000WTNT45 KNHC 290254TCDAT5TROPICAL STORM SHARY DISCUSSION NUMBER 1NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL2020101100 PM AST THU OCT 28 2010SATELLITE...SHIP...AND BUOY DATA INDICATE THAT THE CIRCULATIONASSOCIATED WITH THE LOW PRESSURE AREA SOUTHEAST OF BERMUDA HASBECOME BETTER DEFINED. THE SYSTEM HAS MAINTAINED ORGANIZEDCONVECTION THROUGHOUT MOST OF THE DAY AND HAS ENOUGH ORGANIZATIONTO BE CLASSIFIED AS A TROPICAL CYCLONE. THE CENTER OF THE CYCLONEHAS PASSED JUST SOUTHWEST OF NOAA BUOY 41049 DURING THE PAST COUPLEOF HOURS. THE BUOY REPORTED PEAK 1-MINUTE SUSTAINED WINDS OF 33 KTAT BOTH 0000 AND 0200 UTC. BASED ON THE WIND OBSERVATIONS FROM THEBUOY...THE SYSTEM IS STARTED AS A 35-KT TROPICAL STORM....THEEIGHTEENTH OF THE 2010 ATLANTIC HURRICANE SEASON. SINCE THERE ISENOUGH SEPARATION BETWEEN SHARY AND THE UPPER-LOW TO THESOUTHWEST...AND THERE IS A SMALL RADIUS OF MAXIMUM WINDS...THESYSTEM IS DESIGNATED AS A TROPICAL RATHER THAN A SUBTROPICALCYCLONE.THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 310/20. IT APPEARS THATTHE CENTER HAS REFORMED TO THE NORTHWEST DURING THE PAST SEVERALHOURS...MAKING IT DIFFICULT TO DETERMINE A MORE PRECISE MOTION.SHARY HAS BEEN MOVING BETWEEN A MID-LEVEL RIDGE TO THE NORTHEAST ANDTHE LARGE UPPER-LEVEL LOW ITS SOUTHWEST. THE TROPICAL STORM ISEXPECTED TO TURN TOWARD THE NORTH AND THEN NORTHEAST DURING THENEXT 24-36 HOURS AS THE RIDGE MOVES EAST AND A MID-LATITUDE TROUGHMOVES OFF THE EAST COAST OF THE UNITED STATES. THE TRACK GUIDANCEIS IN GOOD AGREEMENT...ALTHOUGH THERE ARE SOME DIFFERENCES IN THEFUTURE FORWARD SPEED OF SHARY. THE GFS...UKMET...AND ECMWF ARESLOWER THAN THE NOGAPS...GFDL...AND HWRF. FOR NOW THE SLOWERSOLUTION IS PREFERRED...AND THE OFFICIAL FORECAST IS SLOWER THANTHE DYNAMICAL MODEL CONSENSUS.IT APPEARS THAT SHARY WILL BE A RELATIVELY SHORT-LIVED TROPICALCYCLONE. MODERATE SOUTH TO SOUTHEASTERLY SHEAR IS FORECAST TODECREASE DURING THE NEXT 12-24 HOURS...WHICH COULD ALLOW FOR SOMESTRENGTHENING. AFTER 24 HOURS...SHARY WILL BE TRANSITIONING TO ANEXTRATROPICAL CYCLONE AS IT MERGES WITH A COLD FRONT. THE GLOBALMODELS DO NOT SHOW ANY ADDITIONAL INTENSIFICATION OF THE SYSTEM ASAN EXTRATROPICAL CYCLONE. IN FACT...THEY INDICATE THAT THE CYCLONESHOULD WEAKEN IN 3-4 DAYS AND DISSIPATE BY 96 HOURS.FORECAST POSITIONS AND MAX WINDSINITIAL 29/0300Z 27.3N 63.7W 35 KT 12HR VT 29/1200Z 29.6N 65.4W 40 KT 24HR VT 30/0000Z 32.8N 63.9W 45 KT 36HR VT 30/1200Z 35.5N 60.0W 45 KT...POST-TROP/EXTRATROP 48HR VT 31/0000Z 39.3N 54.0W 40 KT...POST-TROP/EXTRATROP 72HR VT 01/0000Z 43.5N 45.0W 30 KT...POST-TROP/EXTRATROP 96HR VT 02/0000Z...DISSIPATED$$FORECASTER BROWN/BERG