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#98541 (Received by flhurricane at: 5:00 PM 19.Jul.2006) TCDAT2 TROPICAL STORM BERYL DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022006 500 PM EDT WED JUL 19 2006 LATEST RECON PASS AROUND 2030Z INDICATED A 57 KT 850 MB FLIGHT-LEVEL WIND IN THE SOUTHWESTERN QUADRANT AND A SURFACE PRESSURE OF 1002 MB. ALSO...A DROPSONDE IN THE NORTHWESTERN QUADRANT REPORTED A SURFACE WIND OF 49 KT. BASED ON THIS INFORMATION AND THE IMPROVING STRUCTURE IN RADAR AND SATELLITE IMAGERY...THE INTENSITY HAS BEEN INCREASED TO 50 KT. THE INITIAL MOTION IS 005/07 KT. RADAR AND SATELLITE POSITION ESTIMATES HAVE BEEN COMING IN 12-18 NMI WEST AND NORTHWEST OF RECON POSITIONS...INDICATING SOME NORTHWESTWARD TILT OF THE VORTEX COLUMN. BUT OVERALL...BERYL HAS BEEN MOVING SLIGHTLY EAST OF DUE NORTH FOR THE PAST 12 HOURS OR SO. THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT 12-24 HOURS AS BERYL MOVES NORTHWARD THROUGH A BREAK IN THE SUBTROPICAL RIDGE AND IS INFLUENCED MAINLY BY DEEP SOUTHERLY STEERING FLOW AS NOTED IN WATER VAPOR-DERIVED WINDS FROM UW-CIMSS. MOST OF THE MODELS TAKE A WEAK AND VERTICALLY SHALLOW BERYL INTO THE NORTHEASTERN U.S. COAST ANYWHERE FROM NEW JERSEY EASTWARD TO SOUTHEASTERN NEW ENGLAND. THE EXCEPTIONS ARE THE CANADIAN MODEL AND ESPECIALLY THE UKMET MODEL. HOWEVER... ALL OF THE MODELS KEEP THE 500 MB CIRCULATION CENTER WELL OFFSHORE LONG ISLAND AND SOUTHEASTERN MASSACHUSETTS. MY FEELING IS THAT BERYL WILL REMAIN A MORE VERTICALLY DEEP SYSTEM AND...THEREFORE... BE STEERED MORE NORTHEAST AND EASTWARD BY A SHORTWAVE TROUGH CURRENTLY APPROACHING THE NORTHEASTERN U.S. THIS SCENARIO IS SIMILAR TO THE PREVIOUS TWO FORECAST TRACKS AND THE UKMET AND CANADIAN MODEL CONSENSUS...AND IS A LITTLE SOUTH OF THE GUNA MODEL. SHOULD BERYL MOVE TO THE LEFT OF THE OFFICIAL FORECAST TRACK... IT IS LIKELY TO DO SO AS A VERY WEAK SYSTEM. SIGNIFICANT DEEP CONVECTION HAS DEVELOPED OVER AND AROUND THE CIRCULATION AND SOME ADDITIONAL SLIGHT STRENGTHENING IS POSSIBLE DURING THE NEXT 12 HOURS OR SO WHILE THE CYCLONE CENTER REMAINS OVER WARM WATER. BY 24-36 HOURS...BERYL WILL BE MOVING OVER SUB-25C SSTS RESULTING IN A WEAKENING TREND. HOWEVER...DUE TO THE CLOSE PROXIMITY OF THE STORM TO THE WARM GULFSTREAM AND THE EXPECTED CONTINUED INFLUX OF WARM UNSTABLE AIR IN THE EASTERN SEMICIRCLE... THUNDERSTORM ACTIVITY SHOULD CONTINUE TO BE GENERATED...WHICH SHOULD ACT TO BOTH KEEP THE INTENSITY HIGHER THAN NORMAL AND MAINTAIN A DEEP VERTICAL STRUCTURE THAT HAS BEEN DISCUSSED IN THE PREVIOUS PARAGRAPH. DUE TO THE ANTICIPATED CLOSE APPROACH OF BERYL TO EXTREME SOUTHEASTERN MASSACHUSETTS... A TROPICAL STORM WATCH IS BEING ISSUED AT THIS TIME. FORECAST POSITIONS AND MAX WINDS INITIAL 19/2100Z 36.3N 73.5W 50 KT 12HR VT 20/0600Z 37.4N 73.3W 55 KT 24HR VT 20/1800Z 38.7N 72.6W 55 KT 36HR VT 21/0600Z 40.3N 70.4W 50 KT...BECOMING EXTRATROPICAL 48HR VT 21/1800Z 42.1N 67.1W 45 KT...EXTRATROPICAL 72HR VT 22/1800Z 45.4N 59.0W 40 KT...EXTRATROPICAL 96HR VT 23/1800Z...MERGED WITH EXTRATROPICAL CYCLONE |