL AND UPPER-LEVEL 36CIRCULATIONS ARE NOT YET VERTICALLY ALIGNED...WHICH SHOULD RESULT 37IN ONLY SLOW INTENSIFICATION IN THE NEAR TERM. HOWEVER...WITH A 38CENTRAL PRESSURE OF 998 MB...VERY MOIST MID-LEVELS...AND LOW 39VERTICAL SHEAR...IT WOULD NOT TAKE MUCH FOR TOMAS TO INTENSIFY AT A 40FASTER THAN NORMAL RATE. WHILE NOT EXPLICITLY INDICATING RAPID 41INTENSIFICATION...THE OFFICIAL INTENSITY FORECAST REFLECTS THESE 42FAVORABLE ENVIRONMENTAL CONDITIONS...AND IS ABOVE THE SHIPS/LGEM 43INTENSITY MODEL GUIDANCE. 44 45FORECAST POSITIONS AND MAX WINDS 46 47INITIAL 29/2100Z 11.1N 57.5W 35 KT 48 12HR VT 30/0600Z 12.0N 59.5W 40 KT 49 24HR VT 30/1800Z 12.9N 61.8W 50 KT 50 36HR VT 31/0600Z 13.5N 64.0W 60 KT 51 48HR VT 31/1800Z 14.1N 66.2W 70 KT 52 72HR VT 01/1800Z 14.8N 70.4W 90 KT 53 96HR VT 02/1800Z 15.2N 74.0W 100 KT 54120HR VT 03/1800Z 16.0N 76.0W 100 KT 55 56$$ 57FORECASTER STEWART 58 59 60WTNT41 KNHC 300003 61TCDAT1 62TROPICAL STORM TOMAS SPECIAL DISCUSSION NUMBER 2 63NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 64800 PM AST FRI OCT 29 2010 65 66ON THE LAST PASS THROUGH THE CENTER OF TOMAS...THE AIR FORCE 67RECONNAISSANCE AIRCRAFT REPORTED A MAXIMUM FLIGHT-LEVEL WIND OF 61 68KT AND SFMR MEASUREMENTS AROUND 50 KT. THE WINDS HAVE INCREASED 69FASTER THAN WAS INDICATED IN THE PREVIOUS ADVISORY...AND A SPECIAL 70ADVISORY IS BEING ISSUED TO INCREASE THE INTENSITY FORECAST THROUGH 71THE FIRST 48 HOURS. IN ADDITION...THE WIND RADII WERE EXPANDED IN 72ACCORDANCE WITH THE RECONNAISSANCE DATA. 73 74BUOY 41101 IS ALREADY REPORTING SEAS OF 13 FT WELL NORTH OF THE 75CENTER...REQUIRING AN EXPANSION OF THE 12-FT SEAS RADII. 76 77FORECAST POSITIONS AND MAX WINDS 78 79INITIAL 30/0000Z 11.6N 57.6W 50 KT 80 12HR VT 30/0600Z 12.0N 59.5W 55 KT 81 24HR VT 30/1800Z 12.9N 61.8W 60 KT 82 36HR VT 31/0600Z 13.5N 64.0W 70 KT 83 48HR VT 31/1800Z 14.1N 66.2W 80 KT 84 72HR VT 01/1800Z 14.8N 70.4W 90 KT 85 96HR VT 02/1800Z 15.2N 74.0W 100 KT 86120HR VT 03/1800Z 16.0N 76.0W 100 KT 87 88$$ 89FORECASTER BERG/BROWN 90 91 92WTNT41 KNHC 300245 93TCDAT1 94TROPICAL STORM TOMAS DISCUSSION NUMBER 3 95NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 961100 PM AST FRI OCT 29 2010 97 98AS MENTIONED IN THE 0000 UTC SPECIAL ADVISORY...THE AIR FORCE 99RECONNAISSANCE AIRCRAFT REPORTED A MAXIMUM FLIGHT-LEVEL WIND OF 61 100KT AND SFMR MEASUREMENTS BETWEEN 50-55 KT...ALBEIT IN SOME HEAVY 101RAIN...ON THE LAST PASS THROUGH THE CENTER. DEEP CONVECTION HAS 102CONTINUED TO INCREASE SINCE THAT TIME WITH A PROMINENT BAND FORMING 103OVER THE WESTERN SEMICIRCLE...SO THE INITIAL INTENSITY IS BEING 104RAISED TO 55 KT ON THIS ADVISORY. 105 106TOMAS IS BENEFITING FROM EXCELLENT UPPER-LEVEL OUTFLOW IN ALMOST ALL 107QUADRANTS...AND THE CYCLONE APPEARS AS THOUGH IT IS GOING THROUGH A 108PERIOD OF RAPID INTENSIFICATION. SHIPS RI GUIDANCE IS INDICATING 109AT LEAST A 40 PERCENT CHANCE OF A 30-KT INCREASE IN INTENSITY OVER 110THE NEXT 24 HOURS...AND IT IS LIKELY THAT TOMAS WILL REACH 111HURRICANE STRENGTH WITHIN THE NEXT 12-24 HOURS. AFTER 24 112HOURS...NEARLY ALL THE INTENSITY GUIDANCE SHOWS THE INTENSITY 113LEVELING OFF OR ONLY INCREASING MORE MODESTLY THROUGH 120 HOURS. 114HOWEVER...GLOBAL MODEL FIELDS SHOW THE ENVIRONMENT OVER THE 115CARIBBEAN BECOMING FAVORABLE FOR CONTINUED INTENSIFICATION...AND IT 116IS NOT OBVIOUS AT THIS POINT WHAT MIGHT LIMIT THAT TREND. THE 117OFFICIAL FORECAST CONTINUES TO SHOW STEADY STRENGTHENING TO 118CATEGORY 3 STRENGTH BY DAY 4 AND REMAINS ABOVE ALL THE RELIABLE 119INTENSITY MODELS. 120 121THE CENTER APPEARED TO HAVE REFORMED TO THE NORTH EARLIER THIS 122EVENING...AND THE INITIAL MOTION IS ESTIMATED AT 300/14. THE NEW 123OFFICIAL TRACK FORECAST REMAINS LARGELY UNCHANGED FROM THE 124PREVIOUS FORECAST...ALTHOUGH THE FIRST 12-24 HOURS OF THE TRACK 125FORECAST HAVE BEEN SHIFTED A LITTLE TO THE NORTH AS AN ARTIFACT OF 126THE REFORMATION OF THE CENTER. THE GFS...ECMWF...AND GFDL ALL 127SUPPORT A RELATIVELY STRONG MID-LEVEL RIDGE NORTH OF THE GREATER 128ANTILLES AND SHOW TOMAS MOVING GENERALLY WESTWARD ACROSS THE 129SOUTH-CENTRAL CARIBBEAN SEA. THESE ARE USUALLY THE MOST 130TRUSTWORTHY OF THE DYNAMICAL MODELS...AND THE OFFICIAL FORECAST 131FAVORS THEIR SCENARIO...LYING JUST TO THE SOUTH OF THE MODEL 132CONSENSUS. 133 134FORECAST POSITIONS AND MAX WINDS 135 136INITIAL 30/0300Z 12.2N 58.4W 55 KT 137 12HR VT 30/1200Z 13.0N 60.2W 65 KT 138 24HR VT 31/0000Z 13.7N 62.7W 75 KT 139 36HR VT 31/1200Z 14.2N 65.0W 85 KT 140 48HR VT 01/0000Z 14.5N 67.1W 90 KT 141 72HR VT 02/0000Z 15.0N 71.0W 95 KT 142 96HR VT 03/0000Z 15.5N 74.0W 100 KT 143120HR VT 04/0000Z 16.0N 76.0W 100 KT 144 145$$ 146FORECASTER BERG/BROWN 147 148 149WTNT41 KNHC 300849 150TCDAT1 151TROPICAL STORM TOMAS DISCUSSION NUMBER 4 152NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 153500 AM AST SAT OCT 30 2010 154 155THE SATELLITE PRESENTATION OF TOMAS HAS IMPROVED OVERNIGHT. AN 156EARLIER GAP IN THE DEEP CONVECTION NEAR THE CENTER HAS FILLED IN 157...AND THE OUTFLOW REMAINS EXCELLENT. ALSO...IMAGERY FROM THE RADAR 158ON MARTINIQUE AND A 0624 UTC TRMM PASS SUGGEST THAT AN EYEWALL 159MAY BE FORMING. BASED ON THESE TRENDS...THE INITIAL INTENSITY IS 160RAISED TO 60 KT. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS 161SCHEDULED TO INVESTIGATE TOMAS LATER THIS MORNING TO GET BETTER 162INFORMATION ON THE STRUCTURE AND INTENSITY OF THE CYCLONE. DURING 163THE NEXT DAY OR SO...CONDITIONS APPEAR FAVORABLE FOR CONTINUED 164INTENSIFICATION. IN FACT...THE SHIPS MODEL RAPID INTENSITY INDEX 165SHOWS A NEARLY 60 PERCENT CHANCE OF A 25-KT INCREASE IN 24 HOURS. 166BEYOND THAT TIME...THE SHIPS MODEL...BASED ON GFS MODEL FIELDS... 167SHOWS AN INCREASE IN SOUTHWESTERLY SHEAR...WHICH SHOULD SLOW THE 168RATE OF INTENSIFICATION SOMEWHAT. AFTER 72 HOURS...THE SHEAR MAY 169RELAX AND ALLOW FOR FURTHER INTENSIFICATION. THE NEW OFFICIAL 170FORECAST REFLECTS THIS THINKING AND IS ABOVE ALL OF THE RELIABLE 171INTENSITY MODELS THROUGH THE PERIOD. 172 173THE CENTER APPEARS TO BE LOCATED A LITTLE NORTH OF THE PREVIOUS 174FORECAST TRACK BASED ON THE RECENT TRMM PASS...AND THE INITIAL 175MOTION ESTIMATE IS 300/13. TOMAS IS CURRENTLY BEING STEERED 176WEST-NORTHWESTWARD TO THE SOUTH OF A MID-LEVEL RIDGE THAT EXTENDS 177FROM THE CENTRAL ATLANTIC INTO THE NORTHEASTERN CARIBBEAN. AS A 178MID-LEVEL TROUGH CURRENTLY SITUATED OVER THE SOUTHWESTERN ATLANTIC 179LIFTS OUT...ANOTHER RIDGE WILL BUILD IN NORTH OF TOMAS...WHICH 180SHOULD IMPART A WEST-NORTHWESTWARD OR WESTWARD MOTION THROUGH 72 181HOURS. BEYOND THAT TIME...THE GLOBAL MODELS SHOW A LONGWAVE TROUGH 182MOVING INTO EASTERN NORTH AMERICA AND A CUTOFF LOW DEVELOPING IN 183THE GULF OF MEXICO. THIS SHOULD WEAKEN THE RIDGE AND CAUSE A 184DECREASE IN FORWARD SPEED LATE IN THE PERIOD...AND POTENTIALLY A 185NORTHWARD TURN. THE TRACK MODEL ENVELOPE HAS SHIFTED NORTHWARD WITH 186THIS CYCLE...BUT THE FORECAST IS ADJUSTED ONLY SLIGHTLY NORTHWARD 187OUT OF RESPECT FOR THE GFS...UKMET...AND ECMWF MODELS WHICH REMAIN 188FARTHER SOUTH. LATE IN THE PERIOD...THE FORWARD SPEED IS QUITE SLOW 189DUE TO THE LARGE UNCERTAINTY IN THE TIMING AND SHARPNESS OF THE 190POTENTIAL NORTHWARD TURN. 191 192FORECAST POSITIONS AND MAX WINDS 193 194INITIAL 30/0900Z 12.9N 59.5W 60 KT 195 12HR VT 30/1800Z 13.5N 61.3W 70 KT 196 24HR VT 31/0600Z 14.1N 63.7W 80 KT 197 36HR VT 31/1800Z 14.6N 65.9W 85 KT 198 48HR VT 01/0600Z 15.1N 68.1W 90 KT 199 72HR VT 02/0600Z 15.5N 71.5W 90 KT 200 96HR VT 03/0600Z 16.0N 73.5W 100 KT 201120HR VT 04/0600Z 16.5N 74.5W 100 KT 202 203$$ 204FORECASTER BRENNAN 205 206 207WTNT41 KNHC 301501 208TCDAT1 209HURRICANE TOMAS DISCUSSION NUMBER 5 210NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 2111100 AM AST SAT OCT 30 2010 212 213AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS 214THIS MORNING FOUND MAXIMUM 700 MB FLIGHT-LEVEL WINDS OF 68 KT IN 215THE SOUTHEAST QUADRANT ALONG WITH SEVERAL 64-66 KT RELIABLE SFMR 216WINDS. IN ADDITION...A DROPSONDE IN THE NORTHEAST EYEWALL INDICATED 217A SURFACE WIND OF 72 KT. HOWEVER...THE BOUNDARY-LAYER WIND PROFILES 218SUGGEST A SLIGHTLY LESSER SURFACE WIND SPEED ESTIMATE OF AROUND 66 219KT. A COMBINATION OF THIS DATA EASILY SUPPORTS A 65-KT HURRICANE... 220AND TOMAS HAS BEEN UPGRADED ACCORDINGLY. 221 222THE INITIAL MOTION ESTIMATE IS 290/13. THE LATEST RECON FIX 223POSITIONS HAVE COME IN RIGHT ON THE PREVIOUS ADVISORY TRACK. 224UPPER-AIR DATA FROM SAN JUAN REVEALED 30-METER 500 MB HEIGHT 225INCREASES DURING THE PAST 24 HOURS...WHICH CLEARLY INDICATES THAT 226MID-LEVEL RIDGING TO THE NORTH OF TOMAS HAS STARTED AS THE 227DEEP-LAYER TROUGH THAT HAS CAPTURED HURRICANE SHARY LIFTS RAPIDLY 228TO THE NORTHEAST AWAY FROM THE CARIBBEAN REGION. LOW- TO MID-LEVEL 229RIDGING IS FORECAST BY ALL OF THE GLOBAL MODELS TO CONTINUE 230BUILDING WESTWARD ACROSS THE LESSER AND GREATER ANTILLES FOR THE 231NEXT 72-96 HOURS. THIS SHOULD GRADUALLY FORCE TOMAS ON A MORE 232WESTERLY TRACK...ESPECIALLY AFTER 48 HOURS. HOWEVER...BY DAY 5...A 233BROAD MID-TROPOSPHERIC TROUGH CURRENTLY LOCATED ALONG THE U.S. WEST 234COAST IS FORECAST TO MOVE EASTWARD INTO THE CENTRAL U.S. BY DAYS 2352-3 AND THEN DIG MORE SOUTHEASTWARD AFTER THAT...AND INTO THE GULF 236OF MEXICO AND SOUTHEASTERN MEXICO BY DAY 5. THIS IS EXPECTED TO 237RESULT IN A SIGNIFICANT EROSION OF THE WESTERN PORTION OF THE RIDGE 238AND A WEAKENING OF THE STEERING CURRENT ACROSS THE WESTERN AND 239CENTRAL CARIBBEAN SEA. THIS WEAK FLOW REGIME SHOULD ALLOW TOMAS TO 240SLOW DOWN AND GRADUALLY MOVE NORTHWARD. THE OFFICIAL FORECAST TRACK 241IS JUST AN UPDATE AND EXTENSION OF THE PREVIOUS ADVISORY TRACK... 242AND REMAINS ALONG THE SOUTHERN EDGE OF THE NHC GUIDANCE ENVELOPE. 243 244TOMAS HAS DEVELOPED A 30-40 NMI DIAMETER EYE NOTED IN RECENT RADAR 245IMAGES FROM MARTINIQUE. THE UPPER-LEVEL OUTFLOW PATTERN IS WELL 246ESTABLISHED AND CONTINUES TO IMPROVE. A COMBINATION OF THE 247AFOREMENTIONED FEATURES ALONG WITH DEEP WARM WATER AHEAD OF THE 248CYCLONE SHOULD RESULT IN CONTINUED STRENGTHENING FOR THE NEXT 24 249HOURS OR SO. AFTER THAT...HOWEVER...WESTERLY 300 MB WINDS ARE 250EXPECTED TO UNDERCUT THE IMPRESSIVE OUTFLOW LAYER AND INDUCE SOME 251SHEAR ON TOMAS...WHICH MAY HALT THE INTENSIFICATION PROCESS. 252USUALLY WITH WESTERLY SHEAR COMES DRY AIR MID-LEVEL AIR...AND THIS 253INHIBITING FACTOR WAS CLEARLY INDICATED IN UPPER-AIR DATA WEST OF 25465W LONGITUDE THIS MORNING. BY 72 HOURS...ENVIRONMENTAL CONDITIONS 255ARE EXPECTED TO IMPROVE AS TOMAS SLOWS DOWN...AND A INTENSIFICATION 256IS EXPECTED TO RESUME. THE OFFICIAL INTENSITY FORECAST IS ABOVE THE 257SHIPS/LGEM MODELS...AND IS SIMILAR TO THE PREVIOUS FORECAST AND 258LAST TWO GFDL MODEL RUNS...WHICH MAKES A TOMAS A MAJOR HURRICANE 259SOUTH OF HISPANIOLA. 260 261FORECAST POSITIONS AND MAX WINDS 262 263INITIAL 30/1500Z 13.3N 60.7W 65 KT 264 12HR VT 31/0000Z 13.8N 62.5W 75 KT 265 24HR VT 31/1200Z 14.4N 64.8W 80 KT 266 36HR VT 01/0000Z 14.8N 67.2W 80 KT 267 48HR VT 01/1200Z 15.2N 69.2W 85 KT 268 72HR VT 02/1200Z 15.6N 72.3W 90 KT 269 96HR VT 03/1200Z 16.0N 74.0W 100 KT 270120HR VT 04/1200Z 16.5N 75.0W 100 KT 271 272$$ 273FORECASTER STEWART 274 275 276WTNT41 KNHC 302046 277TCDAT1 278HURRICANE TOMAS DISCUSSION NUMBER 6 279NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 280500 PM AST SAT OCT 30 2010 281 282AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS 283THIS AFTERNOON FOUND MAXIMUM 700 MB FLIGHT-LEVEL WINDS OF 67 KT IN 284THE NORTH QUADRANT...WHICH EQUATES TO ABOUT 60 KT SURFACE WINDS. 285SATELLITE INTENSITY ESTIMATES ARE A CONSENSUS T4.0/65 KT FROM TAFB 286AND SAB. THE STRUCTURE OF TOMAS HAS IMPROVED CONSIDERABLY IN RADAR 287IMAGERY FROM MARTINIQUE...AND THE CYCLONE NOW POSSESSES A CLOSED 25 288N MI DIAMETER EYE. THE INTENSITY IS BEING HELD AT 65 KT FOR THIS 289ADVISORY...WHICH COULD BE A LITTLE LOW BASED ON SOME OF THE DAMAGE 290REPORTS THAT HAVE BEEN RECEIVED FROM HAM RADIO OPERATORS ON ST. 291LUCIA AND ST. VINCENT. 292 293THE INITIAL MOTION ESTIMATE IS 290/09. TOMAS REMAINS ON TRACK... 294AND THERE IS NO SIGNIFICANT CHANGE TO THE PREVIOUS FORECAST TRACK OR 295REASONING. THE LOW- TO MID-LEVEL RIDGE TO THE NORTH OF TOMAS IS 296EXPECTED TO CONTINUE TO BUILD WESTWARD ACROSS THE GREATER ANTILLES 297FOR THE NEXT 96 HOURS...WHICH SHOULD KEEP TOMAS ON A WEST-NORTHWEST 298TO WESTWARD TRACK. HOWEVER...A BROAD LONGWAVE TROUGH CURRENTLY 299ALONG THE U.S. WEST COAST IS EXPECTED TO MOVE EASTWARD AND THEN 300SOUTHEASTWARD INTO THE SOUTHEASTERN UNITED STATES...AND PINCH OFF A 301CLOSED LOW OVER THE GULF OF MEXICO AND SOUTHEASTERN MEXICO BY 120 302HOURS. THE STRONG SOUTHWESTERLY FLOW ON THE EAST SIDE OF THE 303AFOREMENTIONED TROUGH AND LOW IS EXPECTED TO RESULT IN A 304SIGNIFICANT EROSION OF THE WESTERN PORTION OF THE GREATER ANTILLES 305RIDGE AND CAUSE THE STEERING CURRENTS ACROSS THE WESTERN AND 306CENTRAL CARIBBEAN SEA TO WEAKEN...ALLOWING TOMAS TO SLOW DOWN 307CONSIDERABLY AND BEGIN TO MOVE POLEWARD. MOST OF THE MODEL GUIDANCE 308IS IN GOOD AGREEMENT ON THIS GENERAL TRACK SCENARIO EXCEPT FOR 309SPEED DIFFERENCES. THE OFFICIAL FORECAST TRACK IS JUST AN UPDATE OF 310THE PREVIOUS ADVISORY TRACK...AND REMAINS ALONG THE SOUTHERN EDGE 311OF THE NHC GUIDANCE ENVELOPE...BUT NOT AS FAR SOUTH AS THE GFS AND 312ECMWF MODELS. 313 314WITH A CLOSED EYE AND A FAVORABLE UPPER-LEVEL ENVIRONMENT...TOMAS IS 315FORECAST TO STRENGTHEN FOR THE NEXT 24 HOURS OR SO BEFORE WEAK 316WESTERLY 400-300 MB WINDS UNDERCUT THE IMPRESSIVE OUTFLOW LAYER AND 317ENTRAINMENT OF DRY MID-LEVEL AIR FROM THE WEST COMBINE TO INTERRUPT 318THE STRENGTHENING PROCESS. HOWEVER...BY 48-72 HOURS...ENVIRONMENTAL 319CONDITIONS ARE FORECAST TO IMPROVE...WHICH SHOULD ALLOW TOMAS TO 320RESUME STEADY INTENSIFICATION. THE GFS-BASED SHIPS AND LGEM MODELS 321ARE FORECASTING STEADY WEAKENING AFTER 48 HOURS...BUT THAT IS 322BELIEVED TO BE DUE TO ERRONEOUS MODEL-INDUCED SOUTHWESTERLY 323VERTICAL SHEAR AFFECTING TOMAS AS A RESULT OF THE OFFICIAL FORECAST 324TRACK BEING ABOUT 120 N MI NORTH OF THE LARGE SCALE UPPER-LEVEL 325ANTICYCLONE DEPICTED IN THE GFS MODEL. THE INTENSITY FORECAST 326REMAINS ABOVE THE SHIPS/LGEM MODELS...AND IS SIMILAR TO THE 327PREVIOUS FORECAST AND LAST TWO GFDL MODEL RUNS. 328 329FORECAST POSITIONS AND MAX WINDS 330 331INITIAL 30/2100Z 13.5N 61.4W 65 KT 332 12HR VT 31/0600Z 14.0N 63.4W 75 KT 333 24HR VT 31/1800Z 14.5N 65.7W 80 KT 334 36HR VT 01/0600Z 14.9N 67.9W 80 KT 335 48HR VT 01/1800Z 15.2N 69.7W 85 KT 336 72HR VT 02/1800Z 15.7N 72.4W 90 KT 337 96HR VT 03/1800Z 16.0N 74.0W 95 KT 338120HR VT 04/1800Z 16.5N 74.5W 100 KT 339 340$$ 341FORECASTER STEWART 342 343 344WTNT41 KNHC 302202 345TCDAT1 346HURRICANE TOMAS SPECIAL DISCUSSION NUMBER 7 347NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 348600 PM AST SAT OCT 30 2010 349 350REPORTS FROM THE METEOROLOGICAL SERVICE OF ST. LUCIA INDICATE THAT 351TOMAS HAS STRENGTHENED...WITH MAXIMUM WINDS OF 80 KT. THIS SPECIAL 352ADVISORY IS ISSUED TO INCREASE THE INITIAL AND FORECAST INTENSITY 353OF THE HURRICANE. NO OTHER CHANGES TO THE FORECAST HAVE BEEN MADE. 354 355 356FORECAST POSITIONS AND MAX WINDS 357 358INITIAL 30/2200Z 13.5N 61.6W 80 KT 359 12HR VT 31/0600Z 14.0N 63.4W 85 KT 360 24HR VT 31/1800Z 14.5N 65.7W 90 KT 361 36HR VT 01/0600Z 14.9N 67.9W 90 KT 362 48HR VT 01/1800Z 15.2N 69.7W 95 KT 363 72HR VT 02/1800Z 15.7N 72.4W 95 KT 364 96HR VT 03/1800Z 16.0N 74.0W 95 KT 365120HR VT 04/1800Z 16.5N 74.5W 100 KT 366 367$$ 368FORECASTER BERG/FRANKLIN 369 370 371WTNT41 KNHC 310246 372TCDAT1 373HURRICANE TOMAS DISCUSSION NUMBER 8 374NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 3751100 PM AST SAT OCT 30 2010 376 377THE STRUCTURE OF TOMAS HAS CHANGED LITTLE SINCE THE TIME THE ST. 378LUCIA WEATHER SERVICE REPORTED SUSTAINED WINDS ON THAT ISLAND OF AT 379LEAST 80 KT AROUND 2130 UTC. AN EYE HAS NOT BECOME ESTABLISHED ON 380INFRARED SATELLITE IMAGERY...ALTHOUGH IT IS WELL DEFINED IN RADAR 381DATA FROM MARTINIQUE. THE INITIAL INTENSITY IS KEPT AT 80 KT SINCE 382THERE ARE NO OBVIOUS RECENT CHANGES...BUT IT IS POSSIBLE THIS COULD 383BE A BIT CONSERVATIVE. AN AIR FORCE HURRICANE HUNTER AIRCRAFT IS 384SCHEDULED TO INVESTIGATE TOMAS LATER TONIGHT. 