1WTNT44 KNHC 090851 2TCDAT4 3 4TROPICAL STORM HUMBERTO DISCUSSION NUMBER 3 5NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 6500 AM AST MON SEP 09 2013 7 8SINCE THE PREVIOUS ADVISORY...DEEP CONVECTION WITH A LARGE AREA OF 9CLOUD TOPS COLDER THAN -80C HAS DEVELOPED MAINLY WEST THROUGH NORTH 10OF THE LOW-LEVEL CENTER...WITH A FEW STRONG CELLS HAVING RECENTLY 11FORMED VERY NEAR THE CENTER. THE INITIAL INTENSITY HAS BEEN 12INCREASED TO 35 KT BASED ON CONSENSUS T2.5/35 KT INTENSITY 13ESTIMATES FROM BOTH TAFB AND SAB...AND A 34-KT ADT ESTIMATE. AS A 14RESULT...THE SYSTEM HAS BEEN NAMED HUMBERTO. UPPER-LEVEL OUTFLOW IS 15GOOD IN ALL QUADRANTS EXCEPT TO THE NORTHEAST WHERE SOME MODEST 16NORTHEASTERLY SHEAR IS RESTRICTING THE OUTFLOW. 17 18HUMBERTO IS MOVING AT 280/10 KT...AND THE CYCLONE SHOULD CONTINUE 19THIS GENERAL MOTION FOR THE NEXT DAY OR SO. AFTERWARDS...THE GLOBAL 20AND REGIONAL MODELS ARE IN GOOD AGREEMENT ON AN UPPER-LEVEL LOW 21OVER THE IBERIAN PENINSULA DIGGING SOUTHWESTWARD ACROSS THE CANARY 22ISLANDS DURING THE NEXT FEW DAYS AND ERODING THE STRONG SUBTROPICAL 23RIDGE THAT CURRENTLY EXTENDS FROM THE AZORES SOUTHEASTWARD TO 24WESTERN AFRICA. THIS RADICAL CHANGE IN THE STEERING CURRENTS IS 25EXPECTED TO CAUSE HUMBERTO TO MAKE A SHARP TURN TOWARD THE NORTH OR 26NORTH-NORTHWEST IN 36-48 HOURS AND MAINTAIN THAT MOTION THROUGH 96 27HOURS...AFTER WHICH THE RIDGE IS FORECAST TO RE-BUILD TO THE NORTH 28OF THE CYCLONE AND TURN HUMBERTO WESTWARD OVER HIGHER LATITUDES AND 29COOLER WATER. THE BULK OF THE MODEL GUIDANCE MADE A SIGNIFICANT 30SHIFT TO THE EAST THIS CYCLE...AND THE OFFICIAL FORECAST TRACK WAS 31SHIFTED TO THE RIGHT AS A RESULT...BUT NOT AS FAR TO THE RIGHT AS 32SOME OF THE MORE RELIABLE MODELS LIKE THE GFS...ECMWF...AND FSSE. 33 34MODEST NORTHEASTERLY SHEAR OF ABOUT 12 KT IS FORECAST BY ALL OF 35MODELS TO WEAKEN TO LESS THAN 8 KT AND REMAIN LOW THROUGH AT LEAST 3672 HOURS. SUCH WEAK SHEAR CONDITIONS EXISTING WITHIN A VERY MOIST 37ENVIRONMENT AND OVER ABOVE AVERAGE SSTS OF AT LEAST 28C WOULD TEND 38TO FAVOR SIGNIFICANT STRENGTHENING. IN FACT...THE GFS AND ECMWF 39MODELS DEVELOP AN IMPRESSIVE 200 MB CYCLONIC OUTDRAFT PATTERN BY 72 40HOURS...WHICH IS TYPICAL OF A MAJOR HURRICANE. AS A RESULT...THE 41INTENSITY FORECAST WAS INCREASED OVER THE PREVIOUS ADVISORY AT 72 42HOURS...SIMILAR TO THE ICON CONSENSUS MODEL. THE FORECAST REMAINS ON 43THE CONSERVATIVE SIDE SINCE HUMBERTO WILL BE MOVING OVER SUB-26C 44SSTS AT THAT TIME. IT IS POSSIBLE...HOWEVER...THAT HUMBERTO COULD 45STRENGTHEN MORE THAN INDICATED PRIOR TO THE 72-HOUR TIME PERIOD. BY 46DAYS 4 AND 5...INCREASING SOUTHWESTERLY SHEAR AND COOLER WATERS 47SHOULD INDUCE GRADUAL WEAKENING. 48 49FORECAST POSITIONS AND MAX WINDS 50 51INIT 09/0900Z 13.4N 22.8W 35 KT 40 MPH 52 12H 09/1800Z 13.6N 24.3W 45 KT 50 MPH 53 24H 10/0600Z 14.1N 26.2W 55 KT 65 MPH 54 36H 10/1800Z 14.9N 27.8W 60 KT 70 MPH 55 48H 11/0600Z 16.2N 28.7W 70 KT 80 MPH 56 72H 12/0600Z 20.0N 29.5W 80 KT 90 MPH 57 96H 13/0600Z 23.5N 30.5W 70 KT 80 MPH 58120H 14/0600Z 25.2N 33.4W 60 KT 70 MPH 59 60$$ 61FORECASTER STEWART 62 63 64WTNT44 KNHC 091444 65TCDAT4 66 67TROPICAL STORM HUMBERTO DISCUSSION NUMBER 4 68NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 691100 AM AST MON SEP 09 2013 70 71VISIBLE SATELLITE IMAGERY INDICATES THAT HUMBERTO STILL HAS AN 72ELONGATED LOW-LEVEL CIRCULATION...WITH THE CENTER NEAR THE EASTERN 73EDGE OF THE DEEP CONVECTION. THIS WAS CONFIRMED BY TWO ASCAT 74PASSES FROM EARLIER THIS MORNING...BUT THE SCATTEROMETER DATA ALSO 75INDICATED THAT MAXIMUM WINDS HAVE INCREASED TO 40 KT. THIS 76ESTIMATE IS ALSO SUPPORTED BY AN AVERAGE OF THE DVORAK ESTIMATES 77FROM TAFB AND SAB. 78 79HUMBERTO IS LOCATED TO THE SOUTH OF A STRONG AZORES HIGH AND 80CONTINUES TO MOVE 280/10 KT. THE TRACK FORECAST THINKING HAS NOT 81CHANGED. THE RIDGE IS EXPECTED TO WEAKEN DURING THE NEXT 48 82HOURS...GIVING WAY TO TWO CLOSED MID/UPPER-LEVEL LOWS THAT WILL 83DEVELOP NORTH OF THE CANARY ISLANDS AND OVER THE CENTRAL ATLANTIC. 84THIS PATTERN SHOULD CAUSE HUMBERTO TO TURN SHARPLY NORTHWARD BY DAY 853. AFTER THAT TIME...HIGH PRESSURE AGAIN BUILDS NEAR THE 86AZORES...FORCING HUMBERTO TO TURN BACK TO THE WEST-NORTHWEST BY DAY 875. THE GLOBAL MODELS ARE TIGHTLY CLUSTERED THROUGH THE FIRST 48 88HOURS BUT THEN DIVERGE WITH THE GFS...FLORIDA STATE 89SUPERENSEMBLE...GFDL...AND HWRF INDICATING A SHARPER TURN TOWARD 90THE NORTH. THE GUIDANCE SUPPORTS A SLIGHT NORTHEASTWARD SHIFT FROM 91THE PREVIOUS FORECAST AT THE LATTER END OF THE FORECAST PERIOD. 92 93THE EAST-NORTHEASTERLY SHEAR AFFECTING HUMBERTO IS EXPECTED TO ABATE 94WITHIN THE NEXT 12 HOURS...AND THE THERMODYNAMICS APPEAR 95SUFFICIENTLY CONDUCIVE TO SUPPORT ADDITIONAL INTENSIFICATION DURING 96THE NEXT 72 HOURS. THE SHIPS AND LGEM MODELS CONTINUE TO SHOW THE 97MOST AGGRESSIVE STRENGTHENING...BUT THAT IS COUNTERED BY THE 98HWRF...GFDL...AND FLORIDA STATE SUPERENSEMBLE WHICH EITHER DO NOT OR 99JUST BARELY MAKE HUMBERTO A HURRICANE. THE OFFICIAL FORECAST STILL 100LIES BETWEEN THESE TWO SCENARIOS AND IS JUST A TAD HIGHER THAN THE 101INTENSITY CONSENSUS. THE OFFICIAL FORECAST IS GENERALLY AN UPDATE 102OF THE PREVIOUS ONE...AND IS UNCHANGED FROM DAYS 3 THROUGH 5. 103 104FORECAST POSITIONS AND MAX WINDS 105 106INIT 09/1500Z 13.6N 24.1W 40 KT 45 MPH 107 12H 10/0000Z 13.9N 25.5W 50 KT 60 MPH 108 24H 10/1200Z 14.5N 27.3W 60 KT 70 MPH 109 36H 11/0000Z 15.5N 28.5W 70 KT 80 MPH 110 48H 11/1200Z 17.3N 29.1W 75 KT 85 MPH 111 72H 12/1200Z 21.5N 30.0W 80 KT 90 MPH 112 96H 13/1200Z 24.5N 31.0W 70 KT 80 MPH 113120H 14/1200Z 26.0N 34.5W 60 KT 70 MPH 114 115$$ 116FORECASTER BERG/PASCH 117 118 119WTNT44 KNHC 092040 120TCDAT4 121 122TROPICAL STORM HUMBERTO DISCUSSION NUMBER 5 123NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 124500 PM AST MON SEP 09 2013 125 126SATELLITE IMAGERY INDICATES THAT DEEP CONVECTION ASSOCIATED WITH 127HUMBERTO IS SHOWING MORE PRONOUNCED BANDING...AND THE LOW-LEVEL 128CENTER IS BECOMING MORE EMBEDDED BENEATH THE COLD CLOUD TOPS. 129SUBJECTIVE DVORAK ESTIMATES RANGE FROM T2.5/35 KT FROM SAB AND 130T3.5/55 KT FROM TAFB...AND THE LATEST SATCON INTENSITY ESTIMATE 131FROM THE UNIVERSITY OF WISCONSIN IS 47 KT. BASED ON THESE DATA... 132THE INITIAL INTENSITY IS RAISED TO 45 KT. 133 134HUMBERTO APPEARS TO HAVE BEEN MOVING A BIT FASTER TO THE WEST...AND 135THE CURRENT MOTION ESTIMATE IS 280/11 KT. THE MID-LEVEL 136ANTICYCLONE TO THE NORTH OF THE STORM IS FORECAST TO WEAKEN 137CONSIDERABLY DURING THE NEXT 24 TO 48 HOURS...ALLOWING HUMBERTO TO 138TURN SHARPLY NORTHWARD BY 72 HOURS. BY THE END OF THE FORECAST 139PERIOD...ANOTHER HIGH IS FORECAST TO DEVELOP NEAR THE AZORES AND 140FORCE HUMBERTO TO TURN BACK TO THE WEST-NORTHWEST BY DAY 5. THE 141NHC OFFICIAL FORECAST HAS BEEN SHIFTED A LITTLE FARTHER EAST AND 142NORTH OF THE PREVIOUS FORECAST AFTER 36 HOURS DUE TO AN OVERALL 143EASTWARD TREND IN THE GUIDANCE ENVELOPE. 144 145HUMBERTO CONTINUES ON A GRADUAL STRENGTHENING TREND...AND CONDITIONS 146FAVOR THIS INTENSIFICATION TO CONTINUE FOR THE NEXT 48 TO 72 HOURS. 147THE INTENSITY GUIDANCE HAS CHANGED LITTLE DURING THE PAST FEW 148CYCLES...WITH THE SHIPS AND LGEM MODELS SHOWING THE MOST 149STRENGTHENING AND THE HWRF AND FSU SUPERENSEMBLE BARELY BRINGING 150HUMBERTO TO HURRICANE STRENGTH. THE NHC OFFICIAL FORECAST IS 151THEREFORE RELATIVELY UNCHANGED FROM THE PREVIOUS ONE...AND A PEAK 152IN INTENSITY IS EXPECTED BETWEEN 48 AND 72 HOURS BEFORE HUMBERTO 153REACHES COLDER WATER AND CONTENDS WITH INCREASING SOUTHWESTERLY 154VERTICAL SHEAR. 155 156HUMBERTO IS BEGINNING TO MOVE AWAY FROM THE CAPE VERDE ISLANDS. 157THEREFORE...ALL WARNINGS HAVE BEEN DISCONTINUED FOR THOSE ISLANDS. 158 159FORECAST POSITIONS AND MAX WINDS 160 161INIT 09/2100Z 13.7N 25.3W 45 KT 50 MPH 162 12H 10/0600Z 14.1N 26.6W 55 KT 65 MPH 163 24H 10/1800Z 14.8N 28.0W 65 KT 75 MPH 164 36H 11/0600Z 16.1N 28.8W 75 KT 85 MPH 165 48H 11/1800Z 18.2N 29.3W 80 KT 90 MPH 166 72H 12/1800Z 22.5N 30.0W 80 KT 90 MPH 167 96H 13/1800Z 25.5N 32.0W 65 KT 75 MPH 168120H 14/1800Z 26.5N 35.5W 55 KT 65 MPH 169 170$$ 171FORECASTER BERG 172 173 174WTNT44 KNHC 100246 175TCDAT4 176 177TROPICAL STORM HUMBERTO DISCUSSION NUMBER 6 178NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 1791100 PM AST MON SEP 09 2013 180 181RECENT MICROWAVE IMAGES AND SCATTEROMETER DATA INDICATE THAT THE 182CENTER OF HUMBERTO REMAINS NEAR THE NORTHEASTERN EDGE OF A LARGE 183MASS OF DEEP CONVECTION. THIS SUGGESTS THAT SOME EAST- 184NORTHEASTERLY SHEAR REMAINS OVER THE CYCLONE...ALTHOUGH RECENT 185SATELLITE PICTURES SHOW THAT CIRRUS OUTFLOW IS BEGINNING TO 186EXPAND OUTWARD OVER THE EASTERN PORTION OF THE STORM. THE ASCAT 187DATA INDICATE THAT THE MAXIMUM WINDS HAVE INCREASED TO AROUND 50 188KT...AND THAT THE AREA OF TROPICAL STORM FORCE WINDS HAS ALSO 189EXPANDED SINCE THIS MORNING. 190 191SATELLITE CENTER FIXES OVER THE PAST 12 HOURS SUGGEST THAT HUMBERTO 192IS MOVING A LITTLE SLOWER THAN EARLIER TODAY...WITH A MOTION OF 193285/9 KT. THE MID-LEVEL RIDGE TO THE NORTH OF THE STORM IS 194EXPECTED TO WEAKEN VERY SOON AS A COUPLE OF MID- TO UPPER-LEVEL 195LOWS MOVE SOUTHWARD OVER THE EASTERN ATLANTIC. THIS SHOULD CAUSE 196HUMBERTO TO TURN NORTH-NORTHWESTWARD IN 24 TO 36 HOURS AND A 197GENERAL NORTHWARD MOTION IS FORECAST TO THEN CONTINUE THROUGH 72 198HOURS. AFTER THAT TIME...THE GLOBAL MODELS INDICATE THAT THE RIDGE 199WILL REBUILD TO THE NORTHWEST OF THE AZORES AND THIS SHOULD TURN 200HUMBERTO BACK TO THE WEST-NORTHWEST BY THE END OF THE FORECAST 201PERIOD. 202 203THE VERTICAL SHEAR CURRENTLY OVER HUMBERTO SHOULD DECREASE 204SOON...AND THIS SHOULD ALLOW FOR STEADY STRENGTHENING DURING THE 205NEXT COUPLE OF DAYS WHILE THE CYCLONE REMAINS OVER WARM WATER. THE 206MAJORITY OF THE INTENSITY GUIDANCE BRINGS HUMBERTO TO HURRICANE 207STRENGTH WITHIN 24 HOURS...AND SO DOES THE OFFICIAL FORECAST. THE 208NHC INTENSITY FORECAST SHOWS A SLIGHTLY HIGHER PEAK INTENSITY THAN 209THE PREVIOUS ADVISORY...BUT STILL IT IS NOT AS AGGRESSIVE AS THE 210SHIPS GUIDANCE. AFTER 72 HOURS...THE SHEAR IS FORECAST TO BECOME 211QUITE STRONG OUT OF THE SOUTHWEST...AND THIS IS EXPECTED TO INDUCE 212SIGNIFICANT WEAKENING. 