000 WTPZ43 KNHC 250857 TCDEP3 TROPICAL STORM GENEVIEVE DISCUSSION NUMBER 16 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082008 200 AM PDT FRI JUL 25 2008 THE CONVECTIVE PATTERN HAS AT TIMES BEEN A LITTLE MORE SYMMETRIC RECENTLY...AND THE INITIAL INTENSITY IS INCREASED TO 55 KT BASED ON THE RISE IN SUBJECTIVE DVORAK ESTIMATES. MICROWAVE IMAGERY FROM SSMIS BACK AT 03Z SUGGESTS THE CYCLONE IS STILL A BIT TILTED IN THE VERTICAL...BUT PERHAPS A LITTLE LESS SO THAN EARLIER. THE SEA-SURFACE TEMPERATURES BENEATH GENEVIEVE ARE CURRENTLY ABOUT 26.5 CELSIUS AND WILL DECREASE ONLY SLIGHTLY DURING THE NEXT 24 HOURS. MEANWHILE VERTICAL WIND SHEAR APPEARS TO BE MODEST OUT OF THE SOUTHEAST...WITH NO APPRECIABLE CHANGE FORECAST BY THE GLOBAL MODELS FOR THE NEXT SEVERAL DAYS. AS A RESULT A TEMPORARY STRENGTHENING TREND IS FORECAST IN THE SHORT TERM BY NEARLY ALL OF THE OBJECTIVE INTENSITY GUIDANCE...WITH THE SHIPS AND GFDL FLIRTING WITH HURRICANE STATUS...AND THE NEW OFFICIAL FORECAST PEAKS AT 60 KT IN 24 HOURS. IT CERTAINLY CANNOT BE RULED OUT THAT GENEVIEVE COULD BECOME A HURRICANE TODAY...BUT NOT LIKELY THEREAFTER. COOLER WATERS ALONG THE FORECAST TRACK BEYOND THAT TIME SHOULD INDUCE STEADY WEAKENING UNTIL THE CYCLONE DEGENERATES OVER SSTS LESS THAN 24 CELSIUS VERY LATE IN THE FORECAST PERIOD. NOTHING OUT OF THE ORDINARY ABOUT GENEVIEVE'S MOTION OF 285/8...WHICH IS FORECAST TO BECOME AN EVEN MORE TYPICAL 285/11 OR SO BY THIS TIME TOMORROW...AS THE CYCLONE SPEEDS UP A LITTLE WITHIN DEEP-LAYER EASTERLY FLOW SOUTH OF THE SUBTROPICAL RIDGE. NOT UNTIL THE SYSTEM WEAKENS AND BECOMES A MORE SHALLOW CIRCULATION OVER COOLER WATERS IN A FEW DAYS WILL THE HEADING CHANGE...TO A MORE WESTWARD MOTION IN THE LOW-LEVEL FLOW. THE OFFICIAL FORECAST LEANS JUST SLIGHTLY TO THE GFS/GFDL/HWRF SIDE...OR TO THE NORTH OF...THE CONSENSUS...WHICH ALSO REPRESENTS A SMALL NORTHWARD SHIFT COMPARED TO THE PREVIOUS ADVISORY. FORECAST POSITIONS AND MAX WINDS INITIAL 25/0900Z 16.0N 114.5W 55 KT 12HR VT 25/1800Z 16.4N 116.0W 60 KT 24HR VT 26/0600Z 17.0N 118.2W 60 KT 36HR VT 26/1800Z 17.6N 120.4W 55 KT 48HR VT 27/0600Z 18.2N 122.6W 45 KT 72HR VT 28/0600Z 19.5N 127.0W 35 KT 96HR VT 29/0600Z 19.5N 131.0W 25 KT...REMNANT LOW 120HR VT 30/0600Z 19.5N 134.5W 20 KT...REMNANT LOW $$ FORECASTER KNABB