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| #200841 (Received by flhurricane at: 4:37 PM 13.Jul.2008) TCDAT2 TROPICAL STORM BERTHA DISCUSSION NUMBER 43 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008 500 PM EDT SUN JUL 13 2008 AN AIR FORCE RESERVE RECONNAISSANCE PLANE JUST FINISHED TWO PASSES ACROSS BERTHA. FLIGHT-LEVEL WINDS...SFMR AND DROPSONDES INDICATE THAT BERTHA CONTINUES AS A 55 KT TROPICAL STORM. HIGH RESOLUTION SATELLITE IMAGES SHOW A VIGOROUS LOW-LEVEL CIRCULATION ASSOCIATED WITH THE CYCLONE BUT DEEP CONVECTION IS VERY LIMITED. SOME OF THE DYNAMICAL MODELS INDICATE RESTRENGTHENING WHILE THE SHIPS GUIDANCE MAINTAIN BERTHA WITH BASICALLY THE SAME INTENSITY. THE OFFICIAL FORECAST KEEPS BERTHA AS A 50 KT CYCLONE THROUGH FIVE DAYS....AS INDICATED BY THE SHIPS MODEL. SOME INTENSIFICATION COULD OCCUR IF BERTHA BEGINS TO ACQUIRE EXTRATROPICAL CHARACTERISTICS AS IT INTERACTS WITH THE MID-LATITUDE WESTERLIES. BERTHA FOOLED ME ONCE AGAIN. IT APPEARS THAT BERTHA BEGAN A NORTHWESTWARD DRIFT EARLIER TODAY BUT...IN FACT...IT WAS MOVING IN CIRCLES AND IT COULD BE DOING ONE OF THESE LOOPS AGAIN. MODEL GUIDANCE...WHICH IS NOW MORE IN GOOD AGREEMENT...INSISTS THAT THE NORTHWARD MOTION SHOULD BEGIN TONIGHT AND SO DOES THE OFFICIAL FORECAST. IN ABOUT 48 HOURS...BERTHA IS EXPECTED TO BE EMBEDDED WITHIN THE MID-LATITUDE WESTERLIES AND BE STEERED SLOWLY EASTWARD. THE CIRCULATION SHOULD THEN EXPAND WHILE GRADUALLY ACQUIRING EXTRATROPICAL CHARACTERISTICS. ONE WAY OR ANOTHER IT APPEARS THAT BERTHA COULD BE WITH US FOR SEVERAL MORE DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 13/2100Z 30.2N 63.1W 55 KT 12HR VT 14/0600Z 30.5N 63.3W 50 KT 24HR VT 14/1800Z 32.0N 63.8W 50 KT 36HR VT 15/0600Z 33.5N 63.7W 50 KT 48HR VT 15/1800Z 35.0N 62.5W 50 KT 72HR VT 16/1800Z 35.5N 60.0W 50 KT 96HR VT 17/1800Z 35.0N 57.0W 50 KT 120HR VT 18/1800Z 35.0N 54.0W 50 KT $$ FORECASTER AVILA |