213 214FORECAST POSITIONS AND MAX WINDS 215 216INIT 10/0300Z 13.9N 25.9W 50 KT 60 MPH 217 12H 10/1200Z 14.4N 27.1W 60 KT 70 MPH 218 24H 11/0000Z 15.4N 28.1W 70 KT 80 MPH 219 36H 11/1200Z 16.9N 28.7W 80 KT 90 MPH 220 48H 12/0000Z 19.1N 29.1W 85 KT 100 MPH 221 72H 13/0000Z 23.0N 30.0W 75 KT 85 MPH 222 96H 14/0000Z 25.2N 32.3W 55 KT 65 MPH 223120H 15/0000Z 26.0N 36.0W 45 KT 50 MPH 224 225$$ 226FORECASTER BROWN 227 228 229WTNT44 KNHC 100846 230TCDAT4 231 232TROPICAL STORM HUMBERTO DISCUSSION NUMBER 7 233NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 234500 AM AST TUE SEP 10 2013 235 236HUMBERTO CONTINUES TO STEADILY STRENGTHEN. SATELLITE IMAGES INDICATE 237THAT THE ASSOCIATED BANDING FEATURES HAVE BECOME BETTER ORGANIZED 238AND MORE SYMMETRIC AROUND THE CENTER...INDICATING THAT VERTICAL 239WIND SHEAR IS DECREASING OVER THE CYCLONE. DVORAK CLASSIFICATIONS 240FROM TAFB AND SAB WERE BOTH T3.5 AND UW-CIMSS ADT VALUES ARE ABOUT 241THE SAME. BASED ON THESE ESTIMATES...THE INITIAL WIND SPEED IS 242INCREASED TO 55 KT. 243 244THE TROPICAL STORM IS GRADUALLY TURNING TO THE RIGHT...AND THE 245LATEST INITIAL MOTION ESTIMATE IS 295/8. A TURN TO THE NORTHWEST IS 246EXPECTED TODAY...FOLLOWED BY A NORTHWARD MOTION ON WEDNESDAY. THIS 247ABRUPT CHANGE IN THE FORECAST STORM MOTION IS DUE TO A BREAK DOWN 248OF THE SUBTROPICAL RIDGE THAT WILL BE CAUSED BY A MID- TO 249UPPER-LEVEL LOW MOVING SOUTHWARD OVER THE CENTRAL ATLANTIC AND 250ANOTHER LOW BETWEEN THE CANARY ISLANDS AND THE AZORES. A SHARP 251WESTWARD TURN IS FORECAST TO OCCUR IN ABOUT 4 DAYS WHEN THE RIDGE 252BECOMES RE-ESTABLISHED. THE NHC TRACK FORECAST IS IN FAIR AGREEMENT 253GIVEN THE PRONOUNCED HEADING CHANGES...AND THE LATEST OFFICIAL 254FORECAST IS CLOSE TO THE MULTI-MODEL CONSENSUS TVCA. 255 256THE INTENSIFICATION TREND IS EXPECTED TO CONTINUE FOR ANOTHER 36 257HOURS WHILE HUMBERTO REMAINS OVER WARM WATER AND WITHIN AN 258ENVIRONMENT OF LOW WIND SHEAR AND HIGH MID-LEVEL MOISTURE. AFTER 259THAT TIME...THE GLOBAL MODELS SHOW DRIER AIR AND SOUTHERLY TO 260SOUTHWESTERLY SHEAR AFFECTING HUMBERTO. THESE UNFAVORABLE 261ATMOSPHERIC CONDITIONS COMBINED WITH COOLER SSTS SHOULD CAUSE THE 262SYSTEM TO BEGIN WEAKENING IN A COUPLE OF DAYS. THE NHC INTENSITY 263FORECAST IS NEAR THE HIGH END OF THE MODEL GUIDANCE IN THE SHORT 264TERM AND IS BASICALLY AN UPDATE OF THE PREVIOUS PACKAGE. 265 266FORECAST POSITIONS AND MAX WINDS 267 268INIT 10/0900Z 14.4N 26.6W 55 KT 65 MPH 269 12H 10/1800Z 15.0N 27.5W 65 KT 75 MPH 270 24H 11/0600Z 16.2N 28.3W 75 KT 85 MPH 271 36H 11/1800Z 17.9N 28.8W 85 KT 100 MPH 272 48H 12/0600Z 20.0N 29.1W 85 KT 100 MPH 273 72H 13/0600Z 23.7N 30.0W 75 KT 85 MPH 274 96H 14/0600Z 25.5N 32.5W 55 KT 65 MPH 275120H 15/0600Z 26.0N 36.5W 45 KT 50 MPH 276 277$$ 278FORECASTER CANGIALOSI 279 280 281WTNT44 KNHC 101434 282TCDAT4 283 284TROPICAL STORM HUMBERTO DISCUSSION NUMBER 8 285NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 2861100 AM AST TUE SEP 10 2013 287 288SATELLITE IMAGES INDICATE THAT HUMBERTO HAS STOPPED INTENSIFYING... 289AT LEAST FOR THE MOMENT. RECENT MICROWAVE DATA SHOWED THAT THE 290STORM HAD A SMALL MICROWAVE EYE OVERNIGHT...BUT THAT FEATURE HAS 291SINCE DISSOLVED AND HAS BEEN REPLACED BY A LARGER BUT BROKEN INNER 292BAND OF CONVECTION. IN SOME SENSE...THIS SUGGESTS AN EYEWALL 293REPLACEMENT...EXCEPT THAT HUMBERTO IS STILL A TROPICAL STORM. 294THE INITIAL INTENSITY IS HELD AT 55 KT BASED ON A CONSENSUS OF 295SUBJECTIVE AND OBJECTIVE SATELLITE INTENSITY ESTIMATES. 296 297HUMBERTO HAS MAINTAINED A MOTION OF 295/8 KT...BUT THE STORM IS 298EXPECTED TO TURN NORTHWESTWARD LATER TODAY DUE TO A WEAKENING 299AZORES HIGH TO THE NORTH. TWO DEEP-LAYERED LOWS ARE FORECAST TO 300DEVELOP NORTH OF THE CANARY ISLANDS AND OVER THE CENTRAL ATLANTIC 301OVER THE NEXT COUPLE OF DAYS. THESE FEATURES...ALONG WITH A RIDGE 302EXTENDING WESTWARD FROM NORTH AFRICA...SHOULD STEER HUMBERTO 303NORTHWARD IN ABOUT 36 HOURS. HIGH PRESSURE IS FORECAST TO REBUILD 304NORTH OF HUMBERTO BY DAYS 4 AND 5...WHICH SHOULD TURN THE CYCLONE 305WESTWARD BY THE END OF THE FORECAST PERIOD. CONFIDENCE IN THIS 306FORECAST IS HIGH SINCE THERE IS VERY LITTLE SPREAD IN THE TRACK 307GUIDANCE...AND NO SIGNIFICANT CHANGES TO THE OFFICIAL FORECAST WERE 308REQUIRED ON THIS CYCLE. 309 310ONCE THE INNER CORE OF HUMBERTO REORGANIZES...THERE IS A WINDOW OF 311ABOUT 36 TO 48 HOURS FOR ADDITIONAL STRENGTHENING BEFORE VERTICAL 312SHEAR INCREASES AND THE STORM REACHES A MORE HOSTILE THERMODYNAMIC 313ENVIRONMENT. THE OFFICIAL FORECAST CONTINUES TO SHOW HUMBERTO 314REACHING HURRICANE STRENGTH LATER TODAY...BUT THE FORECAST PEAK 315INTENSITY IN A DAY OR TWO HAS BEEN ADJUSTED DOWNWARD JUST A BIT 316BASED ON THE LATEST INTENSITY GUIDANCE. 317 318FORECAST POSITIONS AND MAX WINDS 319 320INIT 10/1500Z 14.6N 27.7W 55 KT 65 MPH 321 12H 11/0000Z 15.3N 28.5W 65 KT 75 MPH 322 24H 11/1200Z 16.6N 29.2W 70 KT 80 MPH 323 36H 12/0000Z 18.5N 29.5W 80 KT 90 MPH 324 48H 12/1200Z 20.5N 29.8W 80 KT 90 MPH 325 72H 13/1200Z 23.5N 31.0W 70 KT 80 MPH 326 96H 14/1200Z 24.5N 34.5W 55 KT 65 MPH 327120H 15/1200Z 25.0N 39.5W 45 KT 50 MPH 328 329$$ 330FORECASTER BERG 331 332 333WTNT44 KNHC 102031 334TCDAT4 335 336TROPICAL STORM HUMBERTO DISCUSSION NUMBER 9 337NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 338500 PM AST TUE SEP 10 2013 339 340ALTHOUGH CLOUD TOPS HAVE WARMED A BIT...THE CENTRAL DENSE OVERCAST 341HAS BEEN EXPANDING WITH A CONVECTIVE BAND WRAPPING AROUND THE 342SOUTHERN AND WESTERN SIDE OF THE CIRCULATION. DVORAK INTENSITY 343ESTIMATES FROM TAFB AND SAB ARE T4.0/65 KT AND T3.5/55 KT... 344RESPECTIVELY...SO THE INITIAL WINDS ARE RAISED TO 60 KT. THE MAIN 345IMMEDIATE NEGATIVE FACTOR FOR FURTHER STRENGTHENING APPEARS TO BE 346DRIER AND MORE STABLE AIR LOCATED TO THE NORTH OF HUMBERTO THAT MAY 347BE GETTING INTO THE INNER CORE...BUT OTHERWISE LOW VERTICAL SHEAR 348AND WARM WATERS FAVOR AT LEAST SLOW INTENSIFICATION FOR ANOTHER 36 349HOURS OR SO. AFTER THAT TIME...HUMBERTO WILL BE STRADDLING THE 26C 350SST ISOTHERM...BUT IT WILL ALSO BE MOVING INTO AN ENVIRONMENT OF 35120-30 KT OF SOUTHWESTERLY SHEAR. WEAKENING IS THEREFORE 352ANTICIPATED AFTER DAY 2. THE INTENSITY MODELS CONTINUE TO CONVERGE 353ON A PEAK INTENSITY SOMEWHERE BETWEEN 70 AND 80 KT...WITH THE 354STATISTICAL GUIDANCE NOT NEARLY AS AGGRESSIVE AS IT WAS YESTERDAY. 355SUBSEQUENTLY...NO SIGNIFICANT CHANGES WERE REQUIRED TO THE OFFICIAL 356FORECAST. 357 358HUMBERTO HAS TURNED NORTHWESTWARD WITH AN INITIAL MOTION OF 310/7 359KT. THE HIGH TO THE NORTH OF THE STORM IS NOW WEAKENING...AND THE 360EVOLVING PATTERN WILL ALLOW HUMBERTO TO TURN NORTHWARD BY 36 HOURS. 361THEN...JUST AS SHARPLY AS THE CYCLONE WILL BE TURNING NORTHWARD... 362IT WILL TURN SHARPLY WESTWARD BY DAY 5 WHEN A MID-LEVEL ANTICYCLONE 363REBUILDS NORTHWEST OF THE AZORES. THE TRACK GUIDANCE CONTINUES TO 364BE IN GOOD AGREEMENT...AND THE OFFICIAL FORECAST IS VERY CLOSE TO 365THE PREVIOUS FORECAST...THE MULTI-MODEL CONSENSUS TVCA...AND THE 366FLORIDA STATE SUPERENSEMBLE. 367 368FORECAST POSITIONS AND MAX WINDS 369 370INIT 10/2100Z 15.0N 28.1W 60 KT 70 MPH 371 12H 11/0600Z 15.9N 28.7W 65 KT 75 MPH 372 24H 11/1800Z 17.6N 29.1W 75 KT 85 MPH 373 36H 12/0600Z 19.6N 29.4W 80 KT 90 MPH 374 48H 12/1800Z 21.5N 29.8W 75 KT 85 MPH 375 72H 13/1800Z 24.0N 31.5W 65 KT 75 MPH 376 96H 14/1800Z 24.5N 36.0W 50 KT 60 MPH 377120H 15/1800Z 24.5N 41.5W 45 KT 50 MPH 378 379$$ 380FORECASTER BERG 381 382 383WTNT44 KNHC 110251 384TCDAT4 385 386TROPICAL STORM HUMBERTO DISCUSSION NUMBER 10 387NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 3881100 PM AST TUE SEP 10 2013 389 390AN EYE HAS BEEN SHOWING UP INTERMITTENTLY THIS EVENING IN 391HUMBERTO...BUT HAS NOT PERSISTED. MOREOVER...THE DEEP CONVECTION 392HAS BEEN SOMEWHAT ASYMMETRIC AND IS NOT MAINTAINING A CENTRAL DENSE 393OVERCAST CONTINUOUSLY. DVORAK CURRENT INTENSITY ESTIMATES FROM 394TAFB AND SAB HAVE REMAINED THE SAME OVER THE LAST SIX 395HOURS...AVERAGING AT 60 KT...WHILE ADT AND CIMSS AMSU SUGGEST A 396SUBSTANTIALLY WEAKER CYCLONE. IN DEFERENCE TO THE SUBJECTIVE 397DVORAK ANALYSES AND THE INTERMITTENT EYE...THE INITIAL INTENSITY 398REMAINS 60 KT. WHILE NO NEW ASCAT OBSERVATIONS WERE AVAILABLE...A 3992240Z CIRA AMSU SIZE ANALYSIS SUGGESTED A SLIGHTLY LARGER RADIUS OF 400TROPICAL STORM FORCE WINDS...WHICH HAS BEEN SO ADJUSTED. 401 402HUMBERTO SHOULD STILL REACH HURRICANE INTENSITY...AS IT HAS ABOUT 40324-36 HOURS TO GO WHILE TRAVERSING LUKEWARM WATER AND AN 404ENVIRONMENT OF LOW VERTICAL WIND SHEAR. BUT IN ABOUT 36-48 405HOURS...THE VERTICAL SHEAR SHOULD INCREASE SUBSTANTIALLY DUE TO 406HUMBERTO APPROACHING CLOSER TO A LARGE UPPER-LEVEL TROUGH...WHILE 407AT THE SAME TIME THE SSTS SHOULD DROP TO A COOLISH 25-26C. 408GRADUAL...IF NOT RAPID...WEAKENING SHOULD OCCUR BETWEEN DAYS 2 AND 4094. THE INTENSITY GUIDANCE IS RATHER TIGHTLY CLUSTERED AND THE NHC 410PREDICTION MIRRORS THIS AND IS JUST SLIGHTLY LOWER THAN THE 411PREVIOUS ADVISORY. 412 413HUMBERTO IS MOVING AT ABOUT 6 KT TOWARD 315 DEGREES...PRIMARILY DUE 414TO THE INFLUENCE OF A MID-LAYER RIDGE TO ITS NORTHEAST. WITH THE 415RIDGE WEAKENING...THE CYCLONE SHOULD TURN NORTHWARD IN ABOUT A DAY 416AND CONTINUE THIS MOTION FOR ANOTHER DAY OR SO. AROUND DAY 4173...HUMBERTO SHOULD TURN AGAIN...THIS TIME TOWARD THE WEST...AS A 418STRONGER DEEP-LAYER RIDGE BUILDS IN NEAR THE AZORES. THE TRACK 419FORECAST IS BASED UPON A BLEND OF THE GFS...ECMWF...AND FIM GLOBAL 420MODELS...AND IS NEARLY IDENTICAL TO THE PREVIOUS ADVISORY THROUGH 42148 HOURS AND THEN SLIGHTLY SOUTH THEREAFTER. 422 423 424FORECAST POSITIONS AND MAX WINDS 425 426INIT 11/0300Z 15.4N 28.4W 60 KT 70 MPH 427 12H 11/1200Z 16.4N 28.9W 65 KT 75 MPH 428 24H 12/0000Z 18.3N 29.1W 70 KT 80 MPH 429 36H 12/1200Z 20.2N 29.4W 75 KT 85 MPH 430 48H 13/0000Z 21.7N 29.9W 70 KT 80 MPH 431 72H 14/0000Z 23.5N 32.5W 60 KT 70 MPH 432 96H 15/0000Z 24.0N 37.5W 45 KT 50 MPH 433120H 16/0000Z 24.5N 43.0W 40 KT 45 MPH 434 435$$ 436FORECASTER LANDSEA 437 438 439WTNT44 KNHC 110853 440TCDAT4 441 442HURRICANE HUMBERTO DISCUSSION NUMBER 11 443NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 444500 AM AST WED SEP 11 2013 445 446CENTRAL CONVECTION HAS BEEN ON THE INCREASE WITH HUMBERTO DURING THE 447LAST FEW HOURS...WITH A LARGE CURVED BAND WRAPPING AROUND THE 448CYCLONE ALSO BECOMING BETTER DEFINED. THE DVORAK ESTIMATES AT 6Z 449SUPPORTED ANYTHING FROM 55-65 KT...AND GIVEN THE NOTABLE 450STRENGTHENING OF THE CENTRAL DEEP CONVECTION AND OVERALL INCREASE 451IN ORGANIZATION...THE INITIAL WINDS ARE RAISED TO 65 KT. HUMBERTO 452HAS ABOUT A DAY TO STRENGTHEN BEFORE AN INCREASE IN SHEAR AND 453COOLER WATERS SHOULD CAUSE A WEAKENING TREND. IN A FEW DAYS... 454ALTHOUGH WATER TEMPERATURES BEGIN TO RISE...STRONG WESTERLY SHEAR 455AND ENTRAINMENT OF DRIER AIR WILL PROBABLY KEEP THE CYCLONE 456GRADUALLY WEAKENING. THE INTENSITY GUIDANCE SEEMS TO BE WELL 457CLUSTERED...SO THE LATEST NHC WIND SPEED PREDICTION IS CLOSE TO THE 458PREVIOUS FORECAST AND THE MODEL CONSENSUS. 