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| #300256 (Received by flhurricane at: 10:34 PM 07.Oct.2009) TCDAT5 TROPICAL DEPRESSION HENRI DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL102009 1100 PM AST WED OCT 07 2009 SATELLITE IMAGES AND MICROWAVE DATA INDICATE THAT THE LOW-LEVEL CENTER OF HENRI IS LOCATED WELL TO THE WEST OF A PERSISTENT AREA OF OF DEEP CONVECTION. THIS ASYMMETRIC STRUCTURE IS DUE TO ABOUT 25 KT OF SOUTHWESTERLY VERTICAL WIND SHEAR. DVORAK INTENSITY ESTIMATES HAVE DECREASED AND ON THIS BASIS...HENRI IS BEING DOWNGRADED TO A TROPICAL DEPRESSION WITH THE INITIAL INTENSITY SET AT 30 KT. THE STRONG SOUTHWESTERLY SHEAR IS EXPECTED TO PERSIST FOR ANOTHER 12 HOURS WHICH SHOULD CONTINUE TO DECOUPLE THE CYCLONE. GLOBAL MODELS SHOW THAT HENRI...OR ITS REMNANTS...WILL BE MOVING UNDER AN UPPER-LEVEL SHEAR AXIS BETWEEN 12 AND 36 HOURS. THEREAFTER...STRONG NORTHEASTERLY MID- TO UPPER-LEVEL FLOW WILL IMPACT THE SYSTEM. THIS UNFAVORABLE ATMOSPHERIC ENVIRONMENT SHOULD LEAD TO CONTINUED WEAKENING AS UNANIMOUSLY SHOWN BY THE DYNAMICAL MODELS. THE OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS ONE AND CALLS FOR HENRI TO DEGENERATE INTO A REMNANT LOW WITHIN 24 HOURS. THE INITIAL MOTION IS 285/13...SLIGHTLY TO THE SOUTH OF THE PREVIOUS ADVISORY. THIS MOTION IS EXPECTED TO CONTINUE FOR ABOUT ANOTHER DAY. THEREAFTER...A STRONG DEEP-LAYER RIDGE WILL BUILD OVER THE WESTERN ATLANTIC CAUSING HENRI...OR ITS REMNANTS...TO TURN WESTWARD OR SOUTHWESTWARD. THE NEW TRACK FORECAST IS NUDGED A LITTLE TO THE SOUTH TO ACCOUNT FOR THE INITIAL HEADING AND IS NEAR THE BAM SHALLOW. FORECAST POSITIONS AND MAX WINDS INITIAL 08/0300Z 19.5N 59.7W 30 KT 12HR VT 08/1200Z 20.1N 61.3W 30 KT 24HR VT 09/0000Z 20.7N 63.0W 25 KT...REMNANT LOW 36HR VT 09/1200Z 20.9N 65.0W 20 KT...REMNANT LOW 48HR VT 10/0000Z 20.6N 67.1W 20 KT...REMNANT LOW 72HR VT 11/0000Z...DISSIPATED $$ FORECASTER CANGIALOSI/BEVEN |