385 386THE INITIAL MOTION IS 285/8. THE CYCLONE IS EXPECTED TO 387GRADUALLY GAIN LATITUDE FOR THE NEXT 48 HOURS OR SO DUE TO A MID- 388TO UPPER-LEVEL TROUGH THAT IS CURRENTLY LOCATED OVER THE SOUTHWEST 389ATLANTIC. THE TRACK GUIDANCE IS IN GENERALLY GOOD AGREEMENT ON 390THIS SOLUTION...BUT THERE IS MUCH GREATER SPREAD AFTER 48 HOURS. 391THE GFS...ECMWF...UKMET...AND GFDL SUPPORT A STRONGER MID-LEVEL 392RIDGE OVER THE GREATER ANTILLES AND MOVE TOMAS ON A WESTWARD OR 393JUST SOUTH OF WESTWARD MOTION ON DAYS 2-4. THE NOGAPS AND GFDN 394SHOW TOMAS MOVING WELL NORTH OF HISPANIOLA BY DAY 5...AND THE HWRF 395SHOWS THE CYCLONE STALLING OVER THE EASTERN CARIBBEAN SEA. THE 396LATTER THREE MODELS APPEAR TO BE OUTLIERS. THE NEW OFFICIAL 397FORECAST IS JUST A LITTLE SOUTH OF THE PREVIOUS FORECAST TO COME 398INTO BETTER AGREEMENT WITH THE CONSENSUS OF THE MORE SOUTHERN BATCH 399OF MODELS. 400 401THERE CONTINUES TO BE LOW CONFIDENCE IN THE INTENSITY FORECAST. 402NONE OF THE INTENSITY MODELS SHOW MUCH STRENGTHENING BEYOND ABOUT 40390 KT. THE 200-MB FLOW OVER THE CARIBBEAN SEA SHOULD BE FAVORABLE 404FOR STRENGTHENING...ESPECIALLY IF TOMAS MAINTAINS A MORE 405SOUTHERN COURSE. HOWEVER...CROSS-SECTION ANALYSES OF THE GUIDANCE 406DOES INDICATE THAT THE CYCLONE VORTEX COULD BECOME A LITTLE TILTED 407OVER THE NEXT 48 HOURS OR SO...POSSIBLY DUE TO SHEAR BELOW THE 408OUTFLOW LAYER. BECAUSE OF THESE MIXED SIGNALS...THE OFFICIAL 409INTENSITY FORECAST ONLY SHOWS MODEST STRENGTHENING THROUGH 24 HOURS 410AND ESSENTIALLY HOLDS THE INTENSITY FAIRLY STEADY THEREAFTER. 411 412FORECAST POSITIONS AND MAX WINDS 413 414INITIAL 31/0300Z 13.6N 62.1W 80 KT 415 12HR VT 31/1200Z 14.0N 63.8W 90 KT 416 24HR VT 01/0000Z 14.6N 65.9W 95 KT 417 36HR VT 01/1200Z 14.9N 68.0W 95 KT 418 48HR VT 02/0000Z 15.0N 69.7W 95 KT 419 72HR VT 03/0000Z 15.0N 72.5W 95 KT 420 96HR VT 04/0000Z 15.5N 74.0W 100 KT 421120HR VT 05/0000Z 16.0N 74.5W 100 KT 422 423$$ 424FORECASTER BERG/FRANKLIN 425 426 427WTNT41 KNHC 310843 428TCDAT1 429HURRICANE TOMAS DISCUSSION NUMBER 9 430NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 431500 AM AST SUN OCT 31 2010 432 433DATA FROM THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT...ALONG 434WITH SATELLITE AND RADAR IMAGERY...INDICATE THAT TOMAS HAS BECOME 435BETTER ORGANIZED IN THE PAST FEW HOURS. THE INITIAL INTENSITY OF 85 436KT IS BASED ON A 700-MB FLIGHT LEVEL WIND MAXIMUM OF 97 KT AND A 437MAXIMUM SFMR READING OF 85 KT. HOWEVER...DROPSONDE DATA FROM THE 438AIRCRAFT AND A 0350 UTC TRMM PASS INDICATE THAT THE VORTEX IS 439TILTED NORTHEASTWARD WITH HEIGHT. THIS SUGGESTS THAT SOUTHWESTERLY 440SHEAR IS IMPACTING THE CYCLONE AS SEEN IN THE SHIPS MODEL ANALYSIS 441WHICH IS BASED ON ATMOSPHERIC FIELDS FROM THE GFS MODEL. IN THE 442SHORT TERM...THE SHIPS...LGEM...AND GFDL ALL SHOW SOME ADDITIONAL 443INTENSIFICATION...AND SO DOES THE OFFICIAL FORECAST. FROM 24 TO 72 444HOURS...THE SHIPS MODEL SHOWS THE SHEAR INCREASING...AND ALL OF THE 445INTENSITY GUIDANCE WEAKENS TOMAS. ADDITIONALLY...THE GFS AND ECMWF 446SHOW THE MID-LEVEL VORTEX ASSOCIATED WITH TOMAS WEAKENING DURING 447THIS PERIOD. GIVEN THIS...THE OFFICIAL FORECAST WILL SHOW A SLIGHT 448DIP IN THE INTENSITY AT 48 AND 72 HOURS...BUT REMAINS WELL ABOVE 449ALL OF THE GUIDANCE. AROUND 96 HOURS...THE SHEAR MAY DECREASE AND 450ALLOW FOR SOME STRENGTHENING...AS INDICATED BY THE LGEM. 451 452BASED ON RECENT FIXES TOMAS IS A BIT NORTH OF THE PREVIOUS TRACK 453FORECAST AND THE LONG-TERM INITIAL MOTION ESTIMATE IS 290/7. TOMAS 454IS CURRENTLY LOCATED SOUTH OF A MID-LEVEL TROUGH SITUATED OVER THE 455SOUTHWEST ATLANTIC. AS THIS TROUGH MOVES EASTWARD...A MID-LEVEL 456RIDGE BUILDS NORTH OF TOMAS AND SHOULD RESULT IN A TURN TOWARD THE 457WEST IN 2 OR 3 DAYS. LATE IN THE PERIOD...THE RIDGE BREAKS DOWN AS 458A LARGE DEEP-LAYER TROUGH MOVES INTO EASTERN NORTH AMERICA... 459RESULTING IN A SLOWER FORWARD SPEED OF THE CYCLONE AND SOME GAIN IN 460LATITUDE. HOWEVER...THE MODEL SPREAD IS QUITE LARGE AT DAYS 4 AND 5 461DUE TO DIFFERENCES IN THE TIMING AND SHARPNESS OF THE NORTHWARD 462TURN AS TOMAS INTERACTS WITH THE TROUGH. THE NEW NHC TRACK IS A 463LITTLE NORTH OF THE PREVIOUS ONE DUE TO THE INITIAL POSITION...BUT 464IS ON THE SOUTH SIDE OF THE GUIDANCE SUITE IN DEFERENCE TO THE 465GFS...ECMWF...UKMET AND GFDL MODELS...WHICH ARE ALL EVEN FARTHER 466SOUTH. AT DAY 5...A SLOW NORTH-NORTHWESTWARD MOTION IS SHOWN...BUT 467CONFIDENCE IN THE DETAILS OF THE TRACK FORECAST ARE LOWER THAN 468USUAL AT THE END OF THE PERIOD. 469 470FORECAST POSITIONS AND MAX WINDS 471 472INITIAL 31/0900Z 14.0N 62.9W 85 KT 473 12HR VT 31/1800Z 14.4N 64.3W 95 KT 474 24HR VT 01/0600Z 14.8N 66.4W 95 KT 475 36HR VT 01/1800Z 15.1N 68.4W 95 KT 476 48HR VT 02/0600Z 15.1N 70.0W 90 KT 477 72HR VT 03/0600Z 15.0N 72.0W 90 KT 478 96HR VT 04/0600Z 15.5N 73.5W 100 KT 479120HR VT 05/0600Z 16.5N 74.0W 100 KT 480 481$$ 482FORECASTER BRENNAN 483 484 485WTNT41 KNHC 311444 486TCDAT1 487HURRICANE TOMAS DISCUSSION NUMBER 10 488NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 4891100 AM AST SUN OCT 31 2010 490 491DEEP CONVECTION ASSOCIATED WITH TOMAS HAS GENERALLY DECREASED DURING 492THE LAST FEW HOURS AND BANDING FEATURES HAVE BECOME A LITTLE LESS 493ORGANIZED. IN ADDITION...RECENT MICROWAVE IMAGES NO LONGER SHOW AN 494EYE. BASED ON THIS...THE INITIAL WIND SPEED IS LOWERED TO 80 495KT...WHICH IS A BLEND OF THE LATEST SUBJECTIVE AND OBJECTIVE 496SATELLITE INTENSITY ESTIMATES. THE NEXT AIR FORCE RESERVE 497RECONNAISSANCE AIRCRAFT SHOULD PROVIDE A BETTER ASSESSMENT OF THE 498INTENSITY EARLY THIS AFTERNOON. 499 500THE INITIAL MOTION ESTIMATE IS 285/8. A GENERAL WESTWARD TO 501WEST-NORTHWESTWARD MOTION AT ABOUT THE SAME SPEED IS EXPECTED 502DURING THE NEXT COUPLE OF DAYS AS MID-LEVEL RIDGING REMAINS IN 503PLACE TO THE NORTH OF TOMAS. SOME OF THE MODELS EVEN SHOW A SOUTH 504OF WEST MOTION DURING THAT TIME. IN ABOUT 3 DAYS...THE CYCLONE IS 505EXPECTED TO SLOW DOWN AS A LARGE MID- TO UPPER-LEVEL LOW MOVES OVER 506THE GULF OF MEXICO...CAUSING THE RIDGE TO ERODE. TOMAS IS FORECAST 507TO GRADUALLY TURN TOWARD THE NORTH IN 4 TO 5 DAYS AS IT FEELS THE 508INFLUENCE OF SOUTHERLY FLOW TO THE EAST OF THE TROUGH. THE LATEST 509MODEL GUIDANCE HAS CHANGED LITTLE FROM THE LAST CYCLE...AND THE 510OFFICIAL FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS TRACK. 511 512ALTHOUGH TOMAS LIES OVER AN AREA OF HIGH OCEANIC HEAT CONTENT... 513MODERATE SOUTHWESTERLY SHEAR AND SOME MID-LEVEL DRY AIR AS SHOWN BY 514MODEL CROSS SECTIONS COULD BE A LIMITING FACTOR FOR INTENSIFICATION 515DURING THE NEXT COUPLE OF DAYS. IN FACT...SEVERAL OF THE RELIABLE 516MODELS...INCLUDING THE GFS...ECMWF...AND GFDL...SHOW THE VORTEX 517TILTING TO THE NORTHEAST WITH HEIGHT. THIS RESULTS IN THE 518WEAKENING OF THE HURRICANE IN THOSE MODELS DURING THE NEXT COUPLE 519OF DAYS. THE OFFICIAL FORECAST HAS BEEN NUDGED DOWNWARD THROUGH 48 520HOURS BUT REMAINS HIGHER THAN ALL OF THE INTENSITY GUIDANCE DURING 521THAT TIME. A MORE FAVORABLE UPPER-LEVEL WIND PATTERN IS EXPECTED 522DURING THE 3 TO 5 DAY TIME FRAME...AND THAT SHOULD ALLOW FOR STEADY 523STRENGTHENING. 524 525ALTHOUGH TROPICAL STORM WARNINGS FOR THE WINDWARD ISLANDS HAVE BEEN 526DISCONTINUED...THE THREAT OF HEAVY RAINFALL IS EXPECTED TO CONTINUE 527OVER MUCH OF THE LESSER ANTILLES THROUGH TONIGHT. 528 529FORECAST POSITIONS AND MAX WINDS 530 531INITIAL 31/1500Z 14.0N 63.7W 80 KT 532 12HR VT 01/0000Z 14.5N 65.1W 75 KT 533 24HR VT 01/1200Z 14.9N 67.2W 75 KT 534 36HR VT 02/0000Z 15.0N 69.1W 75 KT 535 48HR VT 02/1200Z 15.0N 70.6W 75 KT 536 72HR VT 03/1200Z 15.0N 72.5W 85 KT 537 96HR VT 04/1200Z 15.5N 73.5W 95 KT 538120HR VT 05/1200Z 17.0N 73.5W 100 KT 539 540$$ 541FORECASTER CANGIALOSI/BROWN 542 543 544WTNT41 KNHC 312031 545TCDAT1 546HURRICANE TOMAS DISCUSSION NUMBER 11 547NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 548500 PM AST SUN OCT 31 2010 549 550DATA FROM AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT INDICATE THAT 551TOMAS HAS WEAKENED A LITTLE MORE. THE AIRCRAFT REPORTED A MAXIMUM 552850 MB FLIGHT-LEVEL WIND OF 74 KT...AN SFMR SURFACE WIND OF 64 553KT...AND A MINIMUM PRESSURE OF 994 MB. THESE DATA SUPPORT 554MAINTAINING TOMAS AS A HURRICANE WITH AN INITIAL WIND SPEED OF 65 555KT. 556 557THE INITIAL MOTION IS SLIGHTLY TO THE LEFT AND A LITTLE FASTER THAN 558BEFORE...280/10. TOMAS IS FORECAST TO CONTINUE MOVING WESTWARD FOR 559THE NEXT COUPLE OF DAYS AS IT REMAINS SOUTH OF A MID-LEVEL RIDGE. 560BEYOND THAT TIME...THE CYCLONE IS EXPECTED TO SLOW DOWN AND 561GRADUALLY TURN TOWARD THE NORTH AS THE STEERING CURRENTS WEAKEN DUE 562TO A LARGE MID- TO UPPER-LEVEL TROUGH MOVING ACROSS THE GULF OF 563MEXICO. ALTHOUGH THE TRACK MODEL GUIDANCE IS IN FAIR AGREEMENT IN 564THE EVOLUTION OF THE LARGE-SCALE PATTERN...THERE ARE CONSIDERABLE 565DIFFERENCES AS TO WHERE AND WHEN THE NORTHWARD TURN OCCURS. THE 566OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS ONE FOR THE NEXT 3 TO 5674 DAYS...AND THEN LIES A LITTLE TO THE RIGHT OF THE LAST TRACK TO 568COME INTO BETTER AGREEMENT WITH THE LATEST GUIDANCE. THIS TRACK 569FORECAST IS CLOSE TO A CONSENSUS OF THE GFS...GFDL...ECMWF...AND 570UKMET MODELS. IT SHOULD BE NOTED THAT CONFIDENCE IN THE LONG-TERM 571FORECAST POINTS ARE OF LOWER CONFIDENCE THAN NORMAL. 572 573SOME ADDITIONAL WEAKENING SEEMS LIKELY DURING THE NEXT DAY OR TWO AS 574SOUTHWESTERLY SHEAR OF 20-25 KT AND SOME MID-LEVEL DRY AIR CONTINUE 575TO IMPACT THE CYCLONE. THE OFFICIAL FORECAST FOLLOWS THE TREND IN 576THE GUIDANCE AND IS ONCE AGAIN ADJUSTED DOWNWARD...BRINGING TOMAS 577BELOW HURRICANE STRENGTH WITHIN THE NEXT 12 HOURS. BEYOND A COUPLE 578OF DAYS...THE SHEAR IS EXPECTED TO LESSEN WHILE TOMAS REMAINS OVER 579FAVORABLE OCEANIC CONDITIONS. ALL OF THE INTENSITY MODELS RESPOND 580AND SHOW THE SYSTEM INTENSIFYING IN THE 3 TO 5 DAY RANGE...AND THE 581OFFICIAL FORECAST FOLLOWS SUIT AND IS AT THE HIGH END OF THE 582GUIDANCE THROUGHOUT THE FORECAST PERIOD. 583 584 585FORECAST POSITIONS AND MAX WINDS 586 587INITIAL 31/2100Z 14.4N 64.9W 65 KT 588 12HR VT 01/0600Z 14.7N 66.4W 60 KT 589 24HR VT 01/1800Z 15.0N 68.3W 55 KT 590 36HR VT 02/0600Z 15.0N 69.9W 55 KT 591 48HR VT 02/1800Z 15.0N 71.3W 60 KT 592 72HR VT 03/1800Z 15.3N 72.5W 65 KT 593 96HR VT 04/1800Z 16.0N 73.0W 80 KT 594120HR VT 05/1800Z 18.5N 72.5W 90 KT...INLAND 595 596$$ 597FORECASTER CANGIALOSI/BROWN 598 599 600WTNT41 KNHC 010234 601TCDAT1 602TROPICAL STORM TOMAS DISCUSSION NUMBER 12 603NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 6041100 PM AST SUN OCT 31 2010 605 606RECENT MICROWAVE DATA...PARTICULARLY A 0045 UTC SSMIS PASS... 607INDICATE THAT THE LOW-LEVEL CENTER OF TOMAS IS NOW LOCATED ABOUT 608140 N MI TO THE WEST OF THE DEEP CONVECTION AND HAS BEEN MOVING A 609LITTLE SOUTH OF DUE WEST. DVORAK ESTIMATES HAVE DECREASED TO 610T3.0/4.0 FROM TAFB...T2.5/3.5 FROM SAB...AND T3.4/4.3 FROM THE 611ADT...AND THE INITIAL INTENSITY IS THEREFORE LOWERED TO 55 KT FOR 612THIS ADVISORY. THIS INTENSITY COULD BE A LITTLE GENEROUS...BUT 613ADDITIONAL ADJUSTMENTS CAN BE MADE WHEN THE AIR FORCE HURRICANE 614HUNTER AIRCRAFT INVESTIGATES THE CYCLONE LATER TONIGHT. 615 616SIGNIFICANT MODIFICATIONS HAVE BEEN REQUIRED TO THE INTENSITY 617FORECAST ON THIS ADVISORY. STRONG SOUTHWESTERLY SHEAR BELOW THE 618OUTFLOW LAYER IS EXPECTED TO CONTINUE TO AFFECT TOMAS FOR THE NEXT 61948 HOURS...AS SHOWN BY THE SHIPS GUIDANCE...AND ALL THE INTENSITY 620MODELS ARE SHOWING CONTINUED WEAKENING DURING THAT TIME. THE 621OFFICIAL FORECAST HAS BEEN ADJUSTED DOWNWARD...LEVELING THE 622INTENSITY AT 40 KT BETWEEN 24 AND 48 HOURS. THIS IS STILL ABOVE 623MOST OF THE INTENSITY GUIDANCE...AND IT IS NOT OUT OF THE QUESTION 624THAT TOMAS COULD WEAKEN MORE THAN INDICATED IN THE OFFICIAL 625FORECAST. THE SHEAR IS EXPECTED TO RELAX AFTER 72 HOURS...AND 626THERE WILL BE AN OPPORTUNITY FOR TOMAS TO RESTRENGTHEN...POSSIBLY 627BACK TO HURRICANE INTENSITY...OVER THE CENTRAL CARIBBEAN SEA. 628 629NOW THAT THE LOW- AND MID-LEVEL CIRCULATIONS OF TOMAS HAVE BECOME 630INCREASINGLY DECOUPLED...THE LOW-LEVEL CENTER HAS ACCELERATED OVER 631THE PAST FEW HOURS WITH AN INITIAL MOTION ESTIMATED TO BE 270/13. 632THE SOUTHWESTWARD ADJUSTMENT OF THE INITIAL POSITION HAS CAUSED THE 633NEW FORECAST TRACK TO BE A LITTLE SOUTH AND FASTER THAN THE 634PREVIOUS FORECAST. THE TRACK GUIDANCE IS IN RELATIVELY GOOD 635AGREEMENT ON THE FUTURE TRACK OF TOMAS...BUT THERE CONTINUES TO BE 636SPEED DIFFERENCES MAINLY ON DAYS 4 AND 5 WHEN A DEEP MID-LATITUDE 637TROUGH SWEEPS ACROSS THE GULF OF MEXICO AND NORTHWESTERN CARIBBEAN. 638THE GFDN AND HWRF ARE STILL THE FASTEST MODELS...BUT THEY HAVE BEEN 639JOINED BY THE ECMWF...MAKING A FASTER SCENARIO A LITTLE MORE 640CREDIBLE BY DAY 5. 641 642FORECAST POSITIONS AND MAX WINDS 643 644INITIAL 01/0300Z 14.2N 66.5W 55 KT 645 12HR VT 01/1200Z 14.4N 68.1W 45 KT 646 24HR VT 02/0000Z 14.7N 69.8W 40 KT 647 36HR VT 02/1200Z 14.8N 71.6W 40 KT 648 48HR VT 03/0000Z 14.8N 73.1W 40 KT 649 72HR VT 04/0000Z 15.1N 74.5W 50 KT 650 96HR VT 05/0000Z 16.5N 74.5W 65 KT 651120HR VT 06/0000Z 20.0N 72.5W 70 KT 652 653$$ 654FORECASTER BERG 655 656 657WTNT41 KNHC 010834 658TCDAT1 659TROPICAL STORM TOMAS DISCUSSION NUMBER 13 660NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 661500 AM AST MON NOV 01 2010 662 663WESTERLY VERTICAL SHEAR...WHICH APPEARS TO BE PRIMARILY DUE TO THE 664DIFFERENCES BETWEEN THE LOWER- AND MID-TROPOSPHERIC FLOW... 665CONTINUES TO IMPACT TOMAS. CONSEQUENTLY THE CYCLONE REMAINS HIGHLY 666DECOUPLED AS THE LOW-LEVEL CENTER IS DISPLACED MORE THAN 100 N MI 667WEST OF THE DEEP CONVECTION. SFMR OBSERVATIONS FROM AN AIR FORCE 668RECONNAISSANCE AIRCRAFT INDICATE THAT THE INTENSITY HAS DECREASED 669TO NEAR 45 KT. ADDITIONAL WEAKENING IS LIKELY AS 20 TO 25 KT OF 670SHEAR SHOULD CONTINUE AFFECTING THE TROPICAL CYCLONE FOR ABOUT 671ANOTHER 24 HOURS. THEREAFTER...THE SHIPS/LGEM GUIDANCE INDICATES 672THAT THE SHEAR SHOULD RELAX WHICH WOULD ALLOW FOR TOMAS TO REGAIN 673STRENGTH. THE OFFICIAL INTENSITY FORECAST FOLLOWS THIS SCENARIO 674AND IS CLOSE TO THE CONSENSUS OF THE NUMERICAL INTENSITY GUIDANCE. 