459 460HUMBERTO APPEARS TO BE TURNING TO THE RIGHT...NOW MOVING 330/7. THE 461CYCLONE SHOULD TURN TO THE NORTH SOON AND ACCELERATE SOME WHILE IT 462MOVES BETWEEN A RIDGE OVER NORTHWESTERN AFRICA AND A TROUGH OVER 463THE CENTRAL ATLANTIC OCEAN. IN A COUPLE OF DAYS...HUMBERTO IS 464LIKELY TO TAKE A HARD LEFT TURN DUE TO IT RUNNING AGAINST A RATHER 465STOUT RIDGE IN THE SUBTROPICAL EASTERN ATLANTIC. WITH HUMBERTO 466BECOMING A MORE SHALLOW SYSTEM IN THE LONGER RANGE...IT MAKES SENSE 467TO STAY ON THE SOUTHERN SIDE OF THE GUIDANCE ENVELOPE GIVEN THE 468STRONG LOW-LEVEL RIDGE FORECAST. THE LATEST NHC FORECAST IS 469BASICALLY AN UPDATE OF THE PREVIOUS ONE...STAYING EQUATORWARD OF 470THE MODEL CONSENSUS IN THE MEDIUM RANGE. 471 472 473FORECAST POSITIONS AND MAX WINDS 474 475INIT 11/0900Z 16.0N 28.9W 65 KT 75 MPH 476 12H 11/1800Z 17.2N 29.2W 70 KT 80 MPH 477 24H 12/0600Z 19.0N 29.3W 75 KT 85 MPH 478 36H 12/1800Z 20.9N 29.6W 70 KT 80 MPH 479 48H 13/0600Z 22.5N 30.3W 65 KT 75 MPH 480 72H 14/0600Z 23.8N 33.9W 50 KT 60 MPH 481 96H 15/0600Z 24.2N 39.1W 45 KT 50 MPH 482120H 16/0600Z 25.5N 44.0W 40 KT 45 MPH 483 484$$ 485FORECASTER BLAKE 486 487 488WTNT44 KNHC 111435 489TCDAT4 490 491HURRICANE HUMBERTO DISCUSSION NUMBER 12 492NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 4931100 AM AST WED SEP 11 2013 494 495SATELLITE IMAGERY HAS BEEN REVEALING AN INTERMITTENT RAGGED EYE... 496WHICH IS ALSO DEPICTED AT THE MID-LEVELS ON A SSMI/S PASS EARLY 497THIS MORNING. THE EYE HAS BEEN APPARENT WITHIN A SMALL CENTRAL 498DENSE OVERCAST WHICH IS SURROUNDED BY A COUPLE OF DISTINCT 499CYCLONICALLY-CURVED CONVECTIVE BANDS. SATELLITE INTENSITY ESTIMATES 500ARE 4.0 AND 4.5 FROM TAFB AND SAB...AND THE OBJECTIVE NUMBERS FROM 501THE UNIVERSITY OF WISCONSIN HAVE REACHED 4.4 ON THE DVORAK SCALE. 502ON THIS BASIS..THE INITIAL INTENSITY AS BEEN SET AT 70 KNOTS. 503 504HUMBERTO HAS THE OPPORTUNITY TO STRENGTHEN A LITTLE MORE BEFORE IT 505REACHES COOLER WATER AND INCREASING SHEAR IN A COUPLE OF DAYS...AS 506DIAGNOSED BY THE SHIPS MODEL AND MOST OF THE INTENSITY GUIDANCE. 507GRADUAL WEAKENING SHOULD THEN BEGIN AS INDICATED IN THE NHC 508FORECAST. 509 510AS PREVIOUSLY FORECAST...HUMBERTO HAS MADE THE EXPECTED SHARP TURN 511TO THE NORTH...AND IS NOW MOVING TOWARD 350 DEGREES AT 8 KNOTS. THE 512CYCLONE IS BEEN STEERED BY THE SOUTHERLY FLOW BETWEEN A MID-LEVEL 513LOW OVER THE CENTRAL ATLANTIC AND A RIDGE OVER AFRICA. IN A COUPLE 514OF DAYS...GLOBAL MODELS FORECAST THAT THE LOW WILL WEAKEN AND 515HUMBERTO WILL ENCOUNTER STRONG HIGH PRESSURE TO THE NORTH. THIS 516PATTERN WOULD FORCE THE CYCLONE TO TURN TOWARD THE WEST OR 517WEST-NORTHWEST AND THIS IS THE GENERAL SOLUTION UNANIMOUSLY 518PROVIDED BY THE TRACK GUIDANCE. THE NHC FORECAST FOLLOWS THAT 519SCENARIO AND IS VERY CLOSE TO THE MULTI-MODEL CONSENSUS. THIS TRACK 520WILL KEEP HUMBERTO MOVING OVER THE NORTH ATLANTIC WATERS FOR 521SEVERAL DAYS. 522 523 524FORECAST POSITIONS AND MAX WINDS 525 526INIT 11/1500Z 16.7N 29.1W 70 KT 80 MPH 527 12H 12/0000Z 18.2N 29.4W 75 KT 85 MPH 528 24H 12/1200Z 20.0N 29.6W 70 KT 80 MPH 529 36H 13/0000Z 21.5N 30.0W 70 KT 80 MPH 530 48H 13/1200Z 23.0N 31.0W 65 KT 75 MPH 531 72H 14/1200Z 24.0N 35.5W 50 KT 60 MPH 532 96H 15/1200Z 24.5N 40.5W 45 KT 50 MPH 533120H 16/1200Z 26.0N 45.5W 40 KT 45 MPH 534 535$$ 536FORECASTER AVILA 537 538 539WTNT44 KNHC 112040 540TCDAT4 541 542HURRICANE HUMBERTO DISCUSSION NUMBER 13 543NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 544500 PM AST WED SEP 11 2013 545 546THE CLOUD PATTERN HAS BECOME A LITTLE BETTER ORGANIZED THIS 547AFTERNOON IN BOTH MICROWAVE AND CONVENTIONAL IMAGERY. THE 548EYE...ALTHOUGH RAGGED AND INTERMITTENT...IS EMBEDDED WITHIN A SMALL 549CENTRAL DENSE OVERCAST WITH CONVECTIVE BANDS WRAPPING AROUND 550THE CENTER PRIMARILY IN THE SOUTHERN SEMICIRCLE. SATELLITE 551INTENSITY ESTIMATES ARE UNANIMOUSLY 4.5 ON THE DVORAK SCALE AND ON 552THIS BASIS...THE INITIAL INTENSITY HAS BEEN ADJUSTED UPWARD TO 75 553KNOTS. HUMBERTO HAS THE OPPORTUNITY TO STRENGTHEN A LITTLE MORE 554BEFORE IT REACHES COOLER WATERS AND INCREASING SHEAR IN ABOUT A DAY. 555AFTER THAT TIME...GRADUAL WEAKENING SHOULD BEGIN. 556 557SATELLITE FIXES SUGGEST THAT HUMBERTO IS MOVING TOWARD THE NORTH OR 558350 DEGREES AT 10 KNOTS. THE CYCLONE CONTINUES TO BE STEERED BY THE 559SOUTHERLY FLOW BETWEEN A MID-LEVEL LOW OVER THE CENTRAL ATLANTIC 560AND A RIDGE OVER AFRICA. IN A COUPLE OF DAYS...THE GLOBAL MODELS 561FORECAST THE LOW TO WEAKEN AND HUMBERTO WILL ENCOUNTER 562STRONG HIGH PRESSURE TO THE NORTH. THIS PATTERN WOULD FORCE 563HUMBERTO TO MAKE A HARD LEFT TURN AND THIS SCENARIO IS UNANIMOUSLY 564SHOWN BY THE TRACK GUIDANCE. THE NHC FORECAST IS VERY CLOSE TO 565THE MULTI-MODEL CONSENSUS AND IS IN THE MIDDLE OF THE TRACK 566GUIDANCE ENVELOPE. THE GLOBAL MODELS INDICATE THAT HUMBERTO WILL 567LINGER OVER THE EASTERN ATLANTIC FOR SEVERAL DAYS. 568 569 570FORECAST POSITIONS AND MAX WINDS 571 572INIT 11/2100Z 18.0N 29.0W 75 KT 85 MPH 573 12H 12/0600Z 19.5N 29.4W 80 KT 90 MPH 574 24H 12/1800Z 21.3N 29.9W 75 KT 85 MPH 575 36H 13/0600Z 22.8N 30.6W 65 KT 75 MPH 576 48H 13/1800Z 24.0N 32.0W 60 KT 70 MPH 577 72H 14/1800Z 24.5N 36.5W 45 KT 50 MPH 578 96H 15/1800Z 25.5N 41.5W 40 KT 45 MPH 579120H 16/1800Z 27.0N 46.0W 35 KT 40 MPH 580 581$$ 582FORECASTER AVILA 583 584 585WTNT44 KNHC 120250 586TCDAT4 587 588HURRICANE HUMBERTO DISCUSSION NUMBER 14 589NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 5901100 PM AST WED SEP 11 2013 591 592THE LARGE CENTRAL DENSE OVERCAST OF HUMBERTO IS EXHIBITING QUITE 593COLD CLOUD TOPS WITH A SMALL EYE INTERMITTENTLY APPEARING. DVORAK 594SUBJECTIVE INTENSITY ESTIMATES FROM TAFB AND SAB REMAIN AT ABOUT 59575 KT...WHILE ADT IS SLIGHTLY HIGHER AND CIMSS AMSU SLIGHTLY LOWER. 596THE INTENSITY ANALYSIS REMAINS AT 75 KT. A DIRECT HIT BY AN ASCAT 597SCATTEROMETER SATELLITE AT 2250Z PROVIDED OBSERVATIONS SHOWING THAT 598HUMBERTO IS LARGER IN ITS TROPICAL STORM AND 50-KT WIND RADII THAN 599EARLIER ESTIMATED. THIS IS CONSISTENT WITH THE LARGE CDO AND 600INDEPENDENT ANALYSES FROM CIRA AMSU SIZE VALUES. 601 602CURRENTLY...HUMBERTO HAS BEEN TRAVERSING OVER WATERS OF 26C AND 603THROUGH AN ATMOSPHERE OF WEAK VERTICAL WIND SHEAR...AS WELL AS 604MOIST AND UNSTABLE AIR. IT APPEARS...HOWEVER...THAT HUMBERTO MAY BE 605AT ITS PEAK INTENSITY. AS HUMBERTO TRACKS NORTHWARD THEN WESTWARD 606DURING THE NEXT FEW DAYS...THE CYCLONE WILL APPROACH A STRONG 607TROPICAL UPPER TROPOSPHERIC TROUGH. THIS TROUGH WILL INDUCE 608MODERATE TO STRONG SOUTHWESTERLY VERTICAL SHEAR BEGINNING IN ABOUT 609A DAY AND CONTINUING THROUGH THE END OF THE FORECAST PERIOD. THE 610HOSTILE SHEAR AND COOLER SSTS SHOULD INDUCE SUBSTANTIAL WEAKENING. 611THE INTENSITY PREDICTION IS SLIGHTLY LOWER THAN THAT FROM THE 612PREVIOUS ADVISORY AND CLOSEST TO THE IVCN INTENSITY CONSENSUS 613THROUGH 48 HOURS AND CLOSEST TO THE DECAY-SHIPS STATISTICAL MODEL 614THEREAFTER. THERE ARE SUGGESTIONS BY THE GLOBAL MODELS THAT 615HUMBERTO MAY ATTEMPT A COMEBACK STARTING AROUND DAY 5...BUT IT IS 616QUITE UNCERTAIN HOW MUCH OF A TROPICAL CYCLONE WILL BE REMAINING AT 617THAT TIME AFTER EXPERIENCING SUBSTANTIAL VERTICAL SHEAR FOR NEARLY 618FOUR DAYS. 619 620HUMBERTO IS MOVING DUE NORTH AT 11 KT...PRIMARILY DUE TO THE 621STEERING INDUCED BY A MID-LEVEL RIDGE OVER WEST AFRICA TO ITS EAST. 622IN ABOUT TWO DAYS...A STRONG DEEP-LAYER RIDGE WILL DEVELOP NEAR THE 623AZORES AND FORCE HUMBERTO TOWARD THE WEST FOR THE NEXT FEW DAYS. 624THE TRACK GUIDANCE IS TIGHTLY CLUSTERED AND THE TRACK PREDICTION IS 625NEARLY UNCHANGED FROM THE PREVIOUS ADVISORY. 626 627FORECAST POSITIONS AND MAX WINDS 628 629INIT 12/0300Z 19.1N 29.0W 75 KT 85 MPH 630 12H 12/1200Z 20.7N 29.2W 75 KT 85 MPH 631 24H 13/0000Z 22.3N 29.9W 70 KT 80 MPH 632 36H 13/1200Z 23.5N 31.0W 60 KT 70 MPH 633 48H 14/0000Z 24.2N 32.8W 50 KT 60 MPH 634 72H 15/0000Z 25.2N 37.6W 40 KT 45 MPH 635 96H 16/0000Z 26.0N 42.0W 35 KT 40 MPH 636120H 17/0000Z 27.5N 45.0W 30 KT 35 MPH 637 638$$ 639FORECASTER LANDSEA 640 641 642WTNT44 KNHC 120849 643TCDAT4 644 645HURRICANE HUMBERTO DISCUSSION NUMBER 15 646NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 647500 AM AST THU SEP 12 2013 648 649THE CLOUD PATTERN OF HUMBERTO REMAINS WELL ORGANIZED...WITH THE 650CYCLONE MAINTAINING A WELL-DEFINED CENTRAL DENSE OVERCAST COMPRISED 651OF COLD CLOUD TOPS AND OCCASIONAL HINTS OF A WARM SPOT OR EYE. THE 652OUTER CIRCULATION OF THE CYCLONE CONSISTS OF SEVERAL WELL-DEFINED 653BANDS...AND THE OUTFLOW REMAINS GOOD TO EXCELLENT IN ALL QUADRANTS. 654HOWEVER...SATELLITE DATA IN THE LAST FEW HOURS SUGGEST THAT THE 655STRUCTURE OF THE INNER CORE CONVECTION HAS BECOME LESS SYMMETRIC 656AND THERE HAS BEEN SOME DETERIORATION OF THE EYEWALL JUST RECENTLY. 657THESE DEVELOPMENTS SUGGEST THAT HUMBERTO MAY HAVE PEAKED IN 658INTENSITY. DVORAK INTENSITY ESTIMATES ARE A CONSENSUS T4.5 FROM 659TAFB AND SAB...AND ADT VALUES ARE RUNNING AROUND 4.5. ON THIS 660BASIS...THE INITIAL INTENSITY IS KEPT AT 75 KT. 661 662HUMBERTO HAS BEEN MOVING STEADILY NORTHWARD...005/12....AND A 663NORTHWARD OR NORTH-NORTHWESTWARD MOTION INTO A SIGNIFICANT WEAKNESS 664IN THE SUBTROPICAL RIDGE SHOULD CONTINUE FOR ANOTHER DAY OR SO. 665AFTER THAT...A WEAKENING HUMBERTO SHOULD TURN NORTHWESTWARD AND 666THEN WEST-NORTHWESTWARD IN BETWEEN A BLOCKING LOW- TO MID-LEVEL 667RIDGE OVER THE NORTHEAST ATLANTIC AND A MID- TO UPPER-LEVEL LOW TO 668THE WEST UNTIL ABOUT DAY 4. BY DAY 5...HUMBERTO SHOULD REACH A 669REGION OF WEAK STEERING AND SLOW DOWN WHILE IT TURNS NORTHWARD OR 670PERHAPS EVEN NORTHEASTWARD AHEAD OF A STRONG MID-LATITUDE TROUGH 671ADVANCING ACROSS ATLANTIC CANADA. THE GUIDANCE HAS SHIFTED TO THE 672RIGHT THIS CYCLE...ESPECIALLY BEYOND 48 HOURS...AND THE OFFICIAL 673FORECAST IS ADJUSTED IN THAT DIRECTION. HOW FAST AND IN WHAT 674DIRECTION THE CYCLONE IS STEERED LATE IN THE PERIOD WILL LIKELY BE 675DEPENDENT ON THE STRENGTH OF THE CYCLONE...WHICH IS MORE UNCERTAIN 676THAN NORMAL AT THE MOMENT. 