Show Selection: |
#10985 (Received by flhurricane at: 10:41 PM 30.Sep.2004) TCDAT3 TROPICAL STORM LISA DISCUSSION NUMBER 47 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 PM EDT THU SEP 30 2004 CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY INDICATE THAT LIKELY HAS REMAINED JUST BELOW HURRICANE STRENGTH. A CLOSED LOW-LEVEL EYE FEATURE WAS APPARENT IN 30/2101Z TRMM AND 01/0020Z SSMI OVERPASSES ...AND A BANDING EYE FEATURE HAS BEEN TRYING TO DEVELOP IN VISIBLE AND INFRARED IMAGERY FOR THE PAST 9 HOURS. IN ADDITION...A 30/2117Z UW-CIMSS AMSU OVERPASS INDICATED A PRESSURE ESTIMATE OF 989.6 MB. THEREFORE...THE PRESSURE AND INTENSITY WILL REMAIN THE SAME AT 990 MB AND 60 KT...RESPECTIVELY...AS IN THE PREVIOUS ADVISORY. THE INITIAL MOTION ESTIMATE IS 005/10. THE LAST 9 HOURS OF CONVENTIONAL AND MICROWAVE SATELLITE FIX POSITIONS INDICATE THAT LISA HAS MADE THE TURN TOWARD THE NORTH. A GRADUAL TURN TOWARD THE NORTH-NORTHEAST AND EVENTUALLY TO THE NORTHEAST IS EXPECTED TO OCCUR IN THE 12-24 TIME PERIOD AS AN APPROACHING SHORTWAVE PICKS UP THE CYCLONE. BY 36 HOURS...LISA IS EXPECTED TO ACCELERATE AS THE CYCLONE BEGINS TO TRANSITION OVER TO AN EXTRATROPICAL LOW...OR POSSIBLY BECOME ABSORBED BY A LARGER EXTRATROPICAL CYCLONE. LISA IS EXPECTED TO REMAIN IN FAVORABLE VERTICAL SHEAR CONDITIONS OF 5-10 KT FOR THE NEXT 24 HOURS...EVEN THOUGH THE CYCLONE WILL BE MOVING OVER 24-25C SSTS. AS MENTIONED IN THE PREVIOUS DISCUSSION...ENOUGH MODERATE CONVECTION MAY WRAP AROUND THE CENTER LATER TONIGHT TO FINALLY CLOSE OFF AN EYE IN THE MID- AND UPPER-LEVELS...ALLOWING LISA TO REACH MINIMAL HURRICANE STRENGTH. AFTER 24 HOURS...INCREASING WESTERLY VERTICAL SHEAR AND MUCH COOLER WATER SHOULD BRING ABOUT A WEAKENING TREND. THE OFFICIAL FORECAST IS A LITTLE LOWER THAN THE SHIPS AND GFDL INTENSITY MODELS WHICH BRING LISA TO 63 KT AND 69 KT IN 24 HOURS...RESPECTIVELY. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 01/0300Z 34.6N 47.7W 60 KT 12HR VT 01/1200Z 36.3N 47.3W 60 KT 24HR VT 02/0000Z 39.0N 44.8W 55 KT 36HR VT 02/1200Z 42.2N 40.4W 45 KT...BECOMING EXTRATROPICAL 48HR VT 03/0000Z 45.0N 33.0W 35 KT...EXTRATROPICAL 72HR VT 04/0000Z...ABSORBED BY EXTRATROPICAL LOW |