675THIS IS WELL ABOVE THE LGEM GUIDANCE AND BELOW THE MORE AGGRESSIVE 676GFDL MODEL FORECAST. IT SHOULD BE NOTED THAT THERE IS CONSIDERABLE 677UNCERTAINTY AS TO HOW STRONG TOMAS WILL GET IN THE LATTER PART OF 678THE FORECAST PERIOD. 679 680AIRCRAFT AND SATELLITE FIXES INDICATE THAT THE MOTION IS JUST 681SLIGHTLY SOUTH OF DUE WEST OR 280/12. A WEAKENING LOW- TO 682MID-LEVEL RIDGE TO THE NORTH OF THE STORM SHOULD PRODUCE A 683GENERALLY WESTWARD MOTION WITH DECELERATION OVER THE NEXT 48 HOURS 684OR SO. IN 72 TO 96 HOURS...THE GLOBAL MODELS DEPICT A LARGE 685AMPLITUDE MID-TROPOSPHERIC TROUGH MOVING EASTWARD ACROSS THE GULF OF 686MEXICO. THE FLOW AHEAD OF THIS FEATURE SHOULD TURN TOMAS NORTHWARD 687AND NORTH-NORTHEASTWARD WITH AN INCREASE IN FORWARD SPEED. THE 688OFFICIAL FORECAST IS SOMEWHAT SOUTH OF THE PREVIOUS ONE IN THE 689EARLY PART OF THE FORECAST PERIOD MAINLY DUE TO THE SOUTHWARD SHIFT 690IN RECENT FIXES. AS NOTED EARLIER...THERE IS SOME AGREEMENT 691AMONGST THE TRACK MODELS ON THE GENERAL TRAJECTORY OF TOMAS DURING 692THE LATTER PART OF THE FORECAST PERIOD BUT THERE ARE STILL 693SUBSTANTIAL DIFFERENCES IN THE PREDICTED FORWARD SPEEDS. DUE TO 694THE UNCERTAINTIES ONE SHOULD NOT FOCUS ON THE EXACT FORECAST 695TRACK...PARTICULARLY THE TIMING OF THE 4 AND 5 DAY POINTS. 696 697FORECAST POSITIONS AND MAX WINDS 698 699INITIAL 01/0900Z 13.8N 67.7W 45 KT 700 12HR VT 01/1800Z 14.1N 69.3W 40 KT 701 24HR VT 02/0600Z 14.3N 71.3W 35 KT 702 36HR VT 02/1800Z 14.4N 72.9W 40 KT 703 48HR VT 03/0600Z 14.6N 73.9W 45 KT 704 72HR VT 04/0600Z 15.5N 74.5W 55 KT 705 96HR VT 05/0600Z 17.5N 74.0W 70 KT 706120HR VT 06/0600Z 21.5N 71.5W 65 KT 707 708$$ 709FORECASTER PASCH 710 711 712WTNT41 KNHC 010841 713TCDAT1 714TROPICAL STORM TOMAS DISCUSSION NUMBER 13...CORRECTED 715NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 716500 AM AST MON NOV 01 2010 717 718CORRECTED MOTION TO 260/12 719 720WESTERLY VERTICAL SHEAR...WHICH APPEARS TO BE PRIMARILY DUE TO THE 721DIFFERENCES BETWEEN THE LOWER- AND MID-TROPOSPHERIC FLOW... 722CONTINUES TO IMPACT TOMAS. CONSEQUENTLY THE CYCLONE REMAINS HIGHLY 723DECOUPLED AS THE LOW-LEVEL CENTER IS DISPLACED MORE THAN 100 N MI 724WEST OF THE DEEP CONVECTION. SFMR OBSERVATIONS FROM AN AIR FORCE 725RECONNAISSANCE AIRCRAFT INDICATE THAT THE INTENSITY HAS DECREASED 726TO NEAR 45 KT. ADDITIONAL WEAKENING IS LIKELY AS 20 TO 25 KT OF 727SHEAR SHOULD CONTINUE AFFECTING THE TROPICAL CYCLONE FOR ABOUT 728ANOTHER 24 HOURS. THEREAFTER...THE SHIPS/LGEM GUIDANCE INDICATES 729THAT THE SHEAR SHOULD RELAX WHICH WOULD ALLOW FOR TOMAS TO REGAIN 730STRENGTH. THE OFFICIAL INTENSITY FORECAST FOLLOWS THIS SCENARIO 731AND IS CLOSE TO THE CONSENSUS OF THE NUMERICAL INTENSITY GUIDANCE. 732THIS IS WELL ABOVE THE LGEM GUIDANCE AND BELOW THE MORE AGGRESSIVE 733GFDL MODEL FORECAST. IT SHOULD BE NOTED THAT THERE IS CONSIDERABLE 734UNCERTAINTY AS TO HOW STRONG TOMAS WILL GET IN THE LATTER PART OF 735THE FORECAST PERIOD. 736 737AIRCRAFT AND SATELLITE FIXES INDICATE THAT THE MOTION IS JUST 738SLIGHTLY SOUTH OF DUE WEST OR 260/12. A WEAKENING LOW- TO 739MID-LEVEL RIDGE TO THE NORTH OF THE STORM SHOULD PRODUCE A 740GENERALLY WESTWARD MOTION WITH DECELERATION OVER THE NEXT 48 HOURS 741OR SO. IN 72 TO 96 HOURS...THE GLOBAL MODELS DEPICT A LARGE 742AMPLITUDE MID-TROPOSPHERIC TROUGH MOVING EASTWARD ACROSS THE GULF OF 743MEXICO. THE FLOW AHEAD OF THIS FEATURE SHOULD TURN TOMAS NORTHWARD 744AND NORTH-NORTHEASTWARD WITH AN INCREASE IN FORWARD SPEED. THE 745OFFICIAL FORECAST IS SOMEWHAT SOUTH OF THE PREVIOUS ONE IN THE 746EARLY PART OF THE FORECAST PERIOD MAINLY DUE TO THE SOUTHWARD SHIFT 747IN RECENT FIXES. AS NOTED EARLIER...THERE IS SOME AGREEMENT 748AMONGST THE TRACK MODELS ON THE GENERAL TRAJECTORY OF TOMAS DURING 749THE LATTER PART OF THE FORECAST PERIOD BUT THERE ARE STILL 750SUBSTANTIAL DIFFERENCES IN THE PREDICTED FORWARD SPEEDS. DUE TO 751THE UNCERTAINTIES ONE SHOULD NOT FOCUS ON THE EXACT FORECAST 752TRACK...PARTICULARLY THE TIMING OF THE 4 AND 5 DAY POINTS. 753 754FORECAST POSITIONS AND MAX WINDS 755 756INITIAL 01/0900Z 13.8N 67.7W 45 KT 757 12HR VT 01/1800Z 14.1N 69.3W 40 KT 758 24HR VT 02/0600Z 14.3N 71.3W 35 KT 759 36HR VT 02/1800Z 14.4N 72.9W 40 KT 760 48HR VT 03/0600Z 14.6N 73.9W 45 KT 761 72HR VT 04/0600Z 15.5N 74.5W 55 KT 762 96HR VT 05/0600Z 17.5N 74.0W 70 KT 763120HR VT 06/0600Z 21.5N 71.5W 65 KT 764 765$$ 766FORECASTER PASCH 767 768 769WTNT41 KNHC 011438 770TCDAT1 771TROPICAL STORM TOMAS DISCUSSION NUMBER 14 772NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 7731100 AM AST MON NOV 01 2010 774 775TOMAS IS A HIGHLY SHEARED TROPICAL CYCLONE. THE LOW-LEVEL CENTER IS 776DISPLACED MORE THAN 100 MILES TO THE WEST OF THE MAIN AREA OF DEEP 777CONVECTION. HOWEVER...A SMALL AREA OF THUNDERSTORMS HAS RECENTLY 778FORMED JUST TO THE NORTHEAST OF THE CENTER. SATELLITE INTENSITY 779ESTIMATES CONTINUE TO FALL...AND THE INITIAL INTENSITY IS LOWERED 780TO 40 KT FOR THIS ADVISORY. 781 782THE STORM CONTINUES TO MOVE SOUTH OF DUE WEST...AND THE LATEST 78312-HOUR INITIAL MOTION ESTIMATE IS 255/12. A GENERAL WESTWARD 784HEADING WITH A DECREASE IN FORWARD SPEED IS EXPECTED OVER THE NEXT 78524 TO 36 HOURS AS THE CYCLONE IS STEERED BY LOW- TO MID-LEVEL 786EASTERLY FLOW. BY WEDNESDAY...A LARGE MID- TO UPPER-LEVEL LOW IS 787EXPECTED TO MOVE EASTWARD INTO THE GULF OF MEXICO. GLOBAL MODELS 788ARE IN AGREEMENT IN SHOWING THIS LOW OR TROUGH SWINGING ACROSS THE 789GULF OF MEXICO AND INTO THE NORTHWESTERN CARIBBEAN. AS THIS 790OCCURS...SOUTHWESTERLY FLOW ON THE EAST SIDE OF THE TROUGH WILL 791WEAKEN THE STEERING CURRENTS AND THEN CAUSE TOMAS TO TURN TOWARD 792THE NORTH AND NORTHEAST IN 4 TO 5 DAYS. THE LATEST TRACK MODEL 793GUIDANCE HAS SHIFTED A LITTLE TO THE LEFT...MAINLY DUE TO THE 794RECENT SOUTHWESTWARD MOTION. ALTHOUGH THE NEW OFFICIAL FORECAST IS 795SOUTH OF THE PREVIOUS ONE FOR THE NEXT 3 DAYS...IT ENDS UP ON THE 796PREVIOUS TRACK BY DAYS 4 AND 5. 797 798SOUTHWESTERLY SHEAR OF ABOUT 20 KT AND DRY MID-LEVEL AIR COULD CAUSE 799A LITTLE MORE WEAKENING DURING THE NEXT 24 HOURS. AFTER THAT 800TIME...THE SHEAR IS EXPECTED TO DECREASE AND THE OTHER ATMOSPHERIC 801AND OCEANIC PARAMETERS SHOULD SUPPORT STRENGTHENING. ALL OF 802THE GUIDANCE SHOWS TOMAS RE-INTENSIFYING...ESPECIALLY BEYOND 48 803HOURS...AND THE OFFICIAL FORECAST FOLLOWS THAT THEME. THE NEW WIND 804SPEED FORECAST IS SIMILAR TO THE PREVIOUS ONE AND CLOSE TO THE 805INTENSITY MODEL CONSENSUS. 806 807FORECAST POSITIONS AND MAX WINDS 808 809INITIAL 01/1500Z 13.6N 68.7W 40 KT 810 12HR VT 02/0000Z 13.7N 70.3W 35 KT 811 24HR VT 02/1200Z 13.8N 72.1W 35 KT 812 36HR VT 03/0000Z 14.0N 73.3W 40 KT 813 48HR VT 03/1200Z 14.3N 74.2W 45 KT 814 72HR VT 04/1200Z 15.2N 74.8W 55 KT 815 96HR VT 05/1200Z 17.5N 74.0W 65 KT 816120HR VT 06/1200Z 21.5N 71.5W 65 KT 817 818$$ 819FORECASTER CANGIALOSI 820 821 822WTNT41 KNHC 012045 823TCDAT1 824TROPICAL STORM TOMAS DISCUSSION NUMBER 15 825NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 826500 PM AST MON NOV 01 2010 827 828ALTHOUGH DEEP CONVECTION HAS INCREASED NEAR THE CENTER OF TOMAS 829TODAY...IT IS POORLY ORGANIZED AND LACKS BANDING. VISIBLE SATELLITE 830IMAGES SHOW A SERIES OF ARC CLOUDS PROPAGATING AWAY FROM THE 831CONVECTIVE MASS...INDICATIVE OF DRY AIR NEAR THE CORE. AN ASCAT 832PASS AROUND 1400 UTC SHOWED MAXIMUM WINDS IN THE 30-35 KT RANGE. 833SINCE CONVECTION HAS INCREASED SINCE THAT TIME...THE INITIAL 834INTENSITY IS HELD AT 40 KT...IN AGREEMENT WITH SATELLITE INTENSITY 835ESTIMATES. 836 837TOMAS IS STILL MOVING A LITTLE SOUTH OF DUE WEST...AND THE INITIAL 838MOTION ESTIMATE IS 260/10. THE STORM IS EXPECTED TO MOVE GENERALLY 839WESTWARD FOR THE NEXT DAY OR SO WITHIN EASTERLY FLOW TO THE SOUTH 840OF A LOW- TO MID-LEVEL RIDGE. GLOBAL MODELS REMAIN IN GOOD 841AGREEMENT IN SHOWING A STRONG DEEP-LAYER TROUGH MOVING ACROSS THE 842GULF OF MEXICO AND INTO THE NORTHWESTERN CARIBBEAN BY MID TO LATE 843WEEK. THIS SYNOPTIC PATTERN SHOULD CAUSE THE CYCLONE TO SLOW DOWN 844AND THEN MAKE A TURN TOWARD THE NORTH IN ABOUT 3 DAYS. 845THEREAFTER... A NORTHEASTWARD MOTION WITH AN INCREASE IN FORWARD 846SPEED IS FORECAST AS TOMAS BECOMES EMBEDDED IN SOUTHWESTERLY FLOW 847TO THE EAST OF THE TROUGH. THE LATEST GUIDANCE HAS SHIFTED TO THE 848LEFT ONCE AGAIN THROUGH 72 HOURS....AND THE OFFICIAL FORECAST IS 849ADJUSTED IN THAT DIRECTION. THE NEW TRACK FORECAST IS NEAR A BLEND 850OF THE GFS AND ECMWF MODELS. 851 852DRY MID-LEVEL AIR AND SOUTHWESTERLY SHEAR CONTINUE TO IMPACT THE 853CYCLONE. THE STORM IS EXPECTED TO REMAIN IN THIS UNFAVORABLE 854ENVIRONMENT FOR ANOTHER 12-24 HOURS...WHICH SHOULD PREVENT MUCH 855STRENGTHENING. AFTER THAT TIME...ENVIRONMENTAL WINDS ARE 856ANTICIPATED TO BECOME MORE CONDUCIVE AND MODEL CROSS SECTIONS 857SUGGEST THAT THE ATMOSPHERE WILL MOISTEN. THIS ENVIRONMENT SHOULD 858ALLOW THE STORM TO GAIN STRENGTH...AND THE OFFICIAL FORECAST HAS 859BEEN ADJUSTED UPWARD TO BE IN AGREEMENT WITH THE SHIPS MODEL. 860 861FORECAST POSITIONS AND MAX WINDS 862 863INITIAL 01/2100Z 13.4N 69.7W 40 KT 864 12HR VT 02/0600Z 13.4N 71.2W 40 KT 865 24HR VT 02/1800Z 13.7N 73.0W 45 KT 866 36HR VT 03/0600Z 14.0N 74.2W 50 KT 867 48HR VT 03/1800Z 14.3N 74.9W 55 KT 868 72HR VT 04/1800Z 15.1N 75.0W 65 KT 869 96HR VT 05/1800Z 18.0N 73.5W 80 KT 870120HR VT 06/1800Z 21.0N 71.0W 70 KT 871 872$$ 873FORECASTER CANGIALOSI 874 875 876WTNT41 KNHC 020234 877TCDAT1 878TROPICAL STORM TOMAS DISCUSSION NUMBER 16 879NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 8801100 PM EDT MON NOV 01 2010 881 882THERE HAS BEEN NO APPRECIABLE CHANGE TO THE STRUCTURE OF TOMAS OVER 883THE PAST SEVERAL HOURS. DEEP CONVECTION HAD DIMINISHED AT ONE 884POINT THIS EVENING...BUT A LINEAR BAND HAS RECENTLY RE-DEVELOPED 885ABOUT 60-90 N MI EAST OF THE LOW-LEVEL CENTER. THE INITIAL 886INTENSITY IS HELD AT 40 KT...WHICH IS CONSISTENT WITH SATELLITE 887ESTIMATES OF T2.5/3.0 FROM TAFB AND T2.6/2.7 FROM THE OBJECTIVE 888ADT. ALTHOUGH WEST-SOUTHWESTERLY SHEAR CONTINUES TO IMPACT THE 889CYCLONE...IT IS EXPECTED TO DECREASE IN 24-36 HOURS. IN 890ADDITION...THE MID-LEVEL RELATIVE HUMIDITY IS EXPECTED TO 891INCREASE...AND TOMAS WILL BE MOVING OVER A REGION OF INCREASED 892OCEAN HEAT CONTENT. ALL THESE FACTORS SUGGEST THAT TOMAS SHOULD 893RE-STRENGTHEN...AND THE INTENSITY MODELS ARE IN GENERALLY GOOD 894AGREEMENT THAT IT COULD BECOME A HURRICANE AGAIN BY DAY 3. THE 895PREVIOUS FORECAST IS IN LINE WITH THE NEW INTENSITY GUIDANCE...AND 896NO CHANGES WERE REQUIRED ON THIS ADVISORY. 897 898RECENT MICROWAVE IMAGERY SUGGESTS THAT TOMAS HAS CEASED MOVING 899SOUTH OF DUE WEST AND NOW HAS AN INITIAL MOTION OF 270/10. TRACK 900GUIDANCE INDICATES THAT TOMAS...IN ITS WEAKENED STATE...SHOULD 901CONTINUE TO MOVE WESTWARD IN THE LOW-LEVEL FLOW FOR THE NEXT 36 902HOURS OR SO. ONCE THE CYCLONE BEGINS TO STRENGTHEN...THE DEEPER 903VORTEX SHOULD BE STEERED NORTHWARD AND THEN NORTHEASTWARD IN THE 904SOUTHWESTERLY FLOW AHEAD OF AN APPROACHING MID- TO UPPER-LEVEL 905TROUGH. SINCE THE HWRF AND GFDN APPEAR TO BE NORTHERN OUTLIERS AND 906THE NOGAPS DOES NOT EVEN PULL TOMAS OUT OF THE CARIBBEAN...THE 907OFFICIAL FORECAST IS BASED ON A CONSENSUS OF THE GFS...ECMWF... 908GFDL...AND UKMET. THE GUIDANCE ENVELOPE HAS SHIFTED A BIT TO THE 909WEST ON THIS CYCLE...MAINLY IN THE DAY 2 AND 3 TIME FRAME...AND THE 910NEW OFFICIAL FORECAST FOLLOWS THAT TREND. 911 912FORECAST POSITIONS AND MAX WINDS 913 914INITIAL 02/0300Z 13.5N 70.8W 40 KT 915 12HR VT 02/1200Z 13.7N 72.5W 40 KT 916 24HR VT 03/0000Z 13.9N 73.9W 45 KT 917 36HR VT 03/1200Z 14.2N 74.9W 50 KT 918 48HR VT 04/0000Z 14.6N 75.5W 55 KT 919 72HR VT 05/0000Z 16.0N 75.5W 65 KT 920 96HR VT 06/0000Z 18.5N 73.5W 80 KT...INLAND 921120HR VT 07/0000Z 21.0N 70.5W 70 KT...OVER WATER 922 923$$ 924FORECASTER BERG 925 926 927WTNT41 KNHC 020837 928TCDAT1 929TROPICAL STORM TOMAS DISCUSSION NUMBER 17 930NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 931500 AM EDT TUE NOV 02 2010 932 933TOMAS HAS THE APPEARANCE OF A GRADUALLY STRENGTHENING TROPICAL 934STORM. OVERNIGHT...THERE HAS BEEN A SUBSTANTIAL INCREASE IN THE 935ASSOCIATED DEEP CONVECTION. ALTHOUGH MOST OF THE THUNDERSTORM 936ACTIVITY IS OCCURRING OVER THE EASTERN AND NORTHEASTERN PORTIONS OF 937THE CIRCULATION...DEEP CONVECTION HAS RECENTLY BEEN INCREASING NEAR 938THE CENTER. ENHANCED IR IMAGERY ALSO SUGGESTS SOME BANDING 939FEATURES DEVELOPING OVER THE NORTHEAST QUADRANT. ON THE FINAL PASS 940OF AN AIR FORCE HURRICANE HUNTER PLANE OUTBOUND FROM THE CENTER 941OVER THE NORTHEAST QUADRANT...THE MAXIMUM UNFLAGGED SFMR-MEASURED 942SURFACE WIND SPEED WAS 44 KT. THE INTENSITY IS ADJUSTED SLIGHTLY 943UPWARD...TO 45 KT...ON THIS ADVISORY. TOMAS IS FORECAST TO MOVE 944OVER WATERS OF INCREASINGLY HIGH OCEANIC HEAT CONTENT AND ALTHOUGH 945SOME SOUTHWESTERLY SHEAR WILL PROBABLY IMPACT THE SYSTEM...THE 946SHEAR IS NOT LIKELY TO BECOME VERY STRONG FOR THE NEXT FEW DAYS. 947THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ONE AND 948BRINGS TOMAS TO HURRICANE INTENSITY IN A COUPLE OF DAYS. THIS IS 949SIMILAR TO THE RELIABLE LGEM GUIDANCE BUT BELOW THE GFDL FORECAST 950INTENSITY PREDICTION. 951 952BASED ON THE HURRICANE HUNTER FIXES...THE STORM CONTINUES MOVING 953WESTWARD...OR ABOUT 270/10. THE TRACK FORECAST REASONING FOR THE 954NEXT 3 TO 4 DAYS REMAINS THE SAME AS BEFORE. TOMAS SHOULD BE 955STEERED ALONG THE SOUTHERN AND SOUTHWESTERN PERIPHERY OF A LOW- TO 956MID-LEVEL RIDGE FOR THE NEXT COUPLE OF DAYS. BY 72-96 HOURS...THE 957FLOW AHEAD OF A LARGE MID-TROPOSPHERIC TROUGH SHOULD TURN THE 958DEEPENING CYCLONE SHARPLY NORTHWARD AND NORTH-NORTHEASTWARD. BY 959THE END OF THE FORECAST PERIOD...THE GLOBAL MODELS SUGGEST THAT THE 960TROUGH COULD SWING NORTHEASTWARD AND NOT COMPLETELY PICK UP TOMAS. 961THEREFORE THERE IS A POSSIBILITY THAT THE TROPICAL CYCLONE COULD 962LINGER NEAR NORTHERN HISPANIOLA FOR A DAY OR TWO...BEFORE THE 963WESTERLIES EVENTUALLY CARRY IT FARTHER OUT INTO THE ATLANTIC. THAT 964POSSIBILITY...HOWEVER...IS NOT EXPLICITLY SHOWN IN THE OFFICIAL 965TRACK FORECAST AT THIS TIME. 966 967FORECAST POSITIONS AND MAX WINDS 968 969INITIAL 02/0900Z 13.5N 72.0W 45 KT 970 12HR VT 02/1800Z 13.7N 73.1W 50 KT 971 24HR VT 03/0600Z 14.0N 74.4W 55 KT 972 36HR VT 03/1800Z 14.4N 75.3W 60 KT 973 48HR VT 04/0600Z 15.0N 75.8W 65 KT 974 72HR VT 05/0600Z 16.3N 75.2W 80 KT 975 96HR VT 06/0600Z 19.0N 72.5W 70 KT...INLAND 976120HR VT 07/0600Z 21.5N 70.0W 60 KT...OVER WATER 977 978$$ 979FORECASTER PASCH 980 981 982WTNT41 KNHC 021452 983TCDAT1 984TROPICAL STORM TOMAS DISCUSSION NUMBER 18 985NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 9861100 AM EDT TUE NOV 02 2010 987 988TOMAS HAS CERTAINLY BECOME BETTER ORGANIZED SINCE YESTERDAY...WITH A 989LARGE AREA OF DEEP CONVECTION AND INCREASED BANDING SEEN IN 990CONVENTIONAL SATELLITE AND MICROWAVE DATA. HOWEVER...THE STORM HAS 991CHANGED LITTLE IN ORGANIZATION SINCE THE RECONNAISSANCE AIRCRAFT 992REPORTED SFMR SURFACE WINDS OF 45 KT AROUND 0800 UTC. THEREFORE... 