677 678EVEN THOUGH HUMBERTO IS ALREADY OVER WATERS LESS THAN 26C... 679SUFFICIENT MID-LEVEL MOISTURE AND INSTABILITY HAVE ALLOWED THE 680CYCLONE TO MAINTAIN ITSELF. HOWEVER...WEAKENING IS EXPECTED SOON AS 681A RESULT OF INCREASING SHEAR ASSOCIATED WITH A LARGE AMPLITUDE 682UPPER-LEVEL TROUGH OVER THE EAST-CENTRAL ATLANTIC AND THE 683ENTRAINMENT OF DRIER AIR. SHIPS MODEL OUTPUT SHOWS THE WEST- 684SOUTHWESTERLY SHEAR INCREASING TO GREATER THAN 40 KT IN 2-3 DAYS 685WHILE HUMBERTO IS STILL OVER COOL WATERS...WHICH COULD RESULT IN 686THE CYCLONE DEGENERATING INTO A REMNANT LOW. HOWEVER...GLOBAL 687MODELS SHOW A RESILIENT HUMBERTO...PERHAPS BECAUSE OF THE LARGE 688SIZE OF ITS CIRCULATION...SURVIVING TO REACH WARMER WATERS BY DAY 6894. SOME DECREASE IN THE SHEAR LATE IN THE PERIOD AND POTENTIAL 690INTERACTION WITH THE APPROACHING MID-LATITUDE TROUGH MIGHT ALLOW 691FOR SOME RE-STRENGTHENING...ALTHOUGH THIS IS NOT EXPLICITLY SHOWN 692IN THE FORECAST. THE OFFICIAL INTENSITY FORECAST IS ADJUSTED 693DOWNWARD AND LIES IN BETWEEN THE LOWER SHIPS MODEL GUIDANCE AND THE 694INTENSITY CONSENSUS AIDS AND FLORIDA STATE SUPERENSMBLE OUTPUT. 695 696 697FORECAST POSITIONS AND MAX WINDS 698 699INIT 12/0900Z 20.5N 28.7W 75 KT 85 MPH 700 12H 12/1800Z 22.0N 29.4W 70 KT 80 MPH 701 24H 13/0600Z 23.5N 30.3W 65 KT 75 MPH 702 36H 13/1800Z 24.5N 31.9W 55 KT 65 MPH 703 48H 14/0600Z 25.1N 33.7W 45 KT 50 MPH 704 72H 15/0600Z 26.1N 38.5W 35 KT 40 MPH 705 96H 16/0600Z 27.3N 42.5W 30 KT 35 MPH 706120H 17/0600Z 28.5N 45.0W 30 KT 35 MPH 707 708$$ 709FORECASTER KIMBERLAIN 710 711 712WTNT44 KNHC 121439 713TCDAT4 714 715HURRICANE HUMBERTO DISCUSSION NUMBER 16 716NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 7171100 AM AST THU SEP 12 2013 718 719ALTHOUGH THERE IS SOME EVIDENCE OF SOUTH-SOUTHWESTERLY SHEAR OVER 720THE SYSTEM...HUMBERTO REMAINS FAIRLY WELL ORGANIZED WITH CONTINUED 721HINTS OF A BANDING-TYPE EYE. DVORAK CLASSIFICATIONS FROM TAFB AND 722SAB CONTINUE TO SUPPORT AN INTENSITY OF 75 KT FOR THIS ADVISORY. 723INCREASING WEST-SOUTHWESTERLY SHEAR AND COOL SEA SURFACE 724TEMPERATURES SHOULD CAUSE WEAKENING OVER THE NEXT COUPLE OF DAYS. 725LATER IN THE PERIOD...ALTHOUGH HUMBERTO IS FORECAST TO TRAVERSE THE 726WARMER WATERS WEST OF 40W LONGITUDE...THE SHEAR IS LIKELY TO REMAIN 727STRONG...SO RESTRENGTHENING IS NOT ANTICIPATED AT THIS TIME. THE 728OFFICIAL WIND SPEED FORECAST IS NEAR THE LOW END OF THE NUMERICAL 729GUIDANCE AND LIES BETWEEN THE LATEST DSHIPS AND LGEM PREDICTIONS. 730 731THE HURRICANE IS MOVING NORTHWARD AT A SLIGHTLY FASTER PACE...OR 732360/13. A LARGE MID-LEVEL HIGH PRESSURE SYSTEM CENTERED NORTH OF 733THE AZORES SHOULD CAUSE HUMBERTO TO TURN TOWARD THE NORTHWEST AND 734WEST-NORTHWEST DURING THE FORECAST PERIOD. LATE IN THE 735PERIOD...GLOBAL MODELS PREDICT A WEAKENING OF THE HIGH WHILE A 736MID-LEVEL TROUGH MOVES EASTWARD FROM ATLANTIC CANADA AND THE 737NORTHEASTERN UNITED STATES. BY THIS TIME...THE TROPICAL CYCLONE IS 738EXPECTED TO SLOW ITS FORWARD SPEED DUE TO A WEAKENING STEERING 739CURRENT. THE TRACK GUIDANCE HAS ONCE AGAIN SHIFTED TO THE RIGHT... 740AND THE OFFICIAL FORECAST IS ADJUSTED IN THAT DIRECTION. THIS IS 741VERY CLOSE TO THE LATEST MULTI-MODEL CONSENSUS. 742 743A RECENT ASCAT OVER PASS REVEALED A SIGNIFICANTLY LARGER HURRICANE 744THAN PREVIOUS ESTIMATED...AND THE WIND RADII HAVE BEEN EXPANDED 745ACCORDINGLY. 746 747FORECAST POSITIONS AND MAX WINDS 748 749INIT 12/1500Z 21.8N 29.0W 75 KT 85 MPH 750 12H 13/0000Z 23.3N 29.8W 70 KT 80 MPH 751 24H 13/1200Z 24.6N 31.2W 65 KT 75 MPH 752 36H 14/0000Z 25.4N 33.0W 55 KT 65 MPH 753 48H 14/1200Z 26.0N 35.0W 45 KT 50 MPH 754 72H 15/1200Z 27.5N 39.5W 40 KT 45 MPH 755 96H 16/1200Z 29.0N 43.0W 35 KT 40 MPH 756120H 17/1200Z 31.0N 45.0W 35 KT 40 MPH 757 758$$ 759FORECASTER PASCH 760 761 762WTNT44 KNHC 122034 763TCDAT4 764 765HURRICANE HUMBERTO DISCUSSION NUMBER 17 766NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 767500 PM AST THU SEP 12 2013 768 769THE EYE IS NO LONGER APPARENT ON SATELLITE IMAGES...AND THERE 770CONTINUES TO BE SOME EVIDENCE OF SOUTHWESTERLY SHEAR OVER THE 771HURRICANE. DVORAK-BASED CURRENT INTENSITY ESTIMATES FROM TAFB AND 772SAB HAVE NOT YET DECREASED...SO THE ADVISORY INTENSITY IS KEPT AT 77375 KT. HUMBERTO SHOULD BE IN AN ENVIRONMENT OF MODERATE TO STRONG 774WEST-SOUTHWESTERLY SHEAR AND MARGINAL SEA SURFACE TEMPERATURES FOR 775THE NEXT COUPLE OF DAYS...AND WEAKENING SHOULD OCCUR DURING THAT 776TIME FRAME. LATER ON...THE TROPICAL CYCLONE IS LIKELY TO TRAVERSE 777WARMER WATERS WEST OF 40W LONGITUDE AND THE SHEAR IS FORECAST TO 778RELAX A LITTLE. THUS...THE OFFICIAL WIND SPEED FORECAST HINTS AT 779SOME RE-STRENGTHENING BY LATE IN PERIOD. THIS IS IN GOOD AGREEMENT 780WITH THE LATEST LGEM GUIDANCE. IT SHOULD BE NOTED THAT THE GLOBAL 781MODELS SUGGEST THAT HUMBERTO COULD BE EVEN STRONGER THAN INDICATED 782HERE AT DAYS 4-5. 783 784THE NORTHWARD MOTION CONTINUES...AT 350/12 KT. A LARGE MID- 785TROPOSPHERIC HIGH PRESSURE AREA CENTERED NORTH OF THE AZORES SHOULD 786CAUSE HUMBERTO TO TURN TOWARD THE NORTHWEST AND THEN THE WEST- 787NORTHWEST OVER THE NEXT SEVERAL DAYS. LATER IN THE FORECAST 788PERIOD...THE TROPICAL CYCLONE IS EXPECTED TO TURN BACK TO THE RIGHT 789WITHIN THE FLOW BETWEEN THE HIGH AND A MID-TROPOSPHERIC TROUGH 790MOVING EASTWARD FROM THE NORTHEASTERN U.S. AND ATLANTIC CANADA. THE 791NEW TRACK GUIDANCE...ESPECIALLY THE ECMWF...AND THE OFFICIAL 792FORECAST...ARE A LITTLE FASTER THAN THE PREVIOUS ONES. THE NHC 793TRACK FORECAST FOR THIS ADVISORY IS SIMILAR TO THE MODEL CONSENSUS 794AND ESSENTIALLY SPLITS THE DIFFERENCE BETWEEN THE GFS AND THE 795ECMWF. 796 797FORECAST POSITIONS AND MAX WINDS 798 799INIT 12/2100Z 23.1N 29.2W 75 KT 85 MPH 800 12H 13/0600Z 24.1N 30.3W 70 KT 80 MPH 801 24H 13/1800Z 25.2N 32.0W 65 KT 75 MPH 802 36H 14/0600Z 26.0N 34.2W 55 KT 65 MPH 803 48H 14/1800Z 26.8N 36.5W 45 KT 50 MPH 804 72H 15/1800Z 28.8N 40.8W 45 KT 50 MPH 805 96H 16/1800Z 30.5N 43.5W 45 KT 50 MPH 806120H 17/1800Z 33.0N 45.0W 50 KT 60 MPH 807 808$$ 809FORECASTER PASCH 810 811 812WTNT44 KNHC 130253 813TCDAT4 814 815HURRICANE HUMBERTO DISCUSSION NUMBER 18 816NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 8171100 PM AST THU SEP 12 2013 818 819MICROWAVE IMAGERY...FROM METOP AND SSMIS...INDICATE THAT THE DEEP 820CONVECTION IS BECOMING DISLOCATED FROM THE LOW-LEVEL CENTER OF 821HUMBERTO. SO WHILE THE HURRICANE IS STILL PRODUCTING QUITE COLD 822CLOUD TOPS...WEAKENING OF THE SYSTEM HAS APPARENTLY BEGUN. THE 823INTENSITY OF 70 KT IS A BLEND OF THE HIGHER SUBJECTIVE DVORAK 824CURRENT INTENSITY NUMBERS FROM TAFB AND SAB WITH THE LOWER ADT. A 825RECENT ASCAT SCATTEROMETER PASS ALSO INDICATED THAT THE CYCLONE 826CONTINUES TO GROW LARGER...WITH TROPICAL STORM FORCE WINDS 827EXTENDING OUT ALMOST 200 NM FROM THE CENTER IN THE EASTERN 828SEMICIRCLE. 829 830THE AFOREMENTIONED DISPLACEMENT OF THE CONVECTION IS BEING CAUSED BY 831STRONG SOUTHWESTERLY VERTICAL WIND SHEAR OF OVER 30 KT...PRIMARILY 832DUE TO A RATHER ROBUST TROPICAL UPPER TROPOSPHERIC TROUGH TO THE 833WEST OF HUMBERTO. THIS STRONG SHEAR SHOULD CONTINUE FOR AT LEAST A 834COUPLE OF DAYS...WHICH...IN COMBINATION WITH MARGINAL 835THERMODYNAMICS...SHOULD LEAD TO STEADY WEAKENING. AT THE LONGER 836TIME RANGE...THE SHEAR IS PREDICTED TO LESSEN DUE TO THE FILLING OF 837THE UPPER TROUGH WHILE HUMBERTO ALSO REACHES WARMER WATERS. THE 838GFS MODEL SUGGESTS THIS REDUCTION IN SHEAR WILL OCCUR IN ABOUT 839THREE DAYS...WHILE THE ECMWF MODEL WAITS UNTIL FOUR OR EVEN FIVE 840DAYS FOR THIS TO OCCUR. THIS DIFFERENCE LEADS TO SUBSTANTIAL 841UNCERTAINTY IN HOW MUCH OF A CYCLONE WILL REMAIN AND WHETHER IT 842WILL SIGNIFICANTLY RE-INTENSIFY LATE IN THE PERIOD. THE INTENSITY 843FORECAST IS VERY SIMILAR TO THE PREVIOUS ADVISORY AND IS CLOSE TO 844THE CONSENSUS IN THE FIRST THREE DAYS AND BELOW IT THEREAFTER. 845 846HUMBERTO HAS BEEN MOVING AT 10 KT TOWARD THE NORTH-NORTHWEST...AS IT 847IS PROGRESSING THROUGH A BREAK IN THE MID-LEVEL RIDGE. IN ABOUT A 848DAY...A STRONG DEEP-LAYER RIDGE REBUILDS NEAR THE AZORES AND 849SHOULD ABRUPTLY TURN HUMBERTO TOWARD THE WEST-NORTHWEST. BY DAY 850FIVE...HUMBERTO SHOULD BE ROUNDING THIS RIDGE AND BEGINNING 851RECURVATURE. THE TRACK MODELS ARE TIGHTLY CLUSTERED...BUT ARE 852SOMEWHAT FASTER AND FARTHER NORTH THAN THE PREVIOUS CYCLE. THE 853TRACK FORECAST IS A BLEND OF THE LAST ADVISORY AND AN AVERAGE OF 854THE GFS/ECMWF/FIM GLOBAL MODELS. 855 856 857FORECAST POSITIONS AND MAX WINDS 858 859INIT 13/0300Z 23.4N 29.7W 70 KT 80 MPH 860 12H 13/1200Z 24.4N 30.7W 65 KT 75 MPH 861 24H 14/0000Z 25.3N 32.8W 60 KT 70 MPH 862 36H 14/1200Z 26.2N 35.3W 50 KT 60 MPH 863 48H 15/0000Z 27.4N 37.6W 45 KT 50 MPH 864 72H 16/0000Z 29.5N 41.5W 45 KT 50 MPH 865 96H 17/0000Z 31.5N 44.0W 45 KT 50 MPH 866120H 18/0000Z 34.5N 45.0W 50 KT 60 MPH 867 868$$ 869FORECASTER LANDSEA 870 871 872WTNT44 KNHC 130849 873TCDAT4 874 875HURRICANE HUMBERTO DISCUSSION NUMBER 19 876NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 877500 AM AST FRI SEP 13 2013 878 879HUMBERTO IS ON A WEAKENING TREND...AND IT IS BARELY HANGING ON TO 880HURRICANE STATUS. LATEST GEOSTATIONARY SATELLITE IMAGES INDICATE 881THAT THE ASSOCIATED DEEP CONVECTION IS LOSING ORGANIZATION...AND 882MICROWAVE IMAGES REVEAL THAT THE LOW-LEVEL CENTER IS LOCATED NEAR 883THE SOUTHWESTERN EDGE OF THE DEEP CLOUDINESS. THIS ASYMMETRIC CLOUD 884PATTERN IS DUE TO 20-25 KT OF SOUTHWESTERLY VERTICAL WIND SHEAR. 885THE INITIAL WIND SPEED IS LOWERED TO 65 KT...IN ACCORDANCE WITH AN 886AVERAGE OF THE LATEST DVORAK CI-NUMBERS FROM TAFB...SAB...AND 887UW-CIMSS ADT...AND THIS ESTIMATE COULD BE GENEROUS. 888 889THE TROPICAL CYCLONE IS GRADUALLY TURNING TO THE LEFT AS THE 890STEERING FLOW IS BECOMING MORE DOMINATED BY A DEEP-LAYER RIDGE TO 891ITS NORTH-NORTHWEST. THE LATEST INITIAL MOTION ESTIMATE IS 335/10. 892A TURN TO THE WEST-NORTHWEST IS EXPECTED TO BEGIN LATER TODAY AND 893CONTINUE THROUGH MUCH OF THE WEEKEND WHILE HUMBERTO MOVES ON 894THE SOUTH SIDE OF THE RIDGE. A TURN BACK TO THE NORTH IS FORECAST 895TO OCCUR IN 4 TO 5 DAYS WHEN HUMBERTO MOVES INTO A PRONOUNCED 896WEAKNESS IN THE RIDGE CAUSED BY AN APPROACHING TROUGH. THE NHC 897TRACK FORECAST IS CLOSE TO THE GFS AND ECMWF MODELS. 