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#225896 (Received by flhurricane at: 4:00 AM 06.Nov.2008) TCDAT2 TROPICAL STORM PALOMA DISCUSSION NUMBER 3 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL172008 400 AM EST THU NOV 06 2008 AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING TROPICAL DEPRESSION SEVENTEEN FOUND 850 MB FLIGHT-LEVEL WINDS OF 46 KT ABOUT 20 N MI NORTHWEST OF THE CENTER...AND REPORTED THAT THE CENTRAL PRESSURE HAD DROPPED TO 1000 MB. SATELLITE IMAGERY IS SHOWING INCREASING ORGANIZATION...WITH CLOUD TOPS COLDER THAN -80C OCCURRING JUST WEST OF THE CENTER. BASED ON THE FLIGHT-LEVEL WINDS...THE DEPRESSION IS UPGRADED TO TROPICAL STORM PALOMA WITH 35-KT WINDS. IT SHOULD BE NOTED THAT THE SFMR ESTIMATED SURFACE WINDS IN EXCESS OF 50 KT IN THE NORTHWEST QUADRANT. HOWEVER... THESE WINDS APPEAR SUSPECT DUE TO HEAVY RAIN AND SHOALING ISSUES. UP TO 72 HR...A COMBINATION OF LIGHT VERTICAL WIND SHEAR...GOOD ANTICYCLONIC OUTFLOW...AND WARM SEA SURFACE TEMPERATURES APPEARS FAVORABLE FOR SIGNIFICANT STRENGTHENING. THE RAPID INTENSIFICATION INDEX ATTACHED TO THE SHIPS MODEL SHOWS A 50 PERCENT CHANCE OF 30 KT INTENSIFICATION DURING THE NEXT 24 HR. THE HWRF FORECASTS A PEAK INTENSITY 114 KT AND 921 MB IN 72 HR...WHILE THE GFDL FORECASTS A PEAK INTENSITY OF 97 KT AND 961 MB IN 66 HR. THE INTENSITY FORECASTS IS A LITTLE MORE CONSERVATIVE...CALLING FOR A PEAK INTENSITY OF 90 KT IN 72 HR IN BEST AGREEMENT WITH THE ICON CONSENSUS MODEL. AFTER 72 HR...PALOMA IS EXPECTED TO ENCOUNTER STRONG WESTERLY SHEAR...WITH THE POSSIBILITY THAT THE CYCLONE COULD SHEAR APART VERTICALLY. THUS...THE INTENSITY FORECAST CALLS FOR SIGNIFICANT WEAKENING DURING THAT TIME. THE INITIAL MOTION IS 335/6. PALOMA IS ON THE EAST SIDE OF A MID-LEVEL RIDGE OVER THE CENTRAL AND EASTERN CARIBBEAN...AND IT IS LIKELY TO ENCOUNTER THE SOUTHERN EDGE OF STRONG MID/UPPER-LEVEL WESTERLY FLOW AS IT REACHES 18N IN ABOUT 48 HR. THIS FLOW SHOULD CAUSE THE STORM TO TURN NORTHEASTWARD. THE GUIDANCE MODELS SUGGEST TWO TRACK FORECAST SCENARIOS. FIRST...THE GFDL...HWRF... AND BAMD FORECAST A VERTICALLY DEEP HURRICANE TO MOVE QUICKLY NORTHEAST ACROSS CUBA AND THE BAHAMAS INTO THE ATLANTIC. ON THE OTHER HAND...THE GFS... NOGAPS...UKMET...ECMWF...AND CANADIAN MODELS ALL SHOW PALOMA SHEARING APART AFTER 72 HR AS IT MOVES NORTHEASTWARD... WITH THE REMNANT LOW-LEVEL CIRCULATION TURNING WESTWARD OR NORTHWESTWARD ON THE SOUTH SIDE OF A LOW-LEVEL RIDGE. THE NOGAPS SHOWS THE MOST WESTWARD TRACK...KEEPING PALOMA WEST OF THE CAYMAN ISLANDS. THE GFS IS THE EASTERNMOST OF THIS SET OF SOLUTIONS... SHOWING THE CENTER REACHING THE BAHAMAS. SINCE THE INTENSITY FORECAST IS FOR A STRONG AND VERTICALLY DEEP HURRICANE AT 72 HR... THE TRACK FORECAST LEANS TOWARD THE GFDL/HWRF/BAMD SCENARIO. HOWEVER...THE FORECAST FORWARD SPEED AFTER 72 HR WILL BE SLOWER THAN WHAT THOSE MODELS ARE FORECASTING. IF THE CURRENT MOTION AND STRUCTURE TRENDS CONTINUE...THE TROPICAL STORM-FORCE WINDS ARE LIKELY TO STAY OFF THE COASTS OF NICARAGUA AND HONDURAS. HOWEVER...THOSE WINDS COULD SPREAD ONSHORE IF THE STORM MAKES A LEFT TURN OR GROWS IN SIZE FASTER THAN CURRENTLY FORECAST. FORECAST POSITIONS AND MAX WINDS INITIAL 06/0900Z 15.1N 82.2W 35 KT 12HR VT 06/1800Z 15.8N 82.6W 45 KT 24HR VT 07/0600Z 16.6N 82.9W 55 KT 36HR VT 07/1800Z 17.5N 83.2W 65 KT 48HR VT 08/0600Z 18.5N 82.8W 75 KT 72HR VT 09/0600Z 20.0N 81.0W 90 KT 96HR VT 10/0600Z 22.0N 78.0W 65 KT...INLAND OVER CUBA 120HR VT 11/0600Z 25.0N 73.0W 45 KT...OVER WATER $$ FORECASTER BEVEN |