993THE INITIAL INTENSITY IS HELD AT THAT VALUE...WHICH IS IN LINE WITH 994THE LATEST DVORAK T-NUMBERS OF 2.5 AND 3.5 FROM SAB AND TAFB... 995RESPECTIVELY. THE NEXT AIR FORCE HURRICANE HUNTER AIRCRAFT IS 996SCHEDULED TO INVESTIGATE TOMAS THIS AFTERNOON. 997 998WESTERLY SHEAR CONTINUES TO RELAX AND THE MID-LEVEL ENVIRONMENT 999APPEARS TO BE MOISTENING. THESE ATMOSPHERIC CONDITIONS...COMBINED 1000WITH HIGH OCEANIC HEAT CONTENT...FAVOR INTENSIFICATION DURING THE 1001NEXT FEW DAYS...WHICH IS SHOWN BY MOST OF THE GUIDANCE. IN 1002FACT...THE SHIPS RAPID INTENSIFICATION INDEX GIVES A 48 PERCENT 1003CHANCE OF A 30-KT INCREASE IN WIND SPEED DURING THE NEXT 24 HOURS. 1004THE OFFICIAL FORECAST HAS BEEN ADJUSTED UPWARD FROM THE PREVIOUS 1005ADVISORY AND IS NOW AT OR JUST ABOVE THE HIGH END OF THE INTENSITY 1006GUIDANCE. AFTER A FEW DAYS...LAND INTERACTION...DRIER AIR...AND 1007SOME INCREASE IN SOUTHERLY SHEAR IS LIKELY TO CAUSE WEAKENING. 1008 1009THE INITIAL MOTION ESTIMATE IS A LITTLE SLOWER THAN BEFORE...270/9. 1010A TURN TO THE WEST-NORTHWEST AND NORTHWEST WITH A DECREASE IN 1011FORWARD SPEED IS FORECAST DURING THE NEXT 24-48 HOURS AS A STRONG 1012TROUGH MOVES EASTWARD ACROSS THE GULF OF MEXICO. AS A RESULT... 1013TOMAS IS EXPECTED TO TURN NORTHWARD AND NORTHEASTWARD BEYOND 48 1014HOURS IN DEEP-LAYER SOUTHWESTERLY FLOW ON THE EAST SIDE OF THE 1015TROUGH. SEVERAL OF THE GLOBAL MODELS SUGGEST THAT THE TROUGH WILL 1016NOT COMPLETELY CAPTURE TOMAS AND THERE REMAINS A LARGE DISAGREEMENT 1017IN THE FUTURE POSITION OF THE CYCLONE AT DAYS 4 AND 5. THE OFFICIAL 1018FORECAST IS OF LOW CONFIDENCE DURING THAT TIME PERIOD AND IS NEAR A 1019CONSENSUS OF THE GFS...GFDL... UKMET...NOGAPS...AND ECMWF MODELS. 1020 1021REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...IT APPEARS 1022THAT THE TROPICAL CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY 1023RAINFALL OVER HAITI AND THE DOMINICAN REPUBLIC LATER IN THE WEEK. 1024 1025FORECAST POSITIONS AND MAX WINDS 1026 1027INITIAL 02/1500Z 13.5N 72.6W 45 KT 1028 12HR VT 03/0000Z 13.7N 73.8W 55 KT 1029 24HR VT 03/1200Z 14.1N 75.0W 65 KT 1030 36HR VT 04/0000Z 14.6N 75.8W 70 KT 1031 48HR VT 04/1200Z 15.2N 76.0W 80 KT 1032 72HR VT 05/1200Z 17.2N 74.9W 90 KT 1033 96HR VT 06/1200Z 20.0N 72.0W 65 KT 1034120HR VT 07/1200Z 22.5N 69.5W 60 KT 1035 1036$$ 1037FORECASTER CANGIALOSI/BROWN 1038 1039 1040WTNT41 KNHC 022047 1041TCDAT1 1042TROPICAL STORM TOMAS DISCUSSION NUMBER 19 1043NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 1044500 PM EDT TUE NOV 02 2010 1045 1046AN AIR FORCE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS FOUND THE 1047STORM WEAKER THAN IT WAS EARLY THIS MORNING...WITH A SOMEWHAT 1048ELONGATED CIRCULATION. MAXIMUM FLIGHT-LEVEL AND SFMR SURFACE WINDS 1049SUPPORT LOWERING THE INITIAL INTENSITY TO 35 KT. THE CONVECTIVE 1050STRUCTURE OF TOMAS HAS ALSO BECOME LESS ORGANIZED. 1051 1052THE CONTINUED WEAKENING...OR AT LEAST LACK OF STRENGTHENING...OF 1053TOMAS IS LIKELY DUE TO MID-LEVEL DRY AIR...SOME WESTERLY 1054SHEAR...AND PERHAPS THE PROXIMITY TO SOUTH AMERICA. 1055HOWEVER...INTENSIFICATION STILL SEEMS LIKELY GIVEN THE EXPECTED 1056FAVORABLE ATMOSPHERIC ENVIRONMENT DURING THE NEXT FEW DAYS. THE 1057OFFICIAL FORECAST HAS BEEN ADJUSTED DOWNWARD FROM THE PREVIOUS ONE 1058FOR THE FIRST COUPLE OF DAYS...DUE TO THE LOWER INITIAL 1059INTENSITY...BUT IS OTHERWISE SIMILAR TO THE PREVIOUS ADVISORY. 1060 1061AIRCRAFT AND SATELLITE FIXES INDICATE THAT TOMAS CONTINUES WESTWARD 1062AT AROUND 12 KT. THE TRACK FORECAST REASONING IS UNCHANGED FROM 1063EARLIER. A STRONG MID- TO UPPER-LEVEL TROUGH CURRENTLY MOVING INTO 1064THE WESTERN GULF OF MEXICO IS EXPECTED TO SWING EASTWARD INTO THE 1065NORTHWESTERN CARIBBEAN SEA. THIS PATTERN WILL CAUSE THE SYSTEM TO 1066SLOW DOWN AND TURN TOWARD THE NORTH IN THE NEXT 24 TO 48 HOURS. 1067TOMAS IS THEN FORECAST TO TRACK NORTHEASTWARD WITH SOME INCREASE IN 1068FORWARD SPEED IN THE 2 TO 4 DAY PERIOD. BY DAY 5...MOST OF THE 1069GLOBAL MODELS SHOW THE TROUGH FLATTENING AND LEAVING TOMAS BEHIND. 1070THE LATEST TRACK GUIDANCE HAS SHIFTED TO THE LEFT...AND THE 1071OFFICIAL FORECAST IS ADJUSTED IN THAT DIRECTION. 1072 1073REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...IT APPEARS 1074THAT THE TROPICAL CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY 1075RAINFALL OVER HAITI AND THE DOMINICAN REPUBLIC LATER IN THE WEEK. 1076 1077FORECAST POSITIONS AND MAX WINDS 1078 1079INITIAL 02/2100Z 13.5N 74.6W 35 KT 1080 12HR VT 03/0600Z 13.8N 75.6W 40 KT 1081 24HR VT 03/1800Z 14.2N 76.6W 50 KT 1082 36HR VT 04/0600Z 14.7N 77.0W 60 KT 1083 48HR VT 04/1800Z 15.3N 76.7W 70 KT 1084 72HR VT 05/1800Z 18.1N 74.8W 85 KT 1085 96HR VT 06/1800Z 21.0N 72.5W 75 KT 1086120HR VT 07/1800Z 22.5N 70.5W 60 KT 1087 1088$$ 1089FORECASTER CANGIALOSI/BROWN 1090 1091 1092WTNT41 KNHC 030242 1093TCDAT1 1094TROPICAL STORM TOMAS DISCUSSION NUMBER 20 1095NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 10961100 PM EDT TUE NOV 02 2010 1097 1098SATELLITE IMAGES INDICATE THAT OVERALL CONVECTION HAS DECREASED 1099DURING THE PAST SEVERAL HOURS...THOUGH A CURVED BAND HAS BECOME A 1100LITTLE BETTER-DEFINED RECENTLY. MICROWAVE DATA SUGGEST THE CENTER 1101IS ON THE SOUTHEASTERN SIDE OF THAT BAND...AND REMNANTS OF THE OLD 1102MID-LEVEL CIRCULATION CAN BE SEEN NORTHWEST OF ARUBA. SATELLITE 1103INTENSITY ESTIMATES VARY FROM 35-55 KT...AND NO CHANGE WILL BE MADE 1104TO THE INITIAL WIND SPEED OF 35 KT. AN AIR FORCE HURRICANE HUNTER 1105WILL BE IN THE AREA IN A FEW HOURS TO CHECK ON THE STATUS OF TOMAS. 1106 1107LARGE-SCALE ENVIRONMENTAL PARAMETERS APPEAR TO BE RATHER FAVORABLE 1108FOR FUTURE INTENSIFICATION WITH LOW SHEAR AND VERY WARM WATER FOR 1109THE NEXT FEW DAYS. IT IS UNCERTAIN...HOWEVER...IF TOMAS CAN TAKE 1110ADVANTAGE OF THESE CONDITIONS. A LOOK AT GLOBAL MODEL CROSS- 1111SECTIONS SHOW A TILTED VORTEX INITIALLY...WITH THE GFS/UKMET 1112SUGGESTING A MORE FAVORABLE VERTICAL VORTEX STRUCTURE FOR 1113STRENGTHENING IN A DAY OR TWO. THE ECMWF MODEL...WHICH WAS ONE 1114OF THE FEW MODELS THAT PREDICTED THE WEAKENING OF TOMAS IN THE 1115EASTERN CARIBBEAN...HAS A QUITE DIFFERENT SCENARIO WITH A GOOD DEAL 1116OF TILT REMAINING FOR THE NEXT FEW DAYS AND ONLY A MODEST INCREASE 1117IN WINDS UNTIL AFTER THE TROPICAL CYCLONE LEAVES THE CARIBBEAN. 1118WITH SUCH DIVERGENCE IN THE GUIDANCE...THE NEW FORECAST IS ABOUT 1119THE SAME THE PREVIOUS ONE...A LITTLE HIGHER THAN THE MODEL 1120CONSENSUS. 1121 1122AN UNCERTAIN INITIAL MOTION ESTIMATE IS 280/7. A CONTINUED 1123SLOW-DOWN OF THE TROPICAL CYCLONE IS LIKELY AS RIDGING WEAKENS TO 1124THE NORTH OF TOMAS. A DEEP LAYER LOW ENTERING THE GULF OF MEXICO 1125IS EXPECTED TO ACCELERATE AND TURN TOMAS TO THE NORTH AND NORTHEAST 1126ON THURSDAY. WHILE THE MODELS TAKE VARIOUS SPEEDS AND ROUTES TO 1127GET THERE...THEY REMAIN FOCUSED IN THE DIRECTION OF SOUTHWESTERN 1128HAITI. THE NHC FORECAST IS ADJUSTED SLIGHTLY TO THE RIGHT OF THE 1129PREVIOUS FORECAST DURING THE FIRST COUPLE OF DAYS...AND GENERALLY 1130LIES TO THE SOUTHEAST OF THE MODEL CONSENSUS. THE HWRF AND GFDN 1131HAVE A RATHER DEEP AND INTENSE CIRCULATION...WHICH APPEAR TO BE 1132OUTLIERS AND BIASING TVCN...THE VARIABLE CONSENSUS MODEL...TOO FAR 1133TO THE NORTH. 1134 1135REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...IT APPEARS 1136THAT THE TROPICAL CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY 1137RAINFALL OVER HAITI AND THE DOMINICAN REPUBLIC LATER IN THE WEEK. 1138 1139 1140FORECAST POSITIONS AND MAX WINDS 1141 1142INITIAL 03/0300Z 13.7N 75.1W 35 KT 1143 12HR VT 03/1200Z 14.0N 75.9W 40 KT 1144 24HR VT 04/0000Z 14.4N 76.5W 50 KT 1145 36HR VT 04/1200Z 15.0N 76.6W 60 KT 1146 48HR VT 05/0000Z 16.0N 76.0W 70 KT 1147 72HR VT 06/0000Z 19.0N 73.9W 80 KT 1148 96HR VT 07/0000Z 22.0N 71.5W 70 KT 1149120HR VT 08/0000Z 22.5N 69.5W 60 KT 1150 1151$$ 1152FORECASTER BLAKE 1153 1154 1155WTNT41 KNHC 030840 1156TCDAT1 1157TROPICAL DEPRESSION TOMAS DISCUSSION NUMBER 21 1158NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 1159500 AM EDT WED NOV 03 2010 1160 1161AN AIR FORCE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS A COUPLE 1162OF HOURS AGO FOUND AN ILL-DEFINED AND ELONGATED CIRCULATION WITH NO 1163TROPICAL STORM FORCE WINDS AT EITHER THE 925 MB FLIGHT LEVEL OR THE 1164SURFACE. BASED ON THIS INFORMATION...TOMAS IS BEING DOWNGRADED TO 1165A TROPICAL DEPRESSION AT THIS TIME. THE PERIPHERAL CLOUD PATTERN 1166CONTINUES TO SHOW ORGANIZATION WITH FRAGMENTED OUTER BANDS...BUT 1167THERE IS LITTLE CONVECTIVE ORGANIZATION NEAR THE ESTIMATED CENTER. 1168THE WEAKENING OVER THE PAST 24 HOURS IS DIFFICULT TO EXPLAIN. 1169PRECIPITABLE WATER ANALYSES FROM THE UW/CIMSS DO NOT SUGGEST MUCH 1170OF AN INTRUSION OF DRY AIR INTO THE CIRCULATION. THE CIRRUS 1171MOTIONS FROM SATELLITE IMAGES SHOW A FAIRLY WELL-DEFINED OUTFLOW 1172PATTERN...ESPECIALLY OVER THE NORTHERN SEMICIRCLE. THIS WOULD 1173NORMALLY BE CONSISTENT WITH LIGHT VERTICAL SHEAR. AMSU 1174AREA-AVERAGED WIND SHEAR DERIVED BY CSU/CIRA...HOWEVER...INDICATE A 1175RECENT INCREASE IN MID- TO UPPER-LEVEL SHEAR OVER TOMAS. THIS IS 1176EXPECTED TO BE TEMPORARY AS GLOBAL MODELS PREDICT DECREASING SHEAR 1177OVER THE NEXT COUPLE OF DAYS. THE INTENSITY FORECAST CONTINUES TO 1178CALL FOR TOMAS TO RESTRENGTHEN INTO A HURRICANE BEFORE REACHING 1179LAND. GIVEN THE ERRATIC BEHAVIOR OF THIS TROPICAL CYCLONE THUS 1180FAR...THIS IS A LOW-CONFIDENCE INTENSITY FORECAST. THE NOAA G-IV 1181JET IS CURRENTLY CONDUCTING A SYNOPTIC SURVEILLANCE MISSION AROUND 1182TOMAS WHICH SHOULD GIVE A BETTER ASSESSMENT OF THE DYNAMIC AND 1183THERMODYNAMIC ENVIRONMENT. 1184 1185THE HURRICANE HUNTERS FOUND A BROAD AREA OF LIGHT WINDS SURROUNDING 1186THE LOCATION OF THE MINIMUM PRESSURE...SO THERE IS SIGNIFICANT 1187UNCERTAINTY IN THE CENTER POSITION AND INITIAL MOTION. OUR BEST 1188GUESS AT THE LATTER IS 285/4. THE TRACK FORECAST IS BASICALLY 1189UNCHANGED FROM THE PREVIOUS ADVISORY. TOMAS IS EXPECTED TO TURN 1190NORTHWARD AND NORTHEASTWARD OVER THE NEXT FEW DAYS IN RESPONSE TO 1191THE STEERING FLOW AHEAD OF AN APPROACHING MID-TROPOSPHERIC TROUGH. 1192BY THE END OF THE FORECAST PERIOD...GLOBAL MODELS SHOW THIS TROUGH 1193LIFTING OUT AND LEAVING TOMAS BEHIND OVER THE SUBTROPICS FOR A FEW 1194DAYS. ACCORDINGLY...THE OFFICIAL TRACK FORECAST SHOWS A TURN TO 1195THE RIGHT WITH DECREASING FORWARD SPEED BY DAY 5. 1196 1197REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL 1198CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL... 1199FLOODING...AND POTENTIAL MUD SLIDES OVER HAITI AND THE 1200DOMINICAN REPUBLIC LATER IN THE WEEK. 1201 1202FORECAST POSITIONS AND MAX WINDS 1203 1204INITIAL 03/0900Z 13.5N 75.5W 30 KT 1205 12HR VT 03/1800Z 13.8N 76.1W 35 KT 1206 24HR VT 04/0600Z 14.4N 76.5W 40 KT 1207 36HR VT 04/1800Z 15.3N 76.3W 50 KT 1208 48HR VT 05/0600Z 16.8N 75.3W 65 KT 1209 72HR VT 06/0600Z 20.0N 73.0W 65 KT 1210 96HR VT 07/0600Z 21.5N 71.5W 60 KT 1211120HR VT 08/0600Z 22.0N 69.5W 50 KT 1212 1213$$ 1214FORECASTER PASCH/ROBERTS 1215 1216 1217WTNT41 KNHC 031449 1218TCDAT1 1219TROPICAL DEPRESSION TOMAS DISCUSSION NUMBER 22 1220NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 12211100 AM EDT WED NOV 03 2010 1222 1223TOMAS IS STRUGGLING TO MAINTAIN ITS IDENTITY THIS MORNING. 1224SATELLITE IMAGERY...SURFACE OBSERVATIONS...AND DATA FROM THE NOAA 1225G-IV JET INDICATE THE CYCLONE HAS BECOME PART OF AN ELONGATED AREA 1226OF LOW PRESSURE THAT INCLUDES AN AREA OF DISTURBED WEATHER JUST 1227NORTH OF PANAMA. AS A RESULT...THE CIRCULATION OF TOMAS HAS BEEN 1228LOSING DEFINITION. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT 1229WILL INVESTIGATE THE SYSTEM THIS AFTERNOON TO DETERMINE WHETHER 1230TOMAS STILL HAS ENOUGH CIRCULATION TO BE CONSIDERED A TROPICAL 1231CYCLONE. SATELLITE IMAGERY SHOWS THAT A LARGE CONVECTIVE CLUSTER 1232TO THE EAST OF THE CENTER...AND BASED ON THIS AND THE AIRCRAFT DATA 1233THE INITIAL INTENSITY REMAINS 30 KT. 1234 1235THE INITIAL MOTION IS AN UNCERTAIN 295/5. THERE IS LITTLE CHANGE IN 1236THE FORECAST TRACK OR FORECAST PHILOSOPHY FOR THE FIRST 72 -96 HR 1237OF THE FORECAST. A DEEP-LAYER TROUGH AND ACCOMPANYING COLD FRONT 1238MOVING THROUGH THE GULF OF MEXICO AND THE SOUTHEASTERN UNITED 1239STATES SHOULD CAUSE TOMAS TO RECURVE TOWARD THE NORTHEAST DURING 1240THE NEXT 48 HR...WITH A GENERALLY NORTHEASTWARD MOTION CONTINUING 1241THROUGH 72-96 HR. AFTER THAT TIME...THE GUIDANCE BECOMES 1242DIVERGENT. THE GFDL STALLS THE CYCLONE JUST WEST OF HAITI. THE 1243UKMET AND NOGAPS FORECAST TOMAS TO SHEAR OFF WITH THE REMNANT 1244LOW-LEVEL CIRCULATION MOVING SOUTHWESTWARD. FINALLY...THE GFS AND 1245ECMWF CALL FOR A CONTINUED EASTWARD TO EAST-NORTHEASTWARD MOTION. 1246THE NEW TRACK FORECAST SHOWS A SLOW EAST-NORTHEASTWARD MOTION FROM 124796-120 HR AS A COMPROMISE BETWEEN THESE EXTREMES. OVERALL...THE 1248FORECAST IS SIMILAR TO BUT FASTER THAN THE PREVIOUS FORECAST. 1249 1250THE INTENSITY FORECAST IS PROBLEMATIC. FIRST...THE CYCLONE NEEDS TO 1251SURVIVE ITS CURRENT STATE OF DISORGANIZATION. IF THAT OCCURS... 1252LIGHT VERTICAL WIND SHEAR AND WARM SEA SURFACE TEMPERATURES APPEAR 1253FAVORABLE FOR STRENGTHENING FOR THE NEXT 48-72 HR OR SO IF THE 1254LOW-LEVEL CIRCULATION CAN CONSOLIDATE. THE INTENSITY FORECAST 1255ASSUMES BOTH OF THESE THINGS WILL HAPPEN...AND THUS CALLS FOR SLOW 1256STRENGTHENING DURING THIS TIME. WHILE THE GFDL AND SHIPS MODELS 1257STILL CALL FOR TOMAS TO REGAIN HURRICANE STRENGTH...THE NEW 1258INTENSITY FORECAST WILL NOT FOLLOW THIS SCENARIO DUE TO CURRENT 1259TRENDS AND THE LIKELIHOOD OF LAND INTERACTION WITH HISPANIOLA LATER 1260IN THE FORECAST PERIOD. THE INTENSITY FORECAST IS CLOSE TO BUT 1261SLIGHTLY LOWER THAN THE INTENSITY CONSENSUS MODEL ICON. 1262 1263REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL 1264CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL... 1265FLOODING... AND POTENTIAL MUD SLIDES OVER HAITI AND THE DOMINICAN 1266REPUBLIC LATER IN THE WEEK. 1267 1268FORECAST POSITIONS AND MAX WINDS 1269 1270INITIAL 03/1500Z 14.1N 75.9W 30 KT 1271 12HR VT 04/0000Z 14.5N 76.2W 30 KT 1272 24HR VT 04/1200Z 15.5N 76.2W 35 KT 1273 36HR VT 05/0000Z 16.8N 75.7W 45 KT 1274 48HR VT 05/1200Z 18.1N 74.7W 55 KT 1275 72HR VT 06/1200Z 21.0N 72.5W 60 KT 1276 96HR VT 07/1200Z 23.0N 71.0W 60 KT 1277120HR VT 08/1200Z 23.5N 69.0W 55 KT 1278 1279$$ 1280FORECASTER BEVEN 1281 1282 1283WTNT41 KNHC 032057 1284TCDAT1 1285TROPICAL STORM TOMAS DISCUSSION NUMBER 23 1286NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 1287500 PM EDT WED NOV 03 2010 1288 1289AFTER STRUGGLING TO MAINTAIN ITS IDENTITY THIS MORNING...TOMAS HAS 1290RE-ORGANIZED DURING THE AFTERNOON. AN AIR FORCE RESERVE HURRICANE 1291HUNTER AIRCRAFT HAS FOUND A BETTER-DEFINED CIRCULATION THAN WAS 1292PRESENT DURING THE PREVIOUS AIRCRAFT MISSION...ALTHOUGH THE LIGHT 1293AND VARIABLE WIND CENTER IS STILL RATHER LARGE. THE PLANE FOUND 1294FLIGHT-LEVEL WINDS OF 48 KT BELOW 1500 FT AND ESTIMATED SURFACE 1295WINDS NEAR 40 KT FROM THE SFMR ABOUT 45 N MI EAST OF THE MEAN 1296CENTER. THE MINIMUM CENTRAL PRESSURE WAS 1003 MB. BASED ON THESE 1297DATA...TOMAS IS UPGRADED TO A 40-KT TROPICAL STORM. 