1WTNT42 KNHC 130248 2TCDAT2 3TROPICAL STORM JULIA DISCUSSION NUMBER 3 4NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 51100 PM AST SUN SEP 12 2010 6 7INFRARED AND MICROWAVE SATELLITE IMAGERY SHOW THAT THE CENTER OF 8THE CYCLONE IS LOCATED NEAR THE EASTERN EDGE OF A CURVED BAND OF 9CONVECTION THAT WRAPS AROUND THE WESTERN SEMICIRCLE OF THE SYSTEM. 10SUBJECTIVE DVORAK INTENSITY ESTIMATES ARE 35 KT FROM TAFB AND 30 KT 11FROM SAB. OBJECTIVE DVORAK ESTIMATES FROM UW/CIMMS ARE SLIGHTLY 12HIGHER. A BLEND OF THESE ESTIMATES SUPPORT AN UPGRADE OF THE 13DEPRESSION TO A 35-KT TROPICAL STORM...THE TENTH OF THE 2010 14ATLANTIC HURRICANE SEASON. 15 16THE EASTERLY SHEAR IS EXPECTED TO WEAKEN DURING THE NEXT 12 HOURS 17AND IS FORECAST TO REMAIN LIGHT OVER THE NEXT COUPLE OF DAYS. 18DURING THAT TIME JULIA WILL BE TRAVERSING WARM WATER AND AS A 19RESULT...STEADY STRENGTHENING IS ANTICIPATED. THE SHIPS...LGEM... 20AND GFDL MODELS ALL BRING JULIA TO HURRICANE STATUS WITHIN TWO DAYS 21AND THE NHC FORECAST IS IN GOOD AGREEMENT. THEREAFTER...JULIA WILL 22BE MOVING OVER SLIGHTLY COOLER SEA SURFACE TEMPERATURES AND INTO AN 23AREA OF INCREASING SOUTHWESTERLY SHEAR TO THE EAST OF AN 24UPPER-LEVEL LOW/TROUGH BETWEEN 30W AND 40W. IT IS A BIT SURPRISING 25GIVEN THESE NEGATIVE FACTORS THAT THE INTENSITY GUIDANCE SHOWS 26LITTLE...IF ANY...WEAKENING. BECAUSE OF THAT...THE OFFICIAL 27FORECAST WILL KEEP JULIA AT 65 KT AT DAYS 3-5 FOR NOW. 28 29THE CENTER OF JULIA WAS RELOCATED A LITTLE EAST OF THE PREVIOUS 30ADVISORY POSITION BASED ON THE EARLIER MICROWAVE DATA. THE INITIAL 31MOTION ESTIMATE IS 285/10. THE TRACK FORECAST REASONING REMAINS 32THE SAME AS THE PREVIOUS ADVISORY. JULIA IS FORECAST TO MOVE 33WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN SIDE OF A MID-LEVEL 34RIDGE THAT EXTENDS FROM AFRICA WESTWARD INTO THE EASTERN ATLANTIC. 35IN A COUPLE OF DAYS...THE CYCLONE IS FORECAST TO TURN NORTHWESTWARD 36TOWARD A WEAKNESS IN THE RIDGE. MOST OF THE GUIDANCE INDICATES A 37TURN BACK TOWARD THE WEST-NORTHWEST LATE IN THE PERIOD AS JULIA 38MOVES AROUND THE NORTH SIDE OF AN UPPER-LEVEL LOW THAT CUTS OFF 39NEAR 40W. THE OFFICIAL FORECAST TRACK IS GOOD AGREEMENT WITH THE 40PREVIOUS ADVISORY AND A BLEND OF THE LATEST RUNS OF THE GFS... 41UKMET...GFDL...HWRF...AND ECMWF MODELS. 42 43FORECAST POSITIONS AND MAX WINDS 44 45INITIAL 13/0300Z 13.5N 23.5W 35 KT 46 12HR VT 13/1200Z 14.0N 25.3W 45 KT 47 24HR VT 14/0000Z 14.9N 27.6W 50 KT 48 36HR VT 14/1200Z 15.9N 29.5W 55 KT 49 48HR VT 15/0000Z 17.1N 31.1W 65 KT 50 72HR VT 16/0000Z 20.9N 35.1W 65 KT 51 96HR VT 17/0000Z 24.5N 41.0W 65 KT 52120HR VT 18/0000Z 27.5N 46.5W 65 KT 53 54$$ 55FORECASTER BROWN 56 57 58WTNT42 KNHC 130837 59TCDAT2 60TROPICAL STORM JULIA DISCUSSION NUMBER 4 61NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 62500 AM AST MON SEP 13 2010 63 64THERE HAS NOT BEEN MUCH CHANGE TO THE OVERALL ORGANIZATION OF THE 65CLOUD PATTERN OF JULIA. MOST OF THE BANDING FEATURES ARE OVER THE 66WESTERN SEMICIRCLE OF THE CIRCULATION WITH PERHAPS A SLIGHT 67INCREASE IN DEEP CONVECTION NEAR THE CENTER. DVORAK INTENSITY 68ESTIMATES FROM BOTH SAB AND TAFB ARE 35 KT...SO THE WIND SPEED IS 69UNCHANGED FROM THE PREVIOUS ADVISORY. VERTICAL SHEAR IS EXPECTED 70TO BE WEAK FOR THE NEXT DAY OR TWO AS JULIA MOVES AWAY FROM AN AREA 71OF STRONG UPPER-LEVEL EASTERLIES ASSOCIATED WITH A RIDGE OVER WEST 72AFRICA. LATER IN THE FORECAST PERIOD THE TROPICAL CYCLONE COULD 73EXPERIENCE A SIGNIFICANT INCREASE IN SHEAR DUE TO THE INFLUENCE OF 74AN UPPER-LEVEL TROUGH OVER THE EASTERN SUBTROPICAL ATLANTIC...WHICH 75WOULD LIMIT INTENSIFICATION. THERE IS THE POSSIBILITY THAT A 76CYCLONE WILL CUT OFF FROM THE TROUGH AND BECOME SITUATED TO THE 77SOUTH OR SOUTHWEST OF JULIA. THIS SCENARIO COULD RESULT IN LESS 78SHEAR AND ALLOW MORE STRENGTHENING NEAR THE END OF THE PERIOD. 79HOWEVER...THE GFS INPUT TO THE SHIPS AND LGEM MODELS SHOWS 25 TO 35 80KT OF SHEAR AT 96-120 HOURS. GIVEN THE UNCERTAINTIES THE OFFICIAL 81FORECAST...LIKE THE PREVIOUS ONE...SHOWS NO CHANGE IN STRENGTH 82BEYOND 48 HOURS. THIS IS CLOSE TO THE INTENSITY MODEL CONSENSUS 83THROUGH 48 HOURS AND IS SIMILAR TO THE LGEM GUIDANCE FOR DAYS 3 TO 845. 85 86LATEST CENTER FIXES ARE A BIT TO THE NORTH OF THE PREVIOUS TRACK. 87THIS MAY BE THE RESULT OF SOME REFORMATION OR MERELY BECAUSE THE 88CENTER HAS BEEN DIFFICULT TO LOCATE. AFTER SOME ADJUSTMENTS...THE 89INITIAL MOTION IS ESTIMATED TO BE 300/11. NOTWITHSTANDING THE 90SLIGHT NORTHWARD ADJUSTMENT...THE TRACK FORECAST REASONING REMAINS 91ESSENTIALLY THE SAME AS IN THE PREVIOUS ADVISORY. JULIA IS EXPECTED 92TO MOVE WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN SIDE OF A 93MID-LEVEL RIDGE THAT EXTENDS FROM AFRICA WESTWARD INTO THE EASTERN 94ATLANTIC. IN ABOUT 48 HOURS...A WEAKNESS IN THE RIDGE SHOULD CAUSE 95THE TROPICAL CYCLONE TO TURN NORTHWESTWARD. THERE IS A FAIR AMOUNT 96OF SPREAD IN THE MODEL FORECAST TRACKS FOR DAYS 3 TO 5....AND THE 97OFFICIAL FORECAST IS BASICALLY DOWN THE MIDDLE OF THE SUITE. THIS 98IS CLOSE TO BUT A TAD SLOWER THAN THE MODEL CONSENSUS DURING THE 99LATTER HALF OF THE FORECAST PERIOD...AND ALSO A LITTLE NORTH OF THE 100PREVIOUS NHC FORECAST TRACK DUE TO THE NORTHWARD RELOCATION. 101 102FORECAST POSITIONS AND MAX WINDS 103 104INITIAL 13/0900Z 14.4N 24.6W 35 KT 105 12HR VT 13/1800Z 15.1N 26.2W 45 KT 106 24HR VT 14/0600Z 16.2N 28.2W 50 KT 107 36HR VT 14/1800Z 17.5N 30.1W 55 KT 108 48HR VT 15/0600Z 19.0N 31.9W 65 KT 109 72HR VT 16/0600Z 22.5N 36.0W 65 KT 110 96HR VT 17/0600Z 25.5N 41.0W 65 KT 111120HR VT 18/0600Z 28.5N 46.5W 65 KT 112 113$$ 114FORECASTER PASCH 115 116 117WTNT42 KNHC 131453 118TCDAT2 119TROPICAL STORM JULIA DISCUSSION NUMBER 5 120NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1211100 AM AST MON SEP 13 2010 122 123METEOSAT-9 IMAGERY AND A 0938 UTC SSMIS MICROWAVE OVERPASS INDICATE 124LITTLE CHANGE IN THE CLOUD PATTERN DURING THE PAST 6 HOURS. THE 125MAJORITY OF THE CONVECTIVE BANDING IS SITUATED OVER THE WESTERN 126PORTION OF THE CYCLONE...WHERE THE UPPER-LEVEL OUTFLOW IS THE MOST 127IMPRESSIVE. DVORAK TECHNIQUE INTENSITY ESTIMATES FROM BOTH TAFB 128AND SAB ARE T2.5...35 KT...AND THIS IS THE INITIAL INTENSITY. 129 130THE DYNAMICAL MODELS AND THE SHIPS MODEL SUGGEST THAT THE 131UPPER-LEVEL WIND PATTERN SHOULD REMAIN CONDUCIVE FOR STRENGTHENING 132DURING THE NEXT 48 HOURS. BEYOND THAT TIME...JULIA COULD BE 133IMPACTED BY A SUBSTANTIAL INCREASE IN WESTERLY SHEAR DUE TO AN 134AMPLIFYING UPPER-LEVEL TROUGH OVER THE EASTERN SUBTROPICAL 135ATLANTIC...WHICH SHOULD HINDER FURTHER INTENSIFICATION. THE NHC 136INTENSITY FORECAST REFLECTS THIS SCENARIO BY MAINTAINING JULIA AS A 137LOW-END HURRICANE THROUGH 96 HOURS. AFTERWARD...THE SHIPS... 138LGEM...AND THE LARGE-SCALE MODELS ALL SUGGEST THAT THE UPPER-LEVEL 139OUTFLOW ASSOCIATED WITH HURRICANE IGOR WILL CREATE MODERATE TO 140STRONG NORTHEASTERLY SHEAR OVER JULIA. THIS INCREASE IN SHEAR 141AROUND DAY 5 IS REFLECTED IN THE OFFICIAL FORECAST...WHICH SHOWS 142JULIA WEAKENING INTO A TROPICAL STORM. 143 144BASED ON A NUMBER OF MICROWAVE FIXES...THE INITIAL MOTION IS 145ESTIMATED TO BE WEST-NORTHWESTWARD...295/12...A LITTLE LEFT OF THE 146PREVIOUS ADVISORY. THE DYNAMICAL MODELS ARE IN GOOD AGREEMENT 147THROUGH DAY 5 WITH A NORTHWESTWARD TURN IN 36 HOURS IN RESPONSE TO 148A MID- TO UPPER-LEVEL CUT-OFF LOW LOCATED TO THE NORTHWEST OF 149JULIA. BEYOND THIS TIME...THE EASTERN EXTENT OF THE SUBTROPICAL 150RIDGE GRADUALLY BUILDS NORTHEAST OF THE CYCLONE AS THE CUT-OFF LOW 151WEAKENS AND DISSIPATES. THIS SHOULD ALLOW JULIA TO MAINTAIN A 152GENERAL NORTHWESTWARD MOTION THROUGH DAY 5. THE OFFICIAL FORECAST 153FAVORS THE TVCN MULTI-MODEL CONSENSUS AND LIES BETWEEN THE GFS AND 154ECMWF GLOBAL MODELS. 155 156FORECAST POSITIONS AND MAX WINDS 157 158INITIAL 13/1500Z 14.9N 26.1W 35 KT 159 12HR VT 14/0000Z 15.6N 27.6W 45 KT 160 24HR VT 14/1200Z 16.7N 29.6W 55 KT 161 36HR VT 15/0000Z 18.1N 31.4W 60 KT 162 48HR VT 15/1200Z 19.6N 33.2W 65 KT 163 72HR VT 16/1200Z 22.8N 37.7W 65 KT 164 96HR VT 17/1200Z 25.5N 43.0W 65 KT 165120HR VT 18/1200Z 28.5N 47.5W 60 KT 166 167$$ 168FORECASTER ROBERTS/BRENNAN 169 170 171WTNT42 KNHC 132039 172TCDAT2 173TROPICAL STORM JULIA DISCUSSION NUMBER 6 174NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 175500 PM AST MON SEP 13 2010 176 177SATELLITE IMAGERY SHOWS THAT JULIA HAS BECOME BETTER ORGANIZED THIS 178AFTERNOON...AS THE EASTERLY SHEAR APPEARS TO HAVE DIMINISHED A BIT. 179BANDING CONTINUES TO IMPROVE OVER THE WESTERN SEMICIRCLE AND A 180SMALL IRREGULAR CENTRAL DENSE OVERCAST FEATURE IS DEVELOPING OVER 181THE CENTER. THE INITIAL INTENSITY OF 45 KT IS BASED ON A BLEND OF 182DVORAK ESTIMATES OF 35 AND 45 KT FROM TAFB AND SAB...RESPECTIVELY 183...AND A UW-CIMSS ADT ESTIMATE OF 53 KT USING THE SHEAR PATTERN. 184 185THE LARGE-SCALE MODELS...THE LGEM...AND THE SHIPS MODEL CONTINUE TO 186SHOW AN UPPER-LEVEL WIND ENVIRONMENT CONDUCIVE FOR STRENGTHENING 187DURING THE NEXT 36 TO 48 HOURS. AFTER THAT TIME...THE CYCLONE 188SHOULD FEEL THE AFFECTS OF INCREASING WESTERLY SHEAR DUE TO AN 189AMPLIFYING MID- TO UPPER-LEVEL TROUGH OVER THE EASTERN SUBTROPICAL 190ATLANTIC...WHICH SHOULD CURTAIL FURTHER INTENSIFICATION. THE NHC 191INTENSITY FORECAST CALLS FOR JULIA TO BECOME A HURRICANE IN 24 192HOURS AND THEN BASICALLY MAINTAIN THIS INTENSITY THROUGH DAY 4. 193AFTERWARD...THE DYNAMICAL MODELS ALL SUGGEST THAT THE UPPER-LEVEL 194OUTFLOW ASSOCIATED WITH LARGER HURRICANE IGOR WILL PRODUCE MODERATE 195TO STRONG NORTHEASTERLY SHEAR OVER JULIA. THIS INCREASE IN SHEAR 196IS REFLECTED IN THE NHC FORECAST...WHICH SHOWS JULIA WEAKENING 197TO A TROPICAL STORM AT DAY 5. 198 199THE INITIAL MOTION IS BASICALLY THE SAME AS THE PREVIOUS ADVISORY 200AND IS ESTIMATED TO BE WEST-NORTHWESTWARD...OR 295/12. THE GFS... 201GFS ENSEMBLE MEAN...HWRF...AND THE GFDL ARE NOW INDICATING MORE 202OF A NORTHWESTWARD MOTION DURING THE 24 TO 36 HOUR PERIOD DUE TO A 203DEVELOPING MID- TO UPPER-LEVEL CUT-OFF LOW LOCATED NORTH-NORTHWEST 204OF JULIA. HOWEVER...THE NOGAPS...ECMWF...AND UKMET SHOW A 205CONTINUED WEST-NORTHWESTWARD TRACK...WHICH APPEARS TO BE DUE TO A 206SHALLOWER VERTICAL STRUCTURE OF THE CYCLONE. THROUGH THE REMAINDER 207OF THE FORECAST PERIOD...THE EASTERN EXTENT OF THE SUBTROPICAL 208RIDGE GRADUALLY BUILDS NORTHEAST OF THE JULIA AS THE AFOREMENTIONED 209CUT-OFF LOW WEAKENS AND DISSIPATES. THIS SHOULD ALLOW JULIA TO 210MAINTAIN A GENERAL NORTHWESTWARD MOTION. THE OFFICIAL FORECAST IS 211BASED ON THE TVCN CONSENSUS MODEL AND IS WEIGHTED MORE TOWARD THE 212MODELS THAT INDICATE A TURN TOWARD THE NORTHWEST AROUND 36 HOURS. 213 214FORECAST POSITIONS AND MAX WINDS 215 216INITIAL 13/2100Z 15.3N 27.5W 45 KT 217 12HR VT 14/0600Z 16.0N 29.0W 50 KT 218 24HR VT 14/1800Z 17.3N 30.8W 65 KT 219 36HR VT 15/0600Z 18.8N 32.4W 65 KT 220 48HR VT 15/1800Z 20.5N 34.4W 70 KT 221 72HR VT 16/1800Z 23.8N 39.7W 70 KT 222 96HR VT 17/1800Z 27.0N 46.0W 65 KT 223120HR VT 18/1800Z 30.0N 49.5W 55 KT 224 225$$ 226FORECASTER ROBERTS/BRENNAN 227 228 229WTNT42 KNHC 140255 230TCDAT2 231TROPICAL STORM JULIA DISCUSSION NUMBER 7 232NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 2331100 PM AST MON SEP 13 2010 234 235A RECENT AMSU MICROWAVE PASS SHOWS IMPROVED BANDING OVER THE WESTERN 236SEMICIRCLE AND THAT THE DEEP CONVECTION IS NOW WRAPPING AROUND THE 237SOUTHERN PORTION OF THE CIRCULATION. DESPITE THE IMPROVED 238PRESENTATION...DVORAK ESTIMATES FROM SAB AND TAFB REMAIN 45 KT...SO 239THE INITIAL INTENSITY IS MAINTAINED FOR NOW. THIS IS ALSO 240SUPPORTED BY A 2324 UTC ASCAT PASS THAT SHOWED SEVERAL 35-40 KT 241WIND VECTORS OVER THE NORTHEAST QUADRANT. 242 243THE INITIAL MOTION ESTIMATE IS 295/11 KT. JULIA IS FORECAST TO TURN 244NORTHWESTWARD IN ABOUT 12-24 HOURS AS IT MOVES BETWEEN THE WESTERN 245PERIPHERY OF A MID-LEVEL RIDGE AND AN AMPLIFYING MID- TO 246UPPER-LEVEL TROUGH OVER THE EASTERN ATLANTIC. THEREAFTER JULIA IS 247EXPECTED TO MOVE IN A DIRECTION BETWEEN WEST-NORTHWEST AND NORTHWEST 248AS A MID-LEVEL RIDGE STRENGTHS TO THE NORTH AND NORTHEAST OF THE 249CYCLONE. THE TRACK GUIDANCE IS IN GENERAL AGREEMENT ON THIS 250SCENARIO...BUT THERE IS SOME SIGNIFICANT SPREAD ON WHEN THE 251NORTHWESTWARD TURN WILL OCCUR. THE GFS/GFDL ARE ALONG THE EASTERN 252EDGE OF THE GUIDANCE...WHILE THE UKMET AND NOGAPS ARE ALONG THE 253WESTERN SIDE. THE OFFICIAL FORECAST LIES BETWEEN THE TVCN 254CONSENSUS AND THE GFS/GFDL SOLUTIONS...AND IS CLOSE TO THE PREVIOUS 255NHC ADVISORY. 256 257JULIA WILL BE OVER WARM WATER AND IN A LOW SHEAR ENVIRONMENT DURING 258THE NEXT DAY OR SO. THE SHIPS/LGEM GUIDANCE BRING THE CYCLONE TO 259HURRICANE STRENGTH WITHIN THAT TIME AND SO DOES THE OFFICIAL 260FORECAST. THEREAFTER...INCREASING SOUTHWESTERLY SHEAR AND SLIGHTLY 261COOLER SEA SURFACE TEMPERATURES ARE LIKELY TO HALT ANY ADDITIONAL 262INTENSIFICATION. AFTER 72 HOURS...THE GLOBAL MODELS SUGGEST THAT 263STRONG UPPER-LEVEL NORTHEASTERLY WINDS ASSOCIATED WITH THE OUTFLOW 264FROM IGOR WILL BEGIN TO IMPINGE UPON JULIA. AS A RESULT... 265WEAKENING IS ANTICIPATED AT DAYS 4 AND 5. 266 267THE WIND RADII WERE ADJUSTED OUTWARD BASED ON THE ASCAT DATA. 268 269 270FORECAST POSITIONS AND MAX WINDS 271 272INITIAL 14/0300Z 15.6N 28.0W 45 KT 273 12HR VT 14/1200Z 16.3N 29.4W 55 KT 274 24HR VT 15/0000Z 17.5N 31.1W 65 KT 275 36HR VT 15/1200Z 19.1N 32.7W 70 KT 276 48HR VT 16/0000Z 21.1N 35.1W 70 KT 277 72HR VT 17/0000Z 24.3N 40.9W 65 KT 278 96HR VT 18/0000Z 27.5N 46.5W 55 KT 279120HR VT 19/0000Z 31.5N 50.0W 50 KT 280 281$$ 282FORECASTER BROWN 283 284 285WTNT42 KNHC 140837 286TCDAT2 287HURRICANE JULIA DISCUSSION NUMBER 8 288NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 289500 AM AST TUE SEP 14 2010 290 291JULIA HAS STRENGTHENED THIS MORNING. A RAGGED EYE FEATURE HAS 292OCCASIONALLY BEEN EVIDENT IN GEOSTATIONARY SATELLITE IMAGES DURING 293THE PAST FEW HOURS AND THE CONVECTIVE BANDING HAS BECOME BETTER 294ORGANIZED...ESPECIALLY OVER THE SOUTHERN SEMICIRCLE. DVORAK 295CLASSIFICATIONS FROM TAFB AND SAB WERE 65 KT...AND THE CIMSS ADT 296ESTIMATES ARE ALSO NEAR THAT VALUE. ON THIS BASIS...JULIA IS 297UPGRADED TO A HURRICANE WITH THE INITIAL WIND SPEED SET AT 65 KT. 298 299SOME ADDITIONAL STRENGTHENING APPEARS LIKELY DURING THE NEXT DAY OR 300SO AS UNANIMOUSLY SHOWN BY THE MODEL GUIDANCE. HOWEVER...SEA 301SURFACE TEMPERATURES COOL BELOW 27 C ALONG THE FORECAST TRACK IN 24 302TO 48 HOURS...AND THAT SHOULD LIMIT INTENSIFICATION DURING THAT 303TIME PERIOD. ALTHOUGH JULIA IS EXPECTED TO TRACK OVER WARMER 304WATERS BEYOND A FEW DAYS...STRONG NORTH TO NORTHEASTERLY SHEAR... 305ASSOCIATED WITH THE OUTFLOW OF HURRICANE IGOR...SHOULD INDUCE 306WEAKENING BY THAT TIME. THE OFFICIAL FORECAST IS ADJUSTED UPWARD 307DURING THE FIRST FEW DAYS AND THEN FALLS IN LINE WITH THE PREVIOUS 308FORECAST BY THE END OF THE PERIOD...AND IS IN GOOD AGREEMENT WITH 309THE STATISTICAL-DYNAMICAL GUIDANCE. 310 311THE INITIAL MOTION ESTIMATE IS 295/10. A MID- TO UPPER-LEVEL TROUGH 312OVER THE EASTERN ATLANTIC IS EXPECTED TO CAUSE JULIA TO TURN 313NORTHWESTWARD LATER TODAY AND CONTINUE IN THAT DIRECTION FOR THE 314NEXT 24 TO 48 HOURS. THEREAFTER...THE GLOBAL MODELS ARE IN 315AGREEMENT IN SHOWING A SUBTROPICAL RIDGE TO STRENGTHEN NORTH OF 316JULIA. THIS PATTERN SHOULD CAUSE THE CYCLONE TO TURN BACK TO THE 317WEST-NORTHWEST FOR A COUPLE OF DAYS. BY THE END OF THE FORECAST 318PERIOD...JULIA IS EXPECTED TO MOVE NORTHWESTWARD OR 319NORTH-NORTHWESTWARD ALONG THE WESTERN PERIPHERY OF THE RIDGE. THE 320OFFICIAL FORECAST IS ADJUSTED SLIGHTLY TO THE WEST IN THE 3 TO 5 321DAY RANGE...TRENDING TOWARD THE MULTI-MODEL CONSENSUS. 