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| #293063 (Received by flhurricane at: 4:46 PM 02.Sep.2009) TCDAT1 TROPICAL STORM ERIKA DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062009 500 PM AST WED SEP 02 2009 SATELLITE IMAGES SHOW THAT THE CIRCULATION OF ERIKA IS ELONGATED FROM SOUTHWEST TO NORTHEAST...IN AGREEMENT WITH SURFACE OBSERVATIONS FROM THE LESSER ANTILLES AND REPORTS FROM AN AIR FORCE HURRICANE HUNTER AIRCRAFT. THE SWIRL SOUTHWEST OF GUADELOUPE APPEARS TO BE PART OF THIS ELONGATED CIRCULATION...BUT IS NOT THE MEAN CENTER OF THE OVERALL CYCLONIC ENVELOPE. AIRCRAFT DATA ALSO INDICATE THAT ERIKA IS STILL A TROPICAL STORM. PEAK FLIGHT LEVEL WINDS WERE 44 KT AND SFMR DATA WERE BETWEEN 35-40 KT. HOWEVER THE STRONGEST WINDS WERE NEAR A LARGE THUNDERSTORM COMPLEX WELL SOUTHEAST OF THE CENTER AND NOT DIRECTLY ASSOCIATED WITH THE STORM CIRCULATION. THE INITIAL INTENSITY WILL BE HELD AT 35 KT FOR THIS ADVISORY. ERIKA HAS A DIFFICULT ROAD AHEAD WITH INCREASING SHEAR LIKELY AS THE STORM NEARS THE GREATER ANTILLES. WHILE SOME INTENSIFICATION CAN NOT BE RULED OUT IN THE NEXT DAY OR SO...ALL OF THE GLOBAL MODELS SHOW A VERY HOSTILE ENVIRONMENT WITH 20-30 KT SOUTHWESTERLY WINDS AT 250 MB OVER ERIKA. THESE WINDS ARE FORECAST TO CONTINUE...OR INCREASE...AS THE STORM MOVES NEAR HISPANIOLA. ALTHOUGH MOST OF THE INTENSITY GUIDANCE STILL SHOWS RESTRENGTHENING OF ERIKA...THE GUIDANCE HAS COME DOWN QUITE A BIT FROM THIS MORNING. THE NHC FORECAST IS LOWER THAN THE PREVIOUS ONE...AND SHOWS DISSIPATION OF THE TROPICAL CYCLONE BY 5 DAYS. ONE ALTERNATIVE SOLUTION IS THAT INTERACTION WITH HISPANIOLA CAUSES AN EVEN FASTER DEMISE OF ERIKA. THE LONG-TERM MOTION OF THIS SYSTEM IS ABOUT 275/9. DURING THE NEXT SEVERAL DAYS...THE STORM SHOULD BE STEERED TO THE WEST OR WEST-NORTHWEST PRIMARILY BY A RIDGE OVER THE WESTERN ATLANTIC. THE GLOBAL MODELS HAVE SHIFTED SOUTHWARD WITH THE TRACK FORECAST SINCE THIS MORNING...PERHAPS DUE TO THE WEAKER INITIAL STATE OF ERIKA. THE NHC FORECAST IS SHIFTED SOUTHWARD AS WELL...REMAINING WEST OF THE MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 02/2100Z 16.4N 61.7W 35 KT 12HR VT 03/0600Z 16.8N 62.9W 35 KT 24HR VT 03/1800Z 17.4N 64.6W 35 KT 36HR VT 04/0600Z 18.0N 66.4W 30 KT...INLAND 48HR VT 04/1800Z 18.7N 67.9W 30 KT 72HR VT 05/1800Z 20.0N 70.5W 25 KT 96HR VT 06/1800Z 21.5N 73.5W 20 KT...REMNANT LOW 120HR VT 07/1800Z...DISSIPATED $$ FORECASTER BLAKE/FRANKLIN |
