ZCZC MIATCDEP4 ALL TTAA00 KNHC DDHHMM TROPICAL STORM GENEVIEVE DISCUSSION NUMBER 5 NATIONAL WEATHER SERVICE MIAMI FL 8 PM PDT MON AUG 26 2002 THE TROPICAL CYCLONE HAS BEEN MAINTAINING DEEP BUT SHAPELESS CONVECTION OVER THE LOW-LEVEL CIRCULATION CENTER...WITH NO BANDING FEATURES. DVORAK INTENSITY ESTIMATES ARE 35 KT FROM SAB AND KCWC...AND 45 KT FROM TAFB. ON THIS BASIS THE SYSTEM IS UPGRADED TO TROPICAL STORM GENEVIEVE... PRONOUNCED JEN-AH-VEEV. THE LACK OF FEATURES IN THE CONVECTIVE PATTERN MAKES THE INITIAL POSITION AND MOTION DIFFICULT TO DETERMINE...BUT IT APPEARS THAT THE FORWARD SPEED HAS SLOWED. WITH A NOD TO CONTINUITY THE INITIAL MOTION IS SET AT 255/6. THE SYNOPIC ENVIRONMENT IS COMPLICATED. WATER VAPOR IMAGERY SHOWS AN UPPER LOW NORTHWEST OF THE TROPICAL CYCLONE MOVING SOUTHWESTWARD...WHILE IN THE MID LEVELS A RIDGE APPEARS TO BE CURRENTLY WELL ESTABLISHED TO THE NORTH OF THE CYCLONE. PERHAPS NOT SURPRISINGLY...THE MODEL GUIDANCE IS NOT IN VERY GOOD AGREEMENT. ON ONE SIDE OF THE GUIDANCE SUITE...THE GFDL SLOWS GENEVIEVE SHARPLY AND THEN BENDS THE TRACK TO THE NORTH- NORTHWEST...WHILE ON THE OTHER SIDE...THE AVN MAINTAINS A STEADY TRANSLATION SPEED WHILE ONLY SLOWLY TURNING THE TRACK TO THE WEST-NORTHWEST. AS IT WAS WITH FAUSTO...THE AVN IS THE SOUTHERMOST OF THE GUIDANCE MODELS. WHILE THE AVN PERFORMED EXTREMELY WELL WITH FAUSTO...AND IN FACT IT HAS PERFORMED WELL IN THIS BASIN ALL YEAR...I WONDER WHETHER THE CURRENT APPARENT SLOWDOWN IS A CLUE THAT THE GFDL MIGHT BE ON TO SOMETHING. THE OFFICIAL FORECAST IS ADJUSTED A LITTLE SLOWER AND NORTH OF THE PREVIOUS ADVISORY TRACK...BUT IS STILL CLOSER TO THE AVN THAN TO THE GFDL...AND CLOSE TO BOTH THE UKMET AND NOGAPS SOLUTIONS. PERHAPS A LARGER ADJUSTMENT WILL BE MADE WHEN MORE CONFIDENCE IN THE INITIAL MOTION CAN BE OBTAINED. THE UPPER LOW ALSO COMPLICATES THE INTENSITY FORECAST. AS IT DIGS SOUTHWESTWARD AHEAD OF GENEVIEVE...IT COULD REACH A FAVORABLE RELATIVE LOCATION WHERE THE NORTHWARD UPPER-LEVEL OUTFLOW IS ENHANCED. HOWEVER...THE AVN SUGGESTS THAT THE LOW WILL INCREASE THE SHEAR OVER THE SYSTEM. FURTHERMORE...GENEVIEVE IS LIKELY TO ENCOUNTER COOLER WATERS MIXED UPWARD BY FAUSTO. THEREFORE...THE OFFICIAL FORECAST CALLS FOR UNENTHUSIASTIC STRENGTHENING...CLOSE TO BUT SLIGHTLY BELOW THE SHIPS GUIDANCE. FORECASTER FRANKLIN FORECAST POSITIONS AND MAX WINDS INITIAL 27/0300Z 13.9N 113.6W 35 KTS 12HR VT 27/1200Z 13.7N 114.6W 45 KTS 24HR VT 28/0000Z 13.6N 115.9W 50 KTS 36HR VT 28/1200Z 13.9N 117.2W 55 KTS 48HR VT 29/0000Z 14.5N 118.5W 60 KTS 72HR VT 30/0000Z 16.5N 121.5W 65 KTS NNNN