322 323FORECAST POSITIONS AND MAX WINDS 324 325INITIAL 14/0900Z 16.1N 29.0W 65 KT 326 12HR VT 14/1800Z 16.8N 30.1W 70 KT 327 24HR VT 15/0600Z 18.1N 31.7W 80 KT 328 36HR VT 15/1800Z 19.7N 33.6W 80 KT 329 48HR VT 16/0600Z 21.5N 36.1W 75 KT 330 72HR VT 17/0600Z 24.5N 42.5W 70 KT 331 96HR VT 18/0600Z 27.5N 48.5W 60 KT 332120HR VT 19/0600Z 32.0N 51.0W 50 KT 333 334$$ 335FORECASTER CANGIALOSI 336 337 338WTNT42 KNHC 141444 339TCDAT2 340HURRICANE JULIA DISCUSSION NUMBER 9 341NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 3421100 AM AST TUE SEP 14 2010 343 344SATELLITE IMAGES INDICATE THAT JULIA IS STILL STRENGTHENING. A 0920 345UTC SSM/IS OVERPASS SHOWED A WELL-DEFINED EYEWALL SURROUNDED BY TWO 346PROMINENT BANDS...WHILE CONVENTIONAL IMAGERY SHOWS THE APPEARANCE 347OF A WELL-DEVELOPED CENTRAL DENSE OVERCAST AND A BANDING-TYPE EYE. 348SUBJECTIVE DVORAK T-NUMBERS AT 1200 UTC ARE 4.0 AND 5.0 FROM TAFB 349AND SAB...RESPECTIVELY. THE INITIAL INTENSITY IS RAISED TO 75 350KT...BASED UPON A BLEND OF THESE ESTIMATES. 351 352WHILE SOME ADDITIONAL INTENSIFICATION IS POSSIBLE DURING THE NEXT 12 353TO 24 HOURS...WATER VAPOR IMAGERY SHOWS A MID- TO UPPER-LEVEL 354TROUGH...PARTIALLY RELATED TO THE OUTFLOW OF HURRICANE IGOR... 355LOCATED A FEW HUNDRED MILES NORTHWEST OF JULIA. GLOBAL MODELS 356SUGGEST THAT THIS FEATURE SHOULD BEGIN TO IMPART WESTERLY SHEAR 357OVER THE CYCLONE AFTER ABOUT 24 HOURS...AT ABOUT THE TIME JULIA 358BEGINS TO PASS OVER MARGINAL SEA SURFACE TEMPERATURES. WATERS 359SHOULD BEGIN TO WARM AGAIN ALONG THE FORECAST TRACK IN A FEW 360DAYS...BUT MODEL GUIDANCE SHOWS A STRONG SURGE OF NORTHERLY FLOW 361ASSOCIATED THE OUTFLOW OF IGOR THAT COULD NEGATIVELY IMPACT JULIA 362AFTER 72 HOURS. IN FACT...SHIPS MODEL OUTPUT INDICATES THE 363POTENTIAL FOR 30-40 KT OF NORTHERLY SHEAR. ALTHOUGH NO SIGNIFICANT 364CHANGES WERE MADE TO THE OFFICIAL INTENSITY FORECAST...JULIA 365COULD BE WEAKER THAN FORECAST IF THE PREDICTED SHEAR MATERIALIZES. 366 367THE INITIAL MOTION ESTIMATE IS 295/09...INDICATING THAT JULIA HAS 368RECENTLY SLOWED A BIT. THERE IS AN UNUSUAL AMOUNT OF SPREAD IN THE 369SHORT-TERM TRACK FORECAST. THE GFS/HWRF/GFDL SHOW JULIA TURNING 370TOWARD THE NORTHWEST DURING THE NEXT DAY OR SO AS IT INTERACTS WITH 371AN EXTENSION OF A MID- TO UPPER-LEVEL CYCLONE LOCATED OVER THE 372NORTHEAST ATLANTIC. THE UKMET/ECMWF FAVOR A WEST-NORTHWEST COURSE 373AS A RESULT OF MORE SUBTROPICAL RIDGING. FROM ABOUT 36-72 HR... 374THERE IS BETTER AGREEMENT IN THE MODEL GUIDANCE OF SUBTROPICAL 375RIDGING BUILDING NORTH OF JULIA AND HENCE A MORE WEST-NORTHWESTERLY 376COURSE WITH AN INCREASE IN FORWARD SPEED. AFTER 72 HR...GLOBAL 377MODELS SHOW JULIA TURNING NORTH-NORTHWESTWARD AS IT APPROACHES THE 378WESTERN END OF THE SUBTROPICAL RIDGE AND THE LARGE HURRICANE IGOR 379OVER THE CENTRAL ATLANTIC. THE OFFICIAL NHC FORECAST TRACK IS 380NUDGED A BIT TO THE RIGHT...LYING NEAR A CONSENSUS THAT EXCLUDES 381THE UKMET. 382 383 384FORECAST POSITIONS AND MAX WINDS 385 386INITIAL 14/1500Z 16.2N 29.5W 75 KT 387 12HR VT 15/0000Z 17.2N 30.8W 85 KT 388 24HR VT 15/1200Z 18.7N 32.4W 80 KT 389 36HR VT 16/0000Z 20.3N 34.5W 75 KT 390 48HR VT 16/1200Z 22.2N 37.7W 70 KT 391 72HR VT 17/1200Z 24.7N 44.3W 70 KT 392 96HR VT 18/1200Z 28.0N 49.0W 60 KT 393120HR VT 19/1200Z 32.5N 50.5W 50 KT 394 395$$ 396FORECASTER KIMBERLAIN 397 398 399WTNT42 KNHC 142036 400TCDAT2 401HURRICANE JULIA DISCUSSION NUMBER 10 402NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 403500 PM AST TUE SEP 14 2010 404 405THE CLOUD PATTERN ASSOCIATED WITH JULIA HAS BECOME SOMEWHAT 406ASYMMETRIC DURING THE PAST SEVERAL HOURS...WITH A LARGE MASS OF 407DEEP CONVECTION HAVING FORMED SOUTHWEST OF THE CENTER. THE 408EYE THAT WAS VISIBLE EARLIER IS ALSO NO LONGER AS EVIDENT. THE 409OUTFLOW HAS BECOME A BIT RESTRICTED TO THE WEST...INDICATIVE OF 410SOME UPPER-LEVEL WESTERLY FLOW ALREADY IMPINGING UPON THE CYCLONE. 411DVORAK CI NUMBERS AT 1800 UTC ARE UNCHANGED FROM 1200 UTC...WHILE 412THE 3-HOURLY AVERAGED ADT VALUE IS AT 4.6. THE INITIAL INTENSITY IS 413HELD AT 75 KT FOR THIS ADVISORY IN AGREEMENT WITH SATELLITE 414ESTIMATES. 415 416RECENT FIXES INDICATE THAT JULIA HAS SLOWED A BIT FURTHER...AND THE 417INITIAL MOTION ESTIMATE IS 295/08. WITH THE EXCEPTION OF THE 418UKMET...THE TRACK MODEL GUIDANCE IS IN BETTER AGREEMENT THIS CYCLE 419CONCERNING THE SHORT-TERM TRACK FORECAST. JULIA IS EXPECTED TO 420MOVE ON A GENERAL NORTHWESTERLY COURSE DURING THE NEXT 24 HOURS AS 421IT INTERACTS WITH A MID- TO UPPER-LEVEL TROUGH EXTENDING 422SOUTHWESTWARD FROM A CYCLONE OVER THE NORTHEAST ATLANTIC. 423FROM 24-72 HOURS...GLOBAL MODELS INDICATE THAT JULIA SHOULD TURN 424WEST-NORTHWESTWARD WITH SOME INCREASE IN FORWARD SPEED UNDER THE 425INFLUENCE OF A BUILDING SUBTROPICAL RIDGE TO THE NORTH. BEYOND THAT 426TIME...JULIA IS FORECAST TO TURN NORTH-NORTHWESTWARD AND THEN 427NORTHWARD ONCE IT REACHES THE WESTERN PERIPHERY OF THE SUBTROPICAL 428RIDGE. THE OFFICIAL NHC TRACK FORECAST IS NUDGED TO THE RIGHT AGAIN 429USING A MODEL CONSENSUS THAT EXCLUDES THE UKMET BUT HAS SHIFTED A 430BIT TO THE LEFT LATE IN THE PERIOD...FOLLOWING THE TREND IN THE 431GUIDANCE. 432 433WATER VAPOR IMAGERY SUGGESTS THAT WESTERLY SHEAR ASSOCIATED WITH A 434MID- TO UPPER-LEVEL TROUGH...PARTIALLY RELATED TO THE OUTFLOW OF 435HURRICANE IGOR...MAY ALREADY BE NEGATIVELY IMPACTING JULIA. SHIPS 436MODEL OUTPUT INDICATES SOME INCREASE IN THIS SHEAR DURING THE NEXT 437COUPLE OF DAYS AT THE SAME TIME JULIA TRAVERSES MARGINAL SEA 438SURFACE TEMPERATURES. ALTHOUGH THE CYCLONE IS FORECAST TO MOVE 439OVER WARMER WATERS AGAIN LATER IN THE FORECAST PERIOD...GLOBAL 440MODELS SHOW A STRONG SURGE OF NORTHERLY FLOW ASSOCIATED WITH THE 441OUTFLOW FROM HURRICANE IGOR ADVERSELY AFFECTING JULIA. ALTHOUGH 442FEW CHANGES WERE MADE TO THE OFFICIAL NHC INTENSITY FORECAST... 443JULIA COULD BE WEAKER THAN FORECAST IF THE PREDICTED SHEAR 444MATERIALIZES. 445 446 447FORECAST POSITIONS AND MAX WINDS 448 449INITIAL 14/2100Z 16.7N 30.2W 75 KT 450 12HR VT 15/0600Z 17.8N 31.4W 80 KT 451 24HR VT 15/1800Z 19.5N 33.1W 80 KT 452 36HR VT 16/0600Z 21.3N 35.7W 75 KT 453 48HR VT 16/1800Z 22.8N 39.1W 70 KT 454 72HR VT 17/1800Z 25.0N 46.0W 70 KT 455 96HR VT 18/1800Z 29.1N 50.5W 60 KT 456120HR VT 19/1800Z 33.0N 51.0W 50 KT 457 458$$ 459FORECASTER KIMBERLAIN 460 461 462WTNT42 KNHC 150237 463TCDAT2 464HURRICANE JULIA DISCUSSION NUMBER 11 465NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 4661100 PM AST TUE SEP 14 2010 467 468JULIA HAS AGAIN DEVELOPED A SMALL EYE...AND INTENSE DEEP CONVECTION 469HAS BEEN WRAPPING AROUND THAT FEATURE OVER THE PAST FEW HOURS. 470DVORAK CURRENT INTENSITY ESTIMATES ARE A UNANIMOUS 5.0 FROM TAFB... 471SAB...AND THE OBJECTIVE ADT...SO THE INITIAL INTENSITY IS RAISED TO 47290 KT. MICROWAVE IMAGES INDICATE THAT JULIA HAS A WELL-DEFINED 473CENTER ALTHOUGH THE SATELLITE PRESENTATION IS NOW A LITTLE 474ELONGATED AND OUTFLOW IS RESTRICTED OVER THE WESTERN SIDE OF THE 475HURRICANE...LIKELY DUE TO SHEAR PRODUCED BY AN UPPER-LEVEL TROUGH 476TO ITS NORTHWEST. EVEN THOUGH THE SHEAR IS ALREADY PRESENT...IT 477MAY NOT BE STRONG ENOUGH YET TO LIMIT INTENSIFICATION...AND THE 478OFFICIAL FORECAST INDICATES VERY LITTLE CHANGE IN INTENSITY FOR THE 479NEXT 24-36 HOURS. THIS FOLLOWS THE TREND SHOWN IN THE STATISTICAL 480GUIDANCE. AFTER 36 HOURS...VERTICAL SHEAR IS EXPECTED TO INCREASE 481DRASTICALLY AS JULIA MOVES AROUND THE NORTHERN EDGE OF A MID- TO 482UPPER-LEVEL LOW...AND THEN BEGINS TO FEEL THE INFLUENCE OF 483UPPER-LEVEL OUTFLOW FROM HURRICANE IGOR. THE OFFICIAL FORECAST IS 484JUST A LITTLE HIGHER THAN THE PREVIOUS ONE DUE TO THE RECENT 485INTENSIFICATION...AND IT STILL SHOWS WEAKENING TO A TROPICAL STORM 486BY DAY 5. 487 488THE INITIAL POSITION HAS BEEN ADJUSTED A LITTLE TO THE SOUTH BASED 489ON RECENT MICROWAVE IMAGERY...BUT THE MOTION IS STILL ESTIMATED AT 490295/8. JULIA IS EXPECTED TO TURN TO THE NORTHWEST SHORTLY...BUT IT 491SHOULD TURN BACK TO THE WEST-NORTHWEST WITHIN 36 HOURS AS IT GETS 492STEERED BETWEEN THE NORTHERN EDGE OF THE UPPER LOW AND A BLOCKING 493RIDGE TO THE NORTH. BY DAY 4...JULIA WILL HAVE REACHED THE 494SOUTHWESTERN PERIPHERY OF THE RIDGE AND THE SOUTHERLY FLOW TO THE 495EAST OF IGOR...AND IT SHOULD TURN SHARPLY NORTHWEST THEN TO THE 496NORTH BY DAY 5. THE TRACK GUIDANCE IS TIGHTLY-CLUSTERED THROUGH 497DAY 4 BUT THEN WIDENS ON DAY 5 WITH THE ECMWF TAKING A MORE 498WESTERLY COURSE. THE OFFICIAL FORECAST IS LOCATED JUST TO THE WEST 499OF THE CONSENSUS TVCN ON DAY 5 OUT OF RESPECT FOR THE ECMWF. 500 501FORECAST POSITIONS AND MAX WINDS 502 503INITIAL 15/0300Z 16.7N 30.9W 90 KT 504 12HR VT 15/1200Z 17.8N 32.1W 95 KT 505 24HR VT 16/0000Z 19.4N 34.2W 90 KT 506 36HR VT 16/1200Z 21.0N 37.3W 85 KT 507 48HR VT 17/0000Z 22.4N 40.8W 80 KT 508 72HR VT 18/0000Z 25.0N 47.0W 75 KT 509 96HR VT 19/0000Z 29.0N 51.0W 65 KT 510120HR VT 20/0000Z 33.0N 51.0W 50 KT 511 512$$ 513FORECASTER BERG 514 515 516WTNT42 KNHC 150532 517TCDAT2 518HURRICANE JULIA SPECIAL DISCUSSION NUMBER 12 519NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 5201230 AM AST WED SEP 15 2010 521 522ENHANCED INFRARED SATELLITE IMAGES INDICATE THAT JULIA HAS RAPIDLY 523STRENGTHENED DURING THE LAST FEW HOURS WITH THE EYE NOW MORE 524DISTINCT AND CIRCULAR AND THE LARGER CIRCULATION LESS ELONGATED 525THAN IT WAS EARLIER. CLOUD TOPS COLDER THAN -75 C NOW SURROUND THE 526EYE. A SPECIAL CLASSIFICATION FROM TAFB GAVE A DVORAK T-NUMBER OF 5276.0 OR 115 KT AND OBJECTIVE DVORAK ESTIMATES FROM UW-CIMSS ARE 528CLOSER TO 100 OR 105 KT. BASED ON THESE ESTIMATES...THE NEW 529INITIAL INTENSITY IS SET AT 110 KT. SINCE THE ENVIRONMENT HAS 530OBVIOUSLY BECOME MORE FAVORABLE FOR STRENGTHENING...AT LEAST IN THE 531SHORT TERM...THE OFFICIAL INTENSITY FORECAST HAS BEEN ADJUSTED 532UPWARD FOR THE FIRST COUPLE OF DAYS TO ACCOUNT FOR THESE CHANGES. 533 534FORECAST POSITIONS AND MAX WINDS 535 536INITIAL 15/0530Z 16.9N 31.3W 110 KT 537 12HR VT 15/1200Z 17.8N 32.1W 120 KT 538 24HR VT 16/0000Z 19.4N 34.2W 120 KT 539 36HR VT 16/1200Z 21.0N 37.3W 110 KT 540 48HR VT 17/0000Z 22.4N 40.8W 90 KT 541 72HR VT 18/0000Z 25.0N 47.0W 75 KT 542 96HR VT 19/0000Z 29.0N 51.0W 65 KT 543120HR VT 20/0000Z 33.0N 51.0W 50 KT 544 545$$ 546FORECASTER CANGIALOSI/PASCH 547 548 549WTNT42 KNHC 150859 550TCDAT2 551HURRICANE JULIA DISCUSSION NUMBER 13 552NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 553500 AM AST WED SEP 15 2010 554 555A RAPID STRENGTHENING EPISODE WAS NOTED A FEW HOURS AGO. THIS WAS 556MOSTLY UNEXPECTED...AND REMINDS US OF OUR LIMITED UNDERSTANDING OF 557TROPICAL CYCLONE INTENSITY CHANGE. JULIA IS STILL STRENGTHENING... 558BUT AT A SIGNIFICANTLY SLOWER RATE THAN WAS OBSERVED LAST EVENING 559AND EARLIER THIS MORNING. ALTHOUGH THE EYE HAS NOT WARMED 560MUCH...THE CONVECTIVE BANDING AROUND THE EYE HAS BECOME BETTER 561ORGANIZED. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB ARE 115 562KT...AND THAT WILL BE THE INITIAL WIND SPEED FOR THIS ADVISORY... 563MAKING JULIA A CATEGORY FOUR HURRICANE. JULIA COULD STRENGTHEN A 564LITTLE MORE TODAY AS IT REMAINS OVER RELATIVELY WARM WATER AND IN A 565MODERATE WIND SHEAR ENVIRONMENT. HOWEVER...MUCH OF THE INTENSITY 566GUIDANCE SHOWS GRADUAL WEAKENING BEYOND 12 TO 24 HOURS AS JULIA 567MOVES OVER COOLER WATER AND THEN INTO STRONG NORTHERLY SHEAR 568ASSOCIATED WITH THE OUTFLOW OF HURRICANE IGOR. THE NHC OFFICIAL 569INTENSITY FORECAST IS A LITTLE HIGHER THAN THE PREVIOUS 570ADVISORY...AND IS ABOVE ALL OF THE MODELS FOR THE FIRST FEW DAYS AS 571NONE OF THE GUIDANCE ANTICIPATED THE OBSERVED STRENGTHENING OF 572JULIA. 573 574THE HURRICANE HAS NOW TURNED TO THE NORTHWEST...WITH A 12-HOUR 575INITIAL MOTION ESTIMATE OF 305/9. A CONTINUED NORTHWESTWARD MOTION 576IS EXPECTED FOR THE NEXT DAY OR SO AS JULIA NEARS A MID- TO 577UPPER-LEVEL TROUGH OVER THE EASTERN ATLANTIC. HOWEVER...A TURN 578BACK TO THE WEST-NORTHWEST IS FORECAST IN ABOUT 36 HOURS AS THE 579HURRICANE IS STEERED BETWEEN AN UPPER-LEVEL LOW AND A STRENGTHENING 580SUBTROPICAL RIDGE. JULIA IS EXPECTED TO APPROACH THE WESTERN 581PERIPHERY OF THE RIDGE IN 3 TO 4 DAYS ALLOWING THE SYSTEM TO TURN 582NORTHWARD AND POSSIBLY NORTH-NORTHEASTWARD BY DAY 5. THE OFFICIAL 583TRACK FORECAST IS ADJUSTED SLIGHTLY TO THE RIGHT AND IS A LITTLE 584FASTER THAN THE PREVIOUS ONE TO COME INTO BETTER AGREEMENT WITH THE 585NEW GUIDANCE SUITE. 586 587FORECAST POSITIONS AND MAX WINDS 588 589INITIAL 15/0900Z 17.3N 31.8W 115 KT 590 12HR VT 15/1800Z 18.6N 33.2W 120 KT 591 24HR VT 16/0600Z 20.4N 35.9W 120 KT 592 36HR VT 16/1800Z 22.2N 39.3W 105 KT 593 48HR VT 17/0600Z 23.4N 42.6W 95 KT 594 72HR VT 18/0600Z 26.3N 48.1W 80 KT 595 96HR VT 19/0600Z 30.0N 50.5W 65 KT 596120HR VT 20/0600Z 34.0N 49.5W 50 KT 597 598$$ 599FORECASTER CANGIALOSI 600 601 602WTNT42 KNHC 151454 603TCDAT2 604HURRICANE JULIA DISCUSSION NUMBER 14 605NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 606ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 6071100 AM AST WED SEP 15 2010 608 609RAPID INTENSIFICATION OCCURRED DURING THE OVERNIGHT HOURS WITH 610JULIA WHEN THE HURRICANE REACHED CATEGORY FOUR STRENGTH. THIS 611STRENGTHENING APPPEARS TO HAVE LEVELED OFF THIS MORNING...AS 612OUTFLOW FROM HURRICANE IGOR COMBINED WITH A NEARBY UPPER LEVEL LOW 613IS PRODUCING SOUTHERLY SHEAR OVER JULIA. THIS LEVELING OF ITS 614INTENSITY ALSO SHOWS UP WITH THE T NUMBERS FROM BOTH SAB AND 615TAFB...WHICH HOVER AND DROP SLIGHTLY AROUND/BETWEEN 5 AND 6. 616HOWEVER JULIA MAINTAINS A SOLID CENTRAL DENSE OVERCAST/CORE AND 617CLEAR EYE STRUCTURE WITH IMPRESSIVE CLOUD TOP ENHANCEMENT... THUS 618INITIAL INTENSITY WILL REMAIN AT 115 KTS. JULIA IS EXPECTED TO 619MAINTAIN THIS STRENGTH OVER THE NEXT 24 HRS BEFORE BEGINNING TO 620WEAKEN AS THE SYSTEM INTERACTS WITH MARGINAL AND COOLER SST VALUES. 621 622THE FORECAST SCENARIO HAS NOT BUDGED MUCH BUT THERE REMAINS RATHER 623LARGE SPREAD WITHIN THE GLOBAL AND DYNAMICAL GUIDANCE IN THE EARLY 624MEDIUM RANGE PERIOD. FOR THE NEXT 60 TO 72 HRS...JULIA IS EXPECTED 625TO MOVE AROUND 15 KTS OR GREATER OFF TO THE NORTHWEST OR 626WEST-NORTHWEST AS A BUILDING MID-LEVEL RIDGE BUILDS OVER THE EAST 627CENTRAL ATLANTIC. AFTER 72 HRS...JULIA FORWARD MOTION SLOWS AS A 628NORTHERN STREAM RIDGE BUILDS TO ITS NORTH EAST OF NEWFOUNDLAND 629WHICH KEEPS THE STORM FROM ACCELERATING INTO THE MAIN BAND OF THE 630WESTERLIES. THE OFFICIAL TRACK FORECAST MAINTAINED A TIGHT 631CORRELATION TO THE MODEL CONSENSUS AND KEPT GOOD CONTINUITY. 