898 899ADDITIONAL WEAKENING IS EXPECTED DURING THE NEXT 48 HOURS WHILE 900HUMBERTO REMAINS OVER 25-26C WATERS AND MOVES INTO EVEN STRONGER 901SHEAR AND A DRIER AIRMASS. BEYOND THAT TIME...THE SHEAR IS EXPECTED 902TO LESSEN WHILE HUMBERTO MOVES OVER WARMER WATER. THESE MORE 903FAVORABLE CONDITIONS COULD ALLOW THE CYCLONE TO RE-INTENSIFY. IN 904ADDITION...MOST OF THE GLOBAL MODELS SHOW HUMBERTO DEEPENING IN 3 905TO 5 DAYS WHEN IT INTERACTS WITH A COUPLE OF UPPER-LEVEL TROUGHS. 906THE NHC WIND SPEED PREDICTION FOLLOWS THE INTENSITY MODEL CONSENSUS 907AND IS NOT TOO DIFFERENT FROM THE PREVIOUS ADVISORY. 908 909FORECAST POSITIONS AND MAX WINDS 910 911INIT 13/0900Z 24.4N 30.2W 65 KT 75 MPH 912 12H 13/1800Z 25.2N 31.4W 55 KT 65 MPH 913 24H 14/0600Z 26.0N 33.5W 50 KT 60 MPH 914 36H 14/1800Z 27.1N 36.0W 45 KT 50 MPH 915 48H 15/0600Z 28.2N 38.2W 40 KT 45 MPH 916 72H 16/0600Z 30.3N 41.5W 45 KT 50 MPH 917 96H 17/0600Z 32.5N 44.5W 50 KT 60 MPH 918120H 18/0600Z 35.5N 45.0W 55 KT 65 MPH 919 920$$ 921FORECASTER CANGIALOSI 922 923 924WTNT44 KNHC 131450 925TCDAT4 926 927TROPICAL STORM HUMBERTO DISCUSSION NUMBER 20 928NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 9291100 AM AST FRI SEP 13 2013 930 931VERTICAL SHEAR IS TAKING ITS TOLL ON HUMBERTO. ALL OF THE DEEP 932CONVECTION HAS BEEN SHEARED AWAY FROM THE CIRCULATION...LEAVING AN 933EXPOSED CENTER WITH SOME IMPRESSIVE MESOVORTICES. THE INITIAL WIND 934SPEED IS LOWERED TO 55 KT...BASICALLY AS FAST AS THE DVORAK 935CONSTRAINTS ALLOW. FURTHER WEAKENING SEEMS PROBABLE FOR THE NEXT 936DAY OR SO DUE TO INCREASING SOUTHWESTERLY SHEAR AND MARGINAL SSTS. 937IN A COUPLE OF DAYS...THE VERTICAL WIND SHEAR SHOULD BEGIN TO 938DIMINISH WHILE HUMBERTO MOVES OVER WARMER WATERS...WHICH COULD 939ALLOW FOR SOME RESTRENGTHENING. GLOBAL MODELS SUGGEST THAT THE 940STORM WILL UNDERGO A TROUGH INTERACTION IN THE LONG RANGE...LEAVING 941IT IN A FAVORABLE ENVIRONMENT TO BECOME EVEN STRONGER. THE 942OFFICIAL INTENSITY FORECAST IS LOWERED FROM THE PREVIOUS ONE DURING 943THE FIRST 36 HOURS BASED ON CURRENT TRENDS AND THE RATHER STRONG 944SHEAR FORECAST. AT THE END OF THE PERIOD...THE NHC FORECAST IS A 945LITTLE HIGHER...BUT IS STILL BELOW THE MODEL CONSENSUS. 946 947THE INITIAL MOTION IS 300/9. A WEST-NORTHWEST TRACK OF HUMBERTO IS 948EXPECTED FOR THE NEXT COUPLE OF DAYS DUE TO A STRONG RIDGE OVER THE 949NORTHEASTERN ATLANTIC. THE STORM SHOULD TURN NORTHWARD BY DAYS 4-5 950WHILE IT RECURVES AROUND THE WESTERN SIDE OF THE RIDGE. THE ONLY 951SIGNIFICANT DIFFERENCE IN THE MODEL GUIDANCE IS HOW FAST THE STORM 952ACCELERATES INTO THE FAR NORTH ATLANTIC OCEAN...WHICH DEPENDS ON 953WHAT PARTICULAR SHORTWAVE AMPLIFIES THE NEXT MID-LATITUDE TROUGH. 954THE NEW NHC PREDICTION WILL STAY CLOSE TO THE PREVIOUS ONE...NEAR 955THE FLORIDA STATE SUPERENSEMBLE AND A BIT FASTER THAN THE DYNAMICAL 956MODEL CONSENSUS. 957 958 959FORECAST POSITIONS AND MAX WINDS 960 961INIT 13/1500Z 24.7N 31.3W 55 KT 65 MPH 962 12H 14/0000Z 25.4N 32.7W 45 KT 50 MPH 963 24H 14/1200Z 26.3N 35.0W 40 KT 45 MPH 964 36H 15/0000Z 27.4N 37.3W 40 KT 45 MPH 965 48H 15/1200Z 28.5N 39.4W 40 KT 45 MPH 966 72H 16/1200Z 30.7N 42.5W 45 KT 50 MPH 967 96H 17/1200Z 32.8N 45.0W 55 KT 65 MPH 968120H 18/1200Z 36.5N 44.5W 65 KT 75 MPH 969 970$$ 971FORECASTER BLAKE 972 973 974WTNT44 KNHC 132041 975TCDAT4 976 977TROPICAL STORM HUMBERTO DISCUSSION NUMBER 21 978NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 979500 PM AST FRI SEP 13 2013 980 981DEEP CONVECTION HAS BEEN STRUGGLING TO REDEVELOP NEAR HUMBERTO IN 982THE FACE OF SOME RATHER STRONG SHEAR. DVORAK CONSTRAINTS SUGGEST 983AN INITIAL INTENSITY OF ABOUT 45 KT...THOUGH THIS COULD BE REFINED 984A BIT AFTER THE NEXT SCATTEROMETER PASS. AN EXTREMELY LARGE UPPER- 985LEVEL TROUGH OVER THE CENTRAL ATLANTIC IS CONTINUING TO SHEAR 986HUMBERTO. THIS SHEAR IS NOT FORECAST TO ABATE FOR A COUPLE OF 987DAYS...AND IT WOULD NOT BE SURPRISING TO SEE HUMBERTO DROP TO A 988TROPICAL DEPRESSION AT SOME POINT DURING THAT TIME. HOWEVER...THE 989GLOBAL MODELS CONTINUE TO INSIST THAT THE STORM WILL FIND A MORE 990FAVORABLE ENVIRONMENT FOR STRENGTHENING...AND MOST OF THE RELIABLE 991GUIDANCE SHOWS HUMBERTO AS A HURRICANE AGAIN BY DAY 5. THE 992INTENSITY FORECAST IS AGAIN REDUCED IN THE SHORTER TERM...BUT IS 993KEPT THE SAME AT THE END. 994 995THE MOTION HAS SHIFTED A BIT FARTHER TO THE LEFT...NOW 290/10. 996THERE IS NO CHANGE TO THE SYNOPTIC REASONING FOR THE NEXT FEW DAYS 997WHILE A STRONG RIDGE STEERS THE STORM BASICALLY WEST-NORTHWESTWARD. 998THERE CONTINUE TO BE LARGE MODEL DIFFERENCES AS TO HOW FAST HUMBERTO 999RECURVES OUT TO SEA...WITH THE GFS/GEFS SUGGESTING A MUCH FASTER 1000TRACK THAN MOST OF THE OTHER MODELS. OVERALL...THE GUIDANCE IS 1001TRENDING A LITTLE TO THE SOUTHWEST...AND THE OFFICIAL FORECAST IS 1002SHIFTED IN THAT WAY...FAIRLY CLOSE TO A BLEND OF THE FLORIDA STATE 1003SUPERENSEMBLE AND THE DYNAMICAL MODEL CONSENSUS. 1004 1005 1006FORECAST POSITIONS AND MAX WINDS 1007 1008INIT 13/2100Z 25.0N 32.1W 45 KT 50 MPH 1009 12H 14/0600Z 25.4N 33.7W 40 KT 45 MPH 1010 24H 14/1800Z 26.3N 36.1W 35 KT 40 MPH 1011 36H 15/0600Z 27.3N 38.4W 35 KT 40 MPH 1012 48H 15/1800Z 28.2N 40.4W 35 KT 40 MPH 1013 72H 16/1800Z 30.4N 43.3W 40 KT 45 MPH 1014 96H 17/1800Z 32.5N 45.3W 55 KT 65 MPH 1015120H 18/1800Z 36.0N 45.0W 65 KT 75 MPH 1016 1017$$ 1018FORECASTER BLAKE 1019 1020 1021WTNT44 KNHC 140256 1022TCDAT4 1023 1024TROPICAL STORM HUMBERTO DISCUSSION NUMBER 22 1025NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 10261100 PM AST FRI SEP 13 2013 1027 1028ALTHOUGH HUMBERTO HAS BEEN DEVOID OF DEEP CONVECTION FOR MORE THAN 102910 HOURS...A 13/2307Z ASCAT-B OVERPASS INDICATED WINDS OF 37-38 KT 1030NORTH OF THE CENTER...WHILE MISSING THE EASTERN SEMICIRCLE WHERE 1031STRONGER WINDS COULD HAVE BEEN PRESENT. THEREFORE THE INTENSITY IS 1032ONLY LOWERED TO 40 KT AND THE SYSTEM IS BEING MAINTAINED AS A 1033TROPICAL CYCLONE FOR ONE MORE ADVISORY CYCLE. HOWEVER...INCREASING 1034VERTICAL WIND SHEAR IN EXCESS OF 40 KT ALONG WITH SUB-26C SSTS 1035SHOULD COMBINE TO CAUSE HUMBERTO TO DEGENERATE INTO A NON-CONVECTIVE 1036POST-TROPICAL CYCLONE WITHIN THE NEXT 6-12 HOURS. HUMBERTO IS THEN 1037FORECAST TO REMAIN A REMNANT LOW FOR ABOUT 60-72 HOURS...AT WHICH 1038TIME THE SHEAR IS FORECAST TO DECREASE SHARPLY WHILE THE SYSTEM IS 1039MOVING OVER 28C SSTS. THIS SHOULD ALLOW FOR REGENERATION BACK INTO 1040A TROPICAL CYCLONE BY DAY 3...WITH HUMBERTO POSSIBLY REGAINING 1041HURRICANE STRENGTH BY DAY 5. THE INTENSITY FORECAST CLOSELY FOLLOWS 1042THE STATISTICAL-DYNAMICAL MODELS AND THE TREND OF THE GLOBAL 1043MODELS...ESPECIALLY AT DAYS 3-5. 1044 1045THE INITIAL MOTION ESTIMATE IS 270/08 KT. THERE REMAINS NO 1046SIGNIFICANT CHANGE TO THE PREVIOUS TRACK FORECAST OR SYNOPTIC 1047REASONING. HUMBERTO SHOULD BE STEERED WESTWARD TO WEST- 1048NORTHWESTWARD BY A STRONG RIDGE TO ITS NORTH...AND THEN GRADUALLY 1049RECURVE INTO THE MID-LATITUDE WESTERLIES BY DAYS 3/4 AS A STRONG 1050MID/UPPER-LEVEL TROUGH AND ASSOCIATED COLD FRONT MOVE OFF OF THE 1051U.S. EAST COAST. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE 1052PREVIOUS ADVISORY AND CLOSELY FOLLOWS THE MULTI-MODEL CONSENSUS 1053TVCA. 1054 1055FORECAST POSITIONS AND MAX WINDS 1056 1057INIT 14/0300Z 24.8N 33.0W 40 KT 45 MPH 1058 12H 14/1200Z 25.4N 34.8W 35 KT 40 MPH...POST-TROPICAL 1059 24H 15/0000Z 26.3N 37.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 1060 36H 15/1200Z 27.2N 39.3W 30 KT 35 MPH...POST-TROP/REMNT LOW 1061 48H 16/0000Z 28.2N 41.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 1062 72H 17/0000Z 30.3N 43.7W 35 KT 40 MPH 1063 96H 18/0000Z 32.6N 45.1W 50 KT 60 MPH 1064120H 19/0000Z 36.5N 43.5W 65 KT 75 MPH 1065 1066$$ 1067FORECASTER STEWART 1068 1069 1070WTNT44 KNHC 140850 1071TCDAT4 1072 1073TROPICAL STORM HUMBERTO DISCUSSION NUMBER 23 1074NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 1075500 AM AST SAT SEP 14 2013 1076 1077HUMBERTO IS IN THE PROCESS OF TRANSITIONING TO A POST-TROPICAL 1078CYCLONE. THE SYSTEM HAS BEEN DEVOID OF DEEP CONVECTION FOR A 1079CONSIDERABLE AMOUNT OF TIME...AND IF CONVECTION DOES NOT RETURN 1080SOON IT WILL LIKELY BE DECLARED A POST-TROPICAL CYCLONE LATER 1081TODAY. EVEN THOUGH HUMBERTO LACKS THUNDERSTORM ACTIVITY...IT 1082CONTINUES TO HAVE A LARGE AND WELL-DEFINED LOW-LEVEL CIRCULATION 1083AND IT IS LIKELY STILL PRODUCING WINDS OF TROPICAL STORM FORCE. THE 1084INITIAL WIND SPEED IS SET AT 35 KT...ASSUMING A SPIN DOWN FROM THE 1085EARLIER ASCAT DATA. 1086 1087STRONG SOUTHWESTERLY VERTICAL WIND SHEAR AND DRY STABLE AIR ARE 1088EXPECTED TO CONTINUE AFFECTING HUMBERTO FOR THE NEXT COUPLE OF 1089DAYS...SO THE SYSTEM WILL LIKELY REMAIN A POST-TROPICAL CYCLONE 1090DURING THAT TIME. THE ENVIRONMENTAL CONDITIONS BECOME MORE 1091FAVORABLE BY MONDAY...AND ALL OF THE INTENSITY MODELS SHOW 1092HUMBERTO GAINING STRENGTH IN THE 3 TO 5 DAY TIME FRAME. THE NHC 1093INTENSITY FORECAST FOLLOWS THE TREND OF THE GUIDANCE AND IS IN GOOD 1094AGREEMENT WITH THE PREVIOUS ADVISORY. SOME OF THE EXPECTED 1095INTENSIFICATION APPEARS TO BE ASSOCIATED WITH A FAVORABLE TROUGH 1096INTERACTION. 1097 1098THE STORM IS ON A WESTWARD PATH...AND THE LATEST INITIAL MOTION 1099ESTIMATE IS 275/8. A CONTINUED WESTWARD MOTION IS EXPECTED 1100THROUGHOUT THE DAY WHILE THE SYSTEM REMAINS ON THE SOUTH SIDE OF A 1101DEEP-LAYER RIDGE. AFTER THAT TIME...A GRADUAL TURN TO THE RIGHT IS 1102FORECAST WHEN THE CYCLONE NEARS THE WESTERN EDGE OF THE RIDGE. 1103HUMBERTO...OR ITS REMNANT LOW...IS EXPECTED TO RECURVE IN ABOUT 4 1104DAYS WHEN IT BECOMES EMBEDDED IN SOUTHERLY STEERING FLOW BETWEEN 1105THE RIDGE AN APPROACHING TROUGH. ALTHOUGH THE MODELS AGREE ON THIS 1106OVERALL SCENARIO...THERE ARE SIGNIFICANT DIFFERENCES IN FORWARD 1107SPEED DURING THE RECURVATURE STAGE...WITH THE GFS BEING THE FASTEST 1108AND THE ECMWF THE SLOWEST. THE OFFICIAL TRACK FORECAST IS BETWEEN 1109THOSE MODELS AND LIES VERY NEAR THE CONSENSUS AIDS...TVCA AND TV15. 1110 1111FORECAST POSITIONS AND MAX WINDS 1112 1113INIT 14/0900Z 25.0N 34.0W 35 KT 40 MPH 1114 12H 14/1800Z 25.3N 35.8W 30 KT 35 MPH...POST-TROP/REMNT LOW 1115 24H 15/0600Z 26.2N 38.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 1116 36H 15/1800Z 27.2N 40.