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| #300128 (Received by flhurricane at: 10:37 AM 07.Oct.2009) TCDAT5 TROPICAL STORM HENRI DISCUSSION NUMBER 4 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL102009 1100 AM AST WED OCT 07 2009 SATELLITE IMAGES SHOW THAT THE CENTER OF HENRI HAS BECOME EXPOSED AGAIN TO THE WEST OF A MASS OF DEEP CONVECTION. IN ADDITION...THE LOW-CLOUD CIRCULATION CENTER LOOKS A LITTLE LESS WELL-DEFINED THAN YESTERDAY. DVORAK CLASSIFICATIONS HAVE DECREASED SOMEWHAT...AND THE INITIAL WIND SPEED HAS BEEN REDUCED TO 40 KT FOR THE ADVISORY. FURTHER WEAKENING IS LIKELY DUE TO SOUTHWESTERLY SHEAR FOR THE NEXT DAY OR SO. AFTER THAT TIME...MOST OF GLOBAL MODELS INDICATE THAT HENRI WILL ENCOUNTER A SHARP UPPER-LEVEL SHEAR AXIS...AND THEN COME UNDER THE INFLUENCE OF STRONG...CONVERGENT...NORTHEASTERLY UPPER FLOW. THESE ENVIRONMENTAL CONDITIONS ARE RATHER HOSTILE...AND THE OFFICIAL FORECAST CONTINUES THE TREND OF THE PREVIOUS FORECAST PACKAGES BY SHOWING THE CYCLONE DISSIPATING WITHIN A COUPLE OF DAYS. THE BEST ESTIMATE OF INITIAL MOTION IS 290/13...A LITTLE FASTER THAN BEFORE. SUBTROPICAL RIDGING OVER THE WESTERN ATLANTIC OCEAN SHOULD FAVOR A WEST OR WEST-NORTHWEST MOTION OF HENRI OVER THE NEXT 24-36 HOURS. THIS RIDGE IS EXPECTED BECOME STRONGER AFTER THAT TIME...WHICH SHOULD CAUSE A WESTWARD TURN OF THE TROPICAL CYCLONE OR ITS REMNANT. MOST OF THE MODEL GUIDANCE IS IN AGREEMENT ON THE TRACK...AND THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS ADVISORY...AND ON THE SOUTHERN SIDE OF THE GUIDANCE ENVELOPE. FORECAST POSITIONS AND MAX WINDS INITIAL 07/1500Z 18.9N 57.4W 40 KT 12HR VT 08/0000Z 19.6N 59.2W 35 KT 24HR VT 08/1200Z 20.6N 61.2W 30 KT 36HR VT 09/0000Z 21.2N 62.7W 25 KT...REMNANT LOW 48HR VT 09/1200Z 21.2N 64.2W 20 KT...REMNANT LOW 72HR VT 10/1200Z...DISSIPATED $$ FORECASTER BLAKE/PASCH |
