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#225856 (Received by flhurricane at: 10:00 PM 05.Nov.2008) TCDAT2 TROPICAL DEPRESSION SEVENTEEN DISCUSSION NUMBER 2 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL172008 1000 PM EST WED NOV 05 2008 CONVECTION HAS INCREASED NEAR THE CENTER OF THE DEPRESSION OVER THE PAST FEW HOURS...AND DVORAK T-NUMBERS FROM SAB AND TAFB AT 0000 UTC SUPPORTED AN INTENSITY OF 30 AND 35 KT...RESPECTIVELY. ANALYSIS OF AMBIGUITIES FROM A QUIKSCAT PASS AT 2334 UTC SUGGESTS THAT THE HIGHEST WINDS OUTSIDE OF RAIN NEAR THE CENTER WERE AROUND 25 KT...REASONABLY SUGGESTING THAT WINDS ARE NEAR 30 KT IN THE CONVECTION. ALSO...NOAA BUOY 42057 WELL NORTH OF THE CENTER REPORTED A PEAK WIND OF 29 KT AT 2200 AND 2300 UTC...AND A GUST OF 33 KT. BASED ON ALL OF THIS EVIDENCE...THE INITIAL INTENSITY IS SET AT 30 KT. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT WILL INVESTIGATE THE CYCLONE LATER TONIGHT AND MAY FIND THAT THE SYSTEM HAS REACHED TROPICAL STORM STATUS. THE DEPRESSION HAS BEEN MOVING SLOWLY NORTHWEST OVER THE PAST FEW HOURS. A SLOW MOVEMENT TOWARD THE NORTHWEST IS EXPECTED TO CONTINUE FOR THE NEXT 24 HOURS...WITH A GRADUAL TURN TOWARD THE NORTH EXPECTED BY 48 HOURS AS THE CYCLONE ROUNDS THE WESTERN EDGE OF THE UPPER-LEVEL ANTICYCLONE CENTERED TO ITS EAST. LATER IN THE PERIOD...AN UPPER-LEVEL TROUGH IS FORECAST TO DIG INTO THE GULF OF MEXICO...AND WILL CAUSE THE CYCLONE TO TURN TOWARD THE NORTHEAST WITH AN INCREASE IN FORWARD SPEED. THE CURRENT TRACK FORECAST IS SLIGHTLY FASTER THAN THE PREVIOUS ADVISORY THROUGH ABOUT 36 HOURS...BUT IS STILL SLOWER THAN MOST OF THE MODEL GUIDANCE. AFTER 36 HOURS...THE FORECAST TRACK IS ADJUSTED TO THE LEFT OF THE PREVIOUS FORECAST TOWARD THE DYNAMICAL MODEL CONSENSUS...TVCN. THE UPPER-LEVEL ENVIRONMENT AND WARM SEA-SURFACE TEMPERATURES ARE VERY FAVORABLE FOR INTENSIFICATION THROUGH ABOUT 72 HOURS. THE GFDL AND HWRF BOTH MAKE THE CYCLONE A HURRICANE WITHIN 36 TO 48 HOURS...AND FORECAST AN INTENSITY NEAR MAJOR HURRICANE STATUS BY 72 HOURS. THE SHIPS MODEL FORECASTS THE SYSTEM TO BE NEAR HURRICANE INTENSITY AT 48 HOURS BUT DOES NOT SHOW AS MUCH STRENGTHENING BEYOND THAT TIME. THE INTENSITY FORECAST WAS ADJUSTED UPWARD...AND IS IN EXCELLENT AGREEMENT WITH THE ICON INTENSITY MODEL CONSENSUS. HOWEVER...IF THE CYCLONE IS ABLE TO ESTABLISH AN INNER CORE...MORE RAPID INTENSIFICATION MAY OCCUR THAN IS FORECAST HERE. BEYOND 72 HOURS...THE VERTICAL WIND SHEAR INCREASES RAPIDLY AS THE CYCLONE INTERACTS WITH THE WESTERLIES...AND WEAKENING IS FORECAST AT THOSE TIME PERIODS. FORECAST POSITIONS AND MAX WINDS INITIAL 06/0300Z 14.3N 82.1W 30 KT 12HR VT 06/1200Z 14.8N 82.5W 40 KT 24HR VT 07/0000Z 15.6N 82.9W 50 KT 36HR VT 07/1200Z 16.4N 83.1W 60 KT 48HR VT 08/0000Z 17.3N 83.2W 70 KT 72HR VT 09/0000Z 19.0N 82.0W 90 KT 96HR VT 10/0000Z 20.5N 79.5W 70 KT 120HR VT 11/0000Z 23.5N 74.5W 50 KT $$ FORECASTER BRENNAN/STEWART |