000 WTNT41 KNHC 010901 TCDAT1 TROPICAL STORM NOEL DISCUSSION NUMBER 19 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL162007 500 AM EDT THU NOV 01 2007 NOEL PRODUCED A MAJOR BURST OF CONVECTION EAST OF THE CENTER EARLIER THIS MORNING...WITH CLOUD TOP TEMPERATURES NEAR -90C AT TIMES. HOWEVER...THE BURST HAS ENDED...WITH RADAR DATA FROM MIAMI... NASSAU...AND CAMAGUEY CURRENTLY SHOWING LITTLE PRECIPITATION NEAR THE CENTER. MAJOR COMMUNICATIONS PROBLEMS HAVE DISRUPTED THE FLOW OF DATA FROM THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT MONITORING NOEL. HOWEVER...THE PLANE REPORTED THAT THE CENTRAL PRESSURE HAD FALLEN TO 992 MB AT 05Z. BASED ON THAT AND SATELLITE INTENSITY ESTIMATES...THE INITIAL INTENSITY REMAINS 50 KT. THE INITIAL MOTION IS A SOMEWHAT ERRATIC 000/5. WATER VAPOR IMAGERY AND MODEL ANALYSES INDICATE THAT A LARGE MID/UPPER-LEVEL TROUGH IS MOVING INTO THE EASTERN UNITED STATES...WITH THE LOW/MID-LEVEL RIDGE OVER THE WESTERN ATLANTIC MOVING EASTWARD. THE DYNAMICAL MODELS NOW AGREE THAT NOEL WILL BE PICKED UP BY THE TROUGH... MOVING SLOWLY NORTHWARD FOR 12 HR OR SO AND THEN ACCELERATING NORTHEASTWARD. THE NEW FORECAST TRACK IS AN UPDATE OF THE PREVIOUS TRACK THROUGH 36 HR...AND THEN IS SOMEWHAT TO THE LEFT OF THE PREVIOUS TRACK THEREAFTER IN RESPONSE TO A LEFTWARD SHIFT IN THE MODEL CONSENSUS. IT SHOULD BE NOTED THAT THE MOTION DURING THE FIRST 12 HR COULD BE ERRATIC DUE TO RE-FORMATION OF THE CENTER CAUSED BY CONVECTIVE BURSTS. NOEL HAS AN IMPRESSIVE OUTFLOW PATTERN...ESPECIALLY IN THE NORTHEASTERN SEMICIRCLE. HOWEVER...RAWINSONDE DATA FROM KEY WEST AND MIAMI SHOW THAT THE OUTFLOW IS CONFINED TO ABOVE 200 MB...WITH 20-30 KT OF WESTERLY FLOW BETWEEN 200-400 MB UNDERCUTTING THE OUTFLOW AND CAUSING SHEAR. THE SHEAR IS LIKELY TO INCREASE BY 24 HR...LEAVING ONLY A SMALL WINDOW FOR NOEL TO INTENSIFY AS A TROPICAL CYCLONE. THE INTENSITY FORECAST CALLS FOR NOEL TO STRENGTHEN TO 60 KT IN 12 HR IN ANTICIPATION OF ANOTHER CONVECTIVE BURST SIMILAR TO THE ONE THAT JUST FINISHED. AFTER THAT... INCREASING SHEAR SHOULD STOP DEVELOPMENT. ALL DYNAMICAL MODELS FORECAST NOEL TO BECOME A LARGE AND INTENSE EXTRATROPICAL LOW OVER THE WESTERN ATLANTIC STARING IN 36-48 HR...AND THIS IS REFLECTED IN BOTH THE INTENSITY AND WIND RADII FORECASTS. THE AIRCRAFT FOUND A BAND OF TROPICAL STORM-FORCE WINDS ABOUT 100-115 N MI FROM THE CENTER IN THE NORTHWESTERN QUADRANT....WITH THE AIRCRAFT DATA SUPPORTED BY DOPPLER WINDS FROM THE MIAMI WSR-88D AND A 37 KT SHIP REPORT AT 06Z. THESE WINDS ARE CLOSE ENOUGH TO THE FLORIDA COAST THAT ANY DEVIATION TO THE LEFT OF THE FORECAST TRACK WOULD BRING THEM ON TO THE FLORIDA COAST. THUS...A TROPICAL STORM WARNING IS BEING ISSUED AT THIS TIME FOR THE IMMEDIATE COASTAL AREA OF MIAMI-DADE AND BROWARD COUNTIES. FORECAST POSITIONS AND MAX WINDS INITIAL 01/0900Z 23.7N 78.5W 50 KT 12HR VT 01/1800Z 25.0N 78.1W 60 KT 24HR VT 02/0600Z 27.2N 76.2W 60 KT 36HR VT 02/1800Z 30.5N 73.4W 55 KT...BECOMING EXTRATROPICAL 48HR VT 03/0600Z 34.8N 70.1W 55 KT...EXTRATROPICAL 72HR VT 04/0600Z 43.5N 63.0W 60 KT...EXTRATROPICAL 96HR VT 05/0600Z 53.0N 52.5W 60 KT...EXTRATROPICAL 120HR VT 06/0600Z 57.5N 42.5W 60 KT...EXTRATROPICAL $$ FORECASTER BEVEN