ZCZC MIATCDAT1 ALL TTAA00 KNHC DDHHMM COR TROPICAL STORM FRANCES DISCUSSION NUMBER 5 NATIONAL WEATHER SERVICE MIAMI FL 5 PM EDT WED SEP 09 1998 ...CORRECTION TO NAME... AT 18Z BUOY 42019...LOCATED JUST OFF THE LOWER TEXAS COAST... REPORTED SUSTAINED WINDS OF 35 KNOTS AT 3 METERS. THE LAST AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT REPORTED FLIGHT-LEVEL WINDS OF 40 KNOTS IN THE NORTHWEST QUADRANT. BASED ON THIS DATA TROPICAL DEPRESSION SIX IS BEING UPGRADED TO TROPICAL STORM FRANCES. SEVERAL OIL RIG OBSERVATIONS HAVE BEEN REPORTED 40 TO 50 KNOTS WINDS ...AT ABOUT 30 METERS...OVER THE NORTHWEST GULF...DURING THE DAY. ALTHOUGH THESE STRONG WINDS A LIKELY DUE TO HIGH PRESSURE BUILDING OVER THE SOUTHEAST UNITED STATES. THE TROPICAL STORM FORCE WIND RADII ENCOMPASS THESE WINDS. POSITION ESTIMATES FROM RECONNAISSANCE...RADAR...AND SATELLITE CONTINUE TO SHOW THAT THE CENTER OF THIS SYSTEM IS BROAD AND POORLY DEFINED. HIGH-RESOLUTION VISIBLE SATELLITE IMAGES SUGGEST SEVERAL VORTICES ARE ROTATING AROUND A LARGER CIRCULATION. WHILE EARLIER RECONNAISSANCE WAS ABLE TO FIX A CENTER...ALBEIT WITH 45 NM ACCURACY ...THEY WERE UNABLE TO LOCATE A CENTER ON THE LAST PASS. WITH THE OVERALL ENVIRONMENT CONDUCIVE FOR DEVELOPMENT..I.E. NO APPRECIABLE WIND SHEAR AND 30C SST...THE SYSTEM IS EXPECTED TO DEVELOP. THERE IS A DISTINCT POSSIBLITY THAT THE CENTER WILL REFORM SOUTH OF THE ADVISORY POSITION. THUS... WITH THE CONTINUING UNCERTAINTY SURROUNDING THE EXACT CENTER LOCATION WE WILL HOLD THE POSITION FROM THE 12Z ADVISORY UNTIL A MORE DEFINITIVE CENTER EMERGES. THE INTENSITY FORECAST SHOWS SOME GRADUAL STRENGTHENING ALTHOUGH THIS IS HIGHLY DEPENDANT ON WHERE/IF THE CENTER IS. THE SYSTEM REMAINS STATIONARY. THE TRACK MODEL GUIDANCE CONTINUES TO SHOW HIGHLY DIVERGENT SOLUTIONS. THE EXTREMES ARE CLIPER WHICH BRINGS THE SYSTEM NORTH-NORTHEAST WHILE THE GFDL HOOKS FRANCES SOUTHWEST. THE MAJORITY OF THE GUIDANCE IS STILL WEST-NORTHWEST WITH SEVERAL MODELS NOW SHOWING A MORE NORTHWEST HEADING. THE GFDL...ALONG WITH THE NGM...SHOWS FRANCES ROTATING SOUTH/SOUTHWEST ALONG THE MEXICAN COAST. EXAMINATION OF THE LOWER RESOLUTION FIELDS SUGGEST THAT THE GFDL IS TRACKING A SMALL-SCALE CENTER WITHIN A LARGER CIRCULATION. THE SYNOPTIC PATTERN OF A MID-LEVEL NORTHWEST- SOUTHEAST ORIENