Flhurricane.com - Central Florida Hurricane Center - Tracking Storms since 1995Hurricanes Without the Hype! Since 1995
The Atlantic is quiet
|
Show Selection: |
| #373069 (Received by flhurricane at: 4:55 AM 02.Sep.2010) TCDAT3 TROPICAL STORM FIONA DISCUSSION NUMBER 11 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082010 500 AM AST THU SEP 02 2010 AFTER LITTLE TO NO CONVECTION NEAR THE CENTER OF FIONA...A STRONG BURST OF DEEP CONVECTION DEVELOPED OVER THE CENTER FOR A FEW HOURS EARLIER THIS MORNING...WHICH HAS NOW BEEN SHEARED SLIGHTLY TO THE SOUTHWEST OF THE CENTER. HOWEVER...NIGHTTIME VISIBLE IMAGERY AND A 02/0156Z ASCAT OVERPASS INDICATE FIONA HAS A SMALL BUT VERY WELL-DEFINED CIRCULATION. THE INITIAL INTENSITY OF 45 KT IS BASED ON A BELTON OF SATELLITE INTENSITY ESTIMATES OF 35 KT FROM FROM TAFB AND SAB...AT LEAST 40 KT FROM THE ASCAT PASS...AND UW-CIMSS ADT ESTIMATE OF 49 KT. THE INITIAL MOTION ESTIMATE IS 320/15 BASED ON MOSTLY ON MICROWAVE FIXES AND CONTINUITY WITH THE PREVIOUS ADVISORY MOTION. THE FUTURE TRACK OF FIONA IS HEAVILY DEPENDENT ON THE INTENSITY AND STRUCTURE OF THE CYCLONE. IT IS UNLIKELY THAT FIONA WILL GROW MUCH MORE IN HORIZONTAL SIZE DUE TO THE LARGE CIRCULATION OF POWERFUL HURRICANE EARL SITUATED ABOUT 750 NMI TO THE NORTHWEST. HOWEVER...ALL OF THE GLOBAL MODELS ARE NOW FORECASTING FIONA TO ROUND THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE LOCATED EAST-WEST BETWEEN 27N AND 30N LATITUDE...AND IN 36-48 HOURS MOVE UNDERNEATH A REGION OF LOW VERTICAL SHEAR BETWEEN THE STRONG NORTHERLY OUTFLOW FROM EARL AND THE SOUTHWESTERLY FLOW AHEAD OF A LARGE MID-LATITUDE TROUGH FORECAST TO MOVE OFF THE U.S. EAST COAST IN 24 HOURS AND CAPTURE HURRICANE EARL. IF THIS PATTERN EVOLVES...FIONA WILL REMAIN A DISTINCT ENTITY AND NOT BECOME ABSORBED BY THE LARGE CIRCULATION OF EARL AS QUICKLY AS MOST OF THE GLOBAL MODELS ARE FORECASTING. THE HWRF AND GFDL MODELS KEEP FIONA A SEPARATE SYSTEM THROUGH 120 HOURS AND EVEN MAKE THE CYCLONE A HURRICANE IN 24-36 HOURS. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK THROUGH 24 HOURS... AND THEN A LITTLE TO EAST OR RIGHT OF TRACK AFTER THAT. ON THE FORECAST TRACK...FIONA IS EXPECTED TO PASS VERY NEAR BERMUDA IN ABOUT 48 HOURS...WHICH HAS PROMPTED THE ISSUANCE OF A TROPICAL STORM WATCH FOR THAT ISLAND BY THE BERMUDA WEATHER SERVICE. AS MENTIONED ABOVE...FIONA MAY REMAIN JUST WEST OF THE STRONGEST NORTHEASTERLY VERTICAL WIND SHEAR ASSOCIATED WITH THE OUTFLOW OF EARL FOR THE NEXT 24 HOURS. ALTHOUGH THERE MAY BE FLUCTUATIONS IN THE INTENSITY OF FIONA...THE SHEAR IS NOT EXPECTED TO BE STRONG ENOUGH TO STRIP AWAY ALL OF THE CONVECTION. BY 36-48 HOURS...FIONA MAY MOVE INTO THE AFOREMENTIONED REGION OF LOW SHEAR BENEATH A SMALL UPPER-LEVEL ANTICYCLONE FORECAST BY ALL THE MODELS TO DEVELOP NEAR BERMUDA. THIS WOULD PROVIDE A BRIEF WINDOW OF OPPORTUNITY FOR MORE SIGNIFICANT DEVELOP THAN CURRENTLY INDICATED. THE OFFICIAL FORECAST CALLS FOR FIONA TO MAINTAIN ITS CURRENT INTENSITY FOR THE NEXT 48 HOURS...ALTHOUGH THERE MAY SOME FLUCTUATIONS DURING THAT TIME AS THE SHEAR WAXES AND WANES. THIS SCENARIO IS CONSISTENT WITH THE GFDL AND HWRF MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 02/0900Z 22.6N 65.4W 45 KT 12HR VT 02/1800Z 24.6N 66.6W 45 KT 24HR VT 03/0600Z 27.1N 67.3W 45 KT 36HR VT 03/1800Z 29.7N 67.0W 45 KT 48HR VT 04/0600Z 32.4N 65.8W 45 KT 72HR VT 05/0600Z 36.5N 62.0W 35 KT 96HR VT 06/0600Z...DISSIPATED $$ FORECASTER STEWART |