632 633 634FORECAST POSITIONS AND MAX WINDS 635 636INITIAL 15/1500Z 18.2N 32.7W 115 KT 637 12HR VT 16/0000Z 19.5N 34.4W 115 KT 638 24HR VT 16/1200Z 21.3N 37.5W 115 KT 639 36HR VT 17/0000Z 22.9N 41.0W 105 KT 640 48HR VT 17/1200Z 24.3N 44.2W 95 KT 641 72HR VT 18/1200Z 27.5N 49.0W 80 KT 642 96HR VT 19/1200Z 31.5N 50.0W 65 KT 643120HR VT 20/1200Z 35.0N 47.5W 50 KT 644 645$$ 646FORECASTER MUSHER 647 648 649WTNT42 KNHC 152044 650TCDAT2 651HURRICANE JULIA DISCUSSION NUMBER 15 652NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 653500 PM AST WED SEP 15 2010 654 655THE EYE OF JULIA HAS BEEN APPARENT INTERMITTENTLY IN INFRARED 656SATELLITE IMAGERY THIS AFTERNOON. A 1912 UTC SSMIS MICROWAVE 657OVERPASS INDICATES THAT THERE IS SOME TILT TO THE CIRCULATION WITH 658THE LOW-LEVEL CENTER LOCATED A LITTLE TO THE SOUTH OF THE MID- TO 659UPPER-LEVEL EYE...DUE TO SOUTH-SOUTHWESTERLY SHEAR. JULIA HAS 660LIKELY PEAKED IN INTENSITY. THE INITIAL INTENSITY IS LOWERED TO 661110 KT...BASED ON A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK DATA 662T-NUMBERS THAT HAVE DECREASED SLIGHTLY. THE CYCLONE WILL BE MOVING 663INTO A LESS FAVORABLE ENVIRONMENT WITH MODERATE SOUTHERLY SHEAR AND 664SLIGHTLY COOLER SSTS DURING THE NEXT DAY OR SO. THIS SHOULD RESULT 665IN GRADUAL WEAKENING. AFTER 48 HOURS...THE GLOBAL MODELS SHOW JULIA 666MOVING INTO AN AREA OF INCREASING NORTHEASTERLY UPPER-LEVEL WINDS 667ASSOCIATED WITH THE OUTFLOW FROM HURRICANE IGOR. A FASTER RATE OF 668WEAKENING IS INDICATED BY THE INTENSITY GUIDANCE AND IN THE 669OFFICIAL FORECAST AT THAT TIME. THE NHC FORECAST IS CLOSE TO THE 670INTENSITY CONSENSUS AT DAYS 3-5...BUT IS HIGHER THAN THE SHIPS 671GUIDANCE WHICH WEAKENS THE JULIA VERY RAPIDLY AFTER 72 HOURS. 672 673THE INITIAL MOTION ESTIMATE IS 315/11. JULIA IS FORECAST TO MOVE 674NORTHWESTWARD AROUND AN UPPER-LEVEL LOW TO ITS SOUTHWEST DURING THE 675NEXT 12-24 HOURS. DURING THIS TIME...THE FORWARD SPEED OF JULIA IS 676FORECAST TO INCREASE. BETWEEN 24 AND 72 HOURS...THE HURRICANE WILL 677BE STEERED IN A WEST-NORTHWEST TO NORTHWEST DIRECTION AROUND THE 678WESTERN PERIPHERY OF A MID-LEVEL RIDGE CENTERED BETWEEN JULIA AND 679THE AZORES ISLANDS. THEREAFTER...JULIA SHOULD TURN 680NORTHWARD...THEN NORTHEASTWARD BETWEEN THE NORTHWEST SIDE OF THE 681RIDGE AND HURRICANE IGOR TO THE WEST. THE TRACK GUIDANCE IS IN A 682LITTLE BETTER AGREEMENT FOR THIS CYCLE. THE NEW NHC TRACK FORECAST 683HAS BEEN ADJUSTED SOMEWHAT NORTHWARD AND LIES NEAR THE MIDDLE OF 684THE MODEL ENVELOPE. 685 686 687FORECAST POSITIONS AND MAX WINDS 688 689INITIAL 15/2100Z 19.2N 33.5W 110 KT 690 12HR VT 16/0600Z 20.6N 35.5W 105 KT 691 24HR VT 16/1800Z 22.6N 38.9W 100 KT 692 36HR VT 17/0600Z 24.3N 42.4W 95 KT 693 48HR VT 17/1800Z 26.0N 45.5W 85 KT 694 72HR VT 18/1800Z 30.0N 49.6W 75 KT 695 96HR VT 19/1800Z 34.0N 49.0W 60 KT 696120HR VT 20/1800Z 36.0N 45.0W 45 KT 697 698$$ 699FORECASTER BROWN 700 701 702WTNT42 KNHC 160255 703TCDAT2 704HURRICANE JULIA DISCUSSION NUMBER 16 705NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 7061100 PM AST WED SEP 15 2010 707 708JULIA IS COMING UNDER INCREASING INFLUENCE OF SOUTHERLY SHEAR...AND 709RECENT MICROWAVE IMAGES INDICATE THAT THE LOW-LEVEL CENTER AND THE 710MID-LEVEL EYE ARE DISPLACED FROM ONE ANOTHER. SATELLITE INTENSITY 711ESTIMATES ARE NOW T5.0/5.5 FROM TAFB...T4.0/5.0 FROM SAB...AND 712T5.3/5.7 FROM THE UW-CIMSS ADT. THE INITIAL INTENSITY IS LOWERED 713TO 100 KT FOR THIS ADVISORY...BUT IT IS POSSIBLE THAT JULIA COULD 714BE WEAKER THAN THAT. JULIA IS LOCATED VERY NEAR A DEVELOPING 715CLOSED UPPER-LEVEL LOW...AND STRONG SHEAR IS EXPECTED TO CONTINUE 716OVER THE HURRICANE DURING THE FORECAST PERIOD. THE OFFICIAL 717FORECAST INDICATES GRADUAL WEAKENING DURING THE NEXT 48-72 HOURS 718AND IS IN LINE WITH THE INTENSITY CONSENSUS. JULIA SHOULD WEAKEN 719TO A TROPICAL STORM BY DAYS 4 AND 5...BUT THE FORECAST IS A LITTLE 720ABOVE THE INTENSITY CONSENSUS AT THAT TIME SINCE THE SHIPS 721MODEL...FOR SOME UNKNOWN REASON...SHOWS THE SYSTEM DISSIPATED BY 722DAY 5. THIS SEEMS UNREASONABLE SINCE THE GFS STILL SHOWS AN INTACT 723AREA OF LOW PRESSURE. 724 725THE HURRICANE IS STARTING TO ACCELERATE AND IS NOW MOVING AT 315/14. 726ADDITIONAL ACCELERATION IS EXPECTED OVER THE NEXT 24 HOURS AS JULIA 727IS STEERED BETWEEN A MID-LEVEL HIGH TO ITS NORTHEAST AND THE 728UPPER-LEVEL LOW TO ITS SOUTHWEST...ALMOST LIKE A SLING-SHOT AFFECT. 729JULIA WILL THEN BE STEERED NORTH-NORTHWEST AND THEN NORTH FROM 73048-72 HOURS AS IT REACHES THE WESTERN SIDE OF THE RIDGE AND THE 731EASTERN SIDE OF THE LARGE CIRCULATION ASSOCIATED WITH IGOR. THE 732RECURVATURE TO THE NORTHEAST IS ANTICIPATED BY DAY 5 AS JULIA GETS 733EMBEDDED WITHIN THE MID-LATITUDE WESTERLY FLOW. THE OFFICIAL TRACK 734FORECAST IS VERY CLOSE TO THE PREVIOUS FORECAST...AND LIES JUST TO 735THE WEST OF THE MODEL CONSENSUS. JUST LIKE IN THE CASE WITH 736IGOR...THE ECMWF MODEL LIES AT THE WESTERN SIDE OF THE GUIDANCE 737ENVELOPE AND CANNOT BE IGNORED. 738 739 740FORECAST POSITIONS AND MAX WINDS 741 742INITIAL 16/0300Z 20.2N 34.6W 100 KT 743 12HR VT 16/1200Z 21.7N 36.9W 90 KT 744 24HR VT 17/0000Z 23.6N 40.4W 85 KT 745 36HR VT 17/1200Z 25.3N 43.8W 80 KT 746 48HR VT 18/0000Z 27.0N 46.5W 75 KT 747 72HR VT 19/0000Z 31.5N 49.5W 65 KT 748 96HR VT 20/0000Z 35.0N 48.0W 50 KT 749120HR VT 21/0000Z 36.5N 43.5W 40 KT 750 751$$ 752FORECASTER BERG 753 754 755WTNT42 KNHC 160903 756TCDAT2 757HURRICANE JULIA DISCUSSION NUMBER 17 758NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 759500 AM AST THU SEP 16 2010 760 761THE SATELLITE PRESENTATION OF JULIA HAS CONTINUED TO DETERIORATE 762OVER THE PAST FEW HOURS. MOST OF THE DEEP CONVECTION IS DISPLACED 763NORTH OF THE ESTIMATED CENTER POSITION...AND CLOUD TOPS HAVE 764CONTINUED TO WARM. JULIA IS CURRENTLY SITUATED OVER WATERS OF 76526-27C...AND THE MID- TO UPPER-LEVEL TROUGH/LOW BETWEEN JULIA AND 766HURRICANE IGOR IS IMPARTING 20 TO 30 KT OF SOUTHWESTERLY SHEAR OVER 767JULIA ACCORDING TO THE UW-CIMSS SHEAR ANALYSIS. BASED ON A BLEND 768OF SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY ESTIMATES THE INITIAL 769INTENSITY IS LOWERED TO 90 KT FOR THIS ADVISORY. WHILE THE SHIPS 770MODEL OUTPUT SHOWS THE SHEAR DECREASING TO LESS THAN 20 KT FROM 12 771TO 24 HOURS...JULIA WILL REMAIN OVER MARGINAL SSTS THROUGH THAT 772TIME. THEN BY 36 HOURS OR SO...WHEN JULIA TEMPORARILY MOVES BACK 773OVER WARMER WATERS...THE SHEAR INCREASES TO AROUND 30 KT AND 774REMAINS HIGH FOR THE REST OF THE PERIOD. THIS SCENARIO SHOULD 775RESULT IN A GRADUAL WEAKENING FOR THE FIRST 48 HOURS...WITH MORE 776RAPID WEAKENING TOWARD THE END OF THE PERIOD. THE OFFICIAL FORECAST 777REFLECT THIS AND FOLLOWS A BLEND OF THE LGEM AND SHIPS MODELS 778THROUGH 48 HOURS...AND IS CLOSEST TO THE LGEM THEREAFTER. 779 780WITH A LACK OF MICROWAVE IMAGERY OVER THE PAST FEW HOURS...THE 781INITIAL MOTION ESTIMATE OF 310/16 IS BASED LARGELY ON CONTINUITY 782AND THE ASSUMPTION THAT THE LOW-LEVEL CENTER REMAINS DISPLACED SOUTH 783AND EAST OF THE DEEP CONVECTION. THE TRACK FORECAST REASONING 784REMAINS UNCHANGED FROM THE PREVIOUS PACKAGE. JULIA IS CURRENTLY 785BEING STEERED NORTHWESTWARD BY THE UPPER-LEVEL LOW TO ITS SOUTHWEST 786AND A LARGE MID-LEVEL RIDGE TO ITS EAST...AND THIS WILL CONTINUE 787FOR THE NEXT DAY OR SO. THEN...AS JULIA MOVES AWAY FROM THE 788UPPER-LOW...THE CYCLONE WILL MOVE AROUND THE WESTERN PERIPHERY OF 789THE RIDGE AND TURN EAST-NORTHEASTWARD BY THE END OF THE PERIOD AS 790IT COMES UNDER THE INFLUENCE OF THE MID-LATITUDE WESTERLIES. SOME 791DIFFERENCES REMAIN IN HOW SHARPLY JULIA MOVES AROUND THE RIDGE... 792WITH THE UKMET SHOWING A SHARPER TURN...WHILE THE ECMWF AND HWRF 793SHOW A WIDER TURN. THE OFFICIAL FORECAST HAS BEEN ADJUSTED TOWARD 794THE TVCN MULTI-MODEL CONSENSUS...AND IS CLOSE TO THE GFS FOR 795THE FIRST 72 HOURS...WHICH REPRESENTS A COMPROMISE BETWEEN THE 796ECMWF AND UKMET. THE NEW NHC FORECAST IS ALSO FASTER THAN THE 797PREVIOUS PACKAGE DURING THE FIRST 24 HOURS...ACCOUNTING FOR THE 798OBSERVED ACCELERATION OF JULIA. 799 800FORECAST POSITIONS AND MAX WINDS 801 802INITIAL 16/0900Z 21.2N 36.2W 90 KT 803 12HR VT 16/1800Z 22.8N 38.8W 85 KT 804 24HR VT 17/0600Z 24.6N 42.4W 80 KT 805 36HR VT 17/1800Z 26.4N 45.5W 75 KT 806 48HR VT 18/0600Z 28.3N 47.7W 70 KT 807 72HR VT 19/0600Z 32.5N 49.5W 65 KT 808 96HR VT 20/0600Z 35.0N 46.5W 50 KT 809120HR VT 21/0600Z 36.0N 42.5W 40 KT 810 811$$ 812FORECASTER BRENNAN 813 814 815WTNT42 KNHC 161457 816TCDAT2 817HURRICANE JULIA DISCUSSION NUMBER 18 818NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 8191100 AM AST THU SEP 16 2010 820 821SATELLITE IMAGERY CONTINUES TO INDICATE WARMING OF THE CLOUD TOPS IN 822THE RATHER RAGGED LOOKING CENTRAL DENSE OVERCAST. A 1001Z AMSU 823MICROWAVE OVERPASS INDICATED A 25-30 NMI DIAMETER EYE THAT WAS OPEN 824IN THE SOUTHEAST QUADRANT. WATER VAPOR IMAGERY ALSO SHOWS A LARGE 825SLUG OF DRY AIR BEING ENTRAINED INTO THE EASTERN SEMICIRCLE...WHICH 826LIKELY EXPLAINS THE EROSION OF THE EASTERN EYEWALL NOTED IN THE 827AMSU IMAGERY. DESPITE THE AFOREMENTIONED NEGATIVE FACTORS...JULIA 828HAS MAINTAINED GOOD OUTFLOW TO THE WEST AND NORTH OF THE CYCLONE. 829 830THE INITIAL MOTION ESTIMATE HAS INCREASED SHARPLY TO 300/22. JULIA 831IS EXPECTED TO MOVE TO THE WEST-NORTHWEST AND THEN NORTHWEST 832FOR THE NEXT 36-48 HOURS AS THE HURRICANE ROUNDS THE SOUTHERN 833PERIPHERY OF A LARGE SUBTROPICAL RIDGE SITUATED TO ITS NORTH AND 834NORTHEAST. AFTER THAT...SIGNIFICANT VERTICAL WIND SHEAR MAY WEAKEN 835THE CYCLONE AND CAUSE IT TO BECOME MORE SHALLOW...AND THEN BE 836STEERED MORE NORTHWARD SIMILAR TO THE ECMWF AND GFDL MODELS...BUT 837NOT AS FAR NORTH AND WEST AS THE SHALLOW BAM MODEL. THE OFFICIAL 838TRACK FORECAST HAS BEEN NUDGED TO THE LEFT OF THE PREVIOUS ADVISORY 839THROUGH 72 HOURS...AND IS SIMILAR TO THE MULTI-MODEL CONSENSUS. 840 841DRY AIR AND COOLER SSTS SHOULD CONTINUE THE RECENT WEAKENING 842TREND...ESPECIALLY AFTER 24 HOURS. BY 36-48 HOURS...ALL OF THE 843GLOBAL MODELS INDICATE THAT JULIA WILL BE MOVING INTO A REGION OF 844STRONG UPPER-LEVEL SHEAR CAUSED BY THE PRONOUNCED NORTHERLY OUTFLOW 845EMANATING FROM THE MAJOR HURRICANE IGOR LOCATED TO ITS WEST. WITH 846JULIA MOVING INTO 50-70 KT OF 200 MB WINDS...IT WILL BE HARD FOR 847JULIA TO SURVIVE AS A TROPICAL CYCLONE AS INDICATED BY THE GLOBAL 848MODELS AND GFDL/HWRF MODELS. THE OFFICIAL INTENSITY FORECAST SHOWS 849A FASTER WEAKENING TREND THAN THE PREVIOUS ADVISORY...BUT NOT AS 850FAST AS THE SHIPS MODEL...WHICH DISSIPATES JULIA BY 120 HOURS. 851 852 853FORECAST POSITIONS AND MAX WINDS 854 855INITIAL 16/1500Z 22.4N 38.6W 85 KT 856 12HR VT 17/0000Z 23.7N 41.2W 75 KT 857 24HR VT 17/1200Z 25.5N 44.6W 65 KT 858 36HR VT 18/0000Z 27.3N 47.3W 55 KT 859 48HR VT 18/1200Z 29.3N 49.1W 45 KT 860 72HR VT 19/1200Z 33.2N 49.6W 35 KT 861 96HR VT 20/1200Z 35.8N 46.3W 35 KT 862120HR VT 21/1200Z 38.0N 42.0W 35 KT 863 864$$ 865FORECASTER STEWART 866 867 868WTNT42 KNHC 162040 869TCDAT2 870HURRICANE JULIA DISCUSSION NUMBER 19 871NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 872500 PM AST THU SEP 16 2010 873 874VERTICAL SHEAR APPEARS TO HAVE ABATED FOR THE MOMENT...WITH A 1533 875UTC AMSR-E MICROWAVE PASS SHOWING THAT THE LOW- AND MID-LEVEL 876CENTERS ARE JUST ABOUT VERTICALLY STACKED. HOWEVER...CONVECTIVE 877TOPS HAVE WARMED...AND SATELLITE CURRENT INTENSITY ESTIMATES ARE 878NOW 77 KT FROM TAFB...65 KT FROM SAB...AND 65 KT AND 80 KT FROM TWO 879VERSIONS OF THE UW-CIMSS ADT. THE INITIAL INTENSITY IS THEREFORE 880LOWERED TO 75 KT FOR THIS ADVISORY. 881 882JULIA HAS AN INITIAL MOTION OF 295/22 KT. THERE HAS BEEN A 883SIGNIFICANT WESTWARD SHIFT IN NEARLY ALL THE TRACK GUIDANCE ON THIS 884CYCLE...POSSIBLY DUE TO A STRONGER-THAN-EXPECTED MID-LEVEL HIGH TO 885THE NORTH AND NORTHEAST OF THE HURRICANE. CONSEQUENTLY...THE NEW 886OFFICIAL FORECAST HAS BEEN SHIFTED WESTWARD ABOUT HALFWAY BETWEEN 887OFCI AND THE MODEL CONSENSUS TVCN. SEVERAL MODELS...ESPECIALLY THE 888UKMET AND ECMWF...ARE EVEN FARTHER WEST THAN THIS TRACK SO IT IS 889POSSIBLE THAT ADDITIONAL SHIFTS COULD BE REQUIRED IN THE NEXT FEW 890ADVISORY PACKAGES. GLOBAL MODEL FIELDS INDICATE THAT AFTER JULIA 891MOVES NORTHWARD AROUND THE RIDGE...IT SHOULD TURN TOWARD THE 892NORTHEAST AND DISSIPATE IN THE STRONG SOUTHWESTERLY FLOW TO THE 893EAST OF IGOR IN ABOUT 120 HOURS. 894 895WITH THE WESTWARD SHIFT IN THE FORECAST TRACK...JULIA APPEARS TO 896HAVE A BETTER CHANCE TO MAINTAIN SOME OF ITS INTENSITY OVER THE 897NEXT COUPLE OF DAYS. THE HURRICANE WILL BE BATTLING THE STRONG 898UPPER-LEVEL OUTFLOW OF IGOR DURING THE NEXT 36 HOURS OR SO...BUT 899AFTER THAT THE GLOBAL MODELS SUGGEST THAT JULIA COULD SNEAK 900UNDERNEATH THE UPPER-LEVEL ANTICYCLONE PARTIALLY GENERATED BY IGOR. 901THE SHEAR COULD RELAX JUST ENOUGH DURING THAT TIME AND CAUSE MORE 902MODEST WEAKENING...SO THE NEW INTENSITY FORECAST IS A LITTLE BIT 903HIGHER THAN THE PREVIOUS ONE FROM 36-72 HOURS. INCIDENTALLY... THE 904NEW FORECAST IS STILL LOWER THAN INDICATED BY THE LGEM...THE 905DYNAMICAL MODELS...AND THE INTENSITY CONSENSUS. 906 907FORECAST POSITIONS AND MAX WINDS 908 909INITIAL 16/2100Z 23.1N 41.1W 75 KT 910 12HR VT 17/0600Z 24.2N 43.9W 65 KT 911 24HR VT 17/1800Z 26.0N 47.1W 65 KT 912 36HR VT 18/0600Z 27.9N 49.6W 60 KT 913 48HR VT 18/1800Z 30.1N 51.0W 55 KT 914 72HR VT 19/1800Z 34.0N 50.5W 45 KT 915 96HR VT 20/1800Z 37.0N 47.0W 35 KT 916120HR VT 21/1800Z...DISSIPATED 917 918$$ 919FORECASTER BERG 920 921 922WTNT42 KNHC 170248 923TCDAT2 924HURRICANE JULIA DISCUSSION NUMBER 20 925NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 9261100 PM AST THU SEP 16 2010 927 928THE EYE OF JULIA BECAME BETTER DEFINED IN INFRARED SATELLITE IMAGES 929FOR A PERIOD OF TIME THIS EVENING. HOWEVER...THE AREA OF COLD 930CLOUDS TOPS ASSOCIATED WITH THE HURRICANE HAS DECREASED IN SIZE. 931THE LATEST DVORAK INTENSITY ESTIMATES SUPPORT AN INITIAL INTENSITY 932OF 70 KT. THE GLOBAL MODELS AND WATER VAPOR IMAGERY SHOW THAT 933JULIA WILL BE ENTERING AN AREA OF STRONG NORTHWESTERLY UPPER-LEVEL 934WINDS ASSOCIATED WITH THE OUTFLOW FROM HURRICANE IGOR VERY SHORTLY. 935THE SHIPS GUIDANCE INDICATES 30-40 KT WIND SHEAR DURING THE NEXT 936DAY OR SO. DURING THIS TIME JULIA IS EXPECTED TO WEAKEN 937SIGNIFICANTLY AND THE NEW INTENSITY FORECAST IS A LITTLE LOWER THAN 938THE PREVIOUS ADVISORY THROUGH 36 HOURS. IF JULIA SURVIVES THE 939STRONG SHEAR...THE GLOBAL MODELS SUGGEST THAT THE UPPER-LEVEL 940ENVIRONMENT COULD IMPROVE BETWEEN 36-72 HOURS. DURING THAT TIME 941ONLY GRADUAL WEAKENING IS SHOWN. IN 4-5 DAYS...JULIA IS EXPECTED TO 942DISSIPATE IN THE STRONG SOUTHWESTERLY FLOW TO THE EAST OF IGOR. THE 943OFFICIAL INTENSITY FORECAST IS IN BEST AGREEMENT WITH THE SHIPS 944INTENSITY GUIDANCE. 945 946JULIA CONTINUES TO MOVE QUICKLY WEST-NORTHWESTWARD WITH AN INITIAL 947MOTION OF 290/21 KT. THE FORECAST TRACK REASONING REMAINS UNCHANGED 948AS JULIA WILL BE MOVING AROUND THE WESTERN PORTION OF A MID-LEVEL 949RIDGE CENTERED SOUTHWEST OF THE AZORES. THE TRACK GUIDANCE HAS 950AGAIN SHIFTED WESTWARD AND THE OFFICIAL FORECAST FOLLOWS SUIT. THE 951NEW FORECAST LIES BETWEEN THE GFS...WHICH IS ALONG THE EAST EDGE OF 952THE GUIDANCE...AND THE TVCN CONSENSUS. 953 954 955FORECAST POSITIONS AND MAX WINDS 956 957INITIAL 17/0300Z 23.5N 42.9W 70 KT 958 12HR VT 17/1200Z 24.6N 45.7W 60 KT 959 24HR VT 18/0000Z 26.3N 48.8W 55 KT 960 36HR VT 18/1200Z 28.6N 50.8W 50 KT 961 48HR VT 19/0000Z 31.0N 52.0W 45 KT 962 72HR VT 20/0000Z 35.0N 50.5W 40 KT 963 96HR VT 21/0000Z 39.0N 46.5W 35 KT 964120HR VT 22/0000Z...DISSIPATED 965 966$$ 967FORECASTER BROWN 968 969 970WTNT42 KNHC 170847 971TCDAT2 972HURRICANE JULIA DISCUSSION NUMBER 21 973NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 974500 AM AST FRI SEP 17 2010 975 976UP UNTIL THE LAST HOUR...JULIA HAD EXHIBITED A SMALL BUT WELL- 977DEFINED EYE WITH A SOLID EYEWALL. SUBJECTIVE DVORAK CLASSIFICATIONS 978ARE 77 KT...WITH ADT VALUES USING AN EYE PATTERN SUPPORTING 979ANYWHERE FROM 75-85 KT. GIVEN THAT THE EYE HAS BECOME OBSCURED... 