|
Show Selection: |
| #38131 (Received by flhurricane at: 10:46 AM 07.Aug.2005) TCDAT4 TROPICAL STORM IRENE DISCUSSION NUMBER 12 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 AM EDT SUN AUG 07 2005 THE DEPRESSION IS UPGRADED TO A TROPICAL STORM ON THE BASIS OF A QUIKSCAT PASS AT 0849Z THIS MORNING...SHOWING 40 KT VECTORS JUST OUTSIDE THE DEEP CONVECTION TO THE NORTH OF THE CENTER. THE AMBIGUITY VECTORS FROM THIS PASS ALSO SHOW THE DYING CENTER THAT WAS TRACKED WESTWARD LAST EVENING AND THE BEGINNINGS OF THE NEW CENTER THAT FORMED FARTHER NORTH. THE STORM UPGRADE IS ALSO SUPPORTED BY DVORAK CLASSIFICATIONS OF T2.5 FROM TAFB AND AFWA. SINCE THE TIME OF THE QUIKSCAT PASS...THE DEEP CONVECTION NEAR THE CENTER AS WELL AS THE ORGANIZATION HAS DIMINISHED SOMEWHAT...SO THE INITIAL INTENSITY WILL BE SET AT 35 KT. IT IS SOMETIMES MORE PRODUCTIVE TO TRACK THE OVERALL DISTURBANCE THAN THE CIRCULATION CENTER ITSELF...IN THIS CASE IGNORING THE CIRCULATIONS THAT HAVE FORMED...MOVED MORE WESTWARD...AND THEN DIED...ONLY TO BE REPLACED BY NEW CENTERS TO THE NORTH. DOING SO YIELDS AN OVERALL SYSTEM MOTION OF 300/8. A MID-LEVEL RIDGE CURRENTLY LIES TO THE NORTHWEST OF IRENE. THE GFS...NOGAPS... UKMET...AND ECMWF ALL AGREE THAT THIS RIDGE WILL MOVE WESTWARD AND WEAKEN OVER THE NEXT 5 DAYS. IRENE IS EXPECTED TO CONTINUE A GENERAL...IF ERRATIC...WEST-NORTHWESTWARD TRACK AND THEN TURN NORTHWESTWARD INTO A WEAKNESS TO THE EAST OF THIS RIDGE. THE OFFICIAL FORECAST IS BASED ON A BLEND OF THE GFS AND GFDL SOLUTIONS AND IS ALSO VERY CLOSE TO THE FSU SUPERENSEMBLE. IRENE IS ONLY SLOWLY MAKING ITS WAY TOWARD WARMER WATERS. WATER VAPOR IMAGERY AND GLOBAL MODEL GUIDANCE SUGGEST THAT AN UNFAVORABLE UPPER FLOW PATTERN IS LIKELY TO PERSIST FOR ANOTHER COUPLE OF DAYS. CONSEQUENTLY...LITTLE CHANGE IN STRENGTH IS EXPECTED IN THE SHORT TERM. THE GFDL NO LONGER MAKES IRENE A HURRICANE AND IN FACT SHOWS LITTLE CHANGE OVER THE NEXT 5 DAYS. THE OFFICIAL FORECAST...WHICH FAVORS THE SHIPS GUIDANCE...ALLOWS FOR SOME STRENGTHENING NEAR THE END OF THE FORECAST PERIOD IN RESPONSE TO WARMER WATERS AND THE POSSIBILITY OF LESS SHEAR. THE 2005 HURRICANE SEASON CONTINUES ON ITS RECORD-SETTING PACE. IRENE IS THE EARLIEST NINTH NAMED STORM ON RECORD...BREAKING THE OLD MARK BY 13 DAYS. NORMALLY BY THIS DATE ONLY TWO NAMED STORMS HAVE FORMED. FORECASTER FRANKLIN FORECAST POSITIONS AND MAX WINDS INITIAL 07/1500Z 20.5N 45.5W 35 KT 12HR VT 08/0000Z 20.9N 47.0W 35 KT 24HR VT 08/1200Z 21.5N 49.0W 35 KT 36HR VT 09/0000Z 22.1N 50.6W 35 KT 48HR VT 09/1200Z 22.8N 52.1W 40 KT 72HR VT 10/1200Z 24.5N 55.5W 45 KT 96HR VT 11/1200Z 27.5N 58.0W 50 KT 120HR VT 12/1200Z 31.0N 59.5W 55 KT |