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 1117 48H 16/0600Z 28.1N 41.8W 30 KT 35 MPH...POST-TROP/REMNT LOW 1118 72H 17/0600Z 30.5N 44.0W 40 KT 45 MPH 1119 96H 18/0600Z 33.0N 44.5W 50 KT 60 MPH 1120120H 19/0600Z 37.0N 42.0W 65 KT 75 MPH 1121 1122$$ 1123FORECASTER CANGIALOSI 1124 1125 1126WTNT44 KNHC 161501 1127TCDAT4 1128 1129TROPICAL STORM HUMBERTO DISCUSSION NUMBER 25 1130NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 11311100 AM AST MON SEP 16 2013 1132 1133DEEP CONVECTION IN ASSOCIATION WITH POST-TROPICAL CYCLONE HUMBERTO 1134HAS BEEN BURSTING DURING THE LAST 24 HOURS...AND THE DISTANCE 1135BETWEEN THE CONVECTION AND THE CENTER HAS BEEN GRADUALLY 1136DECREASING. THE SYSTEM NOW HAS ENOUGH ORGANIZED DEEP CONVECTION TO 1137BE CONSIDERED A TROPICAL CYCLONE...AND ADVISORIES ON HUMBERTO HAVE 1138BEEN RESTARTED. THE INITIAL WIND SPEED IS SET AT 35 KT BASED ON 1139TWO ASCAT PASSES FROM THE PAST 24 HOURS THAT INDICATED WINDS TO 1140TROPICAL STORM FORCE. 1141 1142A CONSERVATIVE INITIAL MOTION ESTIMATE IS 300/06. HUMBERTO IS 1143FORECAST TO MOVE INTO A COL AREA IN BETWEEN A MID-LEVEL RIDGE OVER 1144THE NORTHEASTERN ATLANTIC AND A MID-LATITUDE TROUGH OVER ATLANTIC 1145CANADA. THIS SHOULD RESULT IN A NORTHWESTWARD AND THEN 1146NORTH-NORTHWESTWARD TURN AT A SLOW FORWARD SPEED DURING THE NEXT 1147COUPLE OF DAYS. AFTER THAT TIME...THE APPROACHING MID-LATITUDE 1148TROUGH SHOULD CAUSE HUMBERTO TO TURN NORTHWARD AND THEN ACCELERE 1149NORTHEASTWARD. THE NHC FORECAST IS CLOSE TO THE MULTI-MODEL 1150CONSENSUS TVCA AND REPRESENTS A COMPROMISE BETWEEN THE SLOWER AND 1151MORE-EASTERLY ECWMF AND THE FASTER AND MORE-WESTERLY GFS. 1152 1153VERY STRONG WEST-SOUTHWESTERLY SHEAR ASSOCIATED WITH A MIDDLE- TO 1154UPPER-LEVEL TROUGH TO THE NORTHWEST OF HUMBERTO IS FORECAST TO 1155RELAX SOME AS THE TROUGH CUTS OFF AND SHIFTS GENERALLY SOUTHWARD OF 1156THE CYCLONE. THE RELATIVE RELAXATION IN SHEAR FORECAST BY THE 1157GLOBAL MODELS...ALONG WITH A TRACK OVER WARMER WATERS...SHOULD 1158ALLOW HUMBERTO TO INTENSIFY A LITTLE DURING THE NEXT SEVERAL DAYS. 1159A POTENTIAL INTERACTION WITH AN APPROACHING MID-LATITUDE TROUGH ON 1160DAYS 3-5 IS LIKELY TO SPEED UP THE RATE OF INTENSIFICATION. 1161EXTRATROPICAL TRANSITION IS FORECAST TO HAVE OCCURRED BY DAY 5. THE 1162NHC INTENSITY FORECAST IS CLOSE TO THE INTENSITY CONSENSUS AIDS AND 1163LGEM THROUGHOUT THE FORECAST PERIOD. 1164 1165 1166 1167FORECAST POSITIONS AND MAX WINDS 1168 1169INIT 16/1500Z 27.2N 43.2W 35 KT 40 MPH 1170 12H 17/0000Z 28.2N 43.3W 35 KT 40 MPH 1171 24H 17/1200Z 29.5N 44.2W 40 KT 45 MPH 1172 36H 18/0000Z 30.2N 44.9W 40 KT 45 MPH 1173 48H 18/1200Z 31.1N 45.3W 45 KT 50 MPH 1174 72H 19/1200Z 33.1N 44.6W 55 KT 65 MPH 1175 96H 20/1200Z 36.7N 40.7W 65 KT 75 MPH 1176120H 21/1200Z 44.7N 32.1W 60 KT 70 MPH...POST-TROP/EXTRATROP 1177 1178$$ 1179FORECASTER KIMBERLAIN 1180 1181 1182WTNT44 KNHC 162036 1183TCDAT4 1184 1185TROPICAL STORM HUMBERTO DISCUSSION NUMBER 26 1186NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 1187500 PM AST MON SEP 16 2013 1188 1189THE DEEP CONVECTIVE CANOPY THAT WAS NEARLY COVERING THE CENTER 1190EARLIER HAS BEEN SHEARED EASTWARD WHILE THE CLOUD TOP TEMPERATURES 1191HAVE BEEN WARMING DURING THE PAST FEW HOURS. A FRAGMENT OF A BAND 1192LIES TO THE SOUTHEAST OF THE CENTER...BUT IT TOO IS BEING SUBJECTED 1193TO STRONG SHEAR OF ABOUT 30 KT ACCORDING TO SHIPS/UW-CIMSS 1194ANALYSES. NEVERTHELESS...A MORNING ASCAT PASS INDICATED AT LEAST 119540-KT WINDS ABOUT 60 N MI NORTH OF THE CENTER. DESPITE THE 1196DEGRADATION OF THE CLOUD PATTERN IN RECENT HOURS...THE INITIAL 1197INTENSITY IS RAISED TO 40 KT BASED ON THE ASCAT PASS. 1198 1199SEVERAL SMALLER-SCALE VORTICES HAVE BEEN ROTATING AROUND THE MEAN 1200CIRCULATION CENTER OF HUMBERTO TODAY...MAKING AN ESTIMATE OF THE 1201INITIAL MOTION MORE DIFFICULT THAN NORMAL. A LONG-TERM AVERAGE OF 1202FIXES SUGGESTS A MOTION OF 300/05. THE TRACK PHILOSOPHY IS NO 1203DIFFERENT THAN EARLIER. HUMBERTO IS FORECAST TO MOVE SLOWLY 1204NORTHWESTWARD AND THEN NORTH-NORTHWESTWARD FOR THE NEXT COUPLE OF 1205DAYS INTO A COL REGION IN BETWEEN A MID-LEVEL RIDGE OVER THE 1206NORTHEASTERN ATLANTIC AND A MID-LATITUDE SHORTWAVE TROUGH OVER 1207ATLANTIC CANADA. IN ABOUT TWO DAYS...THE CYCLONE SHOULD UNDERGO 1208RECURVATURE AND ACCELERATE WHEN THE AFOREMENTIONED TROUGH 1209APPROACHES FROM THE WEST. THE NEW NHC TRACK FORECAST CONTINUES TO 1210LIE CLOSE TO THE MULTI-MODEL CONSENSUS TVCA...IN BETWEEN THE 1211MORE-WESTERLY GFS AND THE MORE-EASTERLY ECMWF MODEL SOLUTIONS. 1212 1213THE SHEAR OVER HUMBERTO IS STILL FORECAST TO DECREASE SOME DURING 1214THE NEXT COUPLE OF DAYS AS A MID- TO UPPER-LEVEL TROUGH NORTHWEST 1215OF THE STORM SHIFTS EASTWARD. THE RELAXATION OF SHEAR AND WARMER 1216WATERS ALONG THE FORECAST TRACK SUGGEST AN OPPORTUNITY FOR SLOW 1217STRENGTHENING IN THE SHORT TERM. AFTER THAT TIME...THE INTERACTION 1218OF HUMBERTO WITH A SHORTWAVE TROUGH IN THE WESTERLIES SHOULD ALLOW 1219A FASTER RATE OF INTENSIFICATION UNTIL EXTRATROPICAL TRANSITION 1220OCCURS BETWEEN DAYS 4-5. THE NHC INTENSITY FORECAST IS A BLEND OF 1221THE HIGHER SHIPS OUTPUT AND THE LOWER INTENSITY CONSENSUS AIDS/LGEM 1222THROUGH 48 HOURS AND CLOSE TO A BLEND OF ALL THE GUIDANCE AT LATER 1223TIMES. 1224 1225FORECAST POSITIONS AND MAX WINDS 1226 1227INIT 16/2100Z 27.3N 43.5W 40 KT 45 MPH 1228 12H 17/0600Z 28.4N 44.0W 40 KT 45 MPH 1229 24H 17/1800Z 29.5N 44.9W 45 KT 50 MPH 1230 36H 18/0600Z 30.4N 45.4W 50 KT 60 MPH 1231 48H 18/1800Z 31.2N 45.6W 50 KT 60 MPH 1232 72H 19/1800Z 33.5N 44.3W 60 KT 70 MPH 1233 96H 20/1800Z 38.0N 40.0W 65 KT 75 MPH 1234120H 21/1800Z 47.0N 30.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 1235 1236$$ 1237FORECASTER KIMBERLAIN 1238 1239 1240WTNT44 KNHC 170234 1241TCDAT4 1242 1243TROPICAL STORM HUMBERTO DISCUSSION NUMBER 27 1244NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 12451100 PM AST MON SEP 16 2013 1246 1247HUMBERTO HAS WEAKENED A LITTLE THIS EVENING. THE LOW-LEVEL CENTER 1248HAS SEPARATED FROM THE DEEP CONVECTION AND IS NOW LOCATED ABOUT 60 1249NMI TO THE SOUTH-SOUTHWEST OF THE ASSOCIATED THUNDERSTORM 1250ACTIVITY. AN ASCAT PASS AROUND 0000 UTC SHOWED MAXIMUM WINDS OF 1251AROUND 25 KT...WHICH IS CONSIDERABLY LOWER THAN THE PREVIOUS PASS 1252FROM EARLIER TODAY. THE INITIAL WIND SPEED IS CONSERVATIVELY 1253LOWERED TO 35 KT...ASSUMING THAT STRONGER WINDS COULD BE OCCURRING 1254IN THE NORTHEASTERN QUADRANT...WHICH WAS NOT CAPTURED BY THE ASCAT 1255DATA. 1256 1257THE TROPICAL STORM HAS BEEN MEANDERING DURING THE PAST FEW HOURS AS 1258IT IS CURRENTLY ENTANGLED WITH A MID- TO UPPER-LEVEL LOW. THE 1259CYCLONE IS EXPECTED TO BEGIN MOVING NORTH-NORTHWESTWARD OVERNIGHT 1260OR EARLY TUESDAY...HOWEVER...AND THEN TURN NORTHWARD ON WEDNESDAY 1261WHEN IT MOVES ON THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE. 1262AFTER THAT TIME...A FASTER NORTHEASTWARD MOTION IS FORECAST WHEN 1263THE STORM BECOMES EMBEDDED IN THE STRONG SOUTHWESTERLY FLOW ON THE 1264EAST SIDE OF AN APPROACHING TROUGH. THE LATEST NHC TRACK FORECAST 1265REMAINS CLOSE TO THE MULTI-MODEL CONSENSUS TVCA. 1266 1267STRONG SHEAR AND DRY AIR...PARTIALLY ASSOCIATED WITH THE 1268AFOREMENTIONED UPPER-LEVEL LOW...ARE CURRENTLY AFFECTING HUMBERTO. 1269THIS UPPER-LEVEL FEATURE IS EXPECTED TO MOVE SOUTHEASTWARD AND 1270WEAKEN DURING THE NEXT COUPLE OF DAYS...CREATING A MORE FAVORABLE 1271ATMOSPHERIC PATTERN FOR HUMBERTO TO STRENGTHEN. THE NHC INTENSITY 1272FORECAST IS A LITTLE LOWER THAN THE PREVIOUS ONE TO ACCOUNT FOR THE 1273RECENT WEAKENING AND TO COME INTO BETTER AGREEMENT WITH THE 1274LATEST GUIDANCE. HUMBERTO IS FORECAST TO BECOME AN EXTRATROPICAL 1275CYCLONE OVER THE NORTHEASTERN ATLANTIC OCEAN IN 4 TO 5 DAYS. 1276 1277FORECAST POSITIONS AND MAX WINDS 1278 1279INIT 17/0300Z 27.0N 43.3W 35 KT 40 MPH 1280 12H 17/1200Z 28.0N 44.0W 35 KT 40 MPH 1281 24H 18/0000Z 29.0N 44.7W 35 KT 40 MPH 1282 36H 18/1200Z 30.0N 45.1W 40 KT 45 MPH 1283 48H 19/0000Z 30.9N 45.0W 45 KT 50 MPH 1284 72H 20/0000Z 33.7N 43.1W 50 KT 60 MPH 1285 96H 21/0000Z 40.0N 37.5W 60 KT 70 MPH 1286120H 22/0000Z 52.0N 26.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 1287 1288$$ 1289FORECASTER CANGIALOSI 1290 1291 1292WTNT44 KNHC 170846 1293TCDAT4 1294 1295TROPICAL STORM HUMBERTO DISCUSSION NUMBER 28 1296NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 1297500 AM AST TUE SEP 17 2013 1298 1299HUMBERTO CONTINUES TO GO THROUGH CYCLES OF HAVING DEEP CONVECTION 1300NEAR ITS CENTER TO BEING SHEARED WITH ALL THE CONVECTION DISPLACED 1301WELL TO THE NORTHEAST OF THE CENTER. AS OF RIGHT NOW...CONVECTION 1302HAS RE-DEVELOPED NEAR THE CENTER...AND THERE ARE SIGNS THAT THE 1303SHEAR MAY BE RELAXING. THE INITIAL INTENSITY IS HELD AT 35 KT FOR 1304THIS ADVISORY BASED ON A CURRENT INTENSITY ESTIMATE OF 2.5 FROM 1305TAFB AND EARLIER ASCAT DATA. THE LOWEST PRESSURE MEASURED BY A 1306DROPSONDE FROM A RECENT NASA GLOBAL HAWK MISSION WAS 1009 MB WITH A 1307SURFACE WIND OF 15 KT...INDICATING THAT THE MINIMUM PRESSURE IS 1308PROBABLY A LITTLE HIGHER THAN PREVIOUSLY ESTIMATED. 1309 1310THE WAXING AND WANING OF CONVECTION HAS CAUSED THE SURFACE CENTER TO 1311JUMP AND MEANDER FOR THE PAST 12 TO 24 HOURS. HOWEVER...IT APPEARS 1312THAT HUMBERTO IS NOW MOVING AGAIN...AND A LONGER-TERM AVERAGE 1313YIELDS AN ESTIMATED MOTION OF 020/4 KT. THE STORM IS LOCATED TO 1314THE SOUTHWEST OF A MID-LEVEL ANTICYCLONE CENTERED NEAR THE AZORES 1315AND TO THE SOUTHEAST OF A HIGH-AMPLITUDE MID-LATITUDE TROUGH MOVING 1316OFF THE EAST COAST OF NORTH AMERICA. THE RESULTANT STEERING FLOW 1317IS FORECAST TO PUSH HUMBERTO GENERALLY TO THE NORTH DURING THE NEXT 131848 HOURS OR SO...AND THEN THE CYCLONE WILL ACCELERATE TOWARD THE 1319NORTHEAST BEGINNING ON DAY 3 AS THE TROUGH GETS CLOSER. THE HWRF 1320IS THE MAIN OUTLIER IN THE GUIDANCE SUITE...SHOWING A MUCH SLOWER 1321MOTION AND A TRACK TO THE EAST BY DAY 5. THE REST OF THE TRACK 1322MODELS ARE IN REASONABLE AGREEMENT...AND THE OFFICIAL TRACK 1323FORECAST IS FASTER THAN THE MULTI-MODEL CONSENSUS TVCA TO DOWNPLAY 1324THE INFLUENCE OF THE HWRF SOLUTION. 1325 1326THE CIRCULATIONS OF HUMBERTO AND A NEARBY MID-/UPPER-LEVEL LOW 1327ARE BECOMING COLLOCATED...WHICH SHOULD ALLOW THE VERTICAL SHEAR NEAR 1328THE CYCLONE TO DECREASE DURING THE NEXT DAY OR SO. THEREFORE... 