000 WTNT42 KNHC 050235 TCDAT2 TROPICAL STORM EARL DISCUSSION NUMBER 43 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010 1100 PM EDT SAT SEP 04 2010 OVER THE PAST FEW HOURS THE WIND FIELD OF EARL HAS BECOME INCREASINGLY ELONGATED AND THE STRONGEST WINDS ARE NOW WELL REMOVED FROM THE CENTER. DRY AIR ASSOCIATED WITH THE LARGE UPPER TROUGH INTERACTING WITH EARL HAS BEEN ENTRAINED THROUGH THE SOUTHERN SEMICIRCLE OF THE CYCLONE. ALSO...THE EASTERN PORTION OF EARL/S CIRCULATION IS NOW INVOLVED WITH A FRONTAL ZONE. BASED ON ALL OF THIS...EARL IS NOW DECLARED POST-TROPICAL...AND THIS WILL BE THE LAST NHC ADVISORY ON EARL. THE INITIAL INTENSITY IS HELD AT 55 KT BASED ON SURFACE OBSERVATIONS. WEAKENING IS EXPECTED AS EARL COMPLETES THE EXTRATROPICAL TRANSITION PROCESS. THE FORWARD SPEED HAS CONTINUED TO INCREASE...AND IS NOW 030/40. THE GLOBAL MODELS ARE IN RELATIVELY GOOD AGREEMENT ON THE TRACK OF POST-TROPICAL EARL NORTHEASTWARD ACROSS LABRADOR AND INTO THE ATLANTIC OVER THE NEXT DAY OR SO. EARL WILL THEN MOVE SLOWLY NORTHWARD AND NORTHWESTWARD FOR A COUPLE OF DAYS AS IT BECOMES A VERTICALLY STACKED COLD CORE CYCLONE BEFORE ACCELERATING EASTWARD ACROSS THE NORTH ATLANTIC AND DISSIPATING IN 4 OR 5 DAYS. THE OFFICIAL FORECAST IS BASED ON A BLEND OF THE GFS AND ECMWF. EARL IS STILL PRODUCING TROPICAL STORM CONDITIONS OVER PORTIONS OF ATLANTIC CANADA. FOR FURTHER INFORMATION ON POST-TROPICAL EARL IN CANADA...SEE PRODUCTS FROM ENVIRONMENT CANADA. ADDITIONAL INFORMATION ON POST-TROPICAL EARL CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC. FORECAST POSITIONS AND MAX WINDS INITIAL 05/0300Z 50.7N 59.2W 55 KT...POST-TROPICAL 12HR VT 05/1200Z 52.9N 55.4W 40 KT...POST-TROP/EXTRATROP 24HR VT 06/0000Z 55.0N 52.0W 35 KT...POST-TROP/EXTRATROP 36HR VT 06/1200Z 57.0N 53.0W 35 KT...POST-TROP/EXTRATROP 48HR VT 07/0000Z 57.0N 55.0W 35 KT...POST-TROP/EXTRATROP 72HR VT 08/0000Z 54.0N 50.0W 35 KT...POST-TROP/EXTRATROP 96HR VT 09/0000Z 52.0N 36.0W 25 KT...POST-TROP/EXTRATROP 120HR VT 10/0000Z...DISSIPATED $$ FORECASTER BRENNAN