ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM AGATHA DISCUSSION NUMBER 11 NATIONAL WEATHER SERVICE MIAMI FL 8 PM PDT SAT JUN 13 1998 AGATHA HAS A WELL DEFINED CURVED CLOUD BAND THAT WRAPS AROUND THE CENTER...BUT DEEP CONVECTION IS LIMITED. T-NUMBERS FROM ALL AGENCIES ARE BETWEEN 3.0 AND 3.5 ON THE DVORAK SCALE. THEREFORE... THE INITIAL INTENSITY REMAINS AT 55 KNOTS. AGATHA IS ABOUT TO CROSS THE 26 DEGREE ISOTHERM AND IS HEADING FOR COOLER WATERS. SO... WEAKENING SHOULD BEGIN SOON. MODELS ARE BUILDING SUCH A STRONG RIDGE NORTH OF AGATHA THAT THE STORM IS BEING FORECAST...BY SOME MODELS... TO MOVE SOUTHWARD AND EVEN SOUTHEASTWARD. THE UK MODEL HAS NOW JOINED THE GFDL AND THE AVN IN THIS VENTURE. BAM MODELS ARE DECREASING THE FORWARD SPEED OF THE STORM AND THEN TURN IT EASTWARD WHILE NOGAPS AND STATISTICAL MODELS ARE MOVING AGATHA WESTWARD. THIS WOULD MAKE SENSE IF THE STORM WEAKENS FAST AND THE TRACKING ALGORITHM GATHERS SOME OTHER SPURIOUS VORTICES NOT RELATED TO AGATHA. I HARD TO ACCEPT THAT...IN THIS CASE...GLOBAL MODELS AND THE GFDL WOULD BE SO WRONG. AT THIS TIME...WITH SUCH A DISCREPANCY...I WOULD GO WITH GOOD OLD CLIMATOLOGY AND PERSISTENCE...AND MOVE AGATHA ON A GENERAL WEST NORTHWEST TRACK WITH A DECREASE IN FORWARD SPEED WHICH IS NOW ABOUT 17 KNOTS. OBVIOUSLY..IF THE STORM MOVES SOUTHWARD...AS SUGGESTED BY SOME MODELS...THE SST ARGUMENT IS NOT VALID AND THE STORM WILL PROBABLY SURVIVE LONGER. AVILA FORECAST POSITIONS AND MAX WINDS INITIAL 14/0300Z 16.8N 117.1W 55 KTS 12HR VT 14/1200Z 17.8N 119.3W 50 KTS 24HR VT 15/0000Z 18.5N 121.0W 40 KTS 36HR VT 15/1200Z 19.5N 122.5W 30 KTS 48HR VT 16/0000Z 20.0N 124.0W 30 KTS 72HR VT 17/0000Z 21.5N 127.4W 25 KTS NNNN