1298 1299WITH THE RE-FORMATION OF THE CENTER TO THE EAST OF THE PREVIOUS 1300ADVISORY POSITION...THE INITIAL MOTION IS NOW AN UNCERTAIN 335/5. 1301A DEEP-LAYER TROUGH AND ACCOMPANYING COLD FRONT MOVING THROUGH THE 1302GULF OF MEXICO AND THE SOUTHEASTERN UNITED STATES SHOULD CAUSE 1303TOMAS TO RECURVE TOWARD THE NORTHEAST DURING THE NEXT 48 HR...WITH 1304A GENERALLY NORTHEASTWARD MOTION CONTINUING THROUGH 72-96 HR. 1305THERE HAS BEEN A SIGNIFICANT CHANGE IN THE TRACK GUIDANCE SINCE THE 1306PREVIOUS ADVISORY...WITH THE LATEST MODEL RUNS IN GOOD AGREEMENT ON 1307A FASTER MOTION IN THE FIRST 72-96 HR. INDEED THE NOGAPS...WHICH 1308PREVIOUSLY CALLED FOR TOMAS TO SHEAR APART AND TURN SOUTHWEST... 1309NOW CALLS FOR THE STORM TO MOVE STEADILY NORTHEASTWARD THROUGH THE 1310FORECAST PERIOD. BASED ON THIS...THE NEW FORECAST TRACK IS FASTER 1311THAN THE PREVIOUS TRACK THROUGH 96 HR. AFTER THAT TIME...THE 1312GUIDANCE REMAINS VERY DIVERGENT. THE UKMET CONTINUES TO FORECAST 1313TOMAS TO SHEAR APART WITH THE LOW-LEVEL CIRCULATION MOVING 1314SOUTHWESTWARD...WHILE THE CANADIAN FORECAST TOMAS OR ITS 1315EXTRATROPICAL REMNANTS TO REACH NEWFOUNDLAND BY 120 HR. THE OTHER 1316MODELS ARE IN BETWEEN THESE RATHER DRASTIC EXTREMES. THE INTENSITY 1317FORECAST WILL FOLLOW THE SCENARIO OF THE PREVIOUS ADVISORY OF A 1318SLOW EASTWARD MOTION AFTER 96 HR AT A HIGHER LATITUDE THAN 1319PREVIOUSLY FORECAST. 1320 1321NOW THAT TOMAS IS CONSOLIDATING...LIGHT VERTICAL WIND SHEAR AND WARM 1322SEA SURFACE TEMPERATURES FAVOR INTENSIFICATION. THE SHIPS RAPID 1323INTENSIFICATION INDEX SHOWS A 50 PERCENT CHANCE OF 30 KT OF 1324STRENGTHENING DURING THE NEXT 24 HR...ALTHOUGH THE CURRENT 1325ORGANIZATION OF TOMAS ARGUES AGAINST THAT MUCH INTENSIFICATION. 1326THE NEW INTENSITY FORECAST IS A COMPROMISE BETWEEN THE SHIPS AND 1327LGEM MODELS FOR THE FIRST 36-48 HR...CALLING FOR TOMAS TO 1328STRENGTHEN UNTIL LAND INTERACTION WITH HISPANIOLA BEGINS. IT IS 1329NOT OUT OF THE QUESTION THAT TOMAS COULD BECOME A HURRICANE BEFORE 1330REACHING LAND AS FORECAST BY THE SHIPS AND GFDL MODELS. AFTER 1331PASSING HISPANIOLA...INCREASING SOUTHWESTERLY WIND SHEAR IS 1332EXPECTED TO CAUSE TOMAS TO WEAKEN. THE NEW INTENSITY FORECAST IS 1333AGAIN CLOSE TO BUT SLIGHTLY LOWER THAN THE INTENSITY CONSENSUS 1334MODEL ICON. 1335 1336REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL 1337CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL... 1338FLOODING...AND POTENTIAL MUD SLIDES OVER HAITI AND THE DOMINICAN 1339REPUBLIC DURING THE NEXT FEW DAYS. 1340 1341FORECAST POSITIONS AND MAX WINDS 1342 1343INITIAL 03/2100Z 14.9N 74.8W 40 KT 1344 12HR VT 04/0600Z 15.8N 75.0W 45 KT 1345 24HR VT 04/1800Z 16.9N 75.0W 50 KT 1346 36HR VT 05/0600Z 18.4N 74.5W 55 KT 1347 48HR VT 05/1800Z 20.2N 73.2W 60 KT 1348 72HR VT 06/1800Z 23.5N 71.0W 60 KT 1349 96HR VT 07/1800Z 26.0N 69.0W 55 KT 1350120HR VT 08/1800Z 26.0N 67.0W 45 KT 1351 1352$$ 1353FORECASTER BEVEN 1354 1355 1356WTNT41 KNHC 040249 1357TCDAT1 1358TROPICAL STORM TOMAS DISCUSSION NUMBER 24 1359NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 13601100 PM EDT WED NOV 03 2010 1361 1362DATA FROM NOAA AND AIR FORCE RESERVE HURRICANE HUNTER MISSIONS 1363INDICATE THAT THE LOW-LEVEL CENTER OF TOMAS IS STILL NOT QUITE 1364ALIGNED WITH THE MID-LEVEL CENTER. THEY HAVE MOVED CLOSER TOGETHER 1365DURING THE DAY...HOWEVER...AND A 2219 UTC SSMI/S MICROWAVE PASS 1366SHOWS CONSIDERABLY MORE BANDING THAN THIS SYSTEM HAS HAD DURING THE 1367PAST FEW DAYS. THE INITIAL WIND SPEED WILL REMAIN 40 KT...WHICH IS 1368NEAR THE FLIGHT-LEVEL AND SFMR MAXIMA REPORTED BY NOAA. 1369 1370THE LARGE-SCALE ENVIRONMENT IS FAVORABLE FOR STRENGTHENING OF TOMAS 1371WITH LIGHT SOUTHWESTERLY SHEAR AND WARM WATERS. IN FACT...ALL OF 1372THE RELIABLE MODELS THAT DO NOT MOVE TOMAS OVER A SIGNIFICANT 1373PORTION OF HAITI MAKE THE CYCLONE A HURRICANE WITHIN 36-48 HOURS. 1374THE SHIPS RAPID INTENSIFICATION INDEX ALSO SHOWS A 62 PERCENT 1375CHANCE OF A 30-KT INCREASE WITHIN THE NEXT 24 HOURS...THOUGH THIS 1376MODEL WAS TOO HIGH YESTERDAY. THIS SYSTEM HAS BURNED US BEFORE BY 1377DOING THE EXACT OPPOSITE OF THE GUIDANCE...BUT GIVEN THE IMPROVED 1378MICROWAVE PRESENTATION...I AM INCLINED TO RAISE THE FORECAST A 1379LITTLE BIT TO HURRICANE STATUS. THE NEW FORECAST IS NEAR OR 1380SLIGHTLY BELOW A COMPOSITE OF THE GFDL...SHIPS...AND LGEM MODELS. 1381WEAKENING IS FORECAST AT THE END OF THE PERIOD AS THE TROPICAL 1382CYCLONE INTERACTS WITH A COLD FRONT AND VERTICAL WIND SHEAR 1383INCREASES. 1384 1385THE CURRENT MOTION REMAINS 330/5...THOUGH THIS IS MORE UNCERTAIN 1386THAN NORMAL WITH THE NHC INITIAL POSITION ON THE NORTHEASTERN SIDE 1387OF THE BROAD LOW-LEVEL CIRCULATION. A WEAK RIDGE TO THE EAST OF 1388TOMAS IS STEERING THE STORM FOR NOW...BUT A RATHER STRONG DEEP 1389LAYER LOW OVER THE GULF OF MEXICO IS EXPECTED TO CAUSE THE TROPICAL 1390CYCLONE TO TURN TOWARD THE NORTH TOMORROW...AND THE NORTH-NORTHEAST 1391BY EARLY FRIDAY. TOMAS SHOULD BE ACCELERATING AS IT PASSES NEAR 1392HAITI AS THE MID-LATITUDE LOW APPROACHES. ONLY COSMETIC CHANGES 1393WERE MADE TO THE NHC FORECAST WITH THE MOST RELIABLE MODELS STILL 1394FOCUSED ON A TRACK TOWARD SOUTHWESTERN HAITI. AT DAYS 4 AND 13955...THERE ARE SOME INDICATIONS FROM THE MODELS THAT THE GULF OF 1396MEXICO LOW WILL LEAVE TOMAS BEHIND TO THE EAST OF THE BAHAMAS...AND 1397THE OFFICIAL FORECAST IS SHIFTED TO THE RIGHT AT THAT TIME. 1398 1399REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL 1400CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL... 1401FLOODING...AND LIFE-THREATENING MUD SLIDES OVER HAITI AND THE 1402DOMINICAN REPUBLIC DURING THE NEXT FEW DAYS. 1403 1404 1405FORECAST POSITIONS AND MAX WINDS 1406 1407INITIAL 04/0300Z 15.4N 75.2W 40 KT 1408 12HR VT 04/1200Z 16.1N 75.4W 45 KT 1409 24HR VT 05/0000Z 17.4N 75.0W 55 KT 1410 36HR VT 05/1200Z 19.1N 74.0W 65 KT 1411 48HR VT 06/0000Z 21.0N 72.5W 65 KT 1412 72HR VT 07/0000Z 24.0N 70.5W 65 KT 1413 96HR VT 08/0000Z 25.0N 68.5W 55 KT 1414120HR VT 09/0000Z 25.0N 66.5W 45 KT 1415 1416$$ 1417FORECASTER BLAKE 1418 1419 1420WTNT41 KNHC 040841 1421TCDAT1 1422TROPICAL STORM TOMAS DISCUSSION NUMBER 25 1423NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 1424500 AM EDT THU NOV 04 2010 1425 1426SATELLITE PICTURES SUGGEST THAT THE CLOUD PATTERN OF TOMAS HAS NOT 1427CHANGED SIGNIFICANTLY DURING THE LAST SEVERAL HOURS. HOWEVER... 1428DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE 1429THAT THE PRESSURE HAS FALLEN TO 997 MB WITH MAXIMUM SURFACE WINDS 1430OF 41 KT. DESPITE THE AIRCRAFT DATA WHICH ARE INDICATIVE OF SLIGHT 1431STRENGTHENING...THE VORTEX HAS BEEN TILTED IN THE VERTICAL BASED 1432UPON COMPARISON OF EARLIER NOAA AND AIR FORCE AIRCRAFT DATA. 1433GIVEN THE SIGNIFICANTLY LOWER CENTRAL PRESSURE FROM THE AIRCRAFT... 1434THE INITIAL INTENSITY IS INCREASED TO 45 KT FOR THIS ADVISORY. 1435 1436THE CURRENT MOTION ESTIMATE REMAINS 330/06. THE FORECAST PHILOSOPHY 1437REGARDING THE TRACK OF TOMAS IS UNCHANGED. TOMAS SHOULD BE STEERED 1438NORTH-NORTHWESTWARD TO NORTHWARD AROUND A LOW- TO MID-LEVEL RIDGE 1439LOCATED OVER THE WEST CENTRAL ATLANTIC TODAY. AFTER THAT...TOMAS 1440SHOULD BEGIN TO ENCOUNTER AN INCREASING SOUTHWESTERLY FLOW 1441ASSOCIATED WITH AN ANOMALOUSLY DEEP MID- TO UPPER-LEVEL TROUGH 1442MOVING ACROSS EASTERN NORTH AMERICA AND TURN NORTHEASTWARD WHILE 1443ACCELERATING. EVEN THOUGH THE SYNOPTIC REASONING HAS NOT CHANGED 1444FROM THE PREVIOUS PACKAGE...THE OFFICIAL FORECAST TRACK IS SHIFTED 1445TO THE LEFT ON ACCOUNT OF THE MOST RECENT AIRCRAFT CENTER FIXES. 1446 1447ALTHOUGH LARGE-SCALE FACTORS OF MODERATELY LOW SHEAR AND WARM WATERS 1448ARE FAVORABLE FOR FURTHER INTENSIFICATION OF TOMAS...THE VERTICAL 1449TILT OF THE VORTEX AND THE BROAD NATURE OF THE CIRCULATION MAY 1450ARGUE AGAINST A RAPID INCREASE IN STRENGTH. INTERESTINGLY...THE 1451SHIPS RAPID INTENSIFICATION INDEX THAT HAD BEEN SHOWING THE 1452POTENTIAL FOR A 30-KT INCREASE WITHIN THE NEXT 24 HOURS IS NOT AS 1453HIGH AS IT WAS BEFORE. THE NEW NHC FORECAST IS SIMILAR TO THE 1454PREVIOUS ONE AND ASSUMES THAT THE LARGE-SCALE ENVIRONMENT SHOULD BE 1455CONDUCIVE ENOUGH TO ALLOW FOR STENGTHENING DURING THE NEXT 24-36 1456HOURS. BEYOND 36 HOURS...STRONG AND INCREASING SOUTHWESTERLY SHEAR 1457OVER THE WESTERN ATLANTIC IS FORECAST TO CAUSE WEAKENING...PERHAPS 1458AT A MORE RAPID PACE THAN INDICATED IN THE CURRENT FORECAST. THE 1459NEW NHC FORECAST IS REDUCED FROM THE PREVIOUS ONE AT LATER FORECAST 1460TIMES GIVEN THE STRONG FORECAST SHEAR. 1461 1462REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST 1463SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE IS HEAVY RAINFALL... 1464WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES 1465OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF 1466DAYS. 1467 1468FORECAST POSITIONS AND MAX WINDS 1469 1470INITIAL 04/0900Z 15.8N 76.1W 45 KT 1471 12HR VT 04/1800Z 17.0N 76.0W 55 KT 1472 24HR VT 05/0600Z 18.8N 75.0W 65 KT 1473 36HR VT 05/1800Z 21.0N 73.4W 65 KT 1474 48HR VT 06/0600Z 23.5N 71.5W 55 KT 1475 72HR VT 07/0600Z 26.0N 69.5W 45 KT 1476 96HR VT 08/0600Z 28.0N 67.0W 35 KT 1477120HR VT 09/0600Z 28.0N 65.0W 25 KT 1478 1479$$ 1480FORECASTER KIMBERLAIN/PASCH 1481 1482 1483WTNT41 KNHC 041504 1484TCDAT1 1485TROPICAL STORM TOMAS DISCUSSION NUMBER 26 1486NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 14871100 AM EDT THU NOV 04 2010 1488 1489SATELLITE IMAGERY...ALONG WITH REPORTS FROM AIR FORCE RESERVE AND 1490NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT THE CENTER OF TOMAS IS 1491LOCATED NEAR THE WESTERN EDGE OF THE MAIN CONVECTIVE MASS. THE 1492NOAA PLANE HAS MEASURED 700 MB FLIGHT-LEVEL WINDS OF 44 KT...AND A 1493RECENT DROPSONDE SUGGESTS SURFACE WINDS AROUND 40 KT AND A CENTRAL 1494PRESSURE BELOW 997 MB. BASED ON THESE DATA...THE INITIAL INTENSITY 1495REMAINS 40 KT. THE CIRRUS OUTFLOW IS CURRENTLY GOOD OVER THE 1496NORTHEASTERN SEMICIRCLE AND POOR ELSEWHERE. 1497 1498THE INITIAL MOTION IS NOW A SOMEWHAT UNCERTAIN 350/7. A LARGE 1499DEEP-LAYER TROUGH AND ASSOCIATED COLD FRONT SHOULD CAUSE TOMAS TO 1500MOVE NORTHWARD TO NORTHEASTWARD FOR THE NEXT 48 HR OR SO...WITH THE 1501CENTER PASSING NEAR OR OVER JAMAICA...HAITI...EASTERN CUBA...AND 1502THE SOUTHEASTERN BAHAMAS. THE TRACK GUIDANCE IS IN GOOD AGREEMENT 1503WITH THIS SCENARIO...AND THIS PART OF THE FORECAST TRACK IS AN 1504UPDATE OF THE PREVIOUS TRACK. AFTER 48 HR...THE GUIDANCE IS 1505DIVERGENT AND INCONSISTENT. THE ECMWF SHOWS TOMAS MOVING ALONG THE 1506SOUTHERN PERIPHERY OF THE DEEP-LAYER TROUGH...AND THIS IS 1507CONSISTENT WITH ITS PREVIOUS RUN. THE GFS...GFDL...AND HWRF NOW 1508CALL FOR TOMAS TO MOVE RAPIDLY NORTHWARD AND BE ABSORBED INTO THE 1509TROUGH...WHICH IS A MAJOR CHANGE FROM THE 6 HOUR OLD RUNS. ON THE 1510OTHER HAND...THE NOGAPS...WHICH 6 HR AGO WAS CALLING FOR A 1511CONTINUED NORTHWARD MOTION...NOW CALLS FOR AN EASTWARD TURN SIMILAR 1512TO THE ECMWF. OVERALL...THE GUIDANCE ENVELOPE HAS SHIFTED 1513NORTHWARD FROM THE PREVIOUS ADVISORY. THE 72-120 HR PORTION OF THE 1514TRACK WILL ALSO BE SHIFTED NORTHWARD...BUT IS WELL SOUTH OF THE 1515CONSENSUS MODELS AND THE CENTER OF THE GUIDANCE ENVELOPE. THIS 1516PART OF THE FORECAST TRACK IS LOW CONFIDENCE. 1517 1518TOMAS IS EXPERIENCING 10-15 KT OF SOUTH-SOUTHWESTERLY VERTICAL WIND 1519SHEAR...AND THE CYCLONE SHOULD REMAIN IN A LIGHT/MODERATE SHEAR 1520ENVIRONMENT FOR THE NEXT 36-48 HR. THIS SHOULD ALLOW STRENGTHENING 1521AS LONG AS THE CENTER REMAINS OVER WATER. THIS PART OF THE NEW 1522INTENSITY FORECAST IS ONLY SLIGHTLY CHANGED FROM THE PREVIOUS 1523ADVISORY AND IS CLOSEST TO THE SHIPS MODEL. AFTER 48 HR...THE 1524INTENSITY AND EVENTUAL FATE OF TOMAS ARE STRONGLY TIED TO ITS 1525TRACK. A NORTHWARD TRACK WOULD RESULT IN A RAPID EXTRATROPICAL 1526TRANSITION AND ABSORPTION BY THE DEEP-LAYER TROUGH. AN EASTWARD 1527TRACK WOULD KEEP THE SYSTEM NEAR OR JUST AHEAD OF THE COLD FRONT IN 1528AN AREA OF STRONG WIND SHEAR. EITHER WAY...TOMAS SHOULD WEAKEN 1529DURING THIS TIME AND THIS IS REFLECTED IN THE INTENSITY FORECAST. 1530THE 120 HR FORECAST NOW CALLS FOR EXTRATROPICAL TRANSITION...AND 1531THIS COULD OCCUR EARLIER IF THE CYCLONE MOVES FARTHER NORTH THAN 1532FORECAST. 1533 1534REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST 1535SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE IS HEAVY RAINFALL... 1536WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES 1537OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF 1538DAYS. 1539 1540FORECAST POSITIONS AND MAX WINDS 1541 1542INITIAL 04/1500Z 16.3N 76.1W 40 KT 1543 12HR VT 05/0000Z 17.5N 75.9W 50 KT 1544 24HR VT 05/1200Z 19.5N 74.7W 60 KT 1545 36HR VT 06/0000Z 21.8N 73.1W 65 KT 1546 48HR VT 06/1200Z 24.3N 71.3W 55 KT 1547 72HR VT 07/1200Z 28.0N 69.0W 40 KT 1548 96HR VT 08/1200Z 29.5N 66.5W 30 KT 1549120HR VT 09/1200Z 29.5N 63.5W 30 KT...POST-TROP/EXTRATROP 1550 1551$$ 1552FORECASTER BEVEN 1553 1554 1555WTNT41 KNHC 041537 1556TCDAT1 1557TROPICAL STORM TOMAS DISCUSSION NUMBER 26...CORRECTED 1558NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 15591100 AM EDT THU NOV 04 2010 1560 1561CORRECTED INITIAL INTENSITY TO 45 KT 1562 1563SATELLITE IMAGERY...ALONG WITH REPORTS FROM AIR FORCE RESERVE AND 1564NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT THE CENTER OF TOMAS IS 1565LOCATED NEAR THE WESTERN EDGE OF THE MAIN CONVECTIVE MASS. THE 1566NOAA PLANE HAS MEASURED 700 MB FLIGHT-LEVEL WINDS OF 44 KT...AND A 1567RECENT DROPSONDE SUGGESTS SURFACE WINDS AROUND 40-45 KT AND A 1568CENTRAL PRESSURE BELOW 997 MB. BASED ON THESE DATA...THE INITIAL 1569INTENSITY REMAINS 45 KT. THE CIRRUS OUTFLOW IS CURRENTLY GOOD OVER 1570THE NORTHEASTERN SEMICIRCLE AND POOR ELSEWHERE. 1571 1572THE INITIAL MOTION IS NOW A SOMEWHAT UNCERTAIN 350/7. A LARGE 1573DEEP-LAYER TROUGH AND ASSOCIATED COLD FRONT SHOULD CAUSE TOMAS TO 1574MOVE NORTHWARD TO NORTHEASTWARD FOR THE NEXT 48 HR OR SO...WITH THE 1575CENTER PASSING NEAR OR OVER JAMAICA...HAITI...EASTERN CUBA...AND 1576THE SOUTHEASTERN BAHAMAS. THE TRACK GUIDANCE IS IN GOOD AGREEMENT 1577WITH THIS SCENARIO...AND THIS PART OF THE FORECAST TRACK IS AN 1578UPDATE OF THE PREVIOUS TRACK. AFTER 48 HR...THE GUIDANCE IS 1579DIVERGENT AND INCONSISTENT. THE ECMWF SHOWS TOMAS MOVING ALONG THE 1580SOUTHERN PERIPHERY OF THE DEEP-LAYER TROUGH...AND THIS IS 1581CONSISTENT WITH ITS PREVIOUS RUN. THE GFS...GFDL...AND HWRF NOW 1582CALL FOR TOMAS TO MOVE RAPIDLY NORTHWARD AND BE ABSORBED INTO THE 1583TROUGH...WHICH IS A MAJOR CHANGE FROM THE 6 HOUR OLD RUNS. ON THE 1584OTHER HAND...THE NOGAPS...WHICH 6 HR AGO WAS CALLING FOR A 1585CONTINUED NORTHWARD MOTION...NOW CALLS FOR AN EASTWARD TURN SIMILAR 1586TO THE ECMWF. OVERALL...THE GUIDANCE ENVELOPE HAS SHIFTED 1587NORTHWARD FROM THE PREVIOUS ADVISORY. THE 72-120 HR PORTION OF THE 1588TRACK WILL ALSO BE SHIFTED NORTHWARD...BUT IS WELL SOUTH OF THE 1589CONSENSUS MODELS AND THE CENTER OF THE GUIDANCE ENVELOPE. THIS 1590PART OF THE FORECAST TRACK IS LOW CONFIDENCE. 