1329GRADUAL STRENGTHENING IS INDICATED IN THE OFFICIAL FORECAST DURING 1330THE NEXT SEVERAL DAYS...MORE OR LESS IN LINE WITH THE INTENSITY 1331CONSENSUS. HUMBERTO IS NOW FORECAST TO BECOME AN EXTRATROPICAL 1332CYCLONE BY DAY 4...AND EVEN THOUGH THE CYCLONE WILL BE MOVING OVER 1333MUCH COLDER WATER BY THAT TIME...BAROCLINIC INFLUENCES COULD ALLOW 1334STRENGTHENING TO CONTINUE A BIT LONGER. A 5-DAY POSITION IS STILL 1335SHOWN FOR CONTINUITY...BUT IT IS POSSIBLE THAT HUMBERTO COULD BE 1336ABSORBED BY ANOTHER LARGER EXTRATROPICAL CYCLONE BY THAT TIME. 1337 1338FORECAST POSITIONS AND MAX WINDS 1339 1340INIT 17/0900Z 27.8N 42.7W 35 KT 40 MPH 1341 12H 17/1800Z 28.9N 43.5W 35 KT 40 MPH 1342 24H 18/0600Z 29.8N 44.0W 35 KT 40 MPH 1343 36H 18/1800Z 30.7N 43.9W 40 KT 45 MPH 1344 48H 19/0600Z 31.9N 43.5W 40 KT 45 MPH 1345 72H 20/0600Z 35.5N 40.5W 45 KT 50 MPH 1346 96H 21/0600Z 45.0N 33.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 1347120H 22/0600Z 54.0N 26.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 1348 1349$$ 1350FORECASTER BERG 1351 1352 1353WTNT44 KNHC 171457 1354TCDAT4 1355 1356TROPICAL STORM HUMBERTO DISCUSSION NUMBER 29 1357NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 13581100 AM AST TUE SEP 17 2013 1359 1360HUMBERTO HAS BEEN WELL OBSERVED BY DROPSONDE DATA FROM THE NASA 1361GLOBAL HAWK AND ASCAT DATA...WHICH SHOW THAT THE STORM HAS 1362UNDERGONE AN INTERESTING EVOLUTION DURING THE PAST 12 HOURS...AND 1363IS ARGUABLY MORE SUBTROPICAL THAN TROPICAL. OVERNIGHT...THE SYSTEM 1364WAS CHARACTERIZED BY AN EXPOSED CIRCULATION WITH A LARGE RADIUS OF 1365MAXIMUM WIND...ABOUT 130 N MI. THE SURFACE CENTER OF CIRCULATION 1366BEING TRACKED OVERNIGHT DISSIPATED THIS MORNING AND A NEW CENTER 1367FORMED WELL TO THE NORTH...CLOSER TO THE DEEP CONVECTION BUT ALSO 1368DIRECTLY UNDERNEATH THE UPPER LOW. WITH THE UPPER LOW FORECAST TO 1369MOVE SOUTHEASTWARD AWAY FROM HUMBERTO WITHIN THE NEXT 12 TO 24 1370HOURS...HOWEVER...THIS VERTICAL STRUCTURE IS NOT EXPECTED TO 1371PERSIST. CONSEQUENTLY WE HAVE CHOSEN TO MAINTAIN THE TROPICAL 1372CLASSIFICATION FOR CONTINUITY AND TO MINIMIZE CONFUSION...AT LEAST 1373FOR NOW. 1374 1375THE ASCAT DATA INDICATE THAT THE CURRENT INTENSITY IS 40 KT. 1376THE VERTICAL SHEAR IS FORECAST TO REMAIN LOW TO MODERATE DURING THE 1377NEXT DAY OR SO. AFTER THAT TIME...THE SHEAR IS FORECAST TO BECOME 1378NORTHWESTERLY AND INCREASE SOME...THEN INCREASE FURTHER IN 3 TO 4 1379DAYS AS AN UPPER-LEVEL TROUGH APPROACHES THE SYSTEM FROM THE WEST. 1380AS A RESULT...ONLY SLIGHTLY STRENGTHENING IS PREDICTED DURING THE 1381NEXT FEW DAYS. LATER IN THE PERIOD...SOME ADDITIONAL 1382INTENSIFICATION IS POSSIBLE DUE TO BAROCLINIC PROCESSES. 1383 1384BECAUSE OF THE CENTER REFORMATION...A CONFIDENT INITIAL MOTION IS 1385IMPOSSIBLE TO DETERMINE. THE DYNAMICAL MODEL GUIDANCE SUGGESTS 1386THAT HUMBERTO WILL MOVE NORTHWESTWARD AS IT MOVES AWAY FROM THE 1387UPPER LOW. IN 24 TO 36 HOURS...HUMBERTO SHOULD TURN 1388NORTHWARD...THEN BEGIN TO ACCELERATE NORTHEASTWARD IN ABOUT 48 1389HOURS AHEAD OF THE AFOREMENTIONED MID-LATITUDE TROUGH. SOME OF THE 1390GLOBAL MODELS SHOW THAT HUMBERTO COULD BECOME AN OPEN TROUGH IN 1391ABOUT 72 HOURS...WITH A SEPARATE EXTRATROPICAL DEVELOPMENT 1392OCCURRING ALONG A FRONT OVER THE EASTERN ATLANTIC TO THE NORTH OF 1393HUMBERTO. FOR NOW...THE NHC FORECAST WILL KEEP CONTINUITY WITH THE 1394PREVIOUS ADVISORIES BY INDICATING THAT HUMBERTO WILL BECOME THE 1395MAIN EXTRATROPICAL LOW OVER THE NORTH ATLANTIC IN 4 TO 5 DAYS. 1396 1397FORECAST POSITIONS AND MAX WINDS 1398 1399INIT 17/1500Z 29.4N 42.5W 40 KT 45 MPH 1400 12H 18/0000Z 29.7N 43.2W 40 KT 45 MPH 1401 24H 18/1200Z 30.6N 43.5W 45 KT 50 MPH 1402 36H 19/0000Z 31.6N 43.3W 45 KT 50 MPH 1403 48H 19/1200Z 33.0N 42.9W 45 KT 50 MPH 1404 72H 20/1200Z 36.7N 39.5W 45 KT 50 MPH 1405 96H 21/1200Z 47.5N 30.5W 55 KT 65 MPH...POST-TROP/EXTRATROP 1406120H 22/1200Z 60.0N 22.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 1407 1408$$ 1409FORECASTER BROWN 1410 1411 1412WTNT44 KNHC 172032 1413TCDAT4 1414 1415TROPICAL STORM HUMBERTO DISCUSSION NUMBER 30 1416NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 1417500 PM AST TUE SEP 17 2013 1418 1419HUMBERTO HAS NOT CHANGED MUCH SINCE THIS MORNING...AND IT STILL HAS 1420SOME CHARACTERISTICS OF A SUBTROPICAL CYCLONE. THE ASSOCIATED DEEP 1421CONVECTION IS ORGANIZED INTO A BROKEN BAND THAT EXTENDS ABOUT 1422THREE-QUARTERS OF THE WAY AROUND THE CENTER. THE INITIAL WIND SPEED 1423IS HELD AT 40 KT...WHICH IS A LITTLE HIGHER THAN THE DVORAK 1424CLASSIFICATIONS. 1425 1426THE STORM IS LOCATED DIRECTLY BENEATH AN UPPER-LEVEL LOW...WHICH HAS 1427ALLOWED THE SHEAR TO RELAX A LITTLE. THIS UPPER-LEVEL SYSTEM IS 1428EXPECTED TO WEAKEN AND SHIFT EASTWARD DURING THE NEXT DAY OR TWO... 1429AND HUMBERTO COULD LOSE SOME OF THE SUBTROPICAL CHARACTERISTICS 1430WHILE THAT OCCURS. REGARDLESS...THE ATMOSPHERIC AND OCEANIC 1431ENVIRONMENTS FAVOR SLIGHT STRENGTHENING DURING THE NEXT COUPLE OF 1432DAYS...AND THE NHC INTENSITY FORECAST IS NUDGED UPWARD FROM THE 1433PREVIOUS ONE...BUT IT LIES ON THE LOW SIDE OF THE GUIDANCE. 1434HUMBERTO IS FORECAST TO BECOME EXTRATROPICAL IN 3 TO 4 DAYS... 1435ALTHOUGH THERE IS SOME GUIDANCE THAT SHOWS THE CYCLONE DEGENERATING 1436INTO A TROUGH BEFORE THAT OCCURS. 1437 1438HUMBERTO HAS BEEN MOVING NORTHWARD AT ABOUT 10 KT FOR THE PAST FEW 1439HOURS. A SLOWER NORTH-NORTHWESTWARD TO NORTHWARD MOTION IS FORECAST 1440DURING THE NEXT DAY OR SO. AFTER THAT TIME...THE SYSTEM IS EXPECTED 1441TO ACCELERATE NORTHEASTWARD WHEN IT BECOMES EMBEDDDED IN THE 1442STRONGER FLOW TO THE EAST OF AN APPROACHING DEEP-LAYER TROUGH. THE 1443NHC TRACK FORECAST IS NEAR THE MIDDLE OF THE GUIDANCE ENVELOPE. 1444 1445FORECAST POSITIONS AND MAX WINDS 1446 1447INIT 17/2100Z 30.3N 42.8W 40 KT 45 MPH 1448 12H 18/0600Z 30.9N 43.3W 45 KT 50 MPH 1449 24H 18/1800Z 32.0N 43.4W 45 KT 50 MPH 1450 36H 19/0600Z 33.3N 43.2W 50 KT 60 MPH 1451 48H 19/1800Z 35.0N 42.1W 50 KT 60 MPH 1452 72H 20/1800Z 40.7N 37.2W 55 KT 65 MPH 1453 96H 21/1800Z 51.5N 27.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 1454120H 22/1800Z...DISSIPATED 1455 1456$$ 1457FORECASTER CANGIALOSI 1458 1459 1460WTNT44 KNHC 180248 1461TCDAT4 1462 1463TROPICAL STORM HUMBERTO DISCUSSION NUMBER 31 1464NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 14651100 PM AST TUE SEP 17 2013 1466 1467THE TROPICAL STORM IS NOT WELL ORGANIZED THIS EVENING. ONLY SOME 1468FRAGMENTED BANDS ARE ON THE EASTERN SIDE OF THE ELONGATED 1469CIRCULATION...WITH THE CENTER ON THE SOUTHWESTERN SIDE OF THE 1470CONVECTION. AN ASCAT PASS SHOWED A SMALL AREA OF 30-35 KT WINDS... 1471AND 35 KT IS USED AS THE INITIAL INTENSITY. SOME INCREASE IN 1472STRENGTH IS POSSIBLE WHILE THE SHEAR REMAINS LOW AND HUMBERTO 1473REMAINS OVER MARGINAL SSTS DURING THE NEXT COUPLE OF DAYS. SHIPS/ 1474LGEM ARE HIGHER THAN MOST OF THE GUIDANCE AND SHOW HUMBERTO CLOSE 1475TO A HURRICANE AGAIN...ALTHOUGH THE CURRENT AND FORECAST SSTS FROM 1476SHIPS SEEM TOO HIGH COMPARED WITH AVAILABLE OBSERVATIONS. THUS... 1477THE OFFICIAL FORECAST STILL REMAINS ON THE CONSERVATIVE SIDE... 1478CLOSE TO A BLEND OF THE PREVIOUS FORECAST AND THE INTENSITY 1479CONSENSUS. 1480 1481THE INITIAL MOTION HAS BEEN CHALLENGING TO DETERMINE SINCE THE 1482CIRCULATION IS NOT VERY COMPACT...BUT IS ESTIMATED AT 345/6. A 1483TROUGH OVER THE WESTERN ATLANTIC OCEAN SHOULD TURN HUMBERTO TO THE 1484NORTH THEN NORTHEAST OVER THE NEXT COUPLE OF DAYS WITH A 1485SIGNIFICANT INCREASE IN FORWARD SPEED IN THE 48-72H PERIOD. MOST OF 1486THE GLOBAL MODELS SHOW THIS SYSTEM BECOMING EXTRATROPICAL IN ABOUT 14873 DAYS...AND ABSORBED WITHIN A LARGER MID-LATITUDE LOW IN 4-5 DAYS. 1488THE GUIDANCE IS VERY TIGHTLY PACKED AND NO SIGNIFICANT CHANGES WERE 1489MADE TO THE PREVIOUS NHC FORECAST. 1490 1491 1492FORECAST POSITIONS AND MAX WINDS 1493 1494INIT 18/0300Z 30.8N 43.3W 35 KT 40 MPH 1495 12H 18/1200Z 31.6N 43.4W 35 KT 40 MPH 1496 24H 19/0000Z 32.8N 43.4W 40 KT 45 MPH 1497 36H 19/1200Z 34.3N 42.7W 40 KT 45 MPH 1498 48H 20/0000Z 36.3N 41.2W 45 KT 50 MPH 1499 72H 21/0000Z 43.0N 35.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 1500 96H 22/0000Z 54.5N 24.5W 45 KT 50 MPH...POST-TROP/EXTRATROP 1501120H 23/0000Z...ABSORBED 1502 1503$$ 1504FORECASTER BLAKE 1505 1506 1507WTNT44 KNHC 180837 1508TCDAT4 1509 1510TROPICAL STORM HUMBERTO DISCUSSION NUMBER 32 1511NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 1512500 AM AST WED SEP 18 2013 1513 1514IF I JUST WENT BY THE LATEST SATELLITE INTENSITY ESTIMATES...I WOULD 1515PROBABLY DOWNGRADE HUMBERTO TO A TROPICAL DEPRESSION. HOWEVER... 1516TROPICAL CLASSIFICATIONS MIGHT NOT BE PURELY APPLICABLE IN THIS 1517CASE...AND I WOULD RATHER WAIT UNTIL WE RECEIVE ADDITIONAL 1518SUPPORTING DATA BEFORE DECREASING THE INITIAL INTENSITY. AN 1519ARGUMENT COULD ALSO BE MADE THAT MORE DISTINCT BANDING FEATURES 1520HAVE BEGUN TO FORM ON THE EASTERN SIDE OF THE CIRCULATION DURING 1521THE PAST COUPLE OF HOURS...AND IN SOME SENSE HUMBERTO LOOKS A 1522LITTLE MORE ORGANIZED NOW THAN IT DID LAST EVENING. 1523 1524THE LOW-LEVEL CENTER HAS BEEN INCREDIBLY DIFFICULT TO LOCATE... 1525PARTIALLY BECAUSE CLOUDS ASSOCIATED A NEARBY UPPER-LEVEL LOW HAVE 1526BEEN MASKING THE LOW CLOUD MOTIONS. THE BEST ESTIMATE OF THE 1527INITIAL MOTION IS 335/7 KT...BUT HUMBERTO IS FORECAST TO TURN 1528NORTHWARD VERY SOON BETWEEN HIGH PRESSURE NEAR THE AZORES AND A 1529DEEP-LAYER TROUGH MOVING ACROSS THE WESTERN ATLANTIC. THE STORM 1530SHOULD START FEELING THE EFFECTS OF FASTER MID-LATITUDE FLOW IN A 1531DAY OR TWO...AND WILL ACCELERATE NORTH-NORTHEASTWARD TOWARD THE 1532NORTH ATLANTIC BY 48 HOURS. THE SPREAD AMONG THE TRACK GUIDANCE IS 1533FAIRLY NARROW...AND NO MAJOR CHANGES TO THE OFFICIAL TRACK FORECAST 1534WERE REQUIRED ON THIS CYCLE. 1535 1536HUMBERTO WILL BE MOVING INTO A MORE DIFFLUENT UPPER-LEVEL REGIME IN 1537ABOUT 24 HOURS...AND THE VERTICAL SHEAR SHOULD BE LOW ENOUGH TO AT 1538LEAST ALLOW THE CYCLONE TO MAINTAIN ITS INTENSITY. EVEN THOUGH THE 1539SHEAR IS FORECAST TO INCREASE SIGNIFICANTLY AFTER 48 HOURS...SOME 1540STRENGTHENING IS STILL POSSIBLE DUE TO BAROCLINIC INFLUENCES. WITH 1541THE EXCEPTION OF THE GFS...THE GLOBAL MODELS INDICATE THAT HUMBERTO 1542COULD BE ABSORBED BY AN EXTRATROPICAL LOW BY DAY 4...AND THAT IS 1543NOW INDICATED IN THE OFFICIAL FORECAST. 1544 1545FORECAST POSITIONS AND MAX WINDS 1546 1547INIT 18/0900Z 31.4N 43.7W 35 KT 40 MPH 1548 12H 18/1800Z 32.2N 43.6W 35 KT 40 MPH 1549 24H 19/0600Z 33.6N 43.5W 40 KT 45 MPH 1550 36H 19/1800Z 35.1N 42.7W 40 KT 45 MPH 1551 48H 20/0600Z 37.1N 41.1W 45 KT 50 MPH 1552 72H 21/0600Z 45.0N 33.