000 WTNT42 KNHC 170248 TCDAT2 HURRICANE JULIA DISCUSSION NUMBER 20 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010 1100 PM AST THU SEP 16 2010 THE EYE OF JULIA BECAME BETTER DEFINED IN INFRARED SATELLITE IMAGES FOR A PERIOD OF TIME THIS EVENING. HOWEVER...THE AREA OF COLD CLOUDS TOPS ASSOCIATED WITH THE HURRICANE HAS DECREASED IN SIZE. THE LATEST DVORAK INTENSITY ESTIMATES SUPPORT AN INITIAL INTENSITY OF 70 KT. THE GLOBAL MODELS AND WATER VAPOR IMAGERY SHOW THAT JULIA WILL BE ENTERING AN AREA OF STRONG NORTHWESTERLY UPPER-LEVEL WINDS ASSOCIATED WITH THE OUTFLOW FROM HURRICANE IGOR VERY SHORTLY. THE SHIPS GUIDANCE INDICATES 30-40 KT WIND SHEAR DURING THE NEXT DAY OR SO. DURING THIS TIME JULIA IS EXPECTED TO WEAKEN SIGNIFICANTLY AND THE NEW INTENSITY FORECAST IS A LITTLE LOWER THAN THE PREVIOUS ADVISORY THROUGH 36 HOURS. IF JULIA SURVIVES THE STRONG SHEAR...THE GLOBAL MODELS SUGGEST THAT THE UPPER-LEVEL ENVIRONMENT COULD IMPROVE BETWEEN 36-72 HOURS. DURING THAT TIME ONLY GRADUAL WEAKENING IS SHOWN. IN 4-5 DAYS...JULIA IS EXPECTED TO DISSIPATE IN THE STRONG SOUTHWESTERLY FLOW TO THE EAST OF IGOR. THE OFFICIAL INTENSITY FORECAST IS IN BEST AGREEMENT WITH THE SHIPS INTENSITY GUIDANCE. JULIA CONTINUES TO MOVE QUICKLY WEST-NORTHWESTWARD WITH AN INITIAL MOTION OF 290/21 KT. THE FORECAST TRACK REASONING REMAINS UNCHANGED AS JULIA WILL BE MOVING AROUND THE WESTERN PORTION OF A MID-LEVEL RIDGE CENTERED SOUTHWEST OF THE AZORES. THE TRACK GUIDANCE HAS AGAIN SHIFTED WESTWARD AND THE OFFICIAL FORECAST FOLLOWS SUIT. THE NEW FORECAST LIES BETWEEN THE GFS...WHICH IS ALONG THE EAST EDGE OF THE GUIDANCE...AND THE TVCN CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 17/0300Z 23.5N 42.9W 70 KT 12HR VT 17/1200Z 24.6N 45.7W 60 KT 24HR VT 18/0000Z 26.3N 48.8W 55 KT 36HR VT 18/1200Z 28.6N 50.8W 50 KT 48HR VT 19/0000Z 31.0N 52.0W 45 KT 72HR VT 20/0000Z 35.0N 50.5W 40 KT 96HR VT 21/0000Z 39.0N 46.5W 35 KT 120HR VT 22/0000Z...DISSIPATED $$ FORECASTER BROWN