|
Show Selection: |
| #198972 (Received by flhurricane at: 11:08 AM 04.Jul.2008) TCDAT2 TROPICAL STORM BERTHA DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008 1100 AM EDT FRI JUL 04 2008 THE CLOUD PATTERN OF BERTHA CONSISTS OF A COUPLE OF CLUSTERS OF CONVECTION TO THE NORTH AND SOUTH OF THE CENTER EMBEDDED WITHIN A LARGE CYCLONIC CIRCULATION IN THE LOW CLOUDS. A QUIKSCAT OVERPASS THAT WAS RECEIVED JUST AFTER THE ISSUANCE OF THE PREVIOUS ADVISORY...SUGGEST THAT THE MAXIMUM WINDS WERE AROUND 45 KT. THE STRUCTURE OF THE CYCLONE HAS CHANGE LITTLE SINCE THAT TIME AND THE LATEST DVORAK DATA T NUMBERS FROM SAB AND TAFB SUPPORT A 45 KT INITIAL INTENSITY. BERTHA WILL BE PASSING OVER SLIGHTLY COOLER WATERS DURING THE NEXT 24 HOURS...SO NO CHANGE IN INTENSITY IS EXPECTED IN THE NEAR TERM. BETWEEN 24 AND 72 HOURS...CONDITIONS ARE EXPECTED TO BECOME CONDUCIVE FOR GRADUAL STRENGTHENING AS SSTS INCREASE AND THE SHEAR REMAINS LOW. MODELS SUGGEST THAT THE SHEAR COULD INCREASE THEREAFTER...SO THE NEW FORECAST KEEPS THE INTENSITY JUST SHY OF HURRICANE STRENGTH. HOWEVER....IT IS WORTH MENTIONING THAT THE SHIPS...LGEM...AND GFDL MODELS FORECAST BERTHA TO BECOME A HURRICANE IN 3-4 DAYS. BERTHA IS MOVING WEST-NORTHWESTWARD AT A LITTLE FASTER PACE...290/14. THE STORM SHOULD REMAIN ON THIS GENERAL HEADING DURING THE NEXT 2-3 DAYS AS IT IS LOCATED SOUTH OF A MID-LEVEL RIDGE OVER THE EASTERN ATLANTIC. THE GUIDANCE HAS CONTINUED TO SHIFT WESTWARD...BUT THERE REMAINS TWO DISTINCT ENVELOPES...ONE THAT CONSISTS OF THE HWRF AND GFDL THAT TURN THE CYCLONE NORTHWESTWARD BEYOND DAY 3....AND THE OTHER WHICH KEEPS BERTHA ON A MORE WEST-NORTHWEST TRACK. THE OFFICIAL FORECAST TRACK HAS BEEN ADJUSTED WESTWARD TO REFLECT THE SHIFT IN THE GUIDANCE. FORECAST POSITIONS AND MAX WINDS INITIAL 04/1500Z 14.9N 29.7W 45 KT 12HR VT 05/0000Z 15.7N 32.1W 45 KT 24HR VT 05/1200Z 16.5N 35.6W 45 KT 36HR VT 06/0000Z 17.2N 39.2W 50 KT 48HR VT 06/1200Z 17.9N 42.9W 55 KT 72HR VT 07/1200Z 19.5N 49.5W 60 KT 96HR VT 08/1200Z 21.5N 54.5W 60 KT 120HR VT 09/1200Z 24.0N 59.0W 60 KT $$ FORECASTER BROWN |