1591 1592TOMAS IS EXPERIENCING 10-15 KT OF SOUTH-SOUTHWESTERLY VERTICAL WIND 1593SHEAR...AND THE CYCLONE SHOULD REMAIN IN A LIGHT/MODERATE SHEAR 1594ENVIRONMENT FOR THE NEXT 36-48 HR. THIS SHOULD ALLOW STRENGTHENING 1595AS LONG AS THE CENTER REMAINS OVER WATER. THIS PART OF THE NEW 1596INTENSITY FORECAST IS ONLY SLIGHTLY CHANGED FROM THE PREVIOUS 1597ADVISORY AND IS CLOSEST TO THE SHIPS MODEL. AFTER 48 HR...THE 1598INTENSITY AND EVENTUAL FATE OF TOMAS ARE STRONGLY TIED TO ITS 1599TRACK. A NORTHWARD TRACK WOULD RESULT IN A RAPID EXTRATROPICAL 1600TRANSITION AND ABSORPTION BY THE DEEP-LAYER TROUGH. AN EASTWARD 1601TRACK WOULD KEEP THE SYSTEM NEAR OR JUST AHEAD OF THE COLD FRONT IN 1602AN AREA OF STRONG WIND SHEAR. EITHER WAY...TOMAS SHOULD WEAKEN 1603DURING THIS TIME AND THIS IS REFLECTED IN THE INTENSITY FORECAST. 1604THE 120 HR FORECAST NOW CALLS FOR EXTRATROPICAL TRANSITION...AND 1605THIS COULD OCCUR EARLIER IF THE CYCLONE MOVES FARTHER NORTH THAN 1606FORECAST. 1607 1608REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST 1609SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE IS HEAVY RAINFALL... 1610WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES 1611OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF 1612DAYS. 1613 1614 1615 1616FORECAST POSITIONS AND MAX WINDS 1617 1618INITIAL 04/1500Z 16.3N 76.1W 45 KT 1619 12HR VT 05/0000Z 17.5N 75.9W 50 KT 1620 24HR VT 05/1200Z 19.5N 74.7W 60 KT 1621 36HR VT 06/0000Z 21.8N 73.1W 65 KT 1622 48HR VT 06/1200Z 24.3N 71.3W 55 KT 1623 72HR VT 07/1200Z 28.0N 69.0W 40 KT 1624 96HR VT 08/1200Z 29.5N 66.5W 30 KT 1625120HR VT 09/1200Z 29.5N 63.5W 30 KT...POST-TROP/EXTRATROP 1626 1627$$ 1628FORECASTER BEVEN 1629 1630 1631WTNT41 KNHC 042056 1632TCDAT1 1633TROPICAL STORM TOMAS DISCUSSION NUMBER 27 1634NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 1635500 PM EDT THU NOV 04 2010 1636 1637THIS AFTERNOON...TOMAS CONTINUES AS A SHEARED TROPICAL STORM WITH 1638MOST OF THE DEEP CONVECTION LOCATED EAST OF A LOW-LEVEL SWIRL. 1639DESPITE APPEARANCES THAT THE SWIRL IS THE CIRCULATION CENTER...THE 1640AIR FORCE C-130 OBSERVATIONS INDICATE THAT THIS FEATURE HAS BEEN 1641ROTATING AROUND A BROADER MEAN CENTER. THE RECONNAISSANCE ALSO 1642OBSERVED A CENTRAL PRESSURE OF 995 MB AND EQUIVALENT WINDS AT THE 1643SURFACE OF ABOUT 45 KT...THOUGH THIS WIND VALUE COULD BE SLIGHTLY 1644GENEROUS. 1645 1646THE MOTION OF THE CYCLONE IS 350 DEGREES AT 4 KT AS IT IS PRIMARILY 1647BEING STEERED TO THE NORTH AROUND THE WESTERN PERIPHERY OF THE 1648SUBTROPICAL RIDGE. A VIGOROUS SHORT-WAVE TROUGH CURRENTLY OVER THE 1649GULF OF MEXICO SHOULD INDUCE RECURVATURE OF TOMAS TOWARD THE 1650NORTH-NORTHEAST AND ACCELERATION OF ITS FORWARD SPEED DURING THE 36 1651HR OR SO. THE TRACK MODELS ARE IN EXCELLENT AGREEMENT ON THIS 1652POINT AND THE OFFICIAL FORECAST THROUGH 36 HR IS CLOSE TO THE MODEL 1653CONSENSUS AND THE PREVIOUS ADVISORY. AT 48 HR AND 1654BEYOND...HOWEVER...THE EVENTUAL TRACK OF TOMAS IS QUITE UNCERTAIN. 1655ONE GROUP OF MODELS...INCLUDING THE GFS...GFS ENSEMBLE 1656MEAN...NOGAPS...HWRF...AND GFDL...CONTINUE TO SPEED THE CYCLONE 1657NORTH-NORTHEASTWARD AND HAVE IT BECOMING EXTRATROPICAL AS IT 1658ENCOUNTERS A STRONG COLD FRONT. ANOTHER SCENARIO...SHARED BY THE 1659ECMWF AND UKMET MODELS...IS THAT THE CYCLONE WOULD BECOME SHEARED 1660AND SHALLOW...NOT PICKED UP BY THE TROUGH AND FRONT...AND MEANDER 1661EASTWARD FOR A COUPLE DAYS. THE CONSENSUS TECHNIQUES...BY 1662DESIGN...SPLIT THE DIFFERENCE...WHICH IS NOT VERY LIKELY TO BE 1663CORRECT. IN A SOMEWHAT UNCOMFORTABLE COMPROMISE...THIS TRACK 1664FORECAST IS NEARLY IDENTICAL TO THE PREVIOUS ADVISORY BUT IS 1665SOMEWHAT EQUATORWARD OF THE MODEL CONSENSUS. 1666 1667TOMAS HAS ABOUT A DAY OR TWO TO INTENSIFY UNDER THE INFLUENCE OF 1668MODERATE SOUTHERLY VERTICAL SHEAR...A MOIST ENVIRONMENT...VERY WARM 1669WATERS...AND A SOMEWHAT UNSTABLE ATMOSPHERE. BEYOND TWO DAYS...THE 1670CYCLONE SHOULD EXPERIENCE STRONG WESTERLY SHEAR AND INCREASINGLY 1671COOLER WATERS. THE INTENSITY PREDICTION IS QUITE CLOSE TO A 1672CONSENSUS OF DECAY-SHIPS...LGEM...AND GFDL MODELS AND NEARLY THE 1673SAME AS THE PREVIOUS ADVISORY. IT SHOULD BE NOTED THAT IF THE 1674TRACK DOES TAKE THE CYCLONE DIRECTLY OVER EITHER EASTERN CUBA OR 1675HISPANIOLA FOR MORE THAN A FEW HOURS...THE CYCLONE WOULD BE WEAKER 1676THAN INDICATED HERE. 1677 1678REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST 1679SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE IS HEAVY RAINFALL... 1680WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES 1681OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF 1682DAYS. 1683 1684FORECAST POSITIONS AND MAX WINDS 1685 1686INITIAL 04/2100Z 16.6N 76.0W 45 KT 1687 12HR VT 05/0600Z 17.8N 75.6W 50 KT 1688 24HR VT 05/1800Z 20.1N 74.3W 60 KT 1689 36HR VT 06/0600Z 22.6N 72.5W 65 KT 1690 48HR VT 06/1800Z 24.8N 71.1W 55 KT 1691 72HR VT 07/1800Z 27.5N 69.0W 40 KT 1692 96HR VT 08/1800Z 28.5N 66.5W 30 KT 1693120HR VT 09/1800Z 29.0N 64.5W 30 KT...POST-TROP/REMNT LOW 1694 1695$$ 1696FORECASTER LANDSEA/BEVEN 1697 1698 1699WTNT41 KNHC 050244 1700TCDAT1 1701TROPICAL STORM TOMAS DISCUSSION NUMBER 28 1702NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 17031100 PM EDT THU NOV 04 2010 1704 1705THERE HAS BEEN A SHARP INCREASE IN THE INNER-CORE WIND STRUCTURE AND 1706CONVECTIVE ORGANIZATION OF TOMAS DURING THE PAST 6 HOURS. ALTHOUGH 1707BOTH AIR FORCE RESERVE AND NOAA HURRICANE AIRCRAFT INDICATE THERE 1708IS ABOUT 12 NMI NORTHEASTWARD TILT TO THE VORTEX...THIS HAS NOT 1709PREVENTED THE CENTRAL PRESSURE FROM FALLING AND THE WINDS FROM 1710INCREASING. THE MAXIMUM 850-MB FLIGHT-LEVEL WINDS REPORTED BY THE 1711AIR FORCE WAS 61 KT...AND 58 KT WAS REPORTED AT 700 MB BY THE NOAA 1712HURRICANE HUNTERS. MAXIMUM SFMR WINDS HAVE BEEN AROUND 56-58 KT. 1713THE LATEST NOAA RECON PRESSURE WAS DOWN TO 989 MB...AND THAT WAS 1714WITH 13 KT OF WIND AT THE SURFACE. A COMBINATION OF THESE DATA 1715EASILY SUPPORT INCREASING THE INTENSITY TO 55 KT...WHICH COULD BE A 1716LITTLE CONSERVATIVE GIVEN THAT A WARM SPOT HAS APPEARED 1717INTERMITTENTLY WITHIN A RING OF VERY COLD TOPS OF -80C TO -85C NEAR 1718THE CENTER. 1719 1720THE INITIAL MOTION ESTIMATE IS NOW 030/08. TOMAS HAS NOW MOVED NORTH 1721OF A MID-LEVEL RIDGE THAT LIES EAST-WEST ACROSS THE CENTRAL 1722CARIBBEAN SEA. TOMAS SHOULD CONTINUE TO MOVE AROUND THE WESTERN 1723PERIPHERY OF THE RIDGE AND GRADUALLY ACCELERATE NORTHEASTWARD AS IT 1724COMES UNDER THE INFLUENCE OF MODERATE SOUTHWESTERLY FLOW AHEAD OF A 1725DEEP MID-LATITUDE TROUGH CURRENTLY MOVING EASTWARD ACROSS THE 1726EASTERN U.S....FLORIDA...AND THE EASTERN GULF OF MEXICO. THE TRACK 1727MODELS REMAIN IN EXCELLENT AGREEMENT ON THIS DEVELOPING SCENARIO 1728THROUGH 48 HOURS...AND THE MODEL TRACKS HAVE EVEN SHIFTED MORE TO 1729THE EAST ON THE LATEST FORECAST CYCLE. HOWEVER...AFTER THAT TIME... 1730HOWLING WESTERLY WIND SHEAR IN EXCESS OF 60 KT IS EXPECTED TO SHEAR 1731APART TOMAS AND LEAVE BEHIND A REMNANT LOW PRESSURE SYSTEM THAT 1732SHOULD BE STEERED SLOWLY EASTWARD BY WEAKER LOW-LEVEL WESTERLY FLOW 1733ON THE SOUTH SIDE OF AN EXTRATROPICAL LOW PRESSURE SYSTEM. THE GFDL 1734AND HWRF MODELS TAKE TOMAS OR ITS REMNANTS RAPIDLY NORTHWARD AND 1735MERGE IT WITH A DEEP EXTRATROPICAL LOW NEAR THE NORTHEAST U.S. 1736COAST AND THE CANADIAN MARITIMES. HOWEVER...THE GFS...ECMWF... 1737UKMET...AND NOGAPS MODELS SHOW TOMAS SHEARING APART AND REMAINING 1738JUST NORTH OF THE GREATER ANTILLES. THE LATTER SCENARIO IS 1739PREFERRED GIVEN THE EXTREMELY HOSTILE SHEAR CONDITIONS THAT ARE 1740FORECAST TO AFFECT THE CYCLONE BY 72 HOURS AND BEYOND. THE OFFICIAL 1741FORECAST TRACK HAS BEEN SHIFTED A LITTLE TO THE RIGHT OF THE 1742PREVIOUS TRACK...BUT MAINLY TO ACCOUNT FOR THE MORE EASTERLY 1743INITIAL POSITION. 1744 1745TOMAS HAS ABOUT 24 HOURS OR SO TO STRENGTHEN OVER 29C SSTS AND IN A 1746RELATIVELY LOW SHEAR ENVIRONMENT. HOWEVER...BY 36 HOURS...MID-LEVEL 1747HUMIDITIES ARE FORECAST TO DECREASE BELOW 40 PERCENT...WHICH COULD 1748ACT TO ERODE THE INNER-CORE CONVECTION. AS MENTIONED ABOVE...BY 48 1749HOURS THE VERTICAL SHEAR IS EXPECTED TO INCREASE SHARPLY AND TOMAS 1750SHOULD BEGIN A STEADY WEAKENING TREND. THE OFFICIAL INTENSITY 1751FORECAST IS SIMILAR TO BUT SLIGHTLY LOWER THAN THE SHIPS...LGEM... 1752AND GFDL MODELS. 1753 1754REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST 1755SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE WILL BE HEAVY 1756RAINFALL...WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING 1757MUD SLIDES OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT 1758COUPLE OF DAYS. 1759 1760FORECAST POSITIONS AND MAX WINDS 1761 1762INITIAL 05/0300Z 17.3N 75.5W 55 KT 1763 12HR VT 05/1200Z 18.8N 74.6W 65 KT 1764 24HR VT 06/0000Z 21.0N 73.1W 70 KT 1765 36HR VT 06/1200Z 23.4N 71.5W 70 KT 1766 48HR VT 07/0000Z 25.1N 70.2W 55 KT 1767 72HR VT 08/0000Z 27.2N 67.9W 40 KT 1768 96HR VT 09/0000Z 28.3N 65.8W 30 KT...POST-TROPICAL 1769120HR VT 10/0000Z 28.5N 64.0W 30 KT...POST-TROP/REMNT LOW 1770 1771$$ 1772FORECASTER STEWART 1773 1774 1775WTNT41 KNHC 050838 1776TCDAT1 1777HURRICANE TOMAS DISCUSSION NUMBER 29 1778NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 1779500 AM EDT FRI NOV 05 2010 1780 1781TOMAS HAS REGAINED HURRICANE STRENGTH. THE AIR FORCE HURRICANE 1782HUNTERS FOUND A PEAK 850 MB FLIGHT-LEVEL WIND OF 88 KT AND MAXIMUM 1783SFMR-OBSERVED SURFACE WINDS OF 75 KT. THE LATTER OBSERVATION 1784APPEARED TO BE SOMEWHAT OF A SPIKE IN THE RECORD...AND USING A 1785BLEND OF THE SURFACE AND FLIGHT-LEVEL DATA GIVES 70 KT FOR THE 1786CURRENT INTENSITY ESTIMATE. OBSERVATIONS FROM THE AIRCRAFT AND A 1787TRMM MICROWAVE OVERPASS SUGGEST THAT THE CYCLONE IS TILTED 1788NORTHWARD AS A RESULT OF SOUTHERLY OR SOUTH-SOUTHWESTERLY VERTICAL 1789WIND SHEAR. SATELLITE IMAGERY SHOWS A WELL-DEFINED CENTRAL DENSE 1790OVERCAST...WITH CLOUD TOP TEMPS APPROACHING -90C. 1791 1792THE INITIAL MOTION ESTIMATE IS 035/08. TOMAS IS LOCATED ON THE EAST 1793SIDE OF AN UNUSUALLY DEEP MID- TO UPPER-LEVEL TROUGH CURRENTLY 1794AMPLIFYING OVER THE EASTERN UNITED STATES. THE CYCLONE SHOULD 1795GRADUALLY BECOME EMBEDDED IN AN INCREASING SOUTHWESTERLY WIND FLOW 1796AHEAD OF THIS SYSTEM DURING THE NEXT COUPLE OF DAYS AND MOVE ON A 1797GENERAL NORTHEASTWARD COURSE WITH SOME INCREASE IN FORWARD 1798SPEED. AFTER 48 HOURS...TOMAS SHOULD GRADUALLY SLOW DOWN AND TURN 1799EAST-NORTHEASTWARD AND THEN EASTWARD IN A WEAKER LOW-LEVEL 1800WESTERLY STEERING FLOW AS THE INCREASING SHEAR REDUCES TOMAS TO A 1801SHALLOWER FEATURE. THIS IS THE GENERAL SCENARIO DEPICTED BY THE 1802GFS AND U.K. MET. OFFICE GLOBAL MODELS. AN ALTERNATIVE EVOLUTION 1803IS SUGGESTED BY SOME OF THE OTHER GUIDANCE SUCH AS THE ECMWF. THE 1804LATTER MODEL SHOWS A STRONGER CYCLONE NEAR THE END OF THE FORECAST 1805PERIOD...PRESUMABLY DUE TO BAROCLINIC FORCING...THAT MOVES MORE 1806QUICKLY TOWARDS THE NORTHEAST. THE OFFICIAL NHC TRACK FORECAST IS 1807VIRTUALLY UNCHANGED FROM THE PREVIOUS ONE AND IS ON THE EASTERN 1808SIDE OF THE GUIDANCE ENVELOPE. 1809 1810TOMAS STILL HAS ABOUT 24 HOURS OR SO TO STRENGTHEN IN AN ENVIRONMENT 1811OF RELATIVELY LOW SHEAR...HIGH MOISTURE...AND OVER WARM WATERS. 1812AFTER THAT...A RAPID INCREASE IN SOUTHWESTERLY SHEAR ASSOCIATED 1813WITH THE EASTERN U.S. TROUGH...NOT TO MENTION DRIER AND COOLER 1814ASSOCIATED WITH THE SAME FEATURE IMPINGING ON THE CIRCULATION... 1815SHOULD BRING ABOUT A PRONOUNCED WEAKENING PHASE. THE NEW NHC 1816FORECAST IS LOWER THAN THE SHIPS/LGEM INTENSITY GUIDANCE BUT ABOUT 1817THE SAME AS THE PREVIOUS OFFICIAL FORECAST...INDICATING 1818INTENSIFICATION TO HURRICANE STRENGTH WITHIN 24 HOURS AND WEAKENING 1819TO A REMNANT LOW IN 96 HOURS. WEAKENING AFTER 48 HOURS COULD BE 1820MORE RAPID THAN INDICATED...CONSIDERING THAT THE SHEAR COULD BE 1821HIGHER THAN 60 KT AFTER 60 HOURS. 1822 1823REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST 1824SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE SHOULD CONTINUE TO BE 1825HEAVY RAINFALL...WHICH COULD PRODUCE FLASH FLOODING AND LIFE- 1826THREATENING MUD SLIDES OVER PORTIONS OF HAITI AND THE DOMINICAN 1827REPUBLIC DURING THE NEXT COUPLE OF DAYS. 1828 1829FORECAST POSITIONS AND MAX WINDS 1830 1831INITIAL 05/0900Z 18.1N 74.9W 70 KT 1832 12HR VT 05/1800Z 19.8N 73.9W 75 KT 1833 24HR VT 06/0600Z 22.1N 72.4W 75 KT 1834 36HR VT 06/1800Z 24.4N 70.9W 65 KT 1835 48HR VT 07/0600Z 25.8N 69.6W 50 KT 1836 72HR VT 08/0600Z 27.5N 67.5W 35 KT 1837 96HR VT 09/0600Z 28.5N 65.0W 25 KT...POST-TROP/REMNT LOW 1838120HR VT 10/0600Z 28.5N 63.0W 25 KT...POST-TROP/REMNT LOW 1839 1840$$ 1841FORECASTER KIMBERLAIN/PASCH 1842 1843 1844WTNT41 KNHC 051505 1845TCDAT1 1846HURRICANE TOMAS DISCUSSION NUMBER 30 1847NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 18481100 AM EDT FRI NOV 05 2010 1849 1850BEFORE IT DEPARTED TOMAS...THE AIR FORCE RESERVE HURRICANE HUNTER 1851AIRCRAFT REPORTED THAT THE CENTRAL PRESSURE HAD RISEN SLIGHTLY TO 1852987 MB. HOWEVER...THE FLIGHT-LEVEL AND SFMR WINDS STILL SUPPORTED 1853AN INTENSITY OF 75 KT...WHICH IS THE INITIAL INTENSITY FOR THIS 1854ADVISORY. THE CENTRAL CONVECTION IS CURRENTLY LOOKING A LITTLE 1855RAGGED IN SATELLITE IMAGERY AND RADAR DATA FROM CUBA...POSSIBLY DUE 1856TO THE CIRCULATION OF TOMAS INTERACTING WITH THE MOUNTAINS OF 1857HISPANIOLA. THE CIRRUS OUTFLOW IS GOOD TO EXCELLENT OVER THE 1858NORTHERN SEMICIRCLE AND POOR ELSEWHERE. 1859 1860THE INITIAL MOTION IS 030/10. TOMAS IS TO THE EAST OF A STRONG 1861DEEP-LAYER TROUGH AND ASSOCIATED SURFACE FRONTAL SYSTEM OVER THE 1862EASTERN UNITED STATES AND THE WESTERN ATLANTIC. FOR THE NEXT 186336-48 HR...THIS FEATURE SHOULD STEER THE HURRICANE GENERALLY 1864NORTH-NORTHEASTWARD. THE TRACK GUIDANCE IS IN GOOD AGREEMENT WITH 1865THE DIRECTION OF MOTION...BUT THERE ARE DIFFERENCES IN SPEED 1866BETWEEN THE FASTER GFS/GFDL/HWRF AND THE SLOWER UKMET/ECMWF/NOGAPS. 1867THIS PART OF THE FORECAST TRACK IS SIMILAR TO...BUT A LITTLE TO THE 1868LEFT OF...THE PREVIOUS TRACK...AND IN THE MIDDLE OF THE GUIDANCE 1869ENVELOPE. AFTER 36-48 HR...THE GUIDANCE SHOWS SIGNIFICANT SPREAD 1870IN BOTH DIRECTION AND SPEED. THE UKMET AND NOGAPS...WHICH APPEAR 1871TO SHEAR TOMAS APART...SHOW A SLOW EASTWARD MOTION SOUTH OF 25N. 1872THE GFS/GFDL/HWRF MOVE TOMAS MUCH MORE QUICKLY TO THE NORTH OR 1873NORTHEAST AND ABSORB IT INTO THE BAROCLINIC SYSTEMS OVER THE 1874WESTERN ATLANTIC. THE ECMWF IS IN BETWEEN...SHOWING AN EASTWARD 1875TURN FOLLOWED BY AN EAST-NORTHEASTWARD MOTION BY THE END OF THE 1876FORECAST PERIOD. THIS PART OF THE NEW FORECAST TRACK LIES SOUTH OF 1877THE CENTER OF THE GUIDANCE ENVELOPE BETWEEN THE CONSENSUS MODELS 1878AND THE ECMWF...AND SHOWS A SLOWER FORWARD SPEED THE THE ECMWF. 1879THIS PORTION OF THE TRACK FORECAST REMAINS LOW CONFIDENCE. 1880 1881TOMAS STILL HAS ABOUT 24 HR IN WHICH TO STRENGTHEN BEFORE 1882ENCOUNTERING INCREASING VERTICAL WIND SHEAR AND DRIER AIR 1883ASSOCIATED WITH THE TROUGH...WITH THE CAVEAT THAT INTERACTION WITH 1884HISPANIOLA COULD SLOW OR HALT DEVELOPMENT. THE SHIPS...LGEM...AND 1885GFDL MODELS NOW SHOW THE CYCLONE BECOMING A CATEGORY 2 HURRICANE IN 188624 HR...AND THE NEW INTENSITY FORECAST WILL FOLLOW SUIT. AFTER 1887THAT...THE CYCLONE IS EXPECTED TO ENCOUNTER HOSTILE ENOUGH 1888CONDITIONS TO CAUSE WEAKENING REGARDLESS OF THE EXACT TRACK IT 1889TAKES...AND THE FORECAST FOLLOWS THE TREND OF THE PREVIOUS ADVISORY 1890IN SHOWING A QUICK WEAKENING. THE FINAL DEMISE OF TOMAS IS 1891DEPENDENT UPON ITS TRACK...AS A MORE NORTHWARD MOTION WOULD LIKELY 1892LEAD TO EXTRATROPICAL TRANSITION AND A MORE EASTWARD MOTION TO 1893DEGENERATION INTO A REMNANT LOW. THE FORECAST WILL CONTINUE TO USE 1894THE LATTER SCENARIO FOR THE TIME BEING. 