Flhurricane.com - Central Florida Hurricane Center - Tracking Storms since 1995Hurricanes Without the Hype! Since 1995
The Atlantic is quiet
|
Show Selection: |
| #468909 (Received by flhurricane at: 4:38 AM 28.Oct.2011) TCDAT3 TROPICAL STORM RINA DISCUSSION NUMBER 21 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182011 400 AM CDT FRI OCT 28 2011 AFTER AN EARLIER BURST OF VERY COLD-TOPPED CONVECTION OVER THE LOW-LEVEL CENTER...WATER VAPOR IMAGERY INDICATES A SURGE OF 40-KT SOUTHERLY UPPER-LEVEL WINDS HAS STARTED TO SHEAR AWAY THE CONVECTION. AS A RESULT OF THE SHARP DEGRADATION IN THE CONVECTIVE STRUCTURE...THE INITIAL INTENSITY HAS BEEN DECREASED TO 45 KT... WHICH IS CONSISTENT WITH THE DOWNWARD TREND IN WIND SPEEDS NOTED IN NEARBY SURFACE OBSERVATION SITES. THE INITIAL POSITION IS BASED ON A COUPLE OF SURFACE OBS AND POOR RADAR SIGNATURES FROM BOTH CUBAN AND MEXICAN RADARS...WHICH MAKES THE INITIAL MOTION ESTIMATE AN UNCERTAIN 015/04 KT. THE RAGGED APPEARANCE IN RADAR IMAGERY SUGGESTS THAT THE SMALL CIRCULATION OF RINA MAY ALREADY BE SUCCUMBING TO THE INCREASING SOUTHERLY VERTICAL WIND SHEAR. SOME MID-LEVEL ROTATION HAS BECOME APPARENT JUST NORTHEAST OF THE TIP OF YUCATAN...WHEREAS SURFACE OBS INDICATE THE SURFACE CENTER IS STILL OVER LAND. WITH THE VERTICAL CIRCULATIONS FORECAST TO COMPLETELY DECOUPLE DURING THE NEXT 12 HOURS OR SO... THE LOW-LEVEL CENTER IS EXPECTED TO GRADUALLY TURN SLOWLY EASTWARD AND THEN TURN SOUTHWARD BACK OVER THE NORTHWESTERN CARIBBEAN SEA BY 24 HOURS. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY AND IS WELL TO THE RIGHT OF THE CONSENSUS MODELS...TVCN AND TVCA. SINCE THE VERTICAL SHEAR IS FORECAST TO GRADUALLY INCREASE...THE MID-/UPPER-LEVEL CIRCULATION IS EXPECTED TO DECOUPLE FROM THE LOW-LEVEL CIRCULATION AND LIFT OUT TO THE NORTHEAST WHILE THE LOW-LEVEL CIRCULATION REMAINS BEHIND OVER THE NORTHWESTERN CARIBBEAN SEA. THIS STRONG SHEAR PATTERN SHOULD CAUSE RINA TO STEADILY WEAKEN THROUGHOUT THE FORECAST PERIOD...AND THE CYCLONE COULD BECOME A TROPICAL DEPRESSION BY LATER TODAY OR EARLY SATURDAY. RINA IS EXPECTED TO BECOME A REMNANT LOW OVER THE NORTHWESTERN CARIBBEAN BY 48 HOURS...BUT WITH A SLIGHT CHANCE OF REGENERATING INTO A TROPICAL CYCLONE IF IT DOES NOT GET ABSORBED INTO THE BROAD LOW PRESSURE SYSTEM LOCATED EAST OF NICARAGUA. FORECAST POSITIONS AND MAX WINDS INIT 28/0900Z 21.1N 87.0W 45 KT 50 MPH 12H 28/1800Z 21.5N 86.8W 40 KT 45 MPH 24H 29/0600Z 21.3N 86.4W 35 KT 40 MPH 36H 29/1800Z 20.6N 86.1W 30 KT 35 MPH 48H 30/0600Z 20.0N 86.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 31/0600Z 19.2N 86.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 01/0600Z 17.9N 86.8W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 02/0600Z 17.0N 87.1W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ FORECASTER STEWART |
