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| #111650 (Received by flhurricane at: 4:49 PM 18.Sep.2006) TCDAT2 HURRICANE GORDON DISCUSSION NUMBER 32 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072006 500 PM EDT MON SEP 18 2006 GORDON IS STUBBORNLY MAINTAINING ITS INTENSITY WITH A WELL-DEFINED EYE AND A NEARLY COMPLETE COLD CLOUD RING. SUBJECTIVE AND OBJECTIVE DVORAK ESTIMATES REMAIN UNCHANGED AND THE ADVISORY INTENSITY IS LIKEWISE KEPT AT 80 KT. GORDON IS QUICKLY PROGRESSING OVER COOLER WATERS AND WILL BE OVER 24 C SSTS TOMORROW...THOUGH THE DESTABILIZING EFFECTS OF COOLING UPPER TROPOSPHERIC TEMPERATURES MAY SOMEWHAT COUNTERACT THE REDUCTION IN SSTS. VERTICAL WIND SHEAR...ANALYZED BY CIMSS AT ABOUT 20 KT...SHOULD BECOME STRONGER UNDER AN INCREASINGLY BAROCLINIC ENVIRONMENT. AS SUGGESTED IN THE PREVIOUS ADVISORY...GORDON SHOULD BEGIN WEAKENING SHORTLY. THE INTENSITY FORECAST...WHILE THE SYSTEM IS A TROPICAL CYCLONE...IS A BLEND OF THE SHIPS AND GFDL MODELS AND IS SIMILAR TO THE PREVIOUS FORECAST. GORDON IS MOVING TO THE EAST-NORTHEAST...75 DEGREES AT 19 KT...WHICH IS FASTER AND TO THE RIGHT OF THE PREVIOUS ADVISORY. GORDON SHOULD TRACK TO THE EAST FOR THE NEXT 24-36 HOURS UNDER THE ZONAL FLOW PRODUCED BY THE COMBINATION OF A DEEP TROUGH TO ITS NORTH AND THE SUBTROPICAL RIDGE TO ITS SOUTH. IN ABOUT TWO DAYS...GORDON IS EXPECTED TO BEGIN MOVING EAST-NORTHEASTWARD AS IT QUICKLY ACCELERATES AND IS ABSORBED BY A LARGER EXTRATROPICAL SYSTEM. HOWEVER...A COUPLE OF THE GLOBAL MODELS...THE NOGAPS AND UKMET...SUGGEST INSTEAD THAT GORDON WILL RETAIN ITS OWN IDENTITY AS AN EXTRATROPICAL STORM LONGER THAN INDICATED HERE. THE TRACK FORECAST IS CLOSE TO THE MODEL CONSENSUS...MINUS THE NOGAPS...WHICH APPEARS TO HAVE TOO LARGE A VORTEX CARRIED FORWARD IN TIME. ANALYSES FROM THE FSU CYCLONE PHASE SPACE DIAGRAMS SUGGEST THAT ALL NUMERICAL MODELS TRANSITION GORDON TO A VIGOROUS EXTRATROPICAL CYCLONE IN ABOUT 24 HOURS. DUE TO THE RATHER RESILIENT NATURE OF GORDON...HOWEVER...THIS TRANSITION MAY BE DELAYED SLIGHTLY. ON THE FORECAST TRACK...THE SYSTEM WOULD PASS VERY NEAR OR OVER THE AZORES IN 24 TO 36 HOURS. BECAUSE OF THE UNCERTAINTY IN THE TIMING OF THE EXTRATROPICAL TRANSITION...A TROPICAL STORM WATCH IS ISSUED FOR THE AZORES. HOWEVER...REGARDLESS OF THE EXACT STRUCTURE OF THE CYCLONE...STRONG WINDS ARE LIKELY TO BE EXPERIENCED IN THE AZORES. FORECAST POSITIONS AND MAX WINDS INITIAL 18/2100Z 37.8N 44.8W 80 KT 12HR VT 19/0600Z 38.3N 40.8W 70 KT 24HR VT 19/1800Z 38.5N 34.2W 60 KT...BECOMING EXTRATROPICAL 36HR VT 20/0600Z 39.2N 26.5W 55 KT...EXTRATROPICAL 48HR VT 20/1800Z 41.3N 17.9W 50 KT...EXTRATROPICAL 72HR VT 21/1800Z...DISSIPATED $$ FORECASTER AVILA/LANDSEA |