1895 1896REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST 1897SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE SHOULD CONTINUE TO BE 1898HEAVY RAINFALL...WHICH COULD PRODUCE FLASH FLOODING AND LIFE- 1899THREATENING MUD SLIDES OVER PORTIONS OF HAITI AND THE DOMINICAN 1900REPUBLIC DURING THE NEXT COUPLE OF DAYS. 1901 1902FORECAST POSITIONS AND MAX WINDS 1903 1904INITIAL 05/1500Z 19.1N 74.4W 75 KT 1905 12HR VT 06/0000Z 20.8N 73.4W 80 KT 1906 24HR VT 06/1200Z 23.1N 72.1W 90 KT 1907 36HR VT 07/0000Z 25.1N 71.0W 80 KT 1908 48HR VT 07/1200Z 26.0N 69.9W 65 KT 1909 72HR VT 08/1200Z 27.5N 67.5W 40 KT 1910 96HR VT 09/1200Z 28.0N 64.5W 25 KT...POST-TROP/REMNT LOW 1911120HR VT 10/1200Z 29.0N 62.5W 25 KT...POST-TROP/REMNT LOW 1912 1913$$ 1914FORECASTER BEVEN 1915 1916 1917WTNT41 KNHC 052059 1918TCDAT1 1919HURRICANE TOMAS DISCUSSION NUMBER 31 1920NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 1921500 PM EDT FRI NOV 05 2010 1922 1923THE CONVECTIVE STRUCTURE OF HURRICANE TOMAS HAS BEEN DISRUPTED THIS 1924AFTERNOON. WHILE SOME OF THIS DISORGANIZATION MAY HAVE BEEN DUE TO 1925MODERATE SOUTHERLY VERTICAL SHEAR...IT IS MORE LIKELY THAT TOMAS 1926HAS BEEN AFFECTED BY HAVING SOME OF ITS CIRCULATION PASS OVER THE 1927HIGHER TOPOGRAPHIC REGIONS OF EASTERN CUBA AND HAITI. THE HIGHEST 1928FLIGHT-LEVEL WINDS REPORTED BY THE AIR FORCE HURRICANE HUNTERS IS 192962 KT WITH PEAK SFMR SURFACE WINDS OF ABOUT THE SAME. THE CURRENT 1930INTENSITY IS REDUCED TO 65 KT AND THIS MAY BE SLIGHTLY GENEROUS. 1931 1932AS TOMAS PROGRESSES NORTHEASTWARD DURING THE NEXT DAY...IT MOVES 1933AWAY FROM THE GREATER ANTILLES AND HAS A BRIEF OPPORTUNITY TO 1934REINTENSIFY. WHILE THE CYCLONE WILL LIKELY REMAIN OVER WARM WATERS 1935FOR AT LEAST THE NEXT COUPLE OF DAYS...EXPECTED VERY STRONG 1936VERTICAL SHEAR AND STABLE/DRY ATMOSPHERE SHOULD LEAD TO A FAIRLY 1937RAPID WEAKENING. THE FORECAST INTENSITY IS BASED ON A BLEND OF THE 1938SHIPS/LGEM/GFDL MODELS AND IS SLIGHTLY LOWERED FROM THE PREVIOUS 1939ADVISORY. ALTERNATIVELY...IF THE INNER CORE OF TOMAS DOES NOT 1940QUICKLY REORGANIZE...THE SYSTEM MAY SIMPLY CONTINUE TO WEAKEN FROM 1941HERE ON IN. WHILE THE FORECAST HERE CALLS FOR THE CYCLONE TO 1942BECOME A REMNANT LOW AT DAY 4...IT IS QUITE POSSIBLE THAT INSTEAD 1943THE SYSTEM COULD EVOLVE INTO AN EXTRATROPICAL LOW AFTER INTERACTING 1944WITH THE STRONG APPROACHING COLD FRONT. 1945 1946THE HURRICANE IS CURRENTLY MOVING AT 35/12...PRIMARILY DUE TO THE 1947INFLUENCE OF COMBINED INFLUENCE OF A NORTH-SOUTH ORIENTED RIDGE TO 1948ITS EAST AND A VIGOROUS SHORT-WAVE TROUGH TO ITS NORTHWEST. THE 1949CYCLONE SHOULD CONTINUE TO MOVE NORTHEASTWARD AT ABOUT THE SAME 1950SPEED FOR ABOUT THE NEXT 36 H AND NEARLY ALL TRACK MODEL GUIDANCE 1951IS IN AGREEMENT WITH THIS. HOWEVER...BEYOND 36 H...THE MODEL SUITE 1952SHOWS A TREMENDOUS DIVERGENCE THAT FALLS INTO TWO FACTIONS. THE 1953NORTHERN GROUP...WITH MEMBERS AT FIVE DAYS JUST SOUTHEAST OF 1954NEWFOUNDLAND...INCLUDE THE HWRF/GFDL/NOGAPS MODELS. THE ECMWF 1955LIKELY WOULD HAVE ALSO BEEN EXPLICITLY INCLUDED HERE...BUT IT 1956BECOMES ABSORBED BY A LARGE BAROCLINIC SYSTEM AFTER DAY THREE. THE 1957SOUTHERN GROUP...WITH MEMBERS AT FIVE DAYS JUST NORTH OF THE 1958CARIBBEAN...INCLUDE THE GFS/GFS ENSEMBLE/UKMET. THE FORECAST TRACK 1959CHOSEN LEANS MORE TOWARD THE LATTER BUNCH AND IS CONSIDERABLY SOUTH 1960OF THE MODEL CONSENSUS...WHICH IS AN UNREALISTIC PREDICTION...AND 1961SOMEWHAT SOUTH OF THE PREVIOUS ADVISORY. IT ALMOST GOES WITHOUT 1962SAYING...THE EXTENDED FORECAST OF THIS SYSTEM IS VERY UNCERTAIN. 1963 1964REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST 1965SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE SHOULD CONTINUE TO BE 1966HEAVY RAINFALL...WHICH COULD PRODUCE FLASH FLOODING AND LIFE- 1967THREATENING MUD SLIDES OVER PORTIONS OF HAITI AND THE DOMINICAN 1968REPUBLIC DURING THE NEXT COUPLE OF DAYS. 1969 1970 1971FORECAST POSITIONS AND MAX WINDS 1972 1973INITIAL 05/2100Z 20.3N 73.8W 65 KT 1974 12HR VT 06/0600Z 22.0N 72.6W 70 KT 1975 24HR VT 06/1800Z 23.9N 71.5W 80 KT 1976 36HR VT 07/0600Z 24.8N 70.8W 75 KT 1977 48HR VT 07/1800Z 25.4N 69.6W 55 KT 1978 72HR VT 08/1800Z 26.5N 67.0W 30 KT 1979 96HR VT 09/1800Z 26.5N 63.5W 25 KT...POST-TROP/REMNT LOW 1980120HR VT 10/1800Z 27.0N 61.0W 25 KT...POST-TROP/REMNT LOW 1981 1982$$ 1983FORECASTER LANDSEA/BEVEN 1984 1985 1986WTNT41 KNHC 060241 1987TCDAT1 1988HURRICANE TOMAS DISCUSSION NUMBER 32 1989NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 19901100 PM EDT FRI NOV 05 2010 1991 1992BEFORE DEPARTING EARLIER THIS EVENING...THE AIR FORCE RESERVE 1993HURRICANE HUNTER AIRCRAFT FOUND A MAXIMUM 850-MB FLIGHT LEVEL WIND 1994OF 57 KT AND A RISING CENTRAL PRESSURE. THE SATELLITE APPEARANCE OF 1995THE CYCLONE HAD ALSO BECOME A BIT DISHEVELED EARLIER THIS EVENING 1996...HOWEVER COLD CLOUD TOPS HAVE AGAIN INCREASED NEAR THE ESTIMATED 1997CENTER LOCATION. THE INITIAL INTENSITY IS HELD AT 65 KT...AND THE 1998NEXT AIRCRAFT MISSION OVERNIGHT WILL HELP DETERMINE IF TOMAS HAS 1999WEAKENED BELOW HURRICANE INTENSITY. THE 20 KT OF SOUTHERLY SHEAR 2000OVER TOMAS ASSOCIATED WITH THE LARGE DEEP-LAYER TROUGH MOVING 2001ACROSS EASTERN NORTH AMERICA COULD BE PREVENTING THE CYCLONE FROM 2002STRENGTHENING FURTHER. CONSISTENT WITH THIS THINKING...AIRCRAFT 2003DATA AND RECENT MICROWAVE IMAGERY INDICATE THAT THE VORTEX IS NOW 2004TILTED NORTHEASTWARD WITH HEIGHT. GIVEN THE SHEAR AND THE RAPID 2005DETERIORATION OF THE MID-LEVEL ATMOSPHERIC THERMODYNAMICS AS 2006INDICATED BY THE SHIPS MODEL IN THE NEXT 12 TO 24 HOURS...TOMAS MAY 2007HAVE PEAKED IN INTENSITY. BEYOND 24 HOURS...THE SHEAR INCREASES 2008FURTHER...WHICH SHOULD RESULT IN WEAKENING. THE OFFICIAL INTENSITY 2009FORECAST HAS BEEN ADJUSTED DOWNWARD...AND SHOWS LITTLE CHANGE 2010THROUGH 12 HOURS FOLLOWED BY STEADY WEAKENING TO REMNANT LOW STATUS 2011IN 96 HOURS. THIS FORECAST IS CLOSE TO THE LGEM MODEL...WHICH IS 2012DESIGNED TO HANDLE CHANGING ENVIRONMENTAL CONDITIONS DURING THE 2013FORECAST PERIOD. 2014 2015THE LAST FEW AIRCRAFT FIXES INDICATE THAT TOMAS IS MOVING MORE TO 2016THE RIGHT...OR EASTWARD...THAN THE PREVIOUS FORECAST TRACK...AND 2017THE INITIAL MOTION ESTIMATE IS 045/11 KT. THE GLOBAL MODELS ARE IN 2018RELATIVELY GOOD AGREEMENT ON THE EVOLUTION OF THE LARGE-SCALE 2019PATTERN...WHICH IS DOMINATED BY A DEEP-LAYER TROUGH MOVING INTO THE 2020WESTERN ATLANTIC THAT WILL SLOW DOWN AS IT CUTS OFF OFFSHORE OF THE 2021NORTHEASTERN U.S. IN 2 OR 3 DAYS. SIGNIFICANT DIFFERENCES REMAIN IN 2022THE TRACK GUIDANCE AS TO WHETHER TOMAS WILL BE PULLED NORTHWARD 2023INTO THE SURFACE FRONTAL ZONE ASSOCIATED WITH THE TROUGH OR BE 2024SHEARED APART AND MOVE SLOWLY EASTWARD. THE GFS...ECMWF...AND UKMET 2025FAVOR THE LATTER SOLUTION AND LIE ON THE SOUTHERN SIDE OF THE 2026GUIDANCE ENVELOPE. THE GFDL...HWRF AND NOGAPS ARE FARTHER NORTH 2027WITH A DEEPER CYCLONE. GIVEN THE EXTREME SHEAR VALUES LATE IN THE 2028PERIOD AND AN ENVIRONMENT THAT APPEARS UNFAVORABLE FOR DEEP 2029CONVECTION...IT SEEMS UNLIKELY THAT TOMAS WILL REMAIN DEEP ENOUGH 2030TO BE PULLED TOO FAR NORTHWARD. THE OFFICIAL FORECAST FAVORS THE 2031SOUTHERN SOLUTION AND IS BASED ON A BLEND OF THE PREVIOUS FORECAST 2032AND THE TRACKS OF THE UKMET...GFS...AND ECMWF MODELS THROUGH 48 2033HOURS. AT DAYS 3 AND 4...THE NEW NHC FORECAST IS AN UPDATE OF THE 2034PREVIOUS ONE ADJUSTED FOR THE INITIAL POSITION AND MOTION. 2035 2036EVEN THOUGH THE CENTER OF TOMAS HAS PASSED NORTH OF HISPANIOLA... 2037SOUTHERLY FLOW BEHIND TOMAS WILL RESULT IN THE CONTINUATION OF A 2038SIGNIFICANT HEAVY RAINFALL THREAT FOR THE NEXT DAY OR TWO...WHICH 2039COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES OVER 2040PORTIONS OF HAITI AND THE DOMINICAN REPUBLIC. 2041 2042FORECAST POSITIONS AND MAX WINDS 2043 2044INITIAL 06/0300Z 20.8N 72.8W 65 KT 2045 12HR VT 06/1200Z 22.4N 71.7W 65 KT 2046 24HR VT 07/0000Z 23.9N 70.9W 60 KT 2047 36HR VT 07/1200Z 24.7N 70.1W 55 KT 2048 48HR VT 08/0000Z 25.0N 68.8W 45 KT 2049 72HR VT 09/0000Z 26.0N 66.0W 30 KT 2050 96HR VT 10/0000Z 26.0N 63.0W 20 KT...POST-TROP/REMNT LOW 2051120HR VT 11/0000Z...DISSIPATED 2052 2053$$ 2054FORECASTER BRENNAN/ROBERTS 2055 2056 2057WTNT41 KNHC 060848 2058TCDAT1 2059TROPICAL STORM TOMAS DISCUSSION NUMBER 33 2060NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 2061500 AM EDT SAT NOV 06 2010 2062 2063AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING TOMAS 2064FOUND 700-MB FLIGHT-LEVEL WINDS OF 63 KT...PEAK SURFACE SFMR WINDS 2065OF 50-55 KT....AND A CENTRAL PRESSURE OF 993 MB. SATELLITE IMAGERY 2066SHOWS THAT THE THE CONVECTIVE STRUCTURE OF THE CYCLONE CONSISTS OF 2067A CENTRAL MASS OF COLD-TOPPED CONVECTION...THOUGH CLOUD TOPS HAVE 2068BEEN WARMING RECENTLY. THE AIRCRAFT OBSERVATIONS ALSO INDICATE THAT 2069THE SURFACE AND FLIGHT-LEVEL CENTERS ARE MORE ALIGNED THAN THEY 2070WERE PREVIOUSLY. WITH NO OBSERVATIONS TO SUPPORT HURRICANE FORCE 2071WINDS...THE INITIAL INTENSITY IS LOWERED TO 60 KT FOR THIS 2072ADVISORY. TOMAS IS EXPECTED TO REMAIN IN RELATIVELY LOW VERTICAL 2073WIND SHEAR FOR UP TO ANOTHER 24 HOURS. HOWEVER...A LOW-LEVEL 2074BAROCLINIC ZONE ASSOCIATED WITH A LARGE DEEP-LAYER TROUGH OVER THE 2075EASTERN U.S. IS IMPINGING ON THE CIRCULATION OF THE HURRICANE. A 2076DRAMATIC INCREASE IN SHEAR IS FORECAST AFTER 24 HOURS...AND 2077THERMODYNAMIC PARAMETERS ARE EXPECTED TO BECOME INCREASINGLY 2078UNFAVORABLE. WEAKENING SEEMS IMMINENT...WITH THE RATE OF WEAKENING 2079LIKELY INCREASING AFTER 36 HOURS...GIVEN THE EXTREME AMOUNT OF 2080VERTICAL WIND SHEAR DEPICTED BY THE LARGE-SCALE MODELS. THE 2081OFFICIAL NHC FORECAST IS SIMILAR TO THE PREVIOUS ONE BUT INDICATES 2082TOMAS BECOMING A REMNANT LOW SOONER. 2083 2084THE INITIAL MOTION IS 050/13...A BIT FASTER THAN THE PREVIOUS 2085ESTIMATE. GLOBAL MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH 2086RESPECT TO THE OVERALL ENVIRONMENTAL SYNOPTIC PATTERN DURING THE 2087NEXT SEVERAL DAYS. THE CYCLONE SHOULD MOVE NORTHEASTWARD DURING THE 2088NEXT 24-36 HOURS IN A DEEP LAYER OF SOUTHWESTERLY FLOW AHEAD OF A 2089MID- TO UPPER-LEVEL TROUGH MOVING FROM THE EASTERN U.S. INTO THE 2090WESTERN ATLANTIC. AFTER THAT...THE TRACK GUIDANCE DIVERGES... WITH 2091SEVERAL OF THE MORE RELIABLE MODELS SHOWING A HEAVILY SHEARED TOMAS 2092MOVING SLOWLY ON AN EASTWARD TRACK AT THE BASE OF THE WESTERN 2093ATLANTIC TROUGH. A SECOND CAMP OF MODELS SHOWS A DEEPER CYCLONE 2094BEING PULLED NORTHWARD AND BECOMING INVOLVED WITH THE BAROCLINIC 2095ZONE ASSOCIATED ASSOCIATED WITH THE SAME TROUGH. THE OFFICIAL 2096FORECAST CONTINUES TO FAVOR THE FORMER GROUP SINCE IT APPEARS 2097UNLIKELY THAT TOMAS WILL BE ABLE TO MANTAIN ITSELF AS A VIABLE 2098TROPICAL CYCLONE FOR LONG. THE NEW NHC FORECAST IS ADJUSTED TO THE 2099RIGHT DURING THE SHORT TERM TO ACCOUNT FOR THE CURRENT MORE 2100NORTHEASTERLY MOTION BUT IS SIMILAR TO THE PREVIOUS FORECAST BEYOND 210148 HOURS. 2102 2103EVEN THOUGH THE CENTER OF TOMAS HAS PASSED NORTH OF HISPANIOLA... 2104SOUTHERLY FLOW BEHIND TOMAS WILL RESULT IN THE CONTINUATION OF A 2105HEAVY RAINFALL THREAT FOR THE NEXT DAY OR TWO...WHICH 2106COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES OVER 2107PORTIONS OF HAITI AND THE DOMINICAN REPUBLIC. 2108 2109 2110FORECAST POSITIONS AND MAX WINDS 2111 2112INITIAL 06/0900Z 21.9N 71.3W 60 KT 2113 12HR VT 06/1800Z 23.2N 70.2W 60 KT 2114 24HR VT 07/0600Z 24.2N 69.4W 55 KT 2115 36HR VT 07/1800Z 24.7N 68.7W 50 KT 2116 48HR VT 08/0600Z 25.0N 67.5W 40 KT 2117 72HR VT 09/0600Z 25.5N 65.0W 25 KT...POST-TROP/REMNT LOW 2118 96HR VT 10/0600Z 26.5N 60.9W 20 KT...POST-TROP/REMNT LOW 2119120HR VT 11/0600Z...DISSIPATED 2120 2121$$ 2122FORECASTER KIMBERLAIN/FRANKLIN 2123 2124 2125WTNT41 KNHC 061502 2126TCDAT1 2127TROPICAL STORM TOMAS DISCUSSION NUMBER 34 2128NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 21291100 AM EDT SAT NOV 06 2010 2130 2131A NOAA HURRICANE HUNTER AIRCRAFT REPORTED 850 MB FLIGHT-LEVEL WINDS 2132OF 69 KT TO THE SOUTHEAST OF THE CENTER OF TOMAS...WITH SFMR WINDS 2133OF 54 KT. THE MINIMUM CENTRAL PRESSURE HAS BEEN IN THE 990-992 MB 2134RANGE DURING THE LAST SEVERAL FIXES. BASED ON THESE DATA...THE 2135INITIAL INTENSITY IS NUDGED DOWNWARD TO 55 KT. THE STORM STILL HAS 2136A SYMMETRIC BANDED CONVECTIVE PATTERN...AND A RECENT WINDSAT 2137OVERPASS SHOWS A WELL-DEFINED LOW-LEVEL STRUCTURE. HOWEVER... 2138COLD-AIR CLOUDS ARE PRESENT IN SATELLITE IMAGERY NEAR THE WESTERN 2139EDGE OF CONVECTION...INDICATING THAT A COLD FRONT IS APPROACHING 2140THE CYCLONE. 2141 2142THE INITIAL MOTION IS 045/14. ALL GUIDANCE INDICATES THAT TOMAS 2143SHOULD SLOW ITS FORWARD MOTION DURING THE NEXT 24 HR AS PRESSURES 2144RISES TO THE NORTH OF THE CYCLONE AND FALL TO THE EAST OF IT. 2145AFTER THAT TIME...ANOTHER ROUND OF BAROCLINIC CYCLOGENESIS SHOULD 2146OCCUR OVER THE NORTHWESTERN ATLANTIC...WITH A NEW DEEP-LAYER LOW 2147DEVELOPING TO THE NORTH OF TOMAS. WHILE THERE ARE SIGNIFICANT 2148DIFFERENCES IN THE DETAILS BETWEEN THE DYNAMICAL MODELS...THEY ALL 2149FORECAST THIS NEW SYSTEM TO TURN TOMAS EASTWARD. THERE REMAINS A 2150LARGE AMOUNT OF SPREAD IN THE TRACK GUIDANCE AFTER 48 HR...AS THE 2151GFS/ECMWF FAVORING A SLOWER MOTION AT LOWER LATITUDE...WHILE 2152GFDL/HWRF/NOGAPS/UKMET/GFS ENSEMBLE MEAN NOW FAVOR A FASTER MOTION 2153AT HIGHER LATITUDE. THE NEW FORECAST TRACK IS A BLEND OF THESE 2154EXTREMES IN BOTH DIRECTION AND SPEED...AND IS SLOWER THAN THE 2155CONSENSUS MODELS. THE NEW TRACK IS SHIFTED A LITTLE TO THE WEST OF 2156THE PREVIOUS FORECAST DURING THE FIRST 24 HR...AND A LITTLE TO THE 2157NORTH THEREAFTER. 2158 2159TOMAS HAS BEEN SLOWLY WEAKENING EVEN THOUGH THE VERTICAL WIND SHEAR 2160REMAINS LIGHT AND THE SEA SURFACE TEMPERATURES WARM. BASED ON 2161THIS...LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE FIRST 24 HR 2162OF THE FORECAST. HOWEVER...GIVEN THE STRUCTURE...THERE IS STILL 2163SOME CHANCE OF RE-INTENSIFICATION DURING THIS TIME. TOMAS SHOULD 2164ENCOUNTER SIGNIFICANT AMOUNTS OF COOLER/DRIER AIR AND INCREASING 2165WIND SHEAR AFTER 24 HR...WHICH SHOULD CAUSE A STEADY AND POSSIBLY 2166RAPID WEAKENING. THE LATTER PART OF THE NEW INTENSITY FORECAST 2167CALLS FOR THE CYCLONE TO DEGENERATE INTO A REMNANT LOW BY 72 HR AND 2168TO DISSIPATE COMPLETELY BY 120 HR. THERE IS A POSSIBILITY TOMAS 2169COULD UNDERGO EXTRATROPICAL TRANSITION INSTEAD OF 2170DEGENERATION...ESPECIALLY IF IT TAKES A MORE NORTHERLY COURSE AND 2171INTERACTS WITH THE WESTERN ATLANTIC BAROCLINIC LOW. 2172 2173TOMAS IS NOW FAR ENOUGH TO THE NORTH AND EAST THAT THE THREAT OF 2174WIDESPREAD HEAVY RAINS HAS DIMINISHED OVER HAITI AND THE DOMINICAN 2175REPUBLIC. 