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#532356 (Received by flhurricane at: 10:53 PM 06.Aug.2012) TCDAT5 TROPICAL STORM ERNESTO DISCUSSION NUMBER 22 NWS NATIONAL HURRICANE CENTER MIAMI FL AL052012 1100 PM EDT MON AUG 06 2012 DURING THE PAST SEVERAL HOURS...THE INNER CORE CONVECTION OF ERNESTO HAS TAKEN A BEATING DUE TO MID-LEVEL DRY AIR ENTRAINMENT. ONLY A SMALL CONVECTIVE CLUSTER EXISTS OVER THE LOW-LEVEL CENTER...WHILE THE REST OF THE SIGNIFICANT CONVECTION IS OCCURRING MORE THAN 100 NMI NORTHEAST THROUGH SOUTHEAST OF THE CENTER. DESPITE THE CONVECTIVE EROSION...AN AIR FORCE RESERVE RECON AIRCRAFT HAS FOUND THAT THE INNER CORE WIND FIELD REMAINS RATHER TIGHT WITH A RADIUS OF 12-15 NMI. THE STRONGEST 850 MB FLIGHT-LEVEL WIND OBSERVED THUS FAR HAS BEEN 61 KT IN THE NORTHEAST QUADRANT AND THE HIGHEST RAIN-ADJUSTED SFMR SURFACE WIND MEASURED HAS BEEN 46 KT. GIVEN THAT THE RECON FOUND A SURFACE PRESSURE OF ABOUT 994 MB...WHICH IS CLOSE TO THE PREVIOUS ADVISORY PRESSURE...THE INITIAL INTENSITY WILL REMAIN AT 55 KT UNTIL THE AIRCRAFT COMPLETES ITS MISSION. INITIAL MOTION ESTIMATE IS 300/11. THE NHC MODEL GUIDANCE REMAINS IN EXCELLENT AGREEMENT THAT ERNESTO WILL MOVE IN A WEST-NORTHWESTWARD DIRECTION FOR THE NEXT 24-36 HOURS AND MAKE LANDFALL IN ABOUT 30 HOURS NEAR THE COASTS OF NORTHERN BELIZE AND THE SOUTHERN YUCATAN PENINSULA. AFTER LANDFALL OCCURS...A WEAK SUBTROPICAL RIDGE OVER THE NORTHERN GULF OF MEXICO THAT EXTENDS FROM TEXAS EASTWARD TO FLORIDA IS EXPECTED TO STEER THE CYCLONE WESTWARD ACROSS THE BAY OF CAMPECHE...BUT AT A SLOWER FORWARD SPEED. THE OFFICIAL FORECAST TRACK IS CLOSE TO THE PREVIOUS ADVISORY AND IS SIMILAR TO THE TIGHTLY PACKED CONSENSUS MODELS TVCA AND TV15. CONDITIONS ARE FAVORABLE FOR RAPID INTENSIFICATION TO OCCUR...EXCEPT FOR THE LACK OF INNER-CORE DEEP CONVECTION. EVEN THOUGH RECON DATA INDICATE ERNESTO STILL HAS A TIGHT INNER-CORE WIND FIELD...DRY AIR THAT HAS WRAPPED WELL INTO THE CENTER WILL LIKELY PREVENT ANY STRONG CENTRAL CONVECTION FROM BEING ABLE TO PERSIST NEAR THE LOW-LEVEL CENTER. HOWEVER...SINCE ERNESTO WILL BE MOVING OVER SSTS ABOUT 1C WARMER AND INTO EVEN A WEAKER SHEAR ENVIRONMENT IN ABOUT 18-24 HOURS...THESE FAVORABLE CONDITIONS SHOULD ALLOW FOR AT LEAST SOME MODEST STRENGTHENING TO OCCUR...AND ERNESTO COULD STILL BECOME A HURRICANE BEFORE IT MAKES LANDFALL. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY...FOLLOWS THE INTENSITY CONSENSUS MODEL IV15 UNTIL LANDFALL...AND IS CLOSE TO A BLEND OF THE DECAY-SHIPS AND LGEM MODELS AFTER THAT. FORECAST POSITIONS AND MAX WINDS INIT 07/0300Z 17.0N 82.7W 55 KT 65 MPH 12H 07/1200Z 17.5N 84.3W 60 KT 70 MPH 24H 08/0000Z 18.3N 86.8W 70 KT 80 MPH 36H 08/1200Z 18.9N 89.0W 45 KT 50 MPH...INLAND OVER YUCATAN 48H 09/0000Z 19.3N 91.1W 35 KT 40 MPH...OVER WATER 72H 10/0000Z 19.5N 94.8W 60 KT 70 MPH 96H 11/0000Z 19.4N 97.4W 50 KT 60 MPH...INLAND 120H 12/0000Z 19.2N 99.4W 20 KT 25 MPH...DISSIPATING INLAND $$ FORECASTER STEWART |