|
Show Selection: |
| #157349 (Received by flhurricane at: 4:49 AM 31.Oct.2007) TCDAT1 TROPICAL STORM NOEL DISCUSSION NUMBER 15 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL162007 500 AM EDT WED OCT 31 2007 SURFACE AND RADAR OBSERVATIONS INDICATE THAT THE CENTER OF NOEL IS APPROACHING THE NORTHERN COAST OF CUBA NEAR CAYO COCO. RADAR AND SATELLITE IMAGERY SHOW A LARGE AREA OF STRONG CONVECTIVE BANDS NORTH AND EAST OF THE CENTER...ALTHOUGH THERE IS LITTLE CONVECTION NEAR THE CENTER AT THIS TIME. A SURFACE OBSERVATION AT CAYO COCO SUGGESTS THE CENTRAL PRESSURE IS NEAR 1000 MB...AND AN EARLIER ASCAT OVERPASS SUGGESTS THE MAXIMUM WINDS REMAIN NEAR 35 KT. NOEL HAS TURNED TO THE RIGHT OVER THE PAST SEVERAL HOURS. THE 12 HR MOTION IS 330/6...AND THE SHORT-TERM MOTION MAY EVEN BE MORE TOWARD THE NORTH. IT IS UNCLEAR WHETHER THIS IS AN EARLY START OF THE FORECAST NORTHWARD TURN...OR IF IT IS A RE-FORMATION OF THE CENTER. THE DYNAMICAL MODELS SHOW FOUR POSSIBLE SCENARIOS FOR NOEL BASED ON INTERACTIONS WITH A MID/UPPER-LEVEL TROUGH MOVING EASTWARD ACROSS THE GULF OF MEXICO AND A DEEP-LAYER TROUGH MOVING INTO THE EASTERN UNITED STATES. THE FIRST...SUPPORTED BY THE NOGAPS...THE GFDL... AND THE HWRF...IS FOR NOEL TO RECURVE INTO THE WESTERLIES AND BECOME A STRONG EXTRATROPICAL LOW OVER THE NORTHWESTERN ATLANTIC. THE SECOND...SUPPORTED BY THE GFS...IS FOR AN EXTRATROPICAL LOW TO FORM OFF THE FLORIDA COAST WHICH ABSORBS NOEL. THE THIRD... SUPPORTED BY THE UKMET...IS FOR AN EXTRATROPICAL LOW TO FORM OFF THE FLORIDA COAST WITH IT AND NOEL MOVING NORTHEASTWARD IN TANDEM. THE FOURTH...SUPPORTED BY THE ECMWF...IS FOR AN EXTRATROPICAL LOW TO FORM OFF THE FLORIDA COAST AND A WEAKENING NOEL BEING DRIVEN SOUTHWESTWARD INTO THE CARIBBEAN BY THE ASSOCIATED COLD FRONT. THE OFFICIAL FORECAST WILL FOLLOW THE FIRST SCENARIO...WITH NOEL RECURVING INTO THE WESTERLIES DURING THE NEXT 24-36 HR AND THEN ACCELERATING NORTHEASTWARD. THE TRACK FORECAST IS IN GOOD OVERALL AGREEMENT WITH THE VARIOUS CONSENSUS MODELS. ANALYSES FROM CIMSS AT THE UNIVERSITY OF WISCONSIN INDICATE NOEL IS EXPERIENCING 20-25 KT OF WESTERLY VERTICAL WIND SHEAR...MUCH OF IT DUE TO STRONG LOW-LEVEL EASTERLY FLOW. AS NOEL MOVES OFF CUBA... THERE WILL BE A 24 HR OR SO PERIOD OF DECREASED SHEAR THAT COULD ALLOW SOME STRENGTHENING. AFTER THAT...INTENSIFICATION AS A TROPICAL CYCLONE SHOULD STOP AS NOEL ENCOUNTERS STRONGER SHEAR AND BEGINS EXTRATROPICAL TRANSITION. THE CYCLONE IS FORECAST TO STRENGTHEN FURTHER AFTER BECOMING EXTRATROPICAL...WITH A PEAK INTENSITY OF 60 KT. THE STRONG GUSTY WINDS THAT CONTINUE TO AFFECT PORTIONS OF FLORIDA ARE ASSOCIATED WITH THE PRESSURE GRADIENT BETWEEN A STRONG HIGH OVER THE U.S. EAST COAST AND NOEL...BUT ARE NOT DIRECTLY ASSOCIATED WITH THE CIRCULATION OF THE TROPICAL STORM. SEE STATEMENTS FROM NWS LOCAL FORECAST OFFICES. FORECAST POSITIONS AND MAX WINDS INITIAL 31/0900Z 22.1N 78.2W 35 KT...INLAND 12HR VT 31/1800Z 22.9N 78.7W 40 KT...OVER WATER 24HR VT 01/0600Z 23.9N 78.7W 45 KT 36HR VT 01/1800Z 25.6N 77.8W 45 KT 48HR VT 02/0600Z 28.0N 75.7W 45 KT...BECOMING EXTRATROPICAL 72HR VT 03/0600Z 35.0N 69.0W 50 KT...EXTRATROPICAL 96HR VT 04/0600Z 44.0N 61.5W 60 KT...EXTRATROPICAL 120HR VT 05/0600Z 54.0N 53.0W 60 KT...EXTRATROPICAL $$ FORECASTER BEVEN |