2176 2177FORECAST POSITIONS AND MAX WINDS 2178 2179INITIAL 06/1500Z 23.1N 70.6W 55 KT 2180 12HR VT 07/0000Z 24.1N 69.9W 55 KT 2181 24HR VT 07/1200Z 24.8N 69.3W 55 KT 2182 36HR VT 08/0000Z 25.1N 68.5W 50 KT 2183 48HR VT 08/1200Z 25.4N 66.5W 40 KT 2184 72HR VT 09/1200Z 26.5N 62.5W 25 KT...POST-TROP/REMNT LOW 2185 96HR VT 10/1200Z 28.0N 58.0W 20 KT...POST-TROP/REMNT LOW 2186120HR VT 11/1200Z...DISSIPATED 2187 2188$$ 2189FORECASTER BEVEN 2190 2191 2192WTNT41 KNHC 062051 2193TCDAT1 2194TROPICAL STORM TOMAS DISCUSSION NUMBER 35 2195NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 2196500 PM EDT SAT NOV 06 2010 2197 2198TOMAS HAS MAINTAINED DEEP CONVECTION THIS AFTERNOON AND BRIEFLY AN 2199EYE MAY HAVE TRIED TO FORM. A PARTIAL EYEWALL WAS ALSO PRESENT IN 2200THE 1743Z AQUA MICROWAVE IMAGERY. IN THE LAST COUPLE OF HOURS... 2201HOWEVER...THIS FEATURE IS NO LONGER PRESENT AND THE CONVECTIVE 2202STRUCTURE IS SHOWING LESS BANDING CHARACTERISTICS. THE INITIAL 2203INTENSITY IS KEPT AT 55 KT...WHICH IS CONSISTENT WITH A BLEND OF 2204TAFB AND SAB DVORAK CLASSIFICATIONS. 2205 2206DATA FROM NOAA BUOY 41046 INDICATES THAT THE STRONG COLD FRONT 2207OFF OF THE SOUTHEAST U.S. COAST IS NOW IMPACTING THE OUTER 2208CIRCULATION OF TOMAS. WIND...TEMPERATURE...AND DEWPOINT 2209OBSERVATIONS FROM THE BUOY SHOWED THAT THE FRONT HAS REACHED THAT 2210LOCATION. THE INNER CORE OF TOMAS APPEARS...FOR THE MOMENT...TO BE 2211UNAFFECTED BY THE COOLER/DRIER AIR. IT IS LIKELY THAT TOMAS WILL 2212SOON BEGIN ITS FINAL DEMISE WITH BOTH THE FRONTAL AIRMASS AND 2213INCREASINGLY STRONG VERTICAL SHEAR IMPACTING THE CYCLONE. THE 2214INTENSITY FORECAST IS SOMEWHAT BELOW BOTH THE INTENSITY MODEL 2215CONSENSUS AND THE PREVIOUS ADVISORY. THE SYSTEM SHOULD DROP BELOW 2216TROPICAL STORM INTENSITY AFTER 48 H...BUT COULD OCCUR EARLIER IF 2217THE ANTICIPATED VERY STRONG SHEAR AND DRY AIR REMOVES ALL OF THE 2218DEEP CONVECTION. IT SHOULD BE NOTED THAT TOMAS COULD UNDERGO 2219EXTRATROPICAL TRANSITION INSTEAD OF DEGENERATION...ESPECIALLY IF IT 2220GOES NORTH OF THE FORECAST TRACK AND MORE STRONGLY INTERACTS WITH A 2221BAROCLINIC LOW FORECAST TO DEVELOP OVER THE WESTERN ATLANTIC. 2222 2223TOMAS IS CURRENTLY MOVING 30/13...AS IT IS PRIMARILY BEING STEERED 2224BY A VIGOROUS SHORT-WAVE TROUGH TO ITS NORTHWEST. THE TRACK MODEL 2225GUIDANCE IS IN MUCH BETTER AGREEMENT THIS AFTERNOON. THE CYCLONE 2226SHOULD RATHER ABRUPTLY DECELERATE AND TURN TOWARD THE EAST IN ABOUT 222712-24 H...ONCE THE DEEP CONVECTION IS EITHER DECOUPLED FROM THE 2228LOW-LEVEL CIRCULATION OR COMPLETELY ELIMINATED. THEREAFTER...THE 2229SYSTEM SHOULD BE ADVECTED TOWARD THE EAST AND THEN THE NORTHEAST BY 2230THE LARGE BAROCLINIC LOW. THE TRACK FORECAST IS FARTHER NORTH AND 2231FASTER THAN THE PREVIOUS ADVISORY BUT NOT AS QUICK AS THE MODEL 2232CONSENSUS. 2233 2234FORECAST POSITIONS AND MAX WINDS 2235 2236INITIAL 06/2100Z 24.2N 70.0W 55 KT 2237 12HR VT 07/0600Z 25.2N 69.3W 50 KT 2238 24HR VT 07/1800Z 25.6N 68.6W 45 KT 2239 36HR VT 08/0600Z 25.8N 67.2W 40 KT 2240 48HR VT 08/1800Z 26.5N 64.9W 35 KT 2241 72HR VT 09/1800Z 28.5N 59.5W 25 KT...POST-TROP/REMNT LOW 2242 96HR VT 10/1800Z 31.5N 55.5W 20 KT...POST-TROP/REMNT LOW 2243120HR VT 11/1800Z...DISSIPATED 2244 2245$$ 2246FORECASTER LANDSEA/BEVEN 2247 2248 2249WTNT41 KNHC 062343 2250TCDAT1 2251HURRICANE TOMAS SPECIAL DISCUSSION NUMBER 36 2252NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 2253800 PM AST SAT NOV 06 2010 2254 2255DESPITE THE SOMEWHAT RAGGED APPEARANCE OF THE SYSTEM IN INFRARED 2256IMAGERY...DATA FROM A NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT 2257TOMAS HAS RE-INTENSIFIED TO HURRICANE STRENGTH. THE AIRCRAFT 2258MEASURED A PEAK 700-MB FLIGHT LEVEL WIND OF 79 KT EAST OF THE 2259CENTER AND A MAXIMUM SFMR WIND OF 64 KT. BASED ON THESE DATA...THE 2260INITIAL INTENSITY IS SET TO 70 KT FOR THIS SPECIAL ADVISORY. THE 2261INTENSITY FORECAST HAS BEEN ADJUSTED UPWARD THROUGH 24 HOURS TO 2262ACCOUNT FOR THE RE-INTENSIFICATION...AND THE RADII HAVE BEEN 2263MODIFIED ACCORDINGLY. BEYOND 24 HOURS...THE INTENSITY FORECAST 2264REMAINS THE SAME AS THE PREVIOUS PACKAGE...AS INCREASING SHEAR AND 2265DRY AIR SHOULD EVENTUALLY LEAD TO WEAKENING. 2266 2267RECENT MICROWAVE IMAGERY AND DATA FROM THE AIRCRAFT INDICATE THAT 2268TOMAS IS MOVING A LITTLE TO THE LEFT OF THE PREVIOUS TRACK...AND 2269THE INITIAL MOTION ESTIMATE IS 020/13 KT. THE OFFICIAL TRACK 2270FORECAST HAS BEEN ADJUSTED TO THE LEFT...OR NORTH...THROUGH 36 2271HOURS TO ACCOUNT FOR THE INITIAL POSITION AND MOTION. BEYOND 36 2272HOURS...THE TRACK FORECAST IS UNCHANGED FROM THE PREVIOUS PACKAGE. 2273 2274FORECAST POSITIONS AND MAX WINDS 2275 2276INITIAL 07/0000Z 25.0N 69.7W 70 KT 2277 12HR VT 07/0600Z 25.7N 69.3W 60 KT 2278 24HR VT 07/1800Z 26.0N 68.6W 50 KT 2279 36HR VT 08/0600Z 26.0N 67.2W 40 KT 2280 48HR VT 08/1800Z 26.5N 64.9W 35 KT 2281 72HR VT 09/1800Z 28.5N 59.5W 25 KT...POST-TROP/REMNT LOW 2282 96HR VT 10/1800Z 31.5N 55.5W 20 KT...POST-TROP/REMNT LOW 2283120HR VT 11/1800Z...DISSIPATED 2284 2285$$ 2286FORECASTER BRENNAN/BROWN 2287 2288 2289WTNT41 KNHC 070230 2290TCDAT1 2291HURRICANE TOMAS DISCUSSION NUMBER 37 2292NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 22931100 PM AST SAT NOV 06 2010 2294 2295BEFORE EXITING TOMAS...THE NOAA HURRICANE HUNTER AIRCRAFT REPORTED A 2296700-MB FLIGHT-LEVEL WIND MAXIMUM OF 75 KT...A PEAK SFMR WIND OF 61 2297KT...AND A CENTRAL PRESSURE OF 987 MB. THIS SUGGESTS THAT THE 2298INTENSITY HAS LEVELED OFF...AND THE INITIAL INTENSITY REMAINS 70 2299KT. WHILE THE INITIAL SHEAR VALUES FROM SHIPS AND UW-CIMMS ARE 230015-20 KT...TOMAS OBVIOUSLY HAS NOT YET FELT THE EFFECTS OF THIS 2301SHEAR IN THE INNER CORE. HOWEVER...WATER VAPOR IMAGERY AND GOES 2302CLOUD TRACK WINDS SHOW STRONG UPPER-LEVEL SOUTHERLY FLOW AND DRY 2303AIR INCHING CLOSER TO TOMAS...AND THE SHEAR SHOULD INCREASE 2304MARKEDLY IN THE NEXT 12 HOURS. IN FACT...THE SHIPS MODEL SHOWS 2305SHEAR VALUES OF AROUND 50 KT IN 24 HOURS. THE SHEAR...DRIER 2306MID-LEVEL AIR...AND COOLER WATERS SHOULD RESULT IN STEADY 2307WEAKENING...REDUCING TOMAS TO A REMNANT LOW IN 3 DAYS WITH 2308DISSIPATION EXPECTED IN ABOUT 4 DAYS. THE NEW NHC INTENSITY 2309FORECAST IS SIMILAR TO THE PREVIOUS ONE...AND IS CLOSEST TO THE 2310SHIPS MODEL AFTER 24 HOURS. 2311 2312SATELLITE IMAGERY SUGGESTS THAT TOMAS MAY BE SLOWING DOWN...AND THE 2313INITIAL MOTION ESTIMATE IS 025/9. THERE IS GOOD AGREEMENT IN THE 2314GUIDANCE SLOWING TOMAS EVEN FURTHER IN THE NEXT 12 HOURS. AFTER 2315THAT TIME...TOMAS SHOULD BE STEERED EAST-NORTHEASTWARD FOR A DAY OR 2316TWO BY THE DEEP-LAYER TROUGH/LOW ADVANCING INTO THE WESTERN 2317ATLANTIC. A TURN BACK TOWARD THE NORTHEAST IS EXPECTED IN ABOUT 72 2318HOURS...AS WHAT IS LEFT OF TOMAS IS PULLED NORTHWARD AHEAD OF THE 2319WESTERN ATLANTIC LOW. THE GFS AND ECMWF MODELS SHOW THE CIRCULATION 2320OF TOMAS DISSIPATING BY 96 HOURS...AND DISSIPATION IS ALSO 2321INDICATED BY THE SHIPS MODEL BY THAT TIME. IT IS WORTH NOTING 2322THAT THE UKMET MAINTAINS TOMAS AS A DEEPER CYCLONE AND TAKES IT 2323FARTHER NORTHWARD BEFORE MERGING IT WITH A FRONTAL ZONE. HOWEVER... 2324THIS SCENARIO SEEMS UNLIKELY GIVEN THAT TOMAS SHOULD HAVE DIFFICULTY 2325REMAINING A DEEP CYCLONE DUE TO THE SHEAR AND UNFAVORABLE 2326THERMODYNAMIC CONDITIONS. THE NEW NHC TRACK FORECAST IS A BLEND OF 2327THE PREVIOUS ADVISORY AND THE NEW MULTI-MODEL CONSENSUS. 2328 2329FORECAST POSITIONS AND MAX WINDS 2330 2331INITIAL 07/0300Z 25.2N 69.6W 70 KT 2332 12HR VT 07/1200Z 25.8N 69.2W 60 KT 2333 24HR VT 08/0000Z 26.1N 68.1W 50 KT 2334 36HR VT 08/1200Z 26.5N 66.1W 40 KT 2335 48HR VT 09/0000Z 27.4N 63.2W 35 KT 2336 72HR VT 10/0000Z 31.0N 57.5W 25 KT...POST-TROP/REMNT LOW 2337 96HR VT 11/0000Z...DISSIPATED 2338 2339$$ 2340FORECASTER BRENNAN 2341 2342 2343WTNT41 KNHC 070848 2344TCDAT1 2345HURRICANE TOMAS DISCUSSION NUMBER 38 2346NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 2347500 AM AST SUN NOV 07 2010 2348 2349AROUND 06Z...A BURST OF DEEP CONVECTION WITH TOPS COLDER THAN -80C 2350DEVELOPED NEAR THE CENTER...AND A WARM SPOT OR EYE FEATURE BRIEFLY 2351BECAME EVIDENT IN INFRARED IMAGERY. SINCE THAT TIME...HOWEVER... 2352CLOUD TOPS HAVE WARMED AND THE UPPER-LEVEL OUTFLOW HAS BECOME 2353FLATTENED ON THE WEST SIDE AS WESTERLY SHEAR HAS STARTED TO IMPINGE 2354ON THE CYCLONE. A SATELLITE INTENSITY ESTIMATE OF T4.0/65 KT FROM 2355TAFB ALONG WITH AODT AND UW-CIMSS ADT ESTIMATES OF T4.3/72 KT 2356SUPPORT MAINTAINING A SYNOPTIC INTENSITY OF 70 KT AT 06Z. 2357HOWEVER...GIVEN THE RECENT DISHEVELED APPEARANCE TO THE CONVECTIVE 2358CLOUD MASS...THE 09Z ADVISORY INTENSITY IS BEING LOWERED TO 65 KT. 2359 2360THE INITIAL MOTION ESTIMATE IS 040/06. SATELLITE IMAGERY DURING THE 2361PAST COUPLE OF HOURS SUGGESTS THAT TOMAS HAS SLOWED DOWN AND TURNED 2362TOWARD THE NORTHEAST SINCE THE 06Z FIXES. A TURN TOWARD THE 2363EAST-NORTHEAST IS EXPECTED WITHIN THE NEXT 12 HOURS OR SO AS 2364INCREASING WEST-SOUTHWESTERLY MID-/UPPER-LEVEL FLOW AHEAD OF A 2365BROAD EASTWARD-MOVING TROUGH GRADUALLY DECOUPLES THE LOW- AND 2366UPPER-LEVELS CIRCULATIONS...LEAVING THE LOW-LEVEL CIRCULATION TO BE 2367STEERED EASTWARD BY WEAKER FLOW AHEAD OF A COLD FRONT. BY 48 2368HOURS...TOMAS IS FORECAST TO DEGENERATE INTO A NON-CONVECTIVE 2369REMNANT LOW PRESSURE SYSTEM...WHICH IS THEN EXPECTED TO BE 2370CAPTURED BY AND PULLED NORTHEASTWARD INTO A LARGE EXTRATROPICAL 2371CYCLONE AFTER 72 HOURS. MOST OF THE NHC MODEL GUIDANCE IS IN GOOD 2372AGREEMENT ON THIS DEVELOPING SCENARIO. THE OFFICIAL FORECAST TRACK 2373IS SIMILAR TO THE PREVIOUS ADVISORY TRACK AND LIES ALONG THE 2374NORTHERN EDGE OF THE GUIDANCE ENVELOPE. 2375 2376WATER VAPOR IMAGERY AND SATELLITE-DERIVED WINDS INDICATE 40-50 KT 2377WEST-SOUTHWESTERLY MID-LEVEL FLOW IS BEGINNING TO UNDERCUT THE 2378HIGH-LEVEL OUTFLOW LAYER OF TOMAS. AS A RESULT...ASSOCIATED STRONG 2379VERTICAL WIND SHEAR SHOULD INDUCE WEAKENING WITHIN THE NEXT 6-12 2380HOURS...AND TROPICAL CYCLONE DISSIPATION SHOULD BE COMPLETE BY 48 2381HOURS. THE OFFICIAL INTENSITY FORECAST TRACK IS SIMILAR TO THE 2382PREVIOUS ADVISORY AND IS CLOSE TO A BLEND OF THE SHIPS AND LGEM 2383INTENSITY MODELS. HOWEVER...THE COMBINATION OF STRONG WESTERLY 2384SHEAR AND VERY DRY MID-LEVEL AIR COULD RESULT IN MORE RAPID 2385WEAKENING THAN CURRENTLY FORECAST. 2386 2387THE 34-KT WIND RADII AND 12-FT SEAS RADII HAVE BEEN EXPANDED IN THE 2388WESTERN SEMICIRCLE BASED ON REPORTS FROM NOAA BUOYS 41047 AND 238941047. THE INCREASE IN THE OUTER WIND FIELD IS DUE TO A STRONG COLD 2390FRONT AND HIGH PRESSURE SYSTEM MOVING CLOSER TO TOMAS...WHICH HAS 2391ACTED TO TIGHTEN UP THE PRESSURE GRADIENT ON THE WEST SIDE OF THE 2392HURRICANE. 2393 2394FORECAST POSITIONS AND MAX WINDS 2395 2396INITIAL 07/0900Z 26.2N 68.8W 65 KT 2397 12HR VT 07/1800Z 26.5N 68.2W 60 KT 2398 24HR VT 08/0600Z 26.8N 66.6W 50 KT 2399 36HR VT 08/1800Z 27.5N 64.2W 40 KT 2400 48HR VT 09/0600Z 28.6N 61.3W 30 KT...POST-TROP/REMNT LOW 2401 72HR VT 10/0600Z 33.0N 55.5W 25 KT...POST-TROP/REMNT LOW 2402 96HR VT 11/0600Z...DISSIPATED 2403 2404$$ 2405FORECASTER STEWART 2406 2407 2408WTNT41 KNHC 071441 2409TCDAT1 2410TROPICAL STORM TOMAS DISCUSSION NUMBER 39 2411NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 24121100 AM AST SUN NOV 07 2010 2413 2414TOMAS HAS WEAKENED RAPIDLY DURING THE LAST SEVERAL HOURS. DEEP 2415CONVECTION HAS WITHERED AWAY...DUE TO ABOUT 35 KT OF WESTERLY 2416SHEAR...WITH ONLY A VERY SMALL AREA OF THUNDERSTORMS REMAINING NEAR 2417THE CENTER. THE INITIAL INTENSITY IS ESTIMATED TO BE 50 KT...BASED 2418ON A BLEND OF OBJECTIVE AND SUBJECTIVE SATELLITE INTENSITY 2419ESTIMATES AND WIND REPORTS FROM BUOY 41047. TOMAS ALSO APPEARS TO 2420BE GRADUALLY LOSING ITS TROPICAL CHARACTERISTICS. SATELLITE IMAGES 2421SHOW COLD AIR STRATOCUMULUS CLOUDS WRAPPING AROUND THE WESTERN AND 2422SOUTHERN PORTIONS OF THE CIRCULATION...AND SHIP REPORTS SUGGEST 2423THAT THE SYSTEM COULD BE DEVELOPING FRONTAL BOUNDARIES. THE 2424GFS-BASED SHIPS MODEL SHOWS THE SHEAR INCREASING FURTHER...TO NEAR 242550 KT IN 12 HOURS. THIS...COMBINED WITH MID-LEVEL RELATIVE 2426HUMIDITIES BELOW 40 PERCENT...AND COOL WATERS SHOULD CAUSE 2427TOMAS TO BECOME POST-TROPICAL LATER TODAY OR TONIGHT. 2428 2429AN 0624 UTC AMSU OVERPASS AND A 1014 UTC SSMIS IMAGE INDICATE THAT 2430THE LOW-LEVEL CENTER IS LOCATED ABOUT 50 N MI WEST OF THE PREVIOUS 2431ESTIMATE. THESE DATA ALSO SUGGEST THAT TOMAS HAS SLOWED DOWN 2432SUBSTANTIALLY AND TURNED NORTHWARD DURING THE PAST 12-18 HOURS... 2433RESULTING IN AN INITIAL MOTION ESTIMATE OF 005/5. THE CYCLONE IS 2434EXPECTED TO MOVE IN A MOTION BETWEEN NORTHEAST AND EAST-NORTHEAST 2435WITH A GRADUAL INCREASE IN FORWARD SPEED...TO THE SOUTH AND 2436SOUTHEAST OF A STRENGTHENING LARGE BAROCLINIC LOW OVER THE NORTH 2437ATLANTIC. THIS MUCH LARGER LOW SHOULD ABSORB WHATEVER IS LEFT OF 2438TOMAS IN ABOUT 4 DAYS. 2439 2440 2441FORECAST POSITIONS AND MAX WINDS 2442 2443INITIAL 07/1500Z 26.0N 69.6W 50 KT 2444 12HR VT 08/0000Z 26.4N 68.7W 45 KT...POST-TROPICAL 2445 24HR VT 08/1200Z 26.9N 66.5W 35 KT...POST-TROPICAL 2446 36HR VT 09/0000Z 27.9N 63.9W 30 KT...POST-TROP/REMNT LOW 2447 48HR VT 09/1200Z 30.0N 61.0W 25 KT...POST-TROP/REMNT LOW 2448 72HR VT 10/1200Z 36.0N 57.0W 25 KT...POST-TROP/REMNT LOW 2449 96HR VT 11/1200Z...DISSIPATED 2450 2451$$ 2452FORECASTER CANGIALOSI 2453 2454 2455WTNT41 KNHC 072032 2456TCDAT1 2457TROPICAL STORM TOMAS DISCUSSION NUMBER 40 2458NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 2459500 PM AST SUN NOV 07 2010 2460 2461SATELLITE IMAGES...SURFACE OBSERVATIONS...AND MODEL ANALYSES 2462INDICATE THAT TOMAS HAS ACQUIRED FRONTAL CHARACTERISTICS. COLD AIR 2463STRATOCUMULUS CLOUDS ARE NOW WRAPPING INTO THE INNER-CORE REGION... 2464AND ANY LINGERING DEEP CLOUDINESS APPEARS MORE ASSOCIATED WITH THE 2465FRONTAL BOUNDARIES. THEREFORE...TOMAS IS NO LONGER CONSIDERED A 2466TROPICAL CYCLONE...AND THIS IS THE LAST ADVISORY ISSUED BY THE 2467NATIONAL HURRICANE CENTER ON THIS SYSTEM. 2468 2469AN ASCAT PASS AROUND 1500 UTC SHOWED MAXIMUM WINDS IN THE 45-50 KT 2470RANGE OVER THE SOUTHWESTERN QUADRANT...AND THAT IS THE BASIS FOR 2471THE INITIAL INTENSITY. STEADY WEAKENING OF THE POST-TROPICAL 2472CYCLONE IS EXPECTED DURING THE NEXT FEW DAYS. 2473 2474THE INITIAL MOTION ESTIMATE IS 020/3. THE POST-TROPICAL CYCLONE IS 2475FORECAST TO MOVE NORTHEASTWARD OR EAST-NORTHEASTWARD WITH A GRADUAL 2476INCREASE IN FORWARD SPEED UNTIL IT BECOMES ABSORBED BY A MUCH 2477LARGER BAROCLINIC LOW OVER THE NORTH ATLANTIC IN 3 TO 4 DAYS. 2478 2479FUTURE INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS 2480FORECASTS ISSUED BY THE TROPICAL ANALYSIS AND FORECAST BRANCH... 2481UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC. 2482 2483FORECAST POSITIONS AND MAX WINDS 2484 2485INITIAL 07/2100Z 26.1N 69.1W 50 KT...POST-TROP/EXTRATROP 2486 12HR VT 08/0600Z 26.3N 67.9W 40 KT...POST-TROP/EXTRATROP 2487 24HR VT 08/1800Z 26.8N 65.6W 30 KT...POST-TROP/EXTRATROP 2488 36HR VT 09/0600Z 28.4N 62.8W 25 KT...POST-TROP/EXTRATROP 2489 48HR VT 09/1800Z 30.6N 60.0W 25 KT...POST-TROP/EXTRATROP 2490 72HR VT 10/1800Z 37.0N 56.5W 20 KT...POST-TROP/EXTRATROP 2491 96HR VT 11/1800Z...DISSIPATED 2492 2493$$ 2494FORECASTER CANGIALOSI/BROWN 2495 2496 2497