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 1553 96H 22/0600Z...ABSORBED 1554 1555$$ 1556FORECASTER BERG 1557 1558 1559WTNT44 KNHC 181436 1560TCDAT4 1561 1562TROPICAL STORM HUMBERTO DISCUSSION NUMBER 33 1563NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 15641100 AM AST WED SEP 18 2013 1565 1566HUMBERRTO APPEARS DISORGANIZED IN SATELLITE IMAGERY THIS MORNING. 1567THE MOST CONCENTRATED CONVECTION IS IN BANDS LOCATED ABOUT 150 N MI 1568EAST OF THE CENTER...WITH ONLY WIDELY SCATTERED CONVECTIVE CELLS 1569NEAR THE CENTER. IN ADDITION...THE LOW-LEVEL CIRCULATION IS 1570BECOMING ELONGATED FROM NORTH-NORTHWEST TO SOUTH-SOUTHEAST. WATER 1571VAPOR AND AIRMASS IMAGERY SUGGESTS THE LOW-LEVEL CENTER IS STILL 1572CLOSE TO AN UPPER-LEVEL LOW...WHICH MAY BE HINDERING THE CENTRAL 1573CONVECTION. WHILE DVORAK SATELLITE ESTIMATES ARE BELOW TROPICAL 1574STORM STRENGTH...AMSU-BASED INTENSITY ESTIMATES DURING THE NIGHT 1575SUGGEST THE CYCLONE IS STILL A TROPICAL STORM. THE INITIAL 1576INTENSITY IS THUS HELD...PERHAPS GENEROUSLY..AT 35 KT. 1577 1578VISIBLE IMAGERY HAS MADE IT EASIER TO FIND THE CENTER...WHICH IS A 1579LITTLE FARTHER SOUTH THAN PREVIOUSLY ESTIMATED. THE INITIAL MOTION 1580IS NOW 335/4. HUMBERTO IS EXPECTED TO TURN NORTHWARD DURING THE 1581NEXT 12 HOURS OR SO...FOLLOWED BY AN ACCELERATION TOWARD THE 1582NORTH-NORTHEAST AS THE CYCLONE ENTERS THE WESTERLIES. THE SPREAD 1583OF THE TRACK MODEL GUIDANCE REMAINS FAIRLY NARROW...AND THE NEW 1584TRACK FORECAST IS SIMILAR TO THE PREVIOUS FORECAST. 1585 1586THERE IS STILL TIME FOR HUMBERTO TO STRENGTHEN SOME AS IT MOVES INTO 1587A MORE FAVORABLE UPPER-LEVEL WIND ENVIRONMENT NORTH OF THE 1588UPPER-LEVEL LOW. HOWEVER...BY 48 HOURS THE CYCLONE SHOULD UNDERGO 1589EXTRATROPICAL TRANSITION AS IT MERGES WITH A FRONTAL SYSTEM. THE 1590NEW INTENSITY FORECAST IS THE SAME AS THE PREVIOUS FORECAST... 1591CALLING FOR HUMBERTO TO BE A STORM-FORCE EXTRATROPICAL LOW BY 72 1592HOURS...AND THEN BE ABSORBED INTO ANOTHER LOW OVER THE NORTHEASTERN 1593ATLANTIC. AN ALTERNATIVE SCENARIO...FAVORED BY THE GFS...ECMWF... 1594AND CANADIAN MODELS...IS THAT LITTLE STRENGTHENING OCCURS AND THAT 1595HUMBERTO DEGENERATES TO A TROUGH AS IT ENOUCNTERS THE FRONTAL 1596SYSTEM. 1597 1598 1599FORECAST POSITIONS AND MAX WINDS 1600 1601INIT 18/1500Z 31.3N 43.8W 35 KT 40 MPH 1602 12H 19/0000Z 32.3N 43.8W 35 KT 40 MPH 1603 24H 19/1200Z 33.8N 43.4W 40 KT 45 MPH 1604 36H 20/0000Z 36.1N 42.1W 40 KT 45 MPH 1605 48H 20/1200Z 38.7N 40.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 1606 72H 21/1200Z 51.0N 27.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 1607 96H 22/1200Z...ABSORBED 1608 1609$$ 1610FORECASTER BEVEN 1611 1612 1613WTNT44 KNHC 182038 1614TCDAT4 1615 1616TROPICAL STORM HUMBERTO DISCUSSION NUMBER 34 1617NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 1618500 PM AST WED SEP 18 2013 1619 1620CONVECTION HAS INCREASED A LITTLE NEAR THE CENTER OF HUMBERTO... 1621MAINLY IN SKELETAL BANDS IN THE NORTHEASTERN SEMICIRCLE. WATER 1622VAPOR AND AIRMASS IMAGERY SHOWS THAT THE LOW-LEVEL CENTER IS STILL 1623IN CLOSE PROXIMITY TO AN UPPER-LEVEL LOW...AND THIS MAY BE SLOWING 1624THE DEVELOPMENT OF THE CENTRAL CONVECTION. RECENT OSCAT DATA 1625SHOWED A FEW 30-35 KT WIND VECTORS ABOUT 150 N MI FROM THE CENTER 1626IN THE EASTERN SEMICIRCLE. IN ADDITION...RECENT AMSU INTENSITY 1627ESTIMATES FROM CIRA AND CIMSS ARE 37 KT AND 32 KT RESPECTIVELY. 1628BASED ON THESE DATA...THE INITIAL INTENSITY REMAINS A POSSIBLY 1629GENEROUS 35 KT. 1630 1631HUMBERTO HAS MADE ITS EXPECTED NORTHWARD TURN WITH THE INITIAL 1632MOTION NOW 355/5. THE SYSTEM IS EXPECTED TO CONTINUE NORTHWARD 1633DURING THE NEXT 12 HOURS OR SO...FOLLOWED BY AN ACCELERATION TOWARD 1634THE NORTH-NORTHEAST AS THE CYCLONE ENTERS THE WESTERLIES. THE 1635TRACK MODEL GUIDANCE REMAINS TIGHTLY CLUSTERED...AND THE NEW TRACK 1636FORECAST IS AGAIN SIMILAR TO THE PREVIOUS FORECAST. 1637 1638THERE IS STILL TIME FOR HUMBERTO TO STRENGTHEN SOME AS IT MOVES INTO 1639A MORE FAVORABLE UPPER-LEVEL WIND ENVIRONMENT NORTH OF THE 1640UPPER-LEVEL LOW. THE CYCLONE SHOULD APPROACH A FRONTAL ZONE IN 164136-48 HOURS. HOWEVER...THE MODELS ARE IN POOR AGREEMENT ON WHETHER 1642HUMBERTO WILL UNDERGO EXTRATROPICAL TRANSITION...OR WHETHER IT WILL 1643DEGENERATE TO A TROUGH AS ANOTHER LOW BECOMES THE PREDOMINANT 1644SYSTEM. THE INTENSITY FORECAST FOLLOWS THE PREVIOUS FORECAST IN 1645CALLING FOR HUMBERTO TO BECOME EXTRATROPICAL IN 48 HOURS. THAT 1646BEING SAID...REGARDLESS OF THE EXACT EVOLUTION THERE IS LIKELY TO 1647BE A STORM-FORCE EXTRATROPICAL LOW NEAR THE 72 HOUR POINT. 1648 1649 1650FORECAST POSITIONS AND MAX WINDS 1651 1652INIT 18/2100Z 31.8N 43.7W 35 KT 40 MPH 1653 12H 19/0600Z 33.0N 43.6W 35 KT 40 MPH 1654 24H 19/1800Z 34.9N 42.9W 40 KT 45 MPH 1655 36H 20/0600Z 37.4N 41.0W 40 KT 45 MPH 1656 48H 20/1800Z 41.6N 37.1W 45 KT 50 MPH...POST-TROP/EXTRATROP 1657 72H 21/1800Z 54.0N 23.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 1658 96H 22/1800Z...ABSORBED BY EXTRATROPICAL LOW 1659 1660$$ 1661FORECASTER BEVEN 1662 1663 1664WTNT44 KNHC 190254 1665TCDAT4 1666 1667TROPICAL DEPRESSION HUMBERTO DISCUSSION NUMBER 35 1668NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 16691100 PM AST WED SEP 18 2013 1670 1671HUMBERTO IS LOSING ORGANIZATION THIS EVENING. SHORTWAVE-IR IMAGERY 1672INDICATES THAT THE LOW-LEVEL CIRCULATION HAS BECOME STRETCHED FROM 1673THE NORTHWEST TO SOUTHEAST...WITH LITTLE CONVECTION REMAINING. THE 1674INITIAL INTENSITY IS LOWERED TO 30 KT IN AGREEMENT WITH THE LATEST 1675TAFB SATELLITE ESTIMATE. WHILE THE CYCLONE STILL HAS SOME TIME 1676OVER MARGINAL SSTS AND IN LIGHT/MODERATE SHEAR...THE POOR INITIAL 1677STRUCTURE WILL LIKELY PREVENT HUMBERTO FROM SIGNIFICANT 1678STRENGTHENING IN THE SHORT TERM. AFTER 24H...THE SYSTEM SHOULD 1679ACCELERATE TO THE NORTHEAST...AND MOST OF THE GUIDANCE SHOW SOME 1680INCREASE IN STRENGTH DURING EXTRATROPICAL TRANSITION. AFTER 1681ACCOUNTING FOR THE WEAKER INITIAL WINDS...THE LATEST NHC FORECAST 1682IS BASICALLY AN UPDATE OF THE PREVIOUS ONE. 1683 1684SINCE THE CIRCULATION HAS BECOME ELONGATED...THE INITIAL MOTION 1685ESTIMATE IS A VERY UNCERTAIN 010/8. GUIDANCE REMAINS IN GOOD 1686AGREEMENT ON HUMBERTO TURNING TO THE NORTHEAST AND ACCELERATING 1687AHEAD OF A MID-LATITUDE TROUGH. THE OFFICIAL FORECAST IS NUDGED A 1688LITTLE TO THE EAST CLOSER TO THE MODEL CONSENSUS. GLOBAL MODELS 1689SUGGEST THE CYCLONE WILL DISSIPATE OR BE ABSORBED WITHIN A LARGER 1690EXTRATROPICAL LOW BY 72H. THE NHC PREDICTION WILL GO ALONG WITH 1691THE ABSORBED SCENARIO...THOUGH IT WOULD NOT BE SURPRISING IF 1692HUMBERTO OPENED UP INTO A TROUGH BEFORE THAT TIME. 1693 1694FORECAST POSITIONS AND MAX WINDS 1695 1696INIT 19/0300Z 32.5N 43.4W 30 KT 35 MPH 1697 12H 19/1200Z 33.7N 43.0W 30 KT 35 MPH 1698 24H 20/0000Z 35.7N 41.6W 30 KT 35 MPH 1699 36H 20/1200Z 38.6N 38.8W 35 KT 40 MPH 1700 48H 21/0000Z 43.0N 34.5W 45 KT 50 MPH...POST-TROP/EXTRATROP 1701 72H 22/0000Z...ABSORBED 1702 1703$$ 1704FORECASTER BLAKE 1705 1706 1707WTNT44 KNHC 190834 1708TCDAT4 1709 1710TROPICAL DEPRESSION HUMBERTO DISCUSSION NUMBER 36 1711NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 1712500 AM AST THU SEP 19 2013 1713 1714DEEP CONVECTION ASSOCIATED WITH HUMBERTO IS LIMITED TO A CLUSTER OF 1715CELLS LOCATED 100-200 N MI SOUTHEAST OF THE CENTER. THE CYCLONE IS 1716MAINTAINED AS A 30-KT TROPICAL DEPRESSION FOR THIS ADVISORY...BUT 1717IT COULD BE CLOSE TO BECOMING POST-TROPICAL. THE GLOBAL MODELS 1718HAVE ALL TRENDED TOWARDS SHOWING THE SURFACE WIND FIELD OF HUMBERTO 1719OPENING UP INTO A TROUGH IN 12 TO 24 HOURS...AND IT IS POSSIBLE 1720THAT THE DEPRESSION COULD DISSIPATE EARLIER THAN WE HAVE BEEN 1721INDICATING. FOR THE SAKE OF CONTINUITY...THE OFFICIAL FORECAST 1722SHOWS POINTS OUT TO 36 HOURS. IF IT DOES LAST THAT LONG...HUMBERTO 1723SHOULD ULTIMATELY BE ABSORBED BY A FRONTAL ZONE BY 48 HOURS. 1724 1725A MORE WELL-DEFINED SURFACE CENTER HAS FORMED...BUT THAT NOW PUTS 1726HUMBERTO ABOUT A DEGREE WEST OF THE PREVIOUS ESTIMATES. 1727REGARDLESS...THE DEPRESSION IS STILL MOVING GENERALLY NORTHWARD 1728AROUND 7 KT. AN APPROACHING COLD FRONT FROM THE WEST IS EXPECTED 1729TO CAUSE HUMBERTO TO TURN NORTHEASTWARD AND ACCELERATE WITHIN 24 1730HOURS AND THEN MAINTAIN THAT HEADING UNTIL IT IS ABSORBED. THE NHC 1731TRACK FORECAST IS JUST A LITTLE WEST OF THE PREVIOUS ONE DURING THE 1732FIRST 24 HOURS TO ACCOUNT FOR THE ADJUSTED INITIAL POSITION...BUT 1733OTHERWISE THERE ARE NO SIGNIFICANT CHANGES. 1734 1735FORECAST POSITIONS AND MAX WINDS 1736 1737INIT 19/0900Z 33.0N 44.3W 30 KT 35 MPH 1738 12H 19/1800Z 34.5N 43.6W 30 KT 35 MPH 1739 24H 20/0600Z 36.3N 41.4W 30 KT 35 MPH 1740 36H 20/1800Z 38.6N 38.4W 35 KT 40 MPH...POST-TROPICAL 1741 48H 21/0600Z...ABSORBED BY A FRONT 1742 1743$$ 1744FORECASTER BERG 1745 1746 1747WTNT44 KNHC 191441 1748TCDAT4 1749 1750TROPICAL DEPRESSION HUMBERTO DISCUSSION NUMBER 37 1751NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 17521100 AM AST THU SEP 19 2013 1753 1754DEEP CONVECTION ASSOCIATED WITH HUMBERTO IS SPUTTERING THIS MORNING 1755AND BARELY MEETS THE CRITERION NEEDED FOR MAINTAINING THE SYSTEM AS 1756A TROPICAL CYCLONE. WHILE THE SEA SURFACE TEMPERATURES AND 1757ATMOSPHERIC STABILITY ARE CONDUCIVE FOR CONVECTION...DRY CONDITIONS 1758AND STRONG NORTHERLY VERTICAL SHEAR ARE LIKELY TO LEAD TOWARD THE 1759SYSTEM BECOMING A REMNANT LOW BY 24 HOURS...IF NOT SOONER. 1760ADDITIONALLY...ALL OF THE GLOBAL AND MESOSCALE MODEL GUIDANCE 1761INDICATE THAT THE SYSTEM SHOULD BE ABSORBED BY THE APPROACHING 1762LARGE EXTRATROPICAL CYCLONE TO THE WEST OF HUMBERTO IN ABOUT A DAY. 1763THE INTENSITY FORECAST MAINTAINS HUMBERTO AS A 30 KT CYCLONE UNTIL 1764DISSIPATION...AS INDICATED BY THE DYNAMICAL GUIDANCE. 1765 1766THE EXPOSED LOW-LEVEL CENTER OF HUMBERTO HAS BEEN MOVING EASTWARD 1767OVER THE LAST FEW HOURS WITH A LONGER TERM MOTION ESTIMATED AT 25 1768DEGREES AT 5 KT. HUMBERTO SHOULD ACCELERATE NORTHEASTWARD AS IT 1769GETS SWEPT UP IN THE WARM SECTOR OF THE APPROACHING EXTRATROPICAL 1770CYCLONE BEFORE DISSIPATION. THE TRACK FORECAST IS SIMILAR TO THE 1771ONE IN THE PREVIOUS ADVISORY AND BASED UPON THE MULTI-MODEL TRACK 1772ENSEMBLE. 1773 1774 1775FORECAST POSITIONS AND MAX WINDS 1776 1777INIT 19/1500Z 32.8N 43.3W 30 KT 35 MPH 1778 12H 20/0000Z 34.2N 42.2W 30 KT 35 MPH 1779 24H 20/1200Z 36.8N 39.8W 30 KT 35 MPH 1780 36H 21/0000Z...DISSIPATED 1781 1782$$ 1783FORECASTER LANDSEA 1784 1785 1786