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#157037 (Received by flhurricane at: 5:00 AM 29.Oct.2007) TCDAT1 TROPICAL STORM NOEL DISCUSSION NUMBER 7 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL162007 500 AM EDT MON OCT 29 2007 THE RECONNAISSANCE AIRCRAFT WAS NOT ABLE TO FIND A WELL-DEFINED CENTER OF CIRCULATION AT 850 MB...BUT DROPSONDE DATA INDICATE THAT THE CENTER LIKELY REFORMED AGAIN TO THE NORTH...CLOSER TO THE DEEP CONVECTION AND VERY CLOSE TO THE COAST OF HAITI. THE DROPSONDE DATA ALSO INDICATE THAT THE CENTRAL PRESSURE HAS RISEN SINCE THIS AFTERNOON...AND IS NOW LIKELY AROUND 1002 MB. THERE WAS AN SFMR REPORT OF 42 KT...ABOUT 80 NMI EAST OF THE CENTER...AND ON THIS BASIS THE INITIAL INTENSITY IS ESTIMATED TO BE 45 KT. THE INITIAL MOTION IS 340/5. AN UPPER-LEVEL LOW TO THE WEST OF NOEL IS INFLUENCING THE CONVECTIVE ASYMMETRY AND THE CENTER HAS BEEN FOLLOWING THE CONVECTION. THE UPPER LOW IS EXPECTED TO WEAKEN OVER THE NEXT DAY OR SO...AND WITH A MID-LEVEL RIDGE IN PLACE OVER THE SUBTROPICAL WESTERN ATLANTIC...THE TRACK SHOULD BEGIN TO TURN MORE TO THE NORTHWEST OVER THE NEXT TWO TO THREE DAYS. THE RIDGE IS THEN FORECAST BY GLOBAL MODELS TO WEAKEN AND SHIFT EASTWARD WITH THE APPROACH OF A MID-LEVEL SHORTWAVE TROUGH...WHICH IS EXPECTED TO TURN NOEL NORTHWARD AND THEN NORTHEASTWARD. WITH THE EXCEPTION OF THE ECMWF AND UKMET...WHICH RUN A WEAK LOW ALONG OR SOUTH OF CUBA...THE MODEL GUIDANCE IS IN REASONABLE AGREEMENT ON THIS SCENARIO. THE OFFICIAL FORECAST IS SHIFTED TO THE RIGHT OF THE PREVIOUS ADVISORY FOR THE FIRST 48 HOURS...AS A RESULT OF THE NORTHWARD RELOCATION OF THE CENTER. IT NOW APPEARS THAT THE CENTER OF NOEL...WHICH IS NOT WELL-DEFINED TO BEGIN WITH...WILL BE INTERACTING WITH THE TERRAIN OF HAITI FOR THE NEXT 12 HOURS OR SO. ASSUMING IT SURVIVES THE PASSAGE...THE NEGATIVE INFLUENCE OF THE UPPER-LEVEL LOW SHOULD DIMINISH AND ALL GUIDANCE INDICATES RESTRENGTHENING. THE OFFICIAL FORECAST IS CLOSE TO THE DECAY SHIPS AND LGEM...BUT SIGNIFICANTLY BELOW THE GFDL AND HWRF. BY DAYS 4-5...INCREASING WESTERLY SHEAR SHOULD INTERRUPT THE INTENSIFICATION PROCESS...AND BY THE END OF THE PERIOD THE SYSTEM SHOULD BE LOSING ITS TROPICAL CHARACTERISTICS AS IT INTERACTS WITH A FRONTAL ZONE. FORECAST POSITIONS AND MAX WINDS INITIAL 29/0900Z 18.0N 72.3W 45 KT 12HR VT 29/1800Z 19.4N 72.9W 30 KT 24HR VT 30/0600Z 21.1N 74.0W 40 KT 36HR VT 30/1800Z 22.2N 75.0W 50 KT 48HR VT 31/0600Z 23.0N 75.8W 55 KT 72HR VT 01/0600Z 26.0N 76.0W 55 KT 96HR VT 02/0600Z 29.0N 74.0W 50 KT 120HR VT 03/0600Z 32.0N 70.0W 45 KT...EXTRATROPICAL $$ FORECASTER FRANKLIN |