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#536591 (Received by flhurricane at: 10:35 AM 24.Aug.2012) TCDAT5 POST-TROPICAL CYCLONE JOYCE DISCUSSION NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL102012 1100 AM AST FRI AUG 24 2012 VISIBLE SATELLITE IMAGERY INDICATES THAT THE CENTER OF CIRCULATION HAS BECOME ILL DEFINED...AND THE CIRCULATION ITSELF MAY NOT EVEN BE CLOSED ANYMORE. ALTHOUGH THE CYCLONE IS PRODUCING SOME CONVECTION IN THE NORTHERN SEMICIRCLE...THE SHOWERS AND THUNDERSTORMS ARE NOT WELL ORGANIZED. JOYCE NO LONGER SATISFIES THE CRITERIA FOR BEING A TROPICAL CYCLONE...AND IT IS THEREFORE BEING DESIGNATED AS A REMNANT LOW. THIS WILL BE THE LAST ADVISORY UNLESS REGENERATION OCCURS. BASED ON ANALYSES FROM UW-CIMSS...JOYCE IS BEING AFFECTED BY ABOUT 20 KT OF SOUTH-SOUTHEASTERLY SHEAR...AND IT IS EMBEDDED IN A DRY MID-LEVEL ENVIRONMENT. THESE PARAMETERS ARE NOT EXPECTED TO CHANGE APPRECIABLY DURING THE NEXT COUPLE OF DAYS...AND THE PROSPECTS OF REGENERATION AND STRENGTHENING APPEAR LOW AT THIS TIME. THE NHC OFFICIAL FORECAST HOLDS THE CYCLONE AS A REMNANT LOW THROUGH THE 5-DAY FORECAST...BUT IT IS ENTIRELY POSSIBLE THAT THE LOW COULD DISSIPATE AT ANY TIME. THE INITIAL MOTION ESTIMATE IS 300/13. THE LOW IS EXPECTED TO MAINTAIN A WEST-NORTHWESTWARD HEADING WITH SOME ACCELERATION AS IT MOVES ALONG THE SOUTHWESTERN PERIPHERY OF A LOW/MID-LEVEL SUBTROPICAL RIDGE. THE REMNANTS SHOULD REACH THE WESTERN EXTENT OF THE RIDGE IN 3-4 DAYS...AND ARE FORECAST TO RE-CURVE TOWARD THE NORTHEAST BY DAY 5. THE TRACK GUIDANCE IS STILL IN RELATIVELY GOOD AGREEMENT...AND THE NEW NHC FORECAST IS JUST AN UPDATE OF THE PREVIOUS ONE. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC. FORECAST POSITIONS AND MAX WINDS INIT 24/1500Z 17.8N 46.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 12H 25/0000Z 18.7N 48.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 24H 25/1200Z 20.3N 52.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 26/0000Z 22.1N 55.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 26/1200Z 24.5N 58.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 27/1200Z 29.0N 63.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 28/1200Z 33.5N 62.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 29/1200Z 37.5N 53.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ FORECASTER BERG |