980THE INITIAL WINDS ARE ONLY INCREASED TO THE LOWER END OF THOSE 981ESTIMATES...75 KT. THE HURRICANE IS IN A SMALL LOW SHEAR ENVIRONMENT 982TO THE NORTH OF AN UPPER LOW. HOWEVER...JULIA IS ABOUT TO ENCOUNTER 983AN UPPER-LEVEL JET...PART OF THE OUTFLOW FROM IGOR...WHICH SHOULD 984INDUCE SIGNIFICANT SHEAR AND A FAIR AMOUNT OF WEAKENING. JULIA 985SHOULD MOVE AWAY FROM THE MAIN JET CORE IN TWO TO THREE DAYS... 986CAUSING THE SHEAR TO MODERATE SOMEWHAT...BUT SLOW WEAKENING IS 987STILL EXPECTED. BY THE END OF THE FORECAST PERIOD...VERY STRONG 988SHEAR IS FORECAST TO OCCUR...WHICH SHOULD CAUSE RAPID DISSIPATION. 989THE NEW NHC INTENSITY FORECAST IS CLOSE TO THE PREVIOUS ONE AND THE 990SHIPS MODEL...BUT BELOW MOST OF THE REST OF THE GUIDANCE. 991 992JULIA CONTINUES TO MOVE 290/21. THE HURRICANE APPEARS TO BE 993LEAVING THE INFLUENCE OF A MID- TO UPPER-LEVEL LOW TO THE SOUTHEAST 994...AND BECOMING MOSTLY STEERED BY A RIDGE OVER THE EASTERN ATLANTIC 995OCEAN. JULIA SHOULD GRADUALLY GAIN LATITUDE AND EVENTUALLY TURN TO 996THE NORTH AND NORTHEAST AROUND THE WESTERN PORTION OF THE RIDGE. 997THE TRACK GUIDANCE CONTINUES TO SHIFT WESTWARD...PERHAPS DUE TO THE 998FAST WEST-NORTHWESTWARD MOTION AND UNFORESEEN IMPACTS OF THE MID- 999TO UPPER-LEVEL LOW. THE NHC FORECAST IS SHIFTED WESTWARD AGAIN 1000...AND LIES BETWEEN THE GFS ENSEMBLE AND THE MULTI-MODEL CONSENSUS. 1001 1002FORECAST POSITIONS AND MAX WINDS 1003 1004INITIAL 17/0900Z 23.8N 45.1W 75 KT 1005 12HR VT 17/1800Z 25.0N 47.6W 65 KT 1006 24HR VT 18/0600Z 27.2N 50.2W 55 KT 1007 36HR VT 18/1800Z 29.7N 51.9W 50 KT 1008 48HR VT 19/0600Z 32.4N 52.4W 45 KT 1009 72HR VT 20/0600Z 36.0N 49.5W 40 KT 1010 96HR VT 21/0600Z 40.0N 44.5W 35 KT 1011120HR VT 22/0600Z...DISSIPATED 1012 1013$$ 1014FORECASTER BLAKE 1015 1016 1017WTNT42 KNHC 171436 1018TCDAT2 1019HURRICANE JULIA DISCUSSION NUMBER 22 1020NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 10211100 AM AST FRI SEP 17 2010 1022 1023JULIA IS MAINTAINING A CENTRAL DENSE OVERCAST FEATURE THAT IS 1024DISPLACED SLIGHTLY TO THE SOUTH-SOUTHEAST OF THE CENTER. USING A 1025BLEND OF DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB GIVES 75 KT 1026FOR THE CURRENT INTENSITY. THE SYSTEM IS LIKELY TO EXPERIENCE 1027INCREASING NORTHERLY TO NORTHWESTERLY SHEAR ASSOCIATED WITH THE 1028MASSIVE UPPER-LEVEL OUTFLOW PATTERN OF HURRICANE IGOR. GIVEN THE 1029HIGH AMOUNT OF SHEAR EXPECTED TO IMPACT JULIA...THE OFFICIAL 1030INTENSITY FORECAST SHOWS A SOMEWHAT FASTER RATE OF WEAKENING THAN 1031INDICATED BY THE STATISTICAL-DYNAMICAL GUIDANCE MODELS LGEM AND 1032SHIPS. DISSIPATION IS LIKELY BY THE END OF THE FORECAST PERIOD AS 1033MOST OF THE DYNAMICAL MODELS DEPICT JULIA BECOMING ABSORBED WITHIN 1034THE MUCH LARGER CIRCULATION OF IGOR. 1035 1036LATEST CENTER FIXES SHOW THAT THE INITIAL MOTION HAS SLOWED SOMEWHAT 1037AND IS NOW 285/17. THE HURRICANE HAS MOVED UNEXPECTEDLY FAR TO THE 1038WEST...LIKELY BECAUSE THE STEERING EFFECTS OF AN UPPER-LEVEL CYCLONE 1039TO THE SOUTH WERE MORE PRONOUNCED THAN EARLIER ANTICIPATED. 1040NONETHELESS...JULIA IS FORECAST TO MOVE AROUND THE WESTERN PERIPHERY 1041OF A MID-LEVEL SUBTROPICAL ANTICYCLONE OVER THE NEXT 2 TO 4 DAYS. 1042THE OFFICIAL FORECAST TRACK IS ESSENTIALLY AN UPDATE OF THE 1043PREVIOUS ONE AND IS CLOSE TO THE MULTI-MODEL CONSENSUS. 1044 1045FORECAST POSITIONS AND MAX WINDS 1046 1047INITIAL 17/1500Z 24.2N 46.7W 75 KT 1048 12HR VT 18/0000Z 25.8N 48.8W 70 KT 1049 24HR VT 18/1200Z 28.3N 51.1W 65 KT 1050 36HR VT 19/0000Z 30.9N 52.1W 60 KT 1051 48HR VT 19/1200Z 33.2N 51.7W 50 KT 1052 72HR VT 20/1200Z 36.4N 48.5W 40 KT 1053 96HR VT 21/1200Z 40.0N 44.0W 30 KT 1054120HR VT 22/1200Z...DISSIPATED 1055 1056$$ 1057FORECASTER PASCH 1058 1059 1060WTNT42 KNHC 172053 1061TCDAT2 1062HURRICANE JULIA DISCUSSION NUMBER 23 1063NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1064500 PM AST FRI SEP 17 2010 1065 1066JULIA HAS BEEN EXPERIENCING MODERATE NORTHERLY SHEAR...AND 1067AT TIMES IT APPEARS THAT THE LOW-LEVEL CENTER IS BEGINNING TO 1068BECOME EXPOSED. USING A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK 1069T-NUMBERS LEADS TO A CURRENT INTENSITY ESTIMATE OF 65 KT. THE 1070SHEAR...WHICH IS PRIMARILY ASSOCIATED WITH THE MASSIVE OUTFLOW 1071PATTERN OF HURRICANE IGOR...IS NOT LIKELY TO RELENT. IN FACT... 1072THE DYNAMICAL GUIDANCE SUGGESTS THAT THE SHEAR WILL BECOME STRONGER. 1073THE OFFICIAL INTENSITY FORECAST SHOWS STEADY WEAKENING AND IS BASED 1074ON A COMBINATION OF THE STATISTICAL-DYNAMICAL SHIPS AND LGEM 1075MODELS. BY THE END OF THE FORECAST PERIOD...GLOBAL MODELS INDICATE 1076THAT JULIA WILL BECOME ABSORBED BY THE MUCH LARGER CIRCULATION OF 1077POST-TROPICAL IGOR. 1078 1079THE INITIAL MOTION IS ABOUT 300/18. THE FORECAST REASONING IS 1080ESSENTIALLY UNCHANGED. JULIA IS EXPECTED TO MOVE AROUND A 1081MID-LEVEL SUBTROPICAL HIGH FOR THE NEXT FEW DAYS...BEFORE GETTING 1082PULLED INTO THE CIRCULATION OF IGOR. THUS...THE NHC TRACK FORECAST 1083SHOWS A GRADUAL TURN TOWARD THE NORTHWEST...NORTH...AND NORTH- 1084NORTHEAST. THIS IS JUST A LITTLE TO THE WEST OF THE PREVIOUS 1085OFFICIAL TRACK AND GENERALLY TO THE RIGHT OF THE MULTI-MODEL 1086CONSENSUS TVCN. 1087 1088FORECAST POSITIONS AND MAX WINDS 1089 1090INITIAL 17/2100Z 25.2N 48.2W 65 KT 1091 12HR VT 18/0600Z 26.9N 50.0W 60 KT 1092 24HR VT 18/1800Z 29.6N 51.8W 55 KT 1093 36HR VT 19/0600Z 32.5N 52.3W 50 KT 1094 48HR VT 19/1800Z 34.8N 51.2W 45 KT 1095 72HR VT 20/1800Z 38.2N 47.2W 35 KT 1096 96HR VT 21/1800Z 43.0N 43.0W 25 KT 1097120HR VT 22/1800Z...DISSIPATED 1098 1099$$ 1100FORECASTER PASCH 1101 1102 1103WTNT42 KNHC 180241 1104TCDAT2 1105TROPICAL STORM JULIA DISCUSSION NUMBER 24 1106NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 11071100 PM AST FRI SEP 17 2010 1108 1109THE SATELLITE PRESENTATION SHOWS THE CIRCULATION CENTER OF JULIA 1110JUST BENEATH THE NORTHERN EDGE OF THE CLOUD CANOPY. THE SHEARED 1111CLOUD PATTERN IS DUE TO 20-30 KT OF NORTHERLY SHEAR PRODUCED BY A 1112STRONG OUTFLOW CHANNEL ASSOCIATED WITH HURRICANE EARL. SUBSEQUENT 1113BANDING CLOUD TOPS HAVE WARMED CONSIDERABLY THIS EVENING...AND THE 1114SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO 111565 AND 60 KT RESPECTIVELY. BASED ON THESE DATA...THE INITIAL 1116INTENSITY IS LOWERED TO 60 KT. THE GLOBAL AND THE SHIPS MODELS ALL 1117SUGGEST THAT THE SHEAR WILL PERSIST AND STRENGTHEN BY THE 48 HOUR 1118PERIOD AS THE SHEAR VECTOR BECOMES MORE WESTERLY. THE NHC INTENSITY 1119FORECAST INDICATES A GRADUAL WEAKENING TREND BASED ON THE 1120AFOREMENTIONED GUIDANCE...WITH THE CYCLONE ULTIMATELY BECOMING 1121ABSORBED IN 96 HOURS BY THE MUCH LARGER EXTRATROPICAL IGOR. 1122 1123THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS 1124ADVISORY...AND IS ESTIMATED TO BE NORTHWESTWARD OR 310/14. THE 1125DYNAMICAL MODELS SHOW THE CYCLONE MOVING NORTHWESTWARD DURING THE 1126NEXT 36 HOURS WITHIN THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH 1127TO THE NORTHEAST OF JULIA. THROUGH DAY 3...THE MODELS INDICATE 1128THAT THE SYSTEM WILL TURN NORTH-NORTHEASTWARD...AND NORTHEASTWARD 1129AS THE MID-LEVEL HIGH BEGINS TO DRIFT SOUTHWESTWARD OVER THE 1130CENTRAL ATLANTIC. AFTERWARD...THE MODELS ARE IN GOOD AGREEMENT 1131WITH JULIA BECOMING ABSORBED BY IGOR...GENERALLY IN 96 HOURS...OR 1132EARLIER...AS SUGGESTED BY THE SHIPS AND BOTH THE ECMWF AND GFS 1133ENSEMBLE MEANS. THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS 1134ADVISORY AND IS BASED ON A BLEND OF THE GLOBAL AND REGIONAL MODELS. 1135 1136 1137 1138FORECAST POSITIONS AND MAX WINDS 1139 1140INITIAL 18/0300Z 26.0N 49.2W 60 KT 1141 12HR VT 18/1200Z 28.1N 50.8W 55 KT 1142 24HR VT 19/0000Z 31.0N 52.1W 50 KT 1143 36HR VT 19/1200Z 33.5N 52.0W 45 KT 1144 48HR VT 20/0000Z 35.5N 50.6W 40 KT 1145 72HR VT 21/0000Z 39.0N 46.0W 30 KT 1146 96HR VT 22/0000Z...ABSORBED BY A LARGE EXTRATROPICAL LOW 1147 1148$$ 1149FORECASTER ROBERTS/AVILA 1150 1151 1152WTNT42 KNHC 180302 1153TCDAT2 1154TROPICAL STORM JULIA DISCUSSION NUMBER 24...CORRECTED 1155NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 11561100 PM AST FRI SEP 17 2010 1157 1158CORRECTED TO ADD IGOR 1159 1160THE SATELLITE PRESENTATION SHOWS THE CIRCULATION CENTER OF JULIA 1161JUST BENEATH THE NORTHERN EDGE OF THE CLOUD CANOPY. THE SHEARED 1162CLOUD PATTERN IS DUE TO 20-30 KT OF NORTHERLY SHEAR PRODUCED BY A 1163STRONG OUTFLOW CHANNEL ASSOCIATED WITH HURRICANE IGOR. SUBSEQUENT 1164BANDING CLOUD TOPS HAVE WARMED CONSIDERABLY THIS EVENING...AND THE 1165SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO 116665 AND 60 KT RESPECTIVELY. BASED ON THESE DATA...THE INITIAL 1167INTENSITY IS LOWERED TO 60 KT. THE GLOBAL AND THE SHIPS MODELS ALL 1168SUGGEST THAT THE SHEAR WILL PERSIST AND STRENGTHEN BY THE 48 HOUR 1169PERIOD AS THE SHEAR VECTOR BECOMES MORE WESTERLY. THE NHC INTENSITY 1170FORECAST INDICATES A GRADUAL WEAKENING TREND BASED ON THE 1171AFOREMENTIONED GUIDANCE...WITH THE CYCLONE ULTIMATELY BECOMING 1172ABSORBED IN 96 HOURS BY THE MUCH LARGER EXTRATROPICAL IGOR. 1173 1174THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS 1175ADVISORY...AND IS ESTIMATED TO BE NORTHWESTWARD OR 310/14. THE 1176DYNAMICAL MODELS SHOW THE CYCLONE MOVING NORTHWESTWARD DURING THE 1177NEXT 36 HOURS WITHIN THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH 1178TO THE NORTHEAST OF JULIA. THROUGH DAY 3...THE MODELS INDICATE 1179THAT THE SYSTEM WILL TURN NORTH-NORTHEASTWARD...AND NORTHEASTWARD 1180AS THE MID-LEVEL HIGH BEGINS TO DRIFT SOUTHWESTWARD OVER THE 1181CENTRAL ATLANTIC. AFTERWARD...THE MODELS ARE IN GOOD AGREEMENT 1182WITH JULIA BECOMING ABSORBED BY IGOR...GENERALLY IN 96 HOURS...OR 1183EARLIER...AS SUGGESTED BY THE SHIPS AND BOTH THE ECMWF AND GFS 1184ENSEMBLE MEANS. THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS 1185ADVISORY AND IS BASED ON A BLEND OF THE GLOBAL AND REGIONAL MODELS. 1186 1187 1188 1189FORECAST POSITIONS AND MAX WINDS 1190 1191INITIAL 18/0300Z 26.0N 49.2W 60 KT 1192 12HR VT 18/1200Z 28.1N 50.8W 55 KT 1193 24HR VT 19/0000Z 31.0N 52.1W 50 KT 1194 36HR VT 19/1200Z 33.5N 52.0W 45 KT 1195 48HR VT 20/0000Z 35.5N 50.6W 40 KT 1196 72HR VT 21/0000Z 39.0N 46.0W 30 KT 1197 96HR VT 22/0000Z...ABSORBED BY A LARGE EXTRATROPICAL LOW 1198 1199$$ 1200FORECASTER ROBERTS/AVILA 1201 1202 1203WTNT42 KNHC 140837 1204TCDAT2 1205HURRICANE JULIA DISCUSSION NUMBER 8 1206NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1207500 AM AST TUE SEP 14 2010 1208 1209JULIA HAS STRENGTHENED THIS MORNING. A RAGGED EYE FEATURE HAS 1210OCCASIONALLY BEEN EVIDENT IN GEOSTATIONARY SATELLITE IMAGES DURING 1211THE PAST FEW HOURS AND THE CONVECTIVE BANDING HAS BECOME BETTER 1212ORGANIZED...ESPECIALLY OVER THE SOUTHERN SEMICIRCLE. DVORAK 1213CLASSIFICATIONS FROM TAFB AND SAB WERE 65 KT...AND THE CIMSS ADT 1214ESTIMATES ARE ALSO NEAR THAT VALUE. ON THIS BASIS...JULIA IS 1215UPGRADED TO A HURRICANE WITH THE INITIAL WIND SPEED SET AT 65 KT. 1216 1217SOME ADDITIONAL STRENGTHENING APPEARS LIKELY DURING THE NEXT DAY OR 1218SO AS UNANIMOUSLY SHOWN BY THE MODEL GUIDANCE. HOWEVER...SEA 1219SURFACE TEMPERATURES COOL BELOW 27 C ALONG THE FORECAST TRACK IN 24 1220TO 48 HOURS...AND THAT SHOULD LIMIT INTENSIFICATION DURING THAT 1221TIME PERIOD. ALTHOUGH JULIA IS EXPECTED TO TRACK OVER WARMER 1222WATERS BEYOND A FEW DAYS...STRONG NORTH TO NORTHEASTERLY SHEAR... 1223ASSOCIATED WITH THE OUTFLOW OF HURRICANE IGOR...SHOULD INDUCE 1224WEAKENING BY THAT TIME. THE OFFICIAL FORECAST IS ADJUSTED UPWARD 1225DURING THE FIRST FEW DAYS AND THEN FALLS IN LINE WITH THE PREVIOUS 1226FORECAST BY THE END OF THE PERIOD...AND IS IN GOOD AGREEMENT WITH 1227THE STATISTICAL-DYNAMICAL GUIDANCE. 1228 1229THE INITIAL MOTION ESTIMATE IS 295/10. A MID- TO UPPER-LEVEL TROUGH 1230OVER THE EASTERN ATLANTIC IS EXPECTED TO CAUSE JULIA TO TURN 1231NORTHWESTWARD LATER TODAY AND CONTINUE IN THAT DIRECTION FOR THE 1232NEXT 24 TO 48 HOURS. THEREAFTER...THE GLOBAL MODELS ARE IN 1233AGREEMENT IN SHOWING A SUBTROPICAL RIDGE TO STRENGTHEN NORTH OF 1234JULIA. THIS PATTERN SHOULD CAUSE THE CYCLONE TO TURN BACK TO THE 1235WEST-NORTHWEST FOR A COUPLE OF DAYS. BY THE END OF THE FORECAST 1236PERIOD...JULIA IS EXPECTED TO MOVE NORTHWESTWARD OR 1237NORTH-NORTHWESTWARD ALONG THE WESTERN PERIPHERY OF THE RIDGE. THE 1238OFFICIAL FORECAST IS ADJUSTED SLIGHTLY TO THE WEST IN THE 3 TO 5 1239DAY RANGE...TRENDING TOWARD THE MULTI-MODEL CONSENSUS. 1240 1241FORECAST POSITIONS AND MAX WINDS 1242 1243INITIAL 14/0900Z 16.1N 29.0W 65 KT 124412HR VT 14/1800Z 16.8N 30.1W 70 KT 124524HR VT 15/0600Z 18.1N 31.7W 80 KT 124636HR VT 15/1800Z 19.7N 33.6W 80 KT 124748HR VT 16/0600Z 21.5N 36.1W 75 KT 124872HR VT 17/0600Z 24.5N 42.5W 70 KT 124996HR VT 18/0600Z 27.5N 48.5W 60 KT 1250120HR VT 19/0600Z 32.0N 51.0W 50 KT 1251 1252$$ 1253FORECASTER CANGIALOSI 1254 1255 1256 1257 1258WTNT42 KNHC 141444 1259TCDAT2 1260HURRICANE JULIA DISCUSSION NUMBER 9 1261NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 12621100 AM AST TUE SEP 14 2010 1263 1264SATELLITE IMAGES INDICATE THAT JULIA IS STILL STRENGTHENING. A 0920 1265UTC SSM/IS OVERPASS SHOWED A WELL-DEFINED EYEWALL SURROUNDED BY TWO 1266PROMINENT BANDS...WHILE CONVENTIONAL IMAGERY SHOWS THE APPEARANCE 1267OF A WELL-DEVELOPED CENTRAL DENSE OVERCAST AND A BANDING-TYPE EYE. 1268SUBJECTIVE DVORAK T-NUMBERS AT 1200 UTC ARE 4.0 AND 5.0 FROM TAFB 1269AND SAB...RESPECTIVELY. THE INITIAL INTENSITY IS RAISED TO 75 1270KT...BASED UPON A BLEND OF THESE ESTIMATES. 1271 1272WHILE SOME ADDITIONAL INTENSIFICATION IS POSSIBLE DURING THE NEXT 12 1273TO 24 HOURS...WATER VAPOR IMAGERY SHOWS A MID- TO UPPER-LEVEL 1274TROUGH...PARTIALLY RELATED TO THE OUTFLOW OF HURRICANE IGOR... 1275LOCATED A FEW HUNDRED MILES NORTHWEST OF JULIA. GLOBAL MODELS 1276SUGGEST THAT THIS FEATURE SHOULD BEGIN TO IMPART WESTERLY SHEAR 1277OVER THE CYCLONE AFTER ABOUT 24 HOURS...AT ABOUT THE TIME JULIA 1278BEGINS TO PASS OVER MARGINAL SEA SURFACE TEMPERATURES. WATERS 1279SHOULD BEGIN TO WARM AGAIN ALONG THE FORECAST TRACK IN A FEW 1280DAYS...BUT MODEL GUIDANCE SHOWS A STRONG SURGE OF NORTHERLY FLOW 1281ASSOCIATED THE OUTFLOW OF IGOR THAT COULD NEGATIVELY IMPACT JULIA 1282AFTER 72 HOURS. IN FACT...SHIPS MODEL OUTPUT INDICATES THE 1283POTENTIAL FOR 30-40 KT OF NORTHERLY SHEAR. ALTHOUGH NO SIGNIFICANT 1284CHANGES WERE MADE TO THE OFFICIAL INTENSITY FORECAST...JULIA 1285COULD BE WEAKER THAN FORECAST IF THE PREDICTED SHEAR MATERIALIZES. 1286 1287THE INITIAL MOTION ESTIMATE IS 295/09...INDICATING THAT JULIA HAS 1288RECENTLY SLOWED A BIT. THERE IS AN UNUSUAL AMOUNT OF SPREAD IN THE 1289SHORT-TERM TRACK FORECAST. THE GFS/HWRF/GFDL SHOW JULIA TURNING 1290TOWARD THE NORTHWEST DURING THE NEXT DAY OR SO AS IT INTERACTS WITH 1291AN EXTENSION OF A MID- TO UPPER-LEVEL CYCLONE LOCATED OVER THE 1292NORTHEAST ATLANTIC. THE UKMET/ECMWF FAVOR A WEST-NORTHWEST COURSE 1293AS A RESULT OF MORE SUBTROPICAL RIDGING. FROM ABOUT 36-72 HR... 1294THERE IS BETTER AGREEMENT IN THE MODEL GUIDANCE OF SUBTROPICAL 1295RIDGING BUILDING NORTH OF JULIA AND HENCE A MORE WEST-NORTHWESTERLY 1296COURSE WITH AN INCREASE IN FORWARD SPEED. AFTER 72 HR...GLOBAL 1297MODELS SHOW JULIA TURNING NORTH-NORTHWESTWARD AS IT APPROACHES THE 1298WESTERN END OF THE SUBTROPICAL RIDGE AND THE LARGE HURRICANE IGOR 1299OVER THE CENTRAL ATLANTIC. THE OFFICIAL NHC FORECAST TRACK IS 1300NUDGED A BIT TO THE RIGHT...LYING NEAR A CONSENSUS THAT EXCLUDES 1301THE UKMET. 