Flhurricane.com - Central Florida Hurricane Center - Tracking Storms since 1995Hurricanes Without the Hype! Since 1995
The Atlantic is quiet
|
Show Selection: |
| #536092 (Received by flhurricane at: 10:50 AM 22.Aug.2012) TCDAT4 TROPICAL STORM ISAAC DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012 1100 AM AST WED AUG 22 2012 THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT MONITORING ISAAC DURING THE NIGHT REPORTED THAT THE INNER CORE WIND FIELD BECAME DISORGANIZED AFTER 0600 UTC. A COUPLE OF MICROWAVE OVERPASSES SUGGEST THAT THE CIRCULATION CENTER BECAME ELONGATED DURING THIS TIME....AND THE CENTER IS NOT READILY APPARENT IN FRENCH RADAR DATA FROM MARTINIQUE AND GUADELOUPE. THE INITIAL INTENSITY IS HELD AT 40 KT BASED ON AIRCRAFT-REPORTED WINDS NORTH OF THE CENTER. WHILE THE CENTRAL CORE IS DISORGANIZED...THE OVERALL STRUCTURE OF THE STORM IS IMPROVING...AS SATELLITE IMAGERY SHOWS A LARGE OUTER BAND FORMING AROUND THE CENTRAL CONVECTIVE FEATURE. THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 280/15...AS IT IS UNCLEAR HOW MUCH OF THE OBSERVED NORTHWARD NUDGE WAS DUE TO RE-FORMATION OF THE CENTER. OTHER THAN THAT...THERE IS NO SIGNIFICANT CHANGE TO THE PREVIOUS FORECAST TRACK OR REASONING DURING THE FIRST 48-72 HR OF THE TRACK FORECAST. THE EAST-WEST ORIENTED SUBTROPICAL RIDGE TO THE NORTH OF ISAAC ALONG 30N LATITUDE IS FORECAST BY ALL OF THE GLOBAL MODELS TO REMAIN INTACT ACROSS FLORIDA AND THE SOUTHEASTERN U.S. DURING THAT TIME. THIS EARLY PART OF THE FORECAST TRACK IS AN UPDATE OF THE PREVIOUS FORECAST. AFTER THAT TIME...THE RIDGE IS EXPECTED TO WEAKEN SOMEWHAT AS A MID/UPPER-LEVEL TROUGH MOVES ONTO THE EASTERN UNITED STATES. THE MODELS DIVERGE ON THEIR FORECASTS OF THE RIDGE. THE ECMWF DOES NOT BREAK THE RIDGE...AND THUS FORECASTS A MORE WESTWARD MOTION NEAR OR SOUTH OF CUBA. THE CANADIAN AND NOGAPS HAVE A LARGE BREAK IN THE RIDGE AND TURN ISAAC NORTHWARD EAST OF FLORIDA. THE UKMET HAS A BREAK IN THE RIDGE OVER THE NORTHERN GULF COAST AND MOVES THE CYCLONE OVER THE FLORIDA PENINSULA. THE GFS SHOWS A BREAK IN THE RIDGE EAST OF FLORIDA... BUT FORECASTS ISAAC TO BYPASS THE BREAK AND MOVE NEAR THE SOUTHWEST COAST OF FLORIDA. THIS DECREASED-CONFIDENCE PORTION OF THE FORECAST TRACK IS SHIFTED A LITTLE WEST OF THE PREVIOUS TRACK TO LIE NEAR THE CONSENSUS MODELS. WATER VAPOR IMAGERY AND MICROWAVE TOTAL PRECIPITABLE WATER DATA SHOW DRY AIR TO THE NORTHEAST OF ISAAC...AND A LACK OF CONVECTION IN THIS AREA SUGGESTS SOME OF THIS AIR IS ENTRAINING INTO THE CYCLONE. OTHERWISE...ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR INTENSIFICATION UNTIL THE CENTER REACHES HISPANIOLA IN ABOUT 48 HR. AFTER THAT...THE INTENSITY WILL BE DETERMINED BY HOW MUCH TIME ISAAC SPENDS OVER LAND. THE NEW FORECAST IS SIMILAR TO THE PREVIOUS FORECAST THROUGH 48 HR...THEN IS REDUCED A LITTLE BASED ON INCREASED LAND INTERACTION IN THE NEW FORECAST TRACK. A HURRICANE WARNING WILL LIKELY BE REQUIRED FOR PORTIONS OF THE DOMINICAN REPUBLIC THIS AFTERNOON. IT SHOULD BE NOTED THAT WHILE NONE OF THE FORECAST POINTS ARE OVER LAND...THE CYCLONE IS FORECAST TO MOVE OVER HISPANIOLA AND CUBA FROM 48-96 HR. FORECAST POSITIONS AND MAX WINDS INIT 22/1500Z 15.9N 59.3W 40 KT 45 MPH 12H 23/0000Z 16.3N 61.8W 45 KT 50 MPH 24H 23/1200Z 16.8N 64.8W 50 KT 60 MPH 36H 24/0000Z 17.3N 67.8W 60 KT 70 MPH 48H 24/1200Z 17.8N 70.3W 75 KT 85 MPH 72H 25/1200Z 19.5N 74.5W 60 KT 70 MPH 96H 26/1200Z 22.5N 78.5W 60 KT 70 MPH 120H 27/1200Z 25.5N 81.5W 70 KT 80 MPH $$ FORECASTER BEVEN |
