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| #59328 (Received by flhurricane at: 10:17 PM 30.Nov.2005) TCDAT4 TROPICAL STORM EPSILON DISCUSSION NUMBER 7 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 10 PM EST WED NOV 30 2005 EPSILON SHOWS A WELL-DEFINED CURVED CONVECTIVE BAND PATTERN THIS EVENING AROUND A RATHER RAGGED EYE. WHILE THE CONVECTIVE TOPS HAVE COOLED THE PAST FEW HOURS...THEY ARE NOT YET COLD ENOUGH TO JUSTIFY AN UPGRADE TO A HURRICANE...AS THE MAXIMUM SATELLITE INTENSITY ESTIMATES REMAIN 45 KT. A RECENT QUIKSCAT OVERPASS SHOWS WINDS OF NO MORE THAN 50 KT...WHICH IS A BIT LESS THAN SEEN ON THE PREVIOUS PASS. ON THE OTHER HAND...A 2122Z AMSU OVERPASS SHOWED A WARM CORE AND AN ESTIMATED SURFACE WIND SPEED OF 66 KT. GIVEN THE COOLING CONVECTIVE TOPS AND THE UNCHANGED SATELLITE INTENSITY ESTIMATES... THE INITIAL INTENSITY IS HELD AT 60 KT. HOWEVER...IF THE QUIKSCAT DATA IS RIGHT...THIS MIGHT BE A BIT GENEROUS. EPSILON HAS TURNED SOUTHEASTWARD DURING THE PAST 6 HR WITH THE INITIAL MOTION NOW 135/5...AND THE SHORT-TERM MOTION MAY BE EVEN MORE EASTWARD. WATER VAPOR IMAGERY SHOWS THAT EPSILON REMAINS EMBEDDED IN A DEEP-LAYER CYCLONE...WHICH IS SOUTH OF A MID/UPPER- LEVEL RIDGE EXTENDING FROM NEWFOUNDLAND EAST-SOUTHEASTWARD TO 42N40W. A DEEP-LAYER TROUGH AND ASSOCIATED SURFACE FRONT ARE OVER THE EASTERN UNITED STATES AND THE ADJACENT WESTERN ATLANTIC...AND WESTERLY UPPER-LEVEL FLOW FROM THE TROUGH HAS SPREAD EASTWARD TO NEAR 31N60W. THE LARGE-SCALE MODELS FORECAST THE RIDGE TO CONTINUE TO WEAKEN...WITH THE TROUGH PICKING UP EPSILON/DEEP-LAYER LOW AND MOVING IT GENERALLY NORTHEASTWARD THROUGH THE FORECAST PERIOD. HOWEVER...SINCE THE STORM IS WELL SOUTH OF THE STRONGEST MID/UPPER- LEVEL WINDS ASSOCIATED WITH THE TROUGH...IT WILL PROBABLY NOT MOVE TOO QUICKLY. THE NEW FORECAST TRACK IS SHIFTED TO THE SOUTH OF THE PREVIOUS TRACK BASED ON THE INITIAL POSITION AND MOTION. IT CALLS FOR A GENERALLY NORTHEATWARD MOTION THROUGH 120 HR...BUT NEVER FASTER THAN ABOUT 10 KT. THE TRACK IS DOWN THE MIDDLE OF THE GUIDANCE ENVELOPE IN BEST AGREEMENT WITH THE GUNS CONSENSUS MODEL. EPSILON IS CURRENTLY OVER 24C SEA SURFACE TEMPERATURES...AND ANY INCREASE IN ORGANIZATION WOULD ALLOW IT TO BECOME A HURRICANE. HOWEVER...THE OUTFLOW HAS DECREASED AS WESTERLY SHEAR STARTS AFFECTING THE SYSTEM...AND THE WINDOW OF OPPORTUNITY FOR STRENGTHENING SHOULD CLOSE IN 12-24 HR. AFTER THAT...INCREASING SHEAR...COOLER SSTS...AND THE APPROACH OF A FRONTAL SYSTEM SHOULD LEAD TO GRADUAL WEAKENING AND EVENTUAL EXTRATROPICAL TR ANSITON. THE INTENSITY FORECAST WILL HOLD THE INTENSITY AT 60 KT FOR 12 HR...ALTHOUGH A BRIEF NUDGE UP TO HURRICANE STRENGTH IS NOT IMPOSSIBLE. AFTER 12 HR...THE FORECAST CALLS FOR GRADUAL WEAKENING...WITH EPSILON BECOMING EXTRATROPICAL IN 48-72 HR. THE INITIAL AND FORECAST WIND RADII HAVE BEEN REVISED BASED ON THE QUIKSCAT DATA. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 01/0300Z 29.6N 53.4W 60 KT 12HR VT 01/1200Z 30.0N 53.0W 60 KT 24HR VT 02/0000Z 30.9N 51.5W 55 KT 36HR VT 02/1200Z 32.0N 49.8W 55 KT 48HR VT 03/0000Z 33.0N 48.0W 50 KT...BECOMING EXTRATROPICAL 72HR VT 04/0000Z 34.5N 44.0W 50 KT...EXTRATROPICAL 96HR VT 05/0000Z 36.0N 40.0W 45 KT...EXTRATROPICAL 120HR VT 06/0000Z 37.5N 35.5W 40 KT...EXTRATROPICAL |
