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#356579 (Received by flhurricane at: 10:43 PM 30.Jun.2010) TCDAT1 HURRICANE ALEX DISCUSSION NUMBER 22 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010 1000 PM CDT WED JUN 30 2010 OBSERVATIONS FROM THE BROWNSVILLE WSR-88D RADAR AND THE AIR FORCE RESERVE UNIT HURRICANE HUNTERS INDICATE THAT THE EYE OF ALEX CROSSED THE COAST IN A SPARSELY-POPULATED AREA OF NORTHEASTERN MEXICO AROUND 0200 UTC. JUST BEFORE LANDFALL...THE AIRCRAFT MEASURED SURFACE WINDS OF 87 KT FROM THE SFMR INSTRUMENT AND A MINIMUM CENTRAL PRESSURE OF 947 MB. ASSUMING THAT THE PEAK WINDS WERE NOT SAMPLED...AND OUT OF RESPECT FOR THE CONTINUED DROP IN CENTRAL PRESSURE...THE LANDFALL INTENSITY WAS SET AT 90 KT. THE CURRENT INTENSITY ESTIMATE OF 85 KT IS BASED ON AN ASSUMED SLIGHT DECREASE SINCE LANDFALL. CONTINUED WEAKENING WILL OCCUR AS ALEX MOVES OVER LAND...AND THE WEAKENING IS LIKELY TO BE RATHER RAPID AFTER THE TROPICAL CYCLONE REACHES THE VERY HIGH AND RUGGED TERRAIN ASSOCIATED WITH THE SIERRA MADRE ORIENTAL MOUNTAINS OF MEXICO. DISSIPATION IS LIKELY WITHIN 36 TO 48 HOURS...IF NOT SOONER. INITIAL MOTION IS ABOUT 260/9...JUST A TAD SOUTH OF DUE WEST. MID-LEVEL RIDGING TO THE NORTH OF ALEX IS PREDICTED TO BE MORE OR LESS MAINTAINED FOR THE NEXT 24 TO 48 HOURS. THIS WOULD MOVE THE CYCLONE ON A MAINLY WESTWARD TRACK UNTIL DISSIPATION. AS THE WINDS DECREASE AND THE SURGE AND WAVES ALONG THE COAST GRADUALLY DIMINISH...THE PRIMARY THREAT FROM ALEX WILL BE TORRENTIAL RAINS TOTALING AS HIGH AS 20 INCHES...WHICH WOULD LIKELY PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES OVER THE MOUNTAINOUS REGIONS OF MEXICO. ALSO...A FEW TORNADOES ARE POSSIBLE OVERNIGHT WITHIN THE NORTHERN PORTION OF THE CIRCULATION OF ALEX. IT MAY BE OF INTEREST THAT ALEX WAS THE FIRST CATEGORY TWO...AND THE STRONGEST...HURRICANE TO OCCUR IN JUNE SINCE ALMA OF 1966. FORECAST POSITIONS AND MAX WINDS INITIAL 01/0300Z 24.3N 97.8W 85 KT 12HR VT 01/1200Z 24.3N 99.4W 60 KT...INLAND 24HR VT 02/0000Z 24.3N 101.6W 30 KT...INLAND 36HR VT 02/1200Z 24.8N 103.8W 20 KT...INLAND 48HR VT 03/0000Z...DISSIPATED INLAND $$ FORECASTER PASCH/BERG |