000 WTNT42 KNHC 180241 TCDAT2 TROPICAL STORM JULIA DISCUSSION NUMBER 24 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1100 PM AST FRI SEP 17 2010 THE SATELLITE PRESENTATION SHOWS THE CIRCULATION CENTER OF JULIA JUST BENEATH THE NORTHERN EDGE OF THE CLOUD CANOPY. THE SHEARED CLOUD PATTERN IS DUE TO 20-30 KT OF NORTHERLY SHEAR PRODUCED BY A STRONG OUTFLOW CHANNEL ASSOCIATED WITH HURRICANE EARL. SUBSEQUENT BANDING CLOUD TOPS HAVE WARMED CONSIDERABLY THIS EVENING...AND THE SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE DECREASED TO 65 AND 60 KT RESPECTIVELY. BASED ON THESE DATA...THE INITIAL INTENSITY IS LOWERED TO 60 KT. THE GLOBAL AND THE SHIPS MODELS ALL SUGGEST THAT THE SHEAR WILL PERSIST AND STRENGTHEN BY THE 48 HOUR PERIOD AS THE SHEAR VECTOR BECOMES MORE WESTERLY. THE NHC INTENSITY FORECAST INDICATES A GRADUAL WEAKENING TREND BASED ON THE AFOREMENTIONED GUIDANCE...WITH THE CYCLONE ULTIMATELY BECOMING ABSORBED IN 96 HOURS BY THE MUCH LARGER EXTRATROPICAL IGOR. THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS ADVISORY...AND IS ESTIMATED TO BE NORTHWESTWARD OR 310/14. THE DYNAMICAL MODELS SHOW THE CYCLONE MOVING NORTHWESTWARD DURING THE NEXT 36 HOURS WITHIN THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH TO THE NORTHEAST OF JULIA. THROUGH DAY 3...THE MODELS INDICATE THAT THE SYSTEM WILL TURN NORTH-NORTHEASTWARD...AND NORTHEASTWARD AS THE MID-LEVEL HIGH BEGINS TO DRIFT SOUTHWESTWARD OVER THE CENTRAL ATLANTIC. AFTERWARD...THE MODELS ARE IN GOOD AGREEMENT WITH JULIA BECOMING ABSORBED BY IGOR...GENERALLY IN 96 HOURS...OR EARLIER...AS SUGGESTED BY THE SHIPS AND BOTH THE ECMWF AND GFS ENSEMBLE MEANS. THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS ADVISORY AND IS BASED ON A BLEND OF THE GLOBAL AND REGIONAL MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 18/0300Z 26.0N 49.2W 60 KT 12HR VT 18/1200Z 28.1N 50.8W 55 KT 24HR VT 19/0000Z 31.0N 52.1W 50 KT 36HR VT 19/1200Z 33.5N 52.0W 45 KT 48HR VT 20/0000Z 35.5N 50.6W 40 KT 72HR VT 21/0000Z 39.0N 46.0W 30 KT 96HR VT 22/0000Z...ABSORBED BY A LARGE EXTRATROPICAL LOW $$ FORECASTER ROBERTS/AVILA