1302 1303 1304FORECAST POSITIONS AND MAX WINDS 1305 1306INITIAL 14/1500Z 16.2N 29.5W 75 KT 130712HR VT 15/0000Z 17.2N 30.8W 85 KT 130824HR VT 15/1200Z 18.7N 32.4W 80 KT 130936HR VT 16/0000Z 20.3N 34.5W 75 KT 131048HR VT 16/1200Z 22.2N 37.7W 70 KT 131172HR VT 17/1200Z 24.7N 44.3W 70 KT 131296HR VT 18/1200Z 28.0N 49.0W 60 KT 1313120HR VT 19/1200Z 32.5N 50.5W 50 KT 1314 1315$$ 1316FORECASTER KIMBERLAIN 1317 1318 1319 1320 1321WTNT42 KNHC 142036 1322TCDAT2 1323HURRICANE JULIA DISCUSSION NUMBER 10 1324NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1325500 PM AST TUE SEP 14 2010 1326 1327THE CLOUD PATTERN ASSOCIATED WITH JULIA HAS BECOME SOMEWHAT 1328ASYMMETRIC DURING THE PAST SEVERAL HOURS...WITH A LARGE MASS OF 1329DEEP CONVECTION HAVING FORMED SOUTHWEST OF THE CENTER. THE 1330EYE THAT WAS VISIBLE EARLIER IS ALSO NO LONGER AS EVIDENT. THE 1331OUTFLOW HAS BECOME A BIT RESTRICTED TO THE WEST...INDICATIVE OF 1332SOME UPPER-LEVEL WESTERLY FLOW ALREADY IMPINGING UPON THE CYCLONE. 1333DVORAK CI NUMBERS AT 1800 UTC ARE UNCHANGED FROM 1200 UTC...WHILE 1334THE 3-HOURLY AVERAGED ADT VALUE IS AT 4.6. THE INITIAL INTENSITY IS 1335HELD AT 75 KT FOR THIS ADVISORY IN AGREEMENT WITH SATELLITE 1336ESTIMATES. 1337 1338RECENT FIXES INDICATE THAT JULIA HAS SLOWED A BIT FURTHER...AND THE 1339INITIAL MOTION ESTIMATE IS 295/08. WITH THE EXCEPTION OF THE 1340UKMET...THE TRACK MODEL GUIDANCE IS IN BETTER AGREEMENT THIS CYCLE 1341CONCERNING THE SHORT-TERM TRACK FORECAST. JULIA IS EXPECTED TO 1342MOVE ON A GENERAL NORTHWESTERLY COURSE DURING THE NEXT 24 HOURS AS 1343IT INTERACTS WITH A MID- TO UPPER-LEVEL TROUGH EXTENDING 1344SOUTHWESTWARD FROM A CYCLONE OVER THE NORTHEAST ATLANTIC. 1345FROM 24-72 HOURS...GLOBAL MODELS INDICATE THAT JULIA SHOULD TURN 1346WEST-NORTHWESTWARD WITH SOME INCREASE IN FORWARD SPEED UNDER THE 1347INFLUENCE OF A BUILDING SUBTROPICAL RIDGE TO THE NORTH. BEYOND THAT 1348TIME...JULIA IS FORECAST TO TURN NORTH-NORTHWESTWARD AND THEN 1349NORTHWARD ONCE IT REACHES THE WESTERN PERIPHERY OF THE SUBTROPICAL 1350RIDGE. THE OFFICIAL NHC TRACK FORECAST IS NUDGED TO THE RIGHT AGAIN 1351USING A MODEL CONSENSUS THAT EXCLUDES THE UKMET BUT HAS SHIFTED A 1352BIT TO THE LEFT LATE IN THE PERIOD...FOLLOWING THE TREND IN THE 1353GUIDANCE. 1354 1355WATER VAPOR IMAGERY SUGGESTS THAT WESTERLY SHEAR ASSOCIATED WITH A 1356MID- TO UPPER-LEVEL TROUGH...PARTIALLY RELATED TO THE OUTFLOW OF 1357HURRICANE IGOR...MAY ALREADY BE NEGATIVELY IMPACTING JULIA. SHIPS 1358MODEL OUTPUT INDICATES SOME INCREASE IN THIS SHEAR DURING THE NEXT 1359COUPLE OF DAYS AT THE SAME TIME JULIA TRAVERSES MARGINAL SEA 1360SURFACE TEMPERATURES. ALTHOUGH THE CYCLONE IS FORECAST TO MOVE 1361OVER WARMER WATERS AGAIN LATER IN THE FORECAST PERIOD...GLOBAL 1362MODELS SHOW A STRONG SURGE OF NORTHERLY FLOW ASSOCIATED WITH THE 1363OUTFLOW FROM HURRICANE IGOR ADVERSELY AFFECTING JULIA. ALTHOUGH 1364FEW CHANGES WERE MADE TO THE OFFICIAL NHC INTENSITY FORECAST... 1365JULIA COULD BE WEAKER THAN FORECAST IF THE PREDICTED SHEAR 1366MATERIALIZES. 1367 1368 1369FORECAST POSITIONS AND MAX WINDS 1370 1371INITIAL 14/2100Z 16.7N 30.2W 75 KT 137212HR VT 15/0600Z 17.8N 31.4W 80 KT 137324HR VT 15/1800Z 19.5N 33.1W 80 KT 137436HR VT 16/0600Z 21.3N 35.7W 75 KT 137548HR VT 16/1800Z 22.8N 39.1W 70 KT 137672HR VT 17/1800Z 25.0N 46.0W 70 KT 137796HR VT 18/1800Z 29.1N 50.5W 60 KT 1378120HR VT 19/1800Z 33.0N 51.0W 50 KT 1379 1380$$ 1381FORECASTER KIMBERLAIN 1382 1383 1384 1385000 1386 1387WTNT42 KNHC 150237 1388TCDAT2 1389HURRICANE JULIA DISCUSSION NUMBER 11 1390NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 13911100 PM AST TUE SEP 14 2010 1392 1393JULIA HAS AGAIN DEVELOPED A SMALL EYE...AND INTENSE DEEP CONVECTION 1394HAS BEEN WRAPPING AROUND THAT FEATURE OVER THE PAST FEW HOURS. 1395DVORAK CURRENT INTENSITY ESTIMATES ARE A UNANIMOUS 5.0 FROM TAFB... 1396SAB...AND THE OBJECTIVE ADT...SO THE INITIAL INTENSITY IS RAISED TO 139790 KT. MICROWAVE IMAGES INDICATE THAT JULIA HAS A WELL-DEFINED 1398CENTER ALTHOUGH THE SATELLITE PRESENTATION IS NOW A LITTLE 1399ELONGATED AND OUTFLOW IS RESTRICTED OVER THE WESTERN SIDE OF THE 1400HURRICANE...LIKELY DUE TO SHEAR PRODUCED BY AN UPPER-LEVEL TROUGH 1401TO ITS NORTHWEST. EVEN THOUGH THE SHEAR IS ALREADY PRESENT...IT 1402MAY NOT BE STRONG ENOUGH YET TO LIMIT INTENSIFICATION...AND THE 1403OFFICIAL FORECAST INDICATES VERY LITTLE CHANGE IN INTENSITY FOR THE 1404NEXT 24-36 HOURS. THIS FOLLOWS THE TREND SHOWN IN THE STATISTICAL 1405GUIDANCE. AFTER 36 HOURS...VERTICAL SHEAR IS EXPECTED TO INCREASE 1406DRASTICALLY AS JULIA MOVES AROUND THE NORTHERN EDGE OF A MID- TO 1407UPPER-LEVEL LOW...AND THEN BEGINS TO FEEL THE INFLUENCE OF 1408UPPER-LEVEL OUTFLOW FROM HURRICANE IGOR. THE OFFICIAL FORECAST IS 1409JUST A LITTLE HIGHER THAN THE PREVIOUS ONE DUE TO THE RECENT 1410INTENSIFICATION...AND IT STILL SHOWS WEAKENING TO A TROPICAL STORM 1411BY DAY 5. 1412 1413THE INITIAL POSITION HAS BEEN ADJUSTED A LITTLE TO THE SOUTH BASED 1414ON RECENT MICROWAVE IMAGERY...BUT THE MOTION IS STILL ESTIMATED AT 1415295/8. JULIA IS EXPECTED TO TURN TO THE NORTHWEST SHORTLY...BUT IT 1416SHOULD TURN BACK TO THE WEST-NORTHWEST WITHIN 36 HOURS AS IT GETS 1417STEERED BETWEEN THE NORTHERN EDGE OF THE UPPER LOW AND A BLOCKING 1418RIDGE TO THE NORTH. BY DAY 4...JULIA WILL HAVE REACHED THE 1419SOUTHWESTERN PERIPHERY OF THE RIDGE AND THE SOUTHERLY FLOW TO THE 1420EAST OF IGOR...AND IT SHOULD TURN SHARPLY NORTHWEST THEN TO THE 1421NORTH BY DAY 5. THE TRACK GUIDANCE IS TIGHTLY-CLUSTERED THROUGH 1422DAY 4 BUT THEN WIDENS ON DAY 5 WITH THE ECMWF TAKING A MORE 1423WESTERLY COURSE. THE OFFICIAL FORECAST IS LOCATED JUST TO THE WEST 1424OF THE CONSENSUS TVCN ON DAY 5 OUT OF RESPECT FOR THE ECMWF. 1425 1426FORECAST POSITIONS AND MAX WINDS 1427 1428INITIAL 15/0300Z 16.7N 30.9W 90 KT 142912HR VT 15/1200Z 17.8N 32.1W 95 KT 143024HR VT 16/0000Z 19.4N 34.2W 90 KT 143136HR VT 16/1200Z 21.0N 37.3W 85 KT 143248HR VT 17/0000Z 22.4N 40.8W 80 KT 143372HR VT 18/0000Z 25.0N 47.0W 75 KT 143496HR VT 19/0000Z 29.0N 51.0W 65 KT 1435120HR VT 20/0000Z 33.0N 51.0W 50 KT 1436 1437$$ 1438FORECASTER BERG 1439 1440 1441 1442000 1443 1444WTNT42 KNHC 150532 1445TCDAT2 1446HURRICANE JULIA SPECIAL DISCUSSION NUMBER 12 1447NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 14481230 AM AST WED SEP 15 2010 1449 1450ENHANCED INFRARED SATELLITE IMAGES INDICATE THAT JULIA HAS RAPIDLY 1451STRENGTHENED DURING THE LAST FEW HOURS WITH THE EYE NOW MORE 1452DISTINCT AND CIRCULAR AND THE LARGER CIRCULATION LESS ELONGATED 1453THAN IT WAS EARLIER. CLOUD TOPS COLDER THAN -75 C NOW SURROUND THE 1454EYE. A SPECIAL CLASSIFICATION FROM TAFB GAVE A DVORAK T-NUMBER OF 14556.0 OR 115 KT AND OBJECTIVE DVORAK ESTIMATES FROM UW-CIMSS ARE 1456CLOSER TO 100 OR 105 KT. BASED ON THESE ESTIMATES...THE NEW 1457INITIAL INTENSITY IS SET AT 110 KT. SINCE THE ENVIRONMENT HAS 1458OBVIOUSLY BECOME MORE FAVORABLE FOR STRENGTHENING...AT LEAST IN THE 1459SHORT TERM...THE OFFICIAL INTENSITY FORECAST HAS BEEN ADJUSTED 1460UPWARD FOR THE FIRST COUPLE OF DAYS TO ACCOUNT FOR THESE CHANGES. 1461 1462FORECAST POSITIONS AND MAX WINDS 1463 1464INITIAL 15/0530Z 16.9N 31.3W 110 KT 146512HR VT 15/1200Z 17.8N 32.1W 120 KT 146624HR VT 16/0000Z 19.4N 34.2W 120 KT 146736HR VT 16/1200Z 21.0N 37.3W 110 KT 146848HR VT 17/0000Z 22.4N 40.8W 90 KT 146972HR VT 18/0000Z 25.0N 47.0W 75 KT 147096HR VT 19/0000Z 29.0N 51.0W 65 KT 1471120HR VT 20/0000Z 33.0N 51.0W 50 KT 1472 1473$$ 1474FORECASTER CANGIALOSI/PASCH 1475 1476 1477 1478 1479WTNT42 KNHC 150859 1480TCDAT2 1481HURRICANE JULIA DISCUSSION NUMBER 13 1482NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1483500 AM AST WED SEP 15 2010 1484 1485A RAPID STRENGTHENING EPISODE WAS NOTED A FEW HOURS AGO. THIS WAS 1486MOSTLY UNEXPECTED...AND REMINDS US OF OUR LIMITED UNDERSTANDING OF 1487TROPICAL CYCLONE INTENSITY CHANGE. JULIA IS STILL STRENGTHENING... 1488BUT AT A SIGNIFICANTLY SLOWER RATE THAN WAS OBSERVED LAST EVENING 1489AND EARLIER THIS MORNING. ALTHOUGH THE EYE HAS NOT WARMED 1490MUCH...THE CONVECTIVE BANDING AROUND THE EYE HAS BECOME BETTER 1491ORGANIZED. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB ARE 115 1492KT...AND THAT WILL BE THE INITIAL WIND SPEED FOR THIS ADVISORY... 1493MAKING JULIA A CATEGORY FOUR HURRICANE. JULIA COULD STRENGTHEN A 1494LITTLE MORE TODAY AS IT REMAINS OVER RELATIVELY WARM WATER AND IN A 1495MODERATE WIND SHEAR ENVIRONMENT. HOWEVER...MUCH OF THE INTENSITY 1496GUIDANCE SHOWS GRADUAL WEAKENING BEYOND 12 TO 24 HOURS AS JULIA 1497MOVES OVER COOLER WATER AND THEN INTO STRONG NORTHERLY SHEAR 1498ASSOCIATED WITH THE OUTFLOW OF HURRICANE IGOR. THE NHC OFFICIAL 1499INTENSITY FORECAST IS A LITTLE HIGHER THAN THE PREVIOUS 1500ADVISORY...AND IS ABOVE ALL OF THE MODELS FOR THE FIRST FEW DAYS AS 1501NONE OF THE GUIDANCE ANTICIPATED THE OBSERVED STRENGTHENING OF 1502JULIA. 1503 1504THE HURRICANE HAS NOW TURNED TO THE NORTHWEST...WITH A 12-HOUR 1505INITIAL MOTION ESTIMATE OF 305/9. A CONTINUED NORTHWESTWARD MOTION 1506IS EXPECTED FOR THE NEXT DAY OR SO AS JULIA NEARS A MID- TO 1507UPPER-LEVEL TROUGH OVER THE EASTERN ATLANTIC. HOWEVER...A TURN 1508BACK TO THE WEST-NORTHWEST IS FORECAST IN ABOUT 36 HOURS AS THE 1509HURRICANE IS STEERED BETWEEN AN UPPER-LEVEL LOW AND A STRENGTHENING 1510SUBTROPICAL RIDGE. JULIA IS EXPECTED TO APPROACH THE WESTERN 1511PERIPHERY OF THE RIDGE IN 3 TO 4 DAYS ALLOWING THE SYSTEM TO TURN 1512NORTHWARD AND POSSIBLY NORTH-NORTHEASTWARD BY DAY 5. THE OFFICIAL 1513TRACK FORECAST IS ADJUSTED SLIGHTLY TO THE RIGHT AND IS A LITTLE 1514FASTER THAN THE PREVIOUS ONE TO COME INTO BETTER AGREEMENT WITH THE 1515NEW GUIDANCE SUITE. 1516 1517FORECAST POSITIONS AND MAX WINDS 1518 1519INITIAL 15/0900Z 17.3N 31.8W 115 KT 152012HR VT 15/1800Z 18.6N 33.2W 120 KT 152124HR VT 16/0600Z 20.4N 35.9W 120 KT 152236HR VT 16/1800Z 22.2N 39.3W 105 KT 152348HR VT 17/0600Z 23.4N 42.6W 95 KT 152472HR VT 18/0600Z 26.3N 48.1W 80 KT 152596HR VT 19/0600Z 30.0N 50.5W 65 KT 1526120HR VT 20/0600Z 34.0N 49.5W 50 KT 1527 1528$$ 1529FORECASTER CANGIALOSI 1530 1531 1532 1533 1534WTNT42 KNHC 151454 1535TCDAT2 1536HURRICANE JULIA DISCUSSION NUMBER 14 1537NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1538ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 15391100 AM AST WED SEP 15 2010 1540 1541RAPID INTENSIFICATION OCCURRED DURING THE OVERNIGHT HOURS WITH 1542JULIA WHEN THE HURRICANE REACHED CATEGORY FOUR STRENGTH. THIS 1543STRENGTHENING APPPEARS TO HAVE LEVELED OFF THIS MORNING...AS 1544OUTFLOW FROM HURRICANE IGOR COMBINED WITH A NEARBY UPPER LEVEL LOW 1545IS PRODUCING SOUTHERLY SHEAR OVER JULIA. THIS LEVELING OF ITS 1546INTENSITY ALSO SHOWS UP WITH THE T NUMBERS FROM BOTH SAB AND 1547TAFB...WHICH HOVER AND DROP SLIGHTLY AROUND/BETWEEN 5 AND 6. 1548HOWEVER JULIA MAINTAINS A SOLID CENTRAL DENSE OVERCAST/CORE AND 1549CLEAR EYE STRUCTURE WITH IMPRESSIVE CLOUD TOP ENHANCEMENT... THUS 1550INITIAL INTENSITY WILL REMAIN AT 115 KTS. JULIA IS EXPECTED TO 1551MAINTAIN THIS STRENGTH OVER THE NEXT 24 HRS BEFORE BEGINNING TO 1552WEAKEN AS THE SYSTEM INTERACTS WITH MARGINAL AND COOLER SST VALUES. 1553 1554THE FORECAST SCENARIO HAS NOT BUDGED MUCH BUT THERE REMAINS RATHER 1555LARGE SPREAD WITHIN THE GLOBAL AND DYNAMICAL GUIDANCE IN THE EARLY 1556MEDIUM RANGE PERIOD. FOR THE NEXT 60 TO 72 HRS...JULIA IS EXPECTED 1557TO MOVE AROUND 15 KTS OR GREATER OFF TO THE NORTHWEST OR 1558WEST-NORTHWEST AS A BUILDING MID-LEVEL RIDGE BUILDS OVER THE EAST 1559CENTRAL ATLANTIC. AFTER 72 HRS...JULIA FORWARD MOTION SLOWS AS A 1560NORTHERN STREAM RIDGE BUILDS TO ITS NORTH EAST OF NEWFOUNDLAND 1561WHICH KEEPS THE STORM FROM ACCELERATING INTO THE MAIN BAND OF THE 1562WESTERLIES. THE OFFICIAL TRACK FORECAST MAINTAINED A TIGHT 1563CORRELATION TO THE MODEL CONSENSUS AND KEPT GOOD CONTINUITY. 1564 1565 1566FORECAST POSITIONS AND MAX WINDS 1567 1568INITIAL 15/1500Z 18.2N 32.7W 115 KT 156912HR VT 16/0000Z 19.5N 34.4W 115 KT 157024HR VT 16/1200Z 21.3N 37.5W 115 KT 157136HR VT 17/0000Z 22.9N 41.0W 105 KT 157248HR VT 17/1200Z 24.3N 44.2W 95 KT 157372HR VT 18/1200Z 27.5N 49.0W 80 KT 157496HR VT 19/1200Z 31.5N 50.0W 65 KT 1575120HR VT 20/1200Z 35.0N 47.5W 50 KT 1576 1577$$ 1578FORECASTER MUSHER 1579 1580 1581 1582 1583WTNT42 KNHC 152044 1584TCDAT2 1585HURRICANE JULIA DISCUSSION NUMBER 15 1586NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1587500 PM AST WED SEP 15 2010 1588 1589THE EYE OF JULIA HAS BEEN APPARENT INTERMITTENTLY IN INFRARED 1590SATELLITE IMAGERY THIS AFTERNOON. A 1912 UTC SSMIS MICROWAVE 1591OVERPASS INDICATES THAT THERE IS SOME TILT TO THE CIRCULATION WITH 1592THE LOW-LEVEL CENTER LOCATED A LITTLE TO THE SOUTH OF THE MID- TO 1593UPPER-LEVEL EYE...DUE TO SOUTH-SOUTHWESTERLY SHEAR. JULIA HAS 1594LIKELY PEAKED IN INTENSITY. THE INITIAL INTENSITY IS LOWERED TO 1595110 KT...BASED ON A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK DATA 1596T-NUMBERS THAT HAVE DECREASED SLIGHTLY. THE CYCLONE WILL BE MOVING 1597INTO A LESS FAVORABLE ENVIRONMENT WITH MODERATE SOUTHERLY SHEAR AND 1598SLIGHTLY COOLER SSTS DURING THE NEXT DAY OR SO. THIS SHOULD RESULT 1599IN GRADUAL WEAKENING. AFTER 48 HOURS...THE GLOBAL MODELS SHOW JULIA 1600MOVING INTO AN AREA OF INCREASING NORTHEASTERLY UPPER-LEVEL WINDS 1601ASSOCIATED WITH THE OUTFLOW FROM HURRICANE IGOR. A FASTER RATE OF 1602WEAKENING IS INDICATED BY THE INTENSITY GUIDANCE AND IN THE 1603OFFICIAL FORECAST AT THAT TIME. THE NHC FORECAST IS CLOSE TO THE 1604INTENSITY CONSENSUS AT DAYS 3-5...BUT IS HIGHER THAN THE SHIPS 1605GUIDANCE WHICH WEAKENS THE JULIA VERY RAPIDLY AFTER 72 HOURS. 1606 1607THE INITIAL MOTION ESTIMATE IS 315/11. JULIA IS FORECAST TO MOVE 1608NORTHWESTWARD AROUND AN UPPER-LEVEL LOW TO ITS SOUTHWEST DURING THE 1609NEXT 12-24 HOURS. DURING THIS TIME...THE FORWARD SPEED OF JULIA IS 1610FORECAST TO INCREASE. BETWEEN 24 AND 72 HOURS...THE HURRICANE WILL 1611BE STEERED IN A WEST-NORTHWEST TO NORTHWEST DIRECTION AROUND THE 1612WESTERN PERIPHERY OF A MID-LEVEL RIDGE CENTERED BETWEEN JULIA AND 1613THE AZORES ISLANDS. THEREAFTER...JULIA SHOULD TURN 1614NORTHWARD...THEN NORTHEASTWARD BETWEEN THE NORTHWEST SIDE OF THE 1615RIDGE AND HURRICANE IGOR TO THE WEST. THE TRACK GUIDANCE IS IN A 1616LITTLE BETTER AGREEMENT FOR THIS CYCLE. THE NEW NHC TRACK FORECAST 1617HAS BEEN ADJUSTED SOMEWHAT NORTHWARD AND LIES NEAR THE MIDDLE OF 1618THE MODEL ENVELOPE. 1619 1620 1621FORECAST POSITIONS AND MAX WINDS 1622 1623INITIAL 15/2100Z 19.2N 33.5W 110 KT 162412HR VT 16/0600Z 20.6N 35.5W 105 KT 162524HR VT 16/1800Z 22.6N 38.9W 100 KT 162636HR VT 17/0600Z 24.3N 42.4W 95 KT 162748HR VT 17/1800Z 26.0N 45.5W 85 KT 162872HR VT 18/1800Z 30.0N 49.6W 75 KT 162996HR VT 19/1800Z 34.0N 49.0W 60 KT 1630120HR VT 20/1800Z 36.0N 45.0W 45 KT 1631 1632$$ 1633FORECASTER BROWN 1634 1635 1636 1637 1638WTNT42 KNHC 160255 1639TCDAT2 1640HURRICANE JULIA DISCUSSION NUMBER 16 1641NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 16421100 PM AST WED SEP 15 2010 1643 1644JULIA IS COMING UNDER INCREASING INFLUENCE OF SOUTHERLY SHEAR...AND 1645RECENT MICROWAVE IMAGES INDICATE THAT THE LOW-LEVEL CENTER AND THE 1646MID-LEVEL EYE ARE DISPLACED FROM ONE ANOTHER. SATELLITE INTENSITY 1647ESTIMATES ARE NOW T5.0/5.5 FROM TAFB...T4.0/5.0 FROM SAB...AND 1648T5.3/5.7 FROM THE UW-CIMSS ADT. THE INITIAL INTENSITY IS LOWERED 1649TO 100 KT FOR THIS ADVISORY...BUT IT IS POSSIBLE THAT JULIA COULD 1650BE WEAKER THAN THAT. JULIA IS LOCATED VERY NEAR A DEVELOPING 1651CLOSED UPPER-LEVEL LOW...AND STRONG SHEAR IS EXPECTED TO CONTINUE 1652OVER THE HURRICANE DURING THE FORECAST PERIOD. THE OFFICIAL 1653FORECAST INDICATES GRADUAL WEAKENING DURING THE NEXT 48-72 HOURS 1654AND IS IN LINE WITH THE INTENSITY CONSENSUS. JULIA SHOULD WEAKEN 1655TO A TROPICAL STORM BY DAYS 4 AND 5...BUT THE FORECAST IS A LITTLE 1656ABOVE THE INTENSITY CONSENSUS AT THAT TIME SINCE THE SHIPS 1657MODEL...FOR SOME UNKNOWN REASON...SHOWS THE SYSTEM DISSIPATED BY 1658DAY 5. THIS SEEMS UNREASONABLE SINCE THE GFS STILL SHOWS AN INTACT 1659AREA OF LOW PRESSURE. 1660 1661THE HURRICANE IS STARTING TO ACCELERATE AND IS NOW MOVING AT 315/14. 1662ADDITIONAL ACCELERATION IS EXPECTED OVER THE NEXT 24 HOURS AS JULIA 1663IS STEERED BETWEEN A MID-LEVEL HIGH TO ITS NORTHEAST AND THE 1664UPPER-LEVEL LOW TO ITS SOUTHWEST...ALMOST LIKE A SLING-SHOT AFFECT. 1665JULIA WILL THEN BE STEERED NORTH-NORTHWEST AND THEN NORTH FROM 166648-72 HOURS AS IT REACHES THE WESTERN SIDE OF THE RIDGE AND THE 1667EASTERN SIDE OF THE LARGE CIRCULATION ASSOCIATED WITH IGOR. THE 1668RECURVATURE TO THE NORTHEAST IS ANTICIPATED BY DAY 5 AS JULIA GETS 1669EMBEDDED WITHIN THE MID-LATITUDE WESTERLY FLOW. THE OFFICIAL TRACK 1670FORECAST IS VERY CLOSE TO THE PREVIOUS FORECAST...AND LIES JUST TO 1671THE WEST OF THE MODEL CONSENSUS. JUST LIKE IN THE CASE WITH 1672IGOR...THE ECMWF MODEL LIES AT THE WESTERN SIDE OF THE GUIDANCE 1673ENVELOPE AND CANNOT BE IGNORED. 1674 1675 1676FORECAST POSITIONS AND MAX WINDS 1677 1678INITIAL 16/0300Z 20.2N 34.6W 100 KT 167912HR VT 16/1200Z 21.7N 36.9W 90 KT 168024HR VT 17/0000Z 23.6N 40.4W 85 KT 168136HR VT 17/1200Z 25.3N 43.8W 80 KT 168248HR VT 18/0000Z 27.0N 46.5W 75 KT 168372HR VT 19/0000Z 31.5N 49.5W 65 KT 168496HR VT 20/0000Z 35.0N 48.0W 50 KT 1685120HR VT 21/0000Z 36.5N 43.5W 40 KT 1686 1687$$ 1688FORECASTER BERG 1689 1690 1691 1692 1693WTNT42 KNHC 160903 1694TCDAT2 1695HURRICANE JULIA DISCUSSION NUMBER 17 1696NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1697500 AM AST THU SEP 16 2010 1698 1699THE SATELLITE PRESENTATION OF JULIA HAS CONTINUED TO DETERIORATE 1700OVER THE PAST FEW HOURS. MOST OF THE DEEP CONVECTION IS DISPLACED 1701NORTH OF THE ESTIMATED CENTER POSITION...AND CLOUD TOPS HAVE 1702CONTINUED TO WARM. JULIA IS CURRENTLY SITUATED OVER WATERS OF 170326-27C...AND THE MID- TO UPPER-LEVEL TROUGH/LOW BETWEEN JULIA AND 1704HURRICANE IGOR IS IMPARTING 20 TO 30 KT OF SOUTHWESTERLY SHEAR OVER 1705JULIA ACCORDING TO THE UW-CIMSS SHEAR ANALYSIS. BASED ON A BLEND 1706OF SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY ESTIMATES THE INITIAL 1707INTENSITY IS LOWERED TO 90 KT FOR THIS ADVISORY. WHILE THE SHIPS 1708MODEL OUTPUT SHOWS THE SHEAR DECREASING TO LESS THAN 20 KT FROM 12 1709TO 24 HOURS...JULIA WILL REMAIN OVER MARGINAL SSTS THROUGH THAT 1710TIME. THEN BY 36 HOURS OR SO...WHEN JULIA TEMPORARILY MOVES BACK 1711OVER WARMER WATERS...THE SHEAR INCREASES TO AROUND 30 KT AND 1712REMAINS HIGH FOR THE REST OF THE PERIOD. THIS SCENARIO SHOULD 1713RESULT IN A GRADUAL WEAKENING FOR THE FIRST 48 HOURS...WITH MORE 1714RAPID WEAKENING TOWARD THE END OF THE PERIOD. THE OFFICIAL FORECAST 1715REFLECT THIS AND FOLLOWS A BLEND OF THE LGEM AND SHIPS MODELS 1716THROUGH 48 HOURS...AND IS CLOSEST TO THE LGEM THEREAFTER. 1717 1718WITH A LACK OF MICROWAVE IMAGERY OVER THE PAST FEW HOURS...THE 1719INITIAL MOTION ESTIMATE OF 310/16 IS BASED LARGELY ON CONTINUITY 1720AND THE ASSUMPTION THAT THE LOW-LEVEL CENTER REMAINS DISPLACED SOUTH 1721AND EAST OF THE DEEP CONVECTION. THE TRACK FORECAST REASONING 1722REMAINS UNCHANGED FROM THE PREVIOUS PACKAGE. JULIA IS CURRENTLY 1723BEING STEERED NORTHWESTWARD BY THE UPPER-LEVEL LOW TO ITS SOUTHWEST 1724AND A LARGE MID-LEVEL RIDGE TO ITS EAST...AND THIS WILL CONTINUE 1725FOR THE NEXT DAY OR SO. THEN...AS JULIA MOVES AWAY FROM THE 1726UPPER-LOW...THE CYCLONE WILL MOVE AROUND THE WESTERN PERIPHERY OF 1727THE RIDGE AND TURN EAST-NORTHEASTWARD BY THE END OF THE PERIOD AS 1728IT COMES UNDER THE INFLUENCE OF THE MID-LATITUDE WESTERLIES. SOME 1729DIFFERENCES REMAIN IN HOW SHARPLY JULIA MOVES AROUND THE RIDGE... 1730WITH THE UKMET SHOWING A SHARPER TURN...WHILE THE ECMWF AND HWRF 1731SHOW A WIDER TURN. THE OFFICIAL FORECAST HAS BEEN ADJUSTED TOWARD 1732THE TVCN MULTI-MODEL CONSENSUS...AND IS CLOSE TO THE GFS FOR 1733THE FIRST 72 HOURS...WHICH REPRESENTS A COMPROMISE BETWEEN THE 1734ECMWF AND UKMET. THE NEW NHC FORECAST IS ALSO FASTER THAN THE 1735PREVIOUS PACKAGE DURING THE FIRST 24 HOURS...ACCOUNTING FOR THE 1736OBSERVED ACCELERATION OF JULIA. 1737 1738FORECAST POSITIONS AND MAX WINDS 1739 1740INITIAL 16/0900Z 21.2N 36.2W 90 KT 174112HR VT 16/1800Z 22.8N 38.8W 85 KT 174224HR VT 17/0600Z 24.6N 42.4W 80 KT 174336HR VT 17/1800Z 26.4N 45.5W 75 KT 174448HR VT 18/0600Z 28.3N 47.7W 70 KT 174572HR VT 19/0600Z 32.5N 49.5W 65 KT 174696HR VT 20/0600Z 35.0N 46.5W 50 KT 1747120HR VT 21/0600Z 36.0N 42.5W 40 KT 1748 1749$$ 1750FORECASTER BRENNAN 1751 1752 1753 1754 1755WTNT42 KNHC 161457 1756TCDAT2 1757HURRICANE JULIA DISCUSSION NUMBER 18 1758NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 17591100 AM AST THU SEP 16 2010 1760 1761SATELLITE IMAGERY CONTINUES TO INDICATE WARMING OF THE CLOUD TOPS IN 1762THE RATHER RAGGED LOOKING CENTRAL DENSE OVERCAST. A 1001Z AMSU 1763MICROWAVE OVERPASS INDICATED A 25-30 NMI DIAMETER EYE THAT WAS OPEN 1764IN THE SOUTHEAST QUADRANT. WATER VAPOR IMAGERY ALSO SHOWS A LARGE 1765SLUG OF DRY AIR BEING ENTRAINED INTO THE EASTERN SEMICIRCLE...WHICH 1766LIKELY EXPLAINS THE EROSION OF THE EASTERN EYEWALL NOTED IN THE 1767AMSU IMAGERY. DESPITE THE AFOREMENTIONED NEGATIVE FACTORS...JULIA 1768HAS MAINTAINED GOOD OUTFLOW TO THE WEST AND NORTH OF THE CYCLONE. 1769 1770THE INITIAL MOTION ESTIMATE HAS INCREASED SHARPLY TO 300/22. JULIA 1771IS EXPECTED TO MOVE TO THE WEST-NORTHWEST AND THEN NORTHWEST 1772FOR THE NEXT 36-48 HOURS AS THE HURRICANE ROUNDS THE SOUTHERN 1773PERIPHERY OF A LARGE SUBTROPICAL RIDGE SITUATED TO ITS NORTH AND 1774NORTHEAST. AFTER THAT...SIGNIFICANT VERTICAL WIND SHEAR MAY WEAKEN 1775THE CYCLONE AND CAUSE IT TO BECOME MORE SHALLOW...AND THEN BE 1776STEERED MORE NORTHWARD SIMILAR TO THE ECMWF AND GFDL MODELS...BUT 1777NOT AS FAR NORTH AND WEST AS THE SHALLOW BAM MODEL. THE OFFICIAL 1778TRACK FORECAST HAS BEEN NUDGED TO THE LEFT OF THE PREVIOUS ADVISORY 1779THROUGH 72 HOURS...AND IS SIMILAR TO THE MULTI-MODEL CONSENSUS. 1780 1781DRY AIR AND COOLER SSTS SHOULD CONTINUE THE RECENT WEAKENING 1782TREND...ESPECIALLY AFTER 24 HOURS. BY 36-48 HOURS...ALL OF THE 1783GLOBAL MODELS INDICATE THAT JULIA WILL BE MOVING INTO A REGION OF 1784STRONG UPPER-LEVEL SHEAR CAUSED BY THE PRONOUNCED NORTHERLY OUTFLOW 1785EMANATING FROM THE MAJOR HURRICANE IGOR LOCATED TO ITS WEST. WITH 1786JULIA MOVING INTO 50-70 KT OF 200 MB WINDS...IT WILL BE HARD FOR 1787JULIA TO SURVIVE AS A TROPICAL CYCLONE AS INDICATED BY THE GLOBAL 1788MODELS AND GFDL/HWRF MODELS. THE OFFICIAL INTENSITY FORECAST SHOWS 1789A FASTER WEAKENING TREND THAN THE PREVIOUS ADVISORY...BUT NOT AS 1790FAST AS THE SHIPS MODEL...WHICH DISSIPATES JULIA BY 120 HOURS. 1791 1792 1793FORECAST POSITIONS AND MAX WINDS 1794 1795INITIAL 16/1500Z 22.4N 38.6W 85 KT 179612HR VT 17/0000Z 23.7N 41.2W 75 KT 179724HR VT 17/1200Z 25.5N 44.6W 65 KT 179836HR VT 18/0000Z 27.3N 47.3W 55 KT 179948HR VT 18/1200Z 29.3N 49.1W 45 KT 180072HR VT 19/1200Z 33.2N 49.6W 35 KT 180196HR VT 20/1200Z 35.8N 46.3W 35 KT 1802120HR VT 21/1200Z 38.0N 42.0W 35 KT 1803 1804$$ 1805FORECASTER STEWART 1806 1807 1808 1809 1810WTNT42 KNHC 162040 1811TCDAT2 1812HURRICANE JULIA DISCUSSION NUMBER 19 1813NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1814500 PM AST THU SEP 16 2010 1815 1816VERTICAL SHEAR APPEARS TO HAVE ABATED FOR THE MOMENT...WITH A 1533 1817UTC AMSR-E MICROWAVE PASS SHOWING THAT THE LOW- AND MID-LEVEL 1818CENTERS ARE JUST ABOUT VERTICALLY STACKED. HOWEVER...CONVECTIVE 1819TOPS HAVE WARMED...AND SATELLITE CURRENT INTENSITY ESTIMATES ARE 1820NOW 77 KT FROM TAFB...65 KT FROM SAB...AND 65 KT AND 80 KT FROM TWO 1821VERSIONS OF THE UW-CIMSS ADT. THE INITIAL INTENSITY IS THEREFORE 1822LOWERED TO 75 KT FOR THIS ADVISORY. 1823 1824JULIA HAS AN INITIAL MOTION OF 295/22 KT. THERE HAS BEEN A 1825SIGNIFICANT WESTWARD SHIFT IN NEARLY ALL THE TRACK GUIDANCE ON THIS 1826CYCLE...POSSIBLY DUE TO A STRONGER-THAN-EXPECTED MID-LEVEL HIGH TO 1827THE NORTH AND NORTHEAST OF THE HURRICANE. CONSEQUENTLY...THE NEW 1828OFFICIAL FORECAST HAS BEEN SHIFTED WESTWARD ABOUT HALFWAY BETWEEN 1829OFCI AND THE MODEL CONSENSUS TVCN. SEVERAL MODELS...ESPECIALLY THE 1830UKMET AND ECMWF...ARE EVEN FARTHER WEST THAN THIS TRACK SO IT IS 1831POSSIBLE THAT ADDITIONAL SHIFTS COULD BE REQUIRED IN THE NEXT FEW 1832ADVISORY PACKAGES. GLOBAL MODEL FIELDS INDICATE THAT AFTER JULIA 1833MOVES NORTHWARD AROUND THE RIDGE...IT SHOULD TURN TOWARD THE 1834NORTHEAST AND DISSIPATE IN THE STRONG SOUTHWESTERLY FLOW TO THE 1835EAST OF IGOR IN ABOUT 120 HOURS. 1836 1837WITH THE WESTWARD SHIFT IN THE FORECAST TRACK...JULIA APPEARS TO 1838HAVE A BETTER CHANCE TO MAINTAIN SOME OF ITS INTENSITY OVER THE 1839NEXT COUPLE OF DAYS. THE HURRICANE WILL BE BATTLING THE STRONG 1840UPPER-LEVEL OUTFLOW OF IGOR DURING THE NEXT 36 HOURS OR SO...BUT 1841AFTER THAT THE GLOBAL MODELS SUGGEST THAT JULIA COULD SNEAK 1842UNDERNEATH THE UPPER-LEVEL ANTICYCLONE PARTIALLY GENERATED BY IGOR. 1843THE SHEAR COULD RELAX JUST ENOUGH DURING THAT TIME AND CAUSE MORE 1844MODEST WEAKENING...SO THE NEW INTENSITY FORECAST IS A LITTLE BIT 1845HIGHER THAN THE PREVIOUS ONE FROM 36-72 HOURS. INCIDENTALLY... THE 1846NEW FORECAST IS STILL LOWER THAN INDICATED BY THE LGEM...THE 1847DYNAMICAL MODELS...AND THE INTENSITY CONSENSUS. 1848 1849FORECAST POSITIONS AND MAX WINDS 1850 1851INITIAL 16/2100Z 23.1N 41.1W 75 KT 185212HR VT 17/0600Z 24.2N 43.9W 65 KT 185324HR VT 17/1800Z 26.0N 47.1W 65 KT 185436HR VT 18/0600Z 27.9N 49.6W 60 KT 185548HR VT 18/1800Z 30.1N 51.0W 55 KT 185672HR VT 19/1800Z 34.0N 50.5W 45 KT 185796HR VT 20/1800Z 37.0N 47.0W 35 KT 1858120HR VT 21/1800Z...DISSIPATED 1859 1860$$ 1861FORECASTER BERG 1862 1863 1864 1865000 1866 1867WTNT42 KNHC 172053 1868TCDAT2 1869HURRICANE JULIA DISCUSSION NUMBER 23 1870NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1871500 PM AST FRI SEP 17 2010 1872 1873JULIA HAS BEEN EXPERIENCING MODERATE NORTHERLY SHEAR...AND 1874AT TIMES IT APPEARS THAT THE LOW-LEVEL CENTER IS BEGINNING TO 1875BECOME EXPOSED. USING A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK 1876T-NUMBERS LEADS TO A CURRENT INTENSITY ESTIMATE OF 65 KT. THE 1877SHEAR...WHICH IS PRIMARILY ASSOCIATED WITH THE MASSIVE OUTFLOW 1878PATTERN OF HURRICANE IGOR...IS NOT LIKELY TO RELENT. IN FACT... 1879THE DYNAMICAL GUIDANCE SUGGESTS THAT THE SHEAR WILL BECOME STRONGER. 1880THE OFFICIAL INTENSITY FORECAST SHOWS STEADY WEAKENING AND IS BASED 1881ON A COMBINATION OF THE STATISTICAL-DYNAMICAL SHIPS AND LGEM 1882MODELS. BY THE END OF THE FORECAST PERIOD...GLOBAL MODELS INDICATE 1883THAT JULIA WILL BECOME ABSORBED BY THE MUCH LARGER CIRCULATION OF 1884POST-TROPICAL IGOR. 1885 1886THE INITIAL MOTION IS ABOUT 300/18. THE FORECAST REASONING IS 1887ESSENTIALLY UNCHANGED. JULIA IS EXPECTED TO MOVE AROUND A 1888MID-LEVEL SUBTROPICAL HIGH FOR THE NEXT FEW DAYS...BEFORE GETTING 1889PULLED INTO THE CIRCULATION OF IGOR. THUS...THE NHC TRACK FORECAST 1890SHOWS A GRADUAL TURN TOWARD THE NORTHWEST...NORTH...AND NORTH- 1891NORTHEAST. THIS IS JUST A LITTLE TO THE WEST OF THE PREVIOUS 1892OFFICIAL TRACK AND GENERALLY TO THE RIGHT OF THE MULTI-MODEL 1893CONSENSUS TVCN. 1894 1895FORECAST POSITIONS AND MAX WINDS 1896 1897INITIAL 17/2100Z 25.2N 48.2W 65 KT 189812HR VT 18/0600Z 26.9N 50.0W 60 KT 189924HR VT 18/1800Z 29.6N 51.8W 55 KT 190036HR VT 19/0600Z 32.5N 52.3W 50 KT 190148HR VT 19/1800Z 34.8N 51.2W 45 KT 190272HR VT 20/1800Z 38.2N 47.2W 35 KT 190396HR VT 21/1800Z 43.0N 43.0W 25 KT 1904120HR VT 22/1800Z...DISSIPATED 1905 1906$$ 1907FORECASTER PASCH 1908 1909 1910 1911 1912WTNT42 KNHC 180241 1913TCDAT2 1914TROPICAL STORM JULIA DISCUSSION NUMBER 24 1915NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 19161100 PM AST FRI SEP 17 2010 1917 1918THE SATELLITE PRESENTATION SHOWS THE CIRCULATION CENTER OF JULIA 1919JUST BENEATH THE NORTHERN EDGE OF THE CLOUD CANOPY. THE SHEARED 1920CLOUD PATTERN IS DUE TO 20-30 KT OF NORTHERLY SHEAR PRODUCED BY A 1921STRONG OUTFLOW CHANNEL ASSOCIATED WITH HURRICANE EARL. SUBSEQUENT 1922BANDING CLOUD TOPS HAVE WARMED CONSIDERABLY THIS EVENING...AND THE 1923SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO 192465 AND 60 KT RESPECTIVELY. BASED ON THESE DATA...THE INITIAL 1925INTENSITY IS LOWERED TO 60 KT. THE GLOBAL AND THE SHIPS MODELS ALL 1926SUGGEST THAT THE SHEAR WILL PERSIST AND STRENGTHEN BY THE 48 HOUR 1927PERIOD AS THE SHEAR VECTOR BECOMES MORE WESTERLY. THE NHC INTENSITY 1928FORECAST INDICATES A GRADUAL WEAKENING TREND BASED ON THE 1929AFOREMENTIONED GUIDANCE...WITH THE CYCLONE ULTIMATELY BECOMING 1930ABSORBED IN 96 HOURS BY THE MUCH LARGER EXTRATROPICAL IGOR. 1931 1932THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS 1933ADVISORY...AND IS ESTIMATED TO BE NORTHWESTWARD OR 310/14. THE 1934DYNAMICAL MODELS SHOW THE CYCLONE MOVING NORTHWESTWARD DURING THE 1935NEXT 36 HOURS WITHIN THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH 1936TO THE NORTHEAST OF JULIA. THROUGH DAY 3...THE MODELS INDICATE 1937THAT THE SYSTEM WILL TURN NORTH-NORTHEASTWARD...AND NORTHEASTWARD 1938AS THE MID-LEVEL HIGH BEGINS TO DRIFT SOUTHWESTWARD OVER THE 1939CENTRAL ATLANTIC. AFTERWARD...THE MODELS ARE IN GOOD AGREEMENT 1940WITH JULIA BECOMING ABSORBED BY IGOR...GENERALLY IN 96 HOURS...OR 1941EARLIER...AS SUGGESTED BY THE SHIPS AND BOTH THE ECMWF AND GFS 1942ENSEMBLE MEANS. THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS 1943ADVISORY AND IS BASED ON A BLEND OF THE GLOBAL AND REGIONAL MODELS. 1944 1945 1946 1947FORECAST POSITIONS AND MAX WINDS 1948 1949INITIAL 18/0300Z 26.0N 49.2W 60 KT 195012HR VT 18/1200Z 28.1N 50.8W 55 KT 195124HR VT 19/0000Z 31.0N 52.1W 50 KT 195236HR VT 19/1200Z 33.5N 52.0W 45 KT 195348HR VT 20/0000Z 35.5N 50.6W 40 KT 195472HR VT 21/0000Z 39.0N 46.0W 30 KT 195596HR VT 22/0000Z...ABSORBED BY A LARGE EXTRATROPICAL LOW 1956 1957$$ 1958FORECASTER ROBERTS/AVILA 1959 1960 1961 1962 1963WTNT42 KNHC 180302 1964TCDAT2 1965TROPICAL STORM JULIA DISCUSSION NUMBER 24...CORRECTED 1966NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 19671100 PM AST FRI SEP 17 2010 1968 1969CORRECTED TO ADD IGOR 1970 1971THE SATELLITE PRESENTATION SHOWS THE CIRCULATION CENTER OF JULIA 1972JUST BENEATH THE NORTHERN EDGE OF THE CLOUD CANOPY. THE SHEARED 1973CLOUD PATTERN IS DUE TO 20-30 KT OF NORTHERLY SHEAR PRODUCED BY A 1974STRONG OUTFLOW CHANNEL ASSOCIATED WITH HURRICANE IGOR. SUBSEQUENT 1975BANDING CLOUD TOPS HAVE WARMED CONSIDERABLY THIS EVENING...AND THE 1976SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO 197765 AND 60 KT RESPECTIVELY. BASED ON THESE DATA...THE INITIAL 1978INTENSITY IS LOWERED TO 60 KT. THE GLOBAL AND THE SHIPS MODELS ALL 1979SUGGEST THAT THE SHEAR WILL PERSIST AND STRENGTHEN BY THE 48 HOUR 1980PERIOD AS THE SHEAR VECTOR BECOMES MORE WESTERLY. THE NHC INTENSITY 1981FORECAST INDICATES A GRADUAL WEAKENING TREND BASED ON THE 1982AFOREMENTIONED GUIDANCE...WITH THE CYCLONE ULTIMATELY BECOMING 1983ABSORBED IN 96 HOURS BY THE MUCH LARGER EXTRATROPICAL IGOR. 1984 1985THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS 1986ADVISORY...AND IS ESTIMATED TO BE NORTHWESTWARD OR 310/14. THE 1987DYNAMICAL MODELS SHOW THE CYCLONE MOVING NORTHWESTWARD DURING THE 1988NEXT 36 HOURS WITHIN THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH 1989TO THE NORTHEAST OF JULIA. THROUGH DAY 3...THE MODELS INDICATE 1990THAT THE SYSTEM WILL TURN NORTH-NORTHEASTWARD...AND NORTHEASTWARD 1991AS THE MID-LEVEL HIGH BEGINS TO DRIFT SOUTHWESTWARD OVER THE 1992CENTRAL ATLANTIC. AFTERWARD...THE MODELS ARE IN GOOD AGREEMENT 1993WITH JULIA BECOMING ABSORBED BY IGOR...GENERALLY IN 96 HOURS...OR 1994EARLIER...AS SUGGESTED BY THE SHIPS AND BOTH THE ECMWF AND GFS 1995ENSEMBLE MEANS. THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS 1996ADVISORY AND IS BASED ON A BLEND OF THE GLOBAL AND REGIONAL MODELS. 1997 1998 1999 2000FORECAST POSITIONS AND MAX WINDS 2001 2002INITIAL 18/0300Z 26.0N 49.2W 60 KT 200312HR VT 18/1200Z 28.1N 50.8W 55 KT 200424HR VT 19/0000Z 31.0N 52.1W 50 KT 200536HR VT 19/1200Z 33.5N 52.0W 45 KT 200648HR VT 20/0000Z 35.5N 50.6W 40 KT 200772HR VT 21/0000Z 39.0N 46.0W 30 KT 200896HR VT 22/0000Z...ABSORBED BY A LARGE EXTRATROPICAL LOW 2009 2010$$ 2011FORECASTER ROBERTS/AVILA 2012 2013 2014 2015 2016WTNT42 KNHC 180831 2017TCDAT2 2018TROPICAL STORM JULIA DISCUSSION NUMBER 25 2019NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 2020500 AM AST SAT SEP 18 2010 2021 2022STRONG NORTHERLY SHEAR CONTINUES TO WEAKEN JULIA. SATELLITE IMAGES 2023SHOW THAT THE CENTER OF THE STORM IS PARTIALLY EXPOSED ON THE 2024NORTHWESTERN EDGE OF A BURST OF CONVECTION. DVORAK CLASSIFICATIONS 2025ARE DROPPING QUICKLY...AND A BLEND OF THE T/CI NUMBERS FROM 2026TAFB/SAB AND ADT VALUES FROM UW-CIMSS GIVES AN INITIAL WIND SPEED 2027OF 50 KT. A STEADY DECREASE IN STRENGTH IS LIKELY WITH THE STRONG 2028SHEAR EXPECTED TO PERSIST. JULIA SHOULD BECOME A REMNANT LOW BY 72 2029HOURS...IF NOT SOONER BECAUSE OF EXPECTED COOL SSTS. THE NHC 2030FORECAST IS CLOSE TO THE SHIPS MODEL...AND IS BELOW MOST OF THE 2031GUIDANCE. THE REMNANT LOW IS EXPECTED TO BE ABSORBED BY IGOR IN 2032ABOUT 96 HRS. 2033 2034THE INITIAL MOTION CONTINUES TO BEND A LITTLE TO THE RIGHT AND IS 2035NOW 320/16. THE MODEL GUIDANCE IS TIGHTLY CLUSTERED ON A 2036NORTHWESTWARD TRACK TODAY...WITH A NORTHWARD TURN TOMORROW AS JULIA 2037MOVES AROUND A SUBTROPICAL RIDGE. MOST OF THE GUIDANCE SUGGESTS 2038THAT JULIA WILL STAY FAR ENOUGH AWAY FROM IGOR THAT THE LARGER 2039HURRICANE WILL NOT HAVE AN IMMEDIATE IMPACT ON THE TRACK OF JULIA. 2040THE NHC FORECAST IS CLOSE TO THE PREVIOUS ONE...ON THE RIGHT EDGE 2041OF THE GUIDANCE ENVELOPE...AND NOT TOO FAR FROM THE GFS. 2042 2043THE WIND RADII HAVE BEEN ADJUSTED BASED ON AN EARLIER ASCAT PASS. 2044 2045FORECAST POSITIONS AND MAX WINDS 2046 2047INITIAL 18/0900Z 27.4N 50.1W 50 KT 2048 12HR VT 18/1800Z 29.5N 51.5W 45 KT 2049 24HR VT 19/0600Z 32.3N 52.1W 40 KT 2050 36HR VT 19/1800Z 34.5N 51.3W 35 KT 2051 48HR VT 20/0600Z 36.0N 49.0W 30 KT 2052 72HR VT 21/0600Z 39.5N 44.0W 25 KT...POST-TROP/REMNT LOW 2053 96HR VT 22/0600Z...ABSORBED BY IGOR 2054 2055$$ 2056FORECASTER BLAKE 2057 2058 2059WTNT42 KNHC 181447 2060TCDAT2 2061TROPICAL STORM JULIA DISCUSSION NUMBER 26 2062NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 20631100 AM AST SAT SEP 18 2010 2064 2065VISIBLE SATELLITE IMAGES INDICATE THAT STRONG NORTHERLY SHEAR HAS 2066DISPLACED DEEP CONVECTION ASSOCIATED WITH JULIA TO THE SOUTHEAST OF 2067THE NOW EXPOSED LOW-LEVEL CENTER. AS A RESULT...DVORAK T-NUMBERS 2068ARE DECREASING AS QUICKLY AS CONSTRAINTS WILL ALLOW. A BLEND OF 2069T/CI NUMBERS FROM TAFB/SAB REPRESENT THE BASIS FOR AN INITIAL 2070INTENSITY OF 45 KT FOR THIS ADVISORY. THE PERSISTENCE OF STRONG 2071SHEAR ASSOCIATED WITH THE OUTFLOW OF IGOR AND PROGRESSIVELY COOLER 2072WATERS ALONG THE FORECAST TRACK SHOULD LEAD TO A CONTINUED 2073WEAKENING. THE NHC OFFICIAL FORECAST IS NEAR THE STATISTICAL- 2074DYNAMICAL GUIDANCE...AND INDICATES JULIA BECOMING A REMNANT LOW IN 207548 HOURS. HOWEVER...JULIA COULD DEGENERATE INTO A REMNANT LOW 2076SOONER THAN CURRENTLY FORECAST. ULTIMATELY...THE REMNANT 2077CIRCULATION OF JULIA COULD BE ABSORBED BY LARGE HURRICANE IGOR AS 2078IGOR UNDERGOES EXTRATROPICAL TRANSITION BEYOND 72 HOURS. 2079 2080THE INITIAL MOTION ESTIMATE HAS SHIFTED A LITTLE MORE TO THE RIGHT 2081COMPARED TO BEFORE AND IS NOW 320/16. THE MODEL GUIDANCE IS IN 2082GOOD AGREEMENT...SHOWING A TRACK BENDING TOWARD THE NORTH-NORTHWEST 2083LATER TODAY AND TURNING NORTHWARD TOMORROW AS JULIA MOVES AROUND A 2084SUBTROPICAL RIDGE TO THE EAST. THE OFFICIAL NHC FORECAST IS NEAR 2085THE THE PREVIOUS ONE...CLOSE TO THE MIDDLE OF THE GUIDANCE ENVELOPE 2086BUT SLIGHTLY RIGHT OF THE MULTI-MODEL CONSENSUS. 2087 2088 2089FORECAST POSITIONS AND MAX WINDS 2090 2091INITIAL 18/1500Z 28.9N 51.0W 45 KT 2092 12HR VT 19/0000Z 31.1N 51.9W 40 KT 2093 24HR VT 19/1200Z 33.5N 51.8W 35 KT 2094 36HR VT 20/0000Z 35.5N 50.3W 30 KT 2095 48HR VT 20/1200Z 37.0N 48.0W 25 KT...POST-TROP/REMNT LOW 2096 72HR VT 21/1200Z 40.5N 43.0W 20 KT...POST-TROP/REMNT LOW 2097 96HR VT 22/1200Z...DISSIPATED 2098 2099$$ 2100FORECASTER KIMBERLAIN 2101 2102 2103WTNT42 KNHC 182031 2104TCDAT2 2105TROPICAL STORM JULIA DISCUSSION NUMBER 27 2106NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 2107500 PM AST SAT SEP 18 2010 2108 2109SATELLITE PICTURES INDICATE THAT THE CLOUD PATTERN ASSOCIATED WITH 2110JULIA HAS CHANGED LITTLE DURING THE LAST SEVERAL HOURS. THE 2111CYCLONE CONTINUES TO EXPERIENCE STRONG NORTH-NORTHWESTERLY SHEAR... 2112AND THE LOW-LEVEL CENTER REMAINS EXPOSED EVEN THOUGH REPEATED 2113BURSTS OF NEW CONVECTION CONTINUE FORMING NEAR AND TO THE SOUTHEAST 2114OF IT. DESPITE ITS APPEARANCE...RECENT PRESSURE DATA FROM A NUMBER 2115OF DRIFTING BUOYS NEAR JULIA SUGGEST THAT THE CIRCULATION OF JULIA 2116HAS LIKELY RETAINED ITS VIGOR. BASED UPON THESE OBSERVATIONS AND 2117DVORAK CI NUMBERS ARE 2.5 AND 3.5 AT 1800 UTC FROM TAFB AND 2118SAB...THE INTENSITY OF JULIA IS UNCHANGED AT 45 KT. SHIPS MODEL 2119OUTPUT SHOWS NORTHERLY SHEAR ASSOCIATED WITH THE OUTFLOW FROM 2120HURRICANE IGOR INCREASING FURTHER DURING THE NEXT DAY OR TWO WHILE 2121JULIA MOVES OVER PROGRESSIVELY COOLER WATERS. THE COMBINATION OF 2122THESE FACTORS SHOULD RESULT IN A CONTINUED WEAKENING. THE NHC 2123INTENSITY FORECAST IS IS SIMILAR TO THE PREVIOUS ONE AND IN LINE 2124WITH THE LATEST STATISTICAL-DYNAMICAL GUIDANCE. JULIA IS FORECAST 2125TO BECOME A REMNANT LOW IN 48 HOURS...IF NOT SOONER. THE REMNANT 2126CIRCULATION OF JULIA IS LIKELY TO BE ABSORBED BY LARGE HURRICANE 2127IGOR AS IGOR UNDERGOES EXTRATROPICAL IN ABOUT 72 HOURS. 2128 2129THE TRACK OF JULIA CONTINUES BENDING TO THE RIGHT...WITH THE INITIAL 2130MOTION NOW ESTIMATED TO BE 330/17. JULIA IS FORECAST TO TURN TOWARD 2131THE NORTH BY TONIGHT AND TOWARD THE NORTH-NORTHEAST AND THEN 2132NORTHEAST TOMORROW AS JULIA MOVES AROUND THE NORTHWEST SIDE OF A 2133SUBTROPICAL RIDGE TO THE SOUTHEAST. WITH THE EXCEPTION OF THE 2134UKMET SOLUTION WHICH SEEMS LIKE AN OUTLIER...THE MODEL GUIDANCE IS 2135FAIRLY TIGHTLY CLUSTER AND IS IN GOOD AGREEMENT ON THIS SCENARIO. 2136THE OFFICIAL NHC FORECAST CONTINUES TO BE NEAR THE THE PREVIOUS 2137ONE...AND IT CLOSE TO A MULTI-MODEL CONSENSUS THAT EXCLUDES THE 2138UKMET. 2139 2140 2141FORECAST POSITIONS AND MAX WINDS 2142 2143INITIAL 18/2100Z 30.6N 51.8W 45 KT 2144 12HR VT 19/0600Z 32.6N 52.0W 40 KT 2145 24HR VT 19/1800Z 34.8N 51.2W 35 KT 2146 36HR VT 20/0600Z 36.4N 49.4W 30 KT 2147 48HR VT 20/1800Z 38.0N 47.4W 25 KT...POST-TROP/REMNT LOW 2148 72HR VT 21/1800Z 42.0N 43.0W 20 KT...POST-TROP/REMNT LOW 2149 96HR VT 22/1800Z...DISSIPATED 2150 2151$$ 2152FORECASTER KIMBERLAIN 2153 2154 2155WTNT42 KNHC 190233 2156TCDAT2 2157TROPICAL STORM JULIA DISCUSSION NUMBER 28 2158NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 21591100 PM AST SAT SEP 18 2010 2160 2161JULIA HAS MOVED INTO A REGION OF WEAKER VERTICAL SHEAR DURING THE 2162PAST 6 HOURS AND VERY COLD TOPPED CONVECTION HAS DEVELOPED NEAR AND 2163SOUTHEAST OF THE LOW-LEVEL CENTER AS A RESULT. SATELLITE CURRENT 2164INTENSITY ESTIMATES ARE T3.5/55 KT FROM TAFB...T2.5/35 KT FROM 2165SAB...AND ADT VALUES OF T3.4/43 KT FROM UW-CIMSS...RESPECTIVELY. 2166GIVEN THE NEW DEVELOPMENT OF DEEP CONVECTION NEAR THE CENTER...THE 2167INITIAL INTENSITY REMAINS 45 KT...WHICH IS AN AVERAGE OF THE THREE 2168INTENSITY ESTIMATES. 2169 2170JULIA HAS TURNED TOWARD THE NORTH AND IS NOW ESTIMATED TO BE MOVING 2171AT 360/12. JULIA EARLIER ACCELERATED NORTHWARD AT ABOUT 20 KT 2172DURING THE PERIOD WHEN IT POSSESSED NO DEEP CONVECTION NEAR THE 2173CENTER. HOWEVER...NOW THAT CONVECTION HAS REFORMED...THE 2174CIRCULATION HAS LIKELY DEEPENED IN THE VERTICAL AND WILL BE SUBJECT 2175TO A DEEPER AND SLOWER STEERING FLOW. THE NHC MODEL GUIDANCE IS IN 2176GENERAL AGREEMENT ON JULIA MOVING NORTHWARD FOR THE NEXT 12 HOURS 2177AND THEN NORTHEASTWARD AFTER THAT AS THE CYCLONE MOVES AROUND THE 2178WESTERN PERIPHERY OF A LARGE SUBTROPICAL RIDGE LOCATED TO ITS EAST. 2179BY 48 HOURS...A SEVERELY WEAKENED AND SHALLOW JULIA AT THAT TIME IS 2180EXPECTED TO GRADUALLY BECOME ABSORBED INTO THE EASTERN PORTION OF 2181THE VERY LARGE HURRICANE IGOR CIRCULATION. THE OFFICIAL FORECAST IS 2182A LITTLE TO THE LEFT OF THE PREVIOUS ADVISORY TRACK...AND IS 2183SIMILAR TO THE CONSENSUS MODELS...TVCN AND TVCC. 2184 2185WEAKER VERTICAL SHEAR CONDITIONS THAT JULIA HAS BEEN EXPERIENCING 2186THE PAST 6 HOURS WILL BE SHORT-LIVED SINCE THE CYCLONE WILL BE 2187MOVING NORTHWARD INTO A REGION OF STRONG WESTERLY SHEAR OF 30-50 KT 2188EMANATING FROM THE MASSIVE OUTFLOW FROM HURRICANE IGOR IN 6-12 2189HOURS. BY 24 HOURS...JULIA WILL ALSO BE MOVING OVER SUB-26C 2190SSTS...WHICH WHEN COMBINED WITH THE INCREASING WESTERLY SHEAR... 2191SHOULD INDUCE RAPID WEAKENING. JULIA IS EXPECTED TO BECOME A 2192REMNANT LOW IN 36-48 HOURS...IF NOT SOONER. THE OFFICIAL INTENSITY 2193FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY...AND CLOSELY FOLLOWS 2194THE SHIPS/LGEM MODELS...WHICH DISSIPATE JULIA BY AROUND 48 HOURS. 2195 2196FORECAST POSITIONS AND MAX WINDS 2197 2198INITIAL 19/0300Z 32.4N 51.9W 45 KT 2199 12HR VT 19/1200Z 34.3N 51.7W 40 KT 2200 24HR VT 20/0000Z 36.1N 50.4W 30 KT 2201 36HR VT 20/1200Z 37.6N 48.7W 25 KT 2202 48HR VT 21/0000Z 39.1N 46.9W 25 KT...POST-TROP/REMNT LOW 2203 72HR VT 22/0000Z 43.6N 41.8W 20 KT...POST-TROP/REMNT LOW 2204 96HR VT 23/0000Z...DISSIPATED 2205 2206$$ 2207FORECASTER STEWART 2208 2209 2210WTNT42 KNHC 190849 2211TCDAT2 2212TROPICAL STORM JULIA DISCUSSION NUMBER 29 2213NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 2214500 AM AST SUN SEP 19 2010 2215 2216SOMEWHAT UNEXPECTEDLY...THE ASCAT PASS AT 0106Z OVER JULIA SHOWED 50 2217TO 55 KT WINDS AT THE SURFACE...WHICH SUGGESTS THAT THE CYCLONE WAS 2218AT LEAST 55 KT AROUND 0000Z GIVEN THE LOW BIAS OF THAT INSTRUMENT. 2219SINCE THEN...THE CONVECTION HAS WEAKENED AND THE CDO HAS BECOME 2220FRAGMENTED. DVORAK INTENSITY ESTIMATES WERE 3.0...OR 45 KT...FROM 2221TAFB AND 2.5...OR 35 KT...FROM SAB. THE INTENSITY WAS SET AT 222250 KT AT THE SYNOPTIC TIME AND IS 45 KT FOR THIS ADVISORY. 2223 2224THE MOTION OF JULIA IS 355 DEGREES AT 14 KT...WHICH IS FAIRLY WELL 2225KNOWN DUE TO AN 0506Z AQUA PASS THAT WAS JUST RECEIVED. THE CYCLONE 2226IS IN THE PROCESS OF RECURVING AROUND THE DEEP LAYER SUBTROPICAL 2227RIDGE TO ITS SOUTHEAST. A MODEST DECELERATION IS EXPECTED OVER THE 2228NEXT 36 HOURS AS JULIA TURNS TOWARD THE NORTHEAST. THE MODEL 2229GUIDANCE HAS SHIFTED SIGNIFICANTLY SOUTHEASTWARD AND THE TRACK 2230FORECAST IS A BLEND OF THE PREVIOUS ADVISORY AND THE FAIRLY 2231CLUSTERED MODEL CONSENSUS. 2232 2233THE MODEST REINTENSIFICATION OF JULIA IS NOT LIKELY TO BE REPEATED. 2234THE CYCLONE WILL BE MOVING OVER SUB-26C SSTS IN ABOUT A DAY WHILE 2235BEING BLUDGEONED BY ABOUT 50 KT UPPER TROPOSPHERIC NORTHWESTERLIES. 2236GRADUAL DECAY IS EXPECTED OVER THE NEXT TWO DAYS...AFTER WHICH 2237JULIA SHOULD BE ABSORBED INTO THE VERY LARGE CIRCULATION OF IGOR. 2238THE INTENSITY FORECAST IS NEARLY IDENTICAL TO THE PREVIOUS 2239ADVISORY...BUT BELOW THE INTENSITY MODEL CONSENSUS WHICH APPEARS TO 2240HOLD ON TO A ROBUST CYCLONE FOR TOO LONG. 2241 2242THE AFOREMENTIONED ASCAT PASS ALLOWED FOR AN ADJUSTMENT TO THE WIND 2243RADII UTILIZED IN THIS ADVISORY. 2244 2245FORECAST POSITIONS AND MAX WINDS 2246 2247INITIAL 19/0900Z 33.6N 51.8W 45 KT 2248 12HR VT 19/1800Z 35.7N 51.2W 40 KT 2249 24HR VT 20/0600Z 36.8N 49.4W 30 KT 2250 36HR VT 20/1800Z 37.7N 47.5W 25 KT...POST-TROP/REMNT LOW 2251 48HR VT 21/0600Z 39.5N 45.5W 25 KT...POST-TROP/REMNT LOW 2252 72HR VT 22/0600Z...DISSIPATED 2253 2254$$ 2255FORECASTER LANDSEA/BRENNAN 2256 2257 2258WTNT42 KNHC 191458 2259TCDAT2 2260TROPICAL STORM JULIA DISCUSSION NUMBER 30 2261NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 22621100 AM AST SUN SEP 19 2010 2263 2264JULIA HAS HAD ANOTHER BURST OF DEEP CONVECTION OVER THE PAST SEVERAL 2265HOURS...AND SATELLITE INTENSITY ESTIMATES REMAIN AT T3.0/45 KT FROM 2266BOTH TAFB AND SAB. THE INITIAL INTENSITY IS KEPT AT 45 KT FOR THIS 2267ADVISORY...BUT IT APPEARS THAT THE STORM IS AGAIN RUNNING INTO 2268STRONG SHEAR ASSOCIATED WITH OUTFLOW FROM HURRICANE IGOR AND SHOULD 2269WEAKEN SOON. THE SHIPS AND LGEM MODELS SHOW FASTER WEAKENING THAN 2270THE DYNAMICAL GUIDANCE...INCLUDING THE GLOBAL MODELS WHICH SHOULD 2271HAVE A BETTER REPRESENTATION OF THE MID-LATITUDE SYNOPTIC PRESSURE 2272PATTERN. THE OFFICIAL FORECAST IS NEAR OR JUST BELOW THE INTENSITY 2273CONSENSUS...AND INDICATES JULIA WEAKENING TO A TROPICAL DEPRESSION 2274OR REMNANT LOW IN 36-48 HOURS. 2275 2276BASED ON RECENT MICROWAVE DATA AND VISIBLE SATELLITE IMAGERY...THE 2277CENTER OF JULIA HAS BEEN RELOCATED TO THE SOUTH...AND THE INITIAL 2278MOTION HAS VEERED QUICKLY TO 065 DEGREES AT 13 KT. JULIA IS 2279EXPECTED TO CONTINUE MOVING AROUND THE NORTHWESTERN AND NORTHERN 2280SIDE OF A MID-LEVEL HIGH OVER THE NEXT COUPLE OF DAYS. WITH THE 2281ADJUSTED INITIAL POSITION BEING FARTHER SOUTH...THE NEW TRACK 2282FORECAST IS SHIFTED SIGNIFICANTLY TO THE SOUTH OF THE PREVIOUS 2283FORECAST AND LIES ALONG THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE. 2284 2285FORECAST POSITIONS AND MAX WINDS 2286 2287INITIAL 19/1500Z 34.2N 50.3W 45 KT 2288 12HR VT 20/0000Z 34.9N 48.5W 35 KT 2289 24HR VT 20/1200Z 35.6N 46.5W 35 KT 2290 36HR VT 21/0000Z 36.2N 44.5W 30 KT...POST-TROP/REMNT LOW 2291 48HR VT 21/1200Z 37.5N 42.5W 25 KT...POST-TROP/REMNT LOW 2292 72HR VT 22/1200Z...DISSIPATED 2293 2294$$ 2295FORECASTER BERG 2296 2297 2298WTNT42 KNHC 191458 2299TCDAT2 2300TROPICAL STORM JULIA DISCUSSION NUMBER 30 2301NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 23021100 AM AST SUN SEP 19 2010 2303 2304JULIA HAS HAD ANOTHER BURST OF DEEP CONVECTION OVER THE PAST SEVERAL 2305HOURS...AND SATELLITE INTENSITY ESTIMATES REMAIN AT T3.0/45 KT FROM 2306BOTH TAFB AND SAB. THE INITIAL INTENSITY IS KEPT AT 45 KT FOR THIS 2307ADVISORY...BUT IT APPEARS THAT THE STORM IS AGAIN RUNNING INTO 2308STRONG SHEAR ASSOCIATED WITH OUTFLOW FROM HURRICANE IGOR AND SHOULD 2309WEAKEN SOON. THE SHIPS AND LGEM MODELS SHOW FASTER WEAKENING THAN 2310THE DYNAMICAL GUIDANCE...INCLUDING THE GLOBAL MODELS WHICH SHOULD 2311HAVE A BETTER REPRESENTATION OF THE MID-LATITUDE SYNOPTIC PRESSURE 2312PATTERN. THE OFFICIAL FORECAST IS NEAR OR JUST BELOW THE INTENSITY 2313CONSENSUS...AND INDICATES JULIA WEAKENING TO A TROPICAL DEPRESSION 2314OR REMNANT LOW IN 36-48 HOURS. 