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| #151093 (Received by flhurricane at: 10:37 AM 16.Sep.2007) TCDAT3 TROPICAL DEPRESSION INGRID DISCUSSION NUMBER 17 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082007 1100 AM EDT SUN SEP 16 2007 INGRID IS MAINTAINING ITS INTENSITY DESPITE THE HOSTILE UPPER-LEVEL FLOW. IN FACT...THE APPEARANCE OF THE SYSTEM IS LESS DISORGANIZED THAN IT WAS 24 HOURS AGO...WITH THE CENTER NO LONGER EXPOSED FROM THE DEEP CONVECTION. THE CURRENT INTENSITY ESTIMATE REMAINS AT 30 KT IN AGREEMENT WITH A DVORAK ESTIMATE FROM TAFB. ACCORDING TO THE LATEST GFS RUN...VERTICAL SHEAR IS FORECAST TO REMAIN ABOVE 20 KT FOR THE NEXT 48 HOURS. THIS WOULD SEEM TO PRECLUDE ANY SIGNIFICANT RE-STRENGTHENING OVER THE NEXT DAY OR TWO. HOWEVER THE CONSENSUS OF SHIPS...THE GFDL...AND THE HWRF MODEL INDICATES THAT INGRID WILL EVENTUALLY REGAIN TROPICAL STORM STRENGTH...AS THE UPPER-LEVEL ENVIRONMENT IS FORECAST TO BECOME LESS HOSTILE LATE IN THE FORECAST PERIOD. FOR THE SAKE OF CONTINUITY WITH PREVIOUS FORECASTS THAT INDICATED DISSIPATION BY DAY 5...THE CURRENT NHC INTENSITY FORECAST MERELY MAINTAINS INGRID AT ITS CURRENT STRENGTH. HOWEVER THE NEXT NHC ADVISORY PACKAGE MAY NEED TO SHOW SOME RESTRENGTHENING. BASED ON GEOSTATIONARY AND MICROWAVE SATELLITE FIXES...THE INITIAL MOTION IS ONLY SLIGHTLY NORTH OF WEST...280/10. HOWEVER...THE MID-LEVEL RIDGE TO THE NORTH OF INGRID IS FORECAST TO WEAKEN. THIS SHOULD INDUCE A TURN TO THE RIGHT OVER THE NEXT SEVERAL DAYS...AS INDICATED BY THE MAJORITY OF THE TRACK GUIDANCE MODELS. IN 4-5 DAYS A TROUGH DROPPING DOWN OVER THE WESTERN ATLANTIC IS EXPECTED TO TURN INGRID NORTHWARD. HOWEVER THE STEERING CURRENTS ARE NOT VERY WELL DEFINED SO A SLOW MOTION OF ONLY 4-5 KT IS INDICATED BY THE OFFICIAL TRACK FORECAST LATE IN THE PERIOD. THIS IS IN AGREEMENT WITH THE DYNAMICAL MODEL CONSENSUS. SINCE INGRID HAS MOVED SOMEWHAT MORE WESTWARD THAN EXPECTED...AND THERE IS LIMITED SKILL IN FORECASTING INTENSITY CHANGE...INTERESTS IN THE NORTHERN LEEWARD ISLANDS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. FORECAST POSITIONS AND MAX WINDS INITIAL 16/1500Z 17.2N 57.9W 30 KT 12HR VT 17/0000Z 17.7N 59.1W 30 KT 24HR VT 17/1200Z 18.4N 60.3W 30 KT 36HR VT 18/0000Z 19.2N 61.3W 30 KT 48HR VT 18/1200Z 20.0N 62.2W 30 KT 72HR VT 19/1200Z 21.5N 63.5W 30 KT 96HR VT 20/1200Z 23.0N 64.5W 30 KT 120HR VT 21/1200Z 24.5N 64.5W 30 KT $$ FORECASTER PASCH |