2315 2316BASED ON RECENT MICROWAVE DATA AND VISIBLE SATELLITE IMAGERY...THE 2317CENTER OF JULIA HAS BEEN RELOCATED TO THE SOUTH...AND THE INITIAL 2318MOTION HAS VEERED QUICKLY TO 065 DEGREES AT 13 KT. JULIA IS 2319EXPECTED TO CONTINUE MOVING AROUND THE NORTHWESTERN AND NORTHERN 2320SIDE OF A MID-LEVEL HIGH OVER THE NEXT COUPLE OF DAYS. WITH THE 2321ADJUSTED INITIAL POSITION BEING FARTHER SOUTH...THE NEW TRACK 2322FORECAST IS SHIFTED SIGNIFICANTLY TO THE SOUTH OF THE PREVIOUS 2323FORECAST AND LIES ALONG THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE. 2324 2325FORECAST POSITIONS AND MAX WINDS 2326 2327INITIAL 19/1500Z 34.2N 50.3W 45 KT 2328 12HR VT 20/0000Z 34.9N 48.5W 35 KT 2329 24HR VT 20/1200Z 35.6N 46.5W 35 KT 2330 36HR VT 21/0000Z 36.2N 44.5W 30 KT...POST-TROP/REMNT LOW 2331 48HR VT 21/1200Z 37.5N 42.5W 25 KT...POST-TROP/REMNT LOW 2332 72HR VT 22/1200Z...DISSIPATED 2333 2334$$ 2335FORECASTER BERG 2336 2337 2338 2339WTNT42 KNHC 192033 2340TCDAT2 2341TROPICAL STORM JULIA DISCUSSION NUMBER 31 2342NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 2343500 PM AST SUN SEP 19 2010 2344 2345SINCE THIS MORNING...THE CENTER OF JULIA HAS BECOME EXPOSED TO THE 2346NORTHWEST OF A SMALL AREA OF DEEP CONVECTION. AMSU AND ASCAT 2347ESTIMATES FROM AROUND 1200 UTC SUPPORTED AN INTENSITY OF 45 KT...SO 2348THE INITIAL INTENSITY IS LOWERED TO 40 KT NOW THAT THE CYCLONE IS 2349MORE STRONGLY SHEARED. THIS IS ALSO SUPPORTED BY DECREASING 2350T-NUMBERS. THE STATISTICAL MODELS STILL SHOW QUICKER WEAKENING 2351THAN THE DYNAMICAL MODELS...AND THE OFFICIAL FORECAST REMAINS NEAR 2352THE INTENSITY CONSENSUS. JULIA WILL BE BATTLING VERY STRONG 2353NORTHWESTERLY SHEAR...BUT IT SHOULD TAKE SOME TIME FOR THE 2354CIRCULATION TO SPIN DOWN. THE CYCLONE IS EXPECTED TO BECOME A 2355REMNANT LOW IN ABOUT 36 HOURS AND THEN DISSIPATE WITHIN THE 2356SOUTHWESTERLY FLOW EAST OF IGOR IN 48 HOURS. 2357 2358AFTER TAKING A SUDDEN AND QUICK JUMP TO THE EAST-NORTHEAST THIS 2359MORNING...JULIA HAS SETTLED ON A MOTION OF ABOUT 50 DEGREES AT 12 2360KT. THE UKMET...GFDL...AND GFDN SEEM TO UNREALISTICALLY TURN JULIA 2361TOWARD THE NORTHWEST OR NORTH AFTER 24 HOURS...SO THE NHC TRACK 2362FORECAST IS BASED ON A BLEND OF THE OTHER MAJOR DYNAMICAL MODELS. 2363THIS TRACK REMAINS ON THE SOUTHERN SIDE OF THE GUIDANCE ENVELOPE. 2364 2365FORECAST POSITIONS AND MAX WINDS 2366 2367INITIAL 19/2100Z 34.8N 49.7W 40 KT 2368 12HR VT 20/0600Z 35.4N 48.4W 35 KT 2369 24HR VT 20/1800Z 36.3N 46.6W 35 KT 2370 36HR VT 21/0600Z 37.7N 44.4W 30 KT...POST-TROP/REMNT LOW 2371 48HR VT 21/1800Z...DISSIPATED 2372 2373$$ 2374FORECASTER BERG 2375 2376 2377WTNT42 KNHC 200234 2378TCDAT2 2379TROPICAL STORM JULIA DISCUSSION NUMBER 32 2380NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 23811100 PM AST SUN SEP 19 2010 2382 2383JULIA CONTINUES TO WEAKEN THIS EVENING. SATELLITE IMAGES INDICATE 2384THAT DEEP CONVECTION IS CONFINED TO A POORLY ORGANIZED BAND WELL 2385NORTHEAST OF THE ESTIMATED CENTER. DVORAK DATA T-NUMBERS HAVE 2386DECREASED TO 2.0 FROM BOTH TAFB AND SAB. THE INITIAL INTENSITY IS 2387SET TO 35 KT...USING A BLEND OF THE DVORAK DATA T AND CI NUMBERS. 2388ADDITIONAL WEAKENING IS EXPECTED AS STRONG NORTHWESTERLY SHEAR 2389CONTINUES TO IMPACT THE CYCLONE. JULIA IS NOW FORECAST TO BECOME A 2390REMNANT LOW IN 24 HOURS...AS IT IS ANTICIPATED TO BE OVER 25 C 2391WATERS BY THAT TIME...BUT THIS COULD OCCUR SOONER. 2392 2393A 1958 UTC TRMM OVERPASS AND A 2307 UTC SSMIS OVERPASS HAVE BEEN 2394HELPFUL IN LOCATING THE LOW-LEVEL CENTER OF JULIA...WHICH IS VERY 2395NEAR THE PREVIOUS FORECAST TRACK. THE INITIAL MOTION ESTIMATE IS 2396055/11...USING A BLEND OF SATELLITE FIXES AND THE AFOREMENTIONED 2397MICROWAVE DATA. JULIA IS EXPECTED TO CONTINUE MOVING 2398EAST-NORTHEASTWARD TO NORTHEASTWARD ALONG THE NORTHERN PERIPHERY OF 2399A SUBTROPICAL RIDGE UNTIL DISSIPATION. THE OFFICIAL TRACK FORECAST 2400IS AN UPDATE OF THE PREVIOUS ONE AND IN AGREEMENT WITH A CONSENSUS 2401OF THE GFS...ECMWF...NOGAPS...AND HWRF MODELS. 2402 2403FORECAST POSITIONS AND MAX WINDS 2404 2405INITIAL 20/0300Z 35.2N 48.7W 35 KT 2406 12HR VT 20/1200Z 35.8N 47.5W 30 KT 2407 24HR VT 21/0000Z 36.8N 45.7W 30 KT...POST-TROP/REMNT LOW 2408 36HR VT 21/1200Z 38.0N 43.7W 25 KT...POST-TROP/REMNT LOW 2409 48HR VT 22/0000Z...DISSIPATED 2410 2411$$ 2412FORECASTER CANGIALOSI 2413 2414 2415WTNT42 KNHC 200234 2416TCDAT2 2417TROPICAL STORM JULIA DISCUSSION NUMBER 32 2418NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 24191100 PM AST SUN SEP 19 2010 2420 2421JULIA CONTINUES TO WEAKEN THIS EVENING. SATELLITE IMAGES INDICATE 2422THAT DEEP CONVECTION IS CONFINED TO A POORLY ORGANIZED BAND WELL 2423NORTHEAST OF THE ESTIMATED CENTER. DVORAK DATA T-NUMBERS HAVE 2424DECREASED TO 2.0 FROM BOTH TAFB AND SAB. THE INITIAL INTENSITY IS 2425SET TO 35 KT...USING A BLEND OF THE DVORAK DATA T AND CI NUMBERS. 2426ADDITIONAL WEAKENING IS EXPECTED AS STRONG NORTHWESTERLY SHEAR 2427CONTINUES TO IMPACT THE CYCLONE. JULIA IS NOW FORECAST TO BECOME A 2428REMNANT LOW IN 24 HOURS...AS IT IS ANTICIPATED TO BE OVER 25 C 2429WATERS BY THAT TIME...BUT THIS COULD OCCUR SOONER. 2430 2431A 1958 UTC TRMM OVERPASS AND A 2307 UTC SSMIS OVERPASS HAVE BEEN 2432HELPFUL IN LOCATING THE LOW-LEVEL CENTER OF JULIA...WHICH IS VERY 2433NEAR THE PREVIOUS FORECAST TRACK. THE INITIAL MOTION ESTIMATE IS 2434055/11...USING A BLEND OF SATELLITE FIXES AND THE AFOREMENTIONED 2435MICROWAVE DATA. JULIA IS EXPECTED TO CONTINUE MOVING 2436EAST-NORTHEASTWARD TO NORTHEASTWARD ALONG THE NORTHERN PERIPHERY OF 2437A SUBTROPICAL RIDGE UNTIL DISSIPATION. THE OFFICIAL TRACK FORECAST 2438IS AN UPDATE OF THE PREVIOUS ONE AND IN AGREEMENT WITH A CONSENSUS 2439OF THE GFS...ECMWF...NOGAPS...AND HWRF MODELS. 2440 2441FORECAST POSITIONS AND MAX WINDS 2442 2443INITIAL 20/0300Z 35.2N 48.7W 35 KT 2444 12HR VT 20/1200Z 35.8N 47.5W 30 KT 2445 24HR VT 21/0000Z 36.8N 45.7W 30 KT...POST-TROP/REMNT LOW 2446 36HR VT 21/1200Z 38.0N 43.7W 25 KT...POST-TROP/REMNT LOW 2447 48HR VT 22/0000Z...DISSIPATED 2448 2449$$ 2450FORECASTER CANGIALOSI 2451 2452 2453 2454WTNT42 KNHC 200842 2455TCDAT2 2456TROPICAL STORM JULIA DISCUSSION NUMBER 33 2457NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 2458500 AM AST MON SEP 20 2010 2459 2460JULIA AGAIN PROVIDED A SURPRISE FOR A SECOND NIGHT IN A ROW WITH 2461STRONGER SURFACE WINDS MEASURED FROM THE ASCAT SCATTEROMETER THAN 2462WHAT WAS SUGGESTED FROM CONVENTIONAL SATELLITE IMAGERY USING THE 2463DVORAK TECHNIQUE. THE 0046Z ASCAT PASS SHOWED MAXIMUM WINDS OF AT 2464LEAST 45 KT...DESPITE A FAIRLY DISHEVELED APPEARANCE TO THE DEEP 2465CONVECTION. THE 0600Z TAFB AND SAB DATA-T DVORAK NUMBERS REMAIN AT 2466A 2.0...OR 30 KT. THE INITIAL INTENSITY IS SET AT 40 KT...ASSUMING 2467SOME WEAKENING SINCE THE ASCAT PASS. 2468 2469THE CENTER CONTINUES TO BE DISPLACED WEST OF THE LIMITED DEEP 2470CONVECTION DUE TO STRONG WESTERLY VERTICAL SHEAR INDUCED BY 2471EXTREMELY LARGE HURRICANE IGOR. THE INITIAL MOTION OF JULIA IS 2472ESTIMATED TO BE 65 DEGREES AT 8 KT...AND THE CYCLONE IS BEING 2473ADVECTED AROUND THE NORTHERN PERIPHERY OF THE DEEP LAYER 2474SUBTROPICAL RIDGE. THE CYCLONE SHOULD ACCELERATE SOME TOWARD THE 2475NORTH-NORTHEAST IN THE NEXT DAY OR SO. AROUND 36 HOURS...JULIA 2476SHOULD BECOME ABSORBED INTO THE CIRCULATION OF IGOR AS SHOWN BY 2477NEARLY ALL OF THE MODELS. HOWEVER...THE ECMWF MODEL KEEPS THE 2478CYCLONE FAR ENOUGH SOUTH OF IGOR TO PREVENT THE ABSORPTION. 2479INSTEAD...THE ECMWF MAINTAINS JULIA AS A SEPARATE CYCLONE FOR 2480SEVERAL MORE DAYS...THOUGH BECOMING EXTRATROPICAL ABOUT TWO DAYS 2481FROM NOW. THIS TRACK FORECAST GOES WITH THE CONSENSUS...MINUS THE 2482ECMWF...AND IS SLIGHTLY TO THE LEFT OF AND FASTER THAN THE PREVIOUS 2483ADVISORY. 2484 2485AS JULIA SHOULD GRADUALLY ENCOUNTER SUB-26C WATER TEMPERATURES ALONG 2486WITH QUITE HOSTILE VERTICAL SHEAR...GRADUAL WEAKENING IS EXPECTED 2487FOR THE NEXT TWO DAYS UNTIL DISSIPATION. THE INTENSITY FORECAST IS 2488BASED UPON THE MODEL CONSENSUS AND IS SLIGHTLY HIGHER THAN THE 2489PREVIOUS ADVISORY BECAUSE OF THE STRONGER INITIAL CYCLONE. 2490 2491THE AFOREMENTIONED ASCAT PASS ALLOWED FOR AN ENLARGEMENT OF THE 2492TROPICAL STORM WIND RADII. 2493 2494FORECAST POSITIONS AND MAX WINDS 2495 2496INITIAL 20/0900Z 35.5N 47.9W 40 KT 2497 12HR VT 20/1800Z 36.1N 46.8W 35 KT 2498 24HR VT 21/0600Z 37.6N 45.3W 30 KT...POST-TROP/REMNT LOW 2499 36HR VT 21/1800Z 39.6N 43.5W 25 KT...POST-TROP/REMNT LOW 2500 48HR VT 22/0600Z...DISSIPATED 2501 2502$$ 2503FORECASTER LANDSEA/BRENNAN 2504 2505 2506WTNT42 KNHC 201439 2507TCDAT2 2508TROPICAL STORM JULIA DISCUSSION NUMBER 34 2509NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 25101100 AM AST MON SEP 20 2010 2511 2512 2513DEEP CONVECTION HAS BEEN SHEARED OFF TO THE EAST OF THE CENTER BY 2514THE OUTFLOW OF HURRICANE IGOR...WITH THE COLDEST TOPS NOW A COUPLE 2515OF HUNDRED MILES AWAY FROM THE CENTER. THE ASCAT PASS FROM 0046Z 2516LAST NIGHT SHOWED THAT THE CIRCULATION WAS BECOMING ELONGATED EVEN 2517THEN...AND VISIBLE IMAGERY THIS MORNING SHOWS THAT JULIA IS LOSING 2518SOME DEFINITION AS IT BECOMES ENTANGLED WITH A FRONTAL TROUGH TO 2519THE EAST OF THE CYCLONE. BASED ON THESE STRUCTURAL CHANGES...THIS 2520WILL BE THE LAST ADVISORY. 2521 2522MORNING VISIBLE IMAGERY INDICATES THAT JULIA IS A LITTLE SOUTH OF 2523THE PREVIOUS TRACK...AND IS MOVING AT 090/8. THE 00Z ECMWF HANDLED 2524THE OVERNIGHT MOTION OF JULIA BEST...WITH THE OTHER GUIDANCE WELL 2525TO THE LEFT AND SHOWING MORE OF AN INTERACTION WITH THE CIRCULATION 2526OF IGOR. THE OFFICIAL FORECAST FOLLOWS THE ECMWF GUIDANCE WITH A 2527FORECAST MOTION SOUTH OF THE PREVIOUS FORECAST. 2528 2529STRONG UPPER-LEVEL NORTHWESTERLY FLOW SHOULD KEEP THE SHEAR OVER 2530JULIA ELEVATED...AND GIVEN THE MARGINAL SEA SURFACE TEMPERATURES... 2531PREVENT THE SYSTEM FROM REDEVELOPING ORGANIZED DEEP CONVECTION. IF 2532PRESENT TRENDS CONTINUE...THE CIRCULATION OF JULIA WILL BECOME 2533ILL-DEFINED WITHIN A FRONTAL TROUGH OVER THE NEXT DAY OR SO. THAT 2534SCENARIO IS REFLECTED IN THE OFFICIAL FORECAST...ALTHOUGH IT IS 2535POSSIBLE THAT JULIA COULD REMAIN WELL-ENOUGH DEFINED TO LINGER AND 2536MOVE EASTWARD AS A REMNANT LOW FOR SEVERAL DAYS...AS SHOWN BY THE 2537ECMWF. 2538 2539 2540FORECAST POSITIONS AND MAX WINDS 2541 2542INITIAL 20/1500Z 34.7N 46.4W 40 KT...POST-TROPICAL 2543 12HR VT 21/0000Z 34.9N 45.3W 35 KT...POST-TROPICAL 2544 24HR VT 21/1200Z 35.5N 43.0W 30 KT...POST-TROP/REMNT LOW 2545 36HR VT 22/0000Z...DISSIPATED 2546 2547$$ 2548FORECASTER FRANKLIN 2549 2550 2551WTNT42 KNHC 200842 2552TCDAT2 2553TROPICAL STORM JULIA DISCUSSION NUMBER 33 2554NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 2555500 AM AST MON SEP 20 2010 2556 2557JULIA AGAIN PROVIDED A SURPRISE FOR A SECOND NIGHT IN A ROW WITH 2558STRONGER SURFACE WINDS MEASURED FROM THE ASCAT SCATTEROMETER THAN 2559WHAT WAS SUGGESTED FROM CONVENTIONAL SATELLITE IMAGERY USING THE 2560DVORAK TECHNIQUE. THE 0046Z ASCAT PASS SHOWED MAXIMUM WINDS OF AT 2561LEAST 45 KT...DESPITE A FAIRLY DISHEVELED APPEARANCE TO THE DEEP 2562CONVECTION. THE 0600Z TAFB AND SAB DATA-T DVORAK NUMBERS REMAIN AT 2563A 2.0...OR 30 KT. THE INITIAL INTENSITY IS SET AT 40 KT...ASSUMING 2564SOME WEAKENING SINCE THE ASCAT PASS. 2565 2566THE CENTER CONTINUES TO BE DISPLACED WEST OF THE LIMITED DEEP 2567CONVECTION DUE TO STRONG WESTERLY VERTICAL SHEAR INDUCED BY 2568EXTREMELY LARGE HURRICANE IGOR. THE INITIAL MOTION OF JULIA IS 2569ESTIMATED TO BE 65 DEGREES AT 8 KT...AND THE CYCLONE IS BEING 2570ADVECTED AROUND THE NORTHERN PERIPHERY OF THE DEEP LAYER 2571SUBTROPICAL RIDGE. THE CYCLONE SHOULD ACCELERATE SOME TOWARD THE 2572NORTH-NORTHEAST IN THE NEXT DAY OR SO. AROUND 36 HOURS...JULIA 2573SHOULD BECOME ABSORBED INTO THE CIRCULATION OF IGOR AS SHOWN BY 2574NEARLY ALL OF THE MODELS. HOWEVER...THE ECMWF MODEL KEEPS THE 2575CYCLONE FAR ENOUGH SOUTH OF IGOR TO PREVENT THE ABSORPTION. 2576INSTEAD...THE ECMWF MAINTAINS JULIA AS A SEPARATE CYCLONE FOR 2577SEVERAL MORE DAYS...THOUGH BECOMING EXTRATROPICAL ABOUT TWO DAYS 2578FROM NOW. THIS TRACK FORECAST GOES WITH THE CONSENSUS...MINUS THE 2579ECMWF...AND IS SLIGHTLY TO THE LEFT OF AND FASTER THAN THE PREVIOUS 2580ADVISORY. 2581 2582AS JULIA SHOULD GRADUALLY ENCOUNTER SUB-26C WATER TEMPERATURES ALONG 2583WITH QUITE HOSTILE VERTICAL SHEAR...GRADUAL WEAKENING IS EXPECTED 2584FOR THE NEXT TWO DAYS UNTIL DISSIPATION. THE INTENSITY FORECAST IS 2585BASED UPON THE MODEL CONSENSUS AND IS SLIGHTLY HIGHER THAN THE 2586PREVIOUS ADVISORY BECAUSE OF THE STRONGER INITIAL CYCLONE. 2587 2588THE AFOREMENTIONED ASCAT PASS ALLOWED FOR AN ENLARGEMENT OF THE 2589TROPICAL STORM WIND RADII. 2590 2591FORECAST POSITIONS AND MAX WINDS 2592 2593INITIAL 20/0900Z 35.5N 47.9W 40 KT 2594 12HR VT 20/1800Z 36.1N 46.8W 35 KT 2595 24HR VT 21/0600Z 37.6N 45.3W 30 KT...POST-TROP/REMNT LOW 2596 36HR VT 21/1800Z 39.6N 43.5W 25 KT...POST-TROP/REMNT LOW 2597 48HR VT 22/0600Z...DISSIPATED 2598 2599$$ 2600FORECASTER LANDSEA/BRENNAN 2601 2602 2603 2604WTNT42 KNHC 201439 2605TCDAT2 2606TROPICAL STORM JULIA DISCUSSION NUMBER 34 2607NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 26081100 AM AST MON SEP 20 2010 2609 2610 2611DEEP CONVECTION HAS BEEN SHEARED OFF TO THE EAST OF THE CENTER BY 2612THE OUTFLOW OF HURRICANE IGOR...WITH THE COLDEST TOPS NOW A COUPLE 2613OF HUNDRED MILES AWAY FROM THE CENTER. THE ASCAT PASS FROM 0046Z 2614LAST NIGHT SHOWED THAT THE CIRCULATION WAS BECOMING ELONGATED EVEN 2615THEN...AND VISIBLE IMAGERY THIS MORNING SHOWS THAT JULIA IS LOSING 2616SOME DEFINITION AS IT BECOMES ENTANGLED WITH A FRONTAL TROUGH TO 2617THE EAST OF THE CYCLONE. BASED ON THESE STRUCTURAL CHANGES...THIS 2618WILL BE THE LAST ADVISORY. 2619 2620MORNING VISIBLE IMAGERY INDICATES THAT JULIA IS A LITTLE SOUTH OF 2621THE PREVIOUS TRACK...AND IS MOVING AT 090/8. THE 00Z ECMWF HANDLED 2622THE OVERNIGHT MOTION OF JULIA BEST...WITH THE OTHER GUIDANCE WELL 2623TO THE LEFT AND SHOWING MORE OF AN INTERACTION WITH THE CIRCULATION 2624OF IGOR. THE OFFICIAL FORECAST FOLLOWS THE ECMWF GUIDANCE WITH A 2625FORECAST MOTION SOUTH OF THE PREVIOUS FORECAST. 2626 2627STRONG UPPER-LEVEL NORTHWESTERLY FLOW SHOULD KEEP THE SHEAR OVER 2628JULIA ELEVATED...AND GIVEN THE MARGINAL SEA SURFACE TEMPERATURES... 2629PREVENT THE SYSTEM FROM REDEVELOPING ORGANIZED DEEP CONVECTION. IF 2630PRESENT TRENDS CONTINUE...THE CIRCULATION OF JULIA WILL BECOME 2631ILL-DEFINED WITHIN A FRONTAL TROUGH OVER THE NEXT DAY OR SO. THAT 2632SCENARIO IS REFLECTED IN THE OFFICIAL FORECAST...ALTHOUGH IT IS 2633POSSIBLE THAT JULIA COULD REMAIN WELL-ENOUGH DEFINED TO LINGER AND 2634MOVE EASTWARD AS A REMNANT LOW FOR SEVERAL DAYS...AS SHOWN BY THE 2635ECMWF. 2636 2637 2638FORECAST POSITIONS AND MAX WINDS 2639 2640INITIAL 20/1500Z 34.7N 46.4W 40 KT...POST-TROPICAL 2641 12HR VT 21/0000Z 34.9N 45.3W 35 KT...POST-TROPICAL 2642 24HR VT 21/1200Z 35.5N 43.0W 30 KT...POST-TROP/REMNT LOW 2643 36HR VT 22/0000Z...DISSIPATED 2644 2645$$ 2646FORECASTER FRANKLIN 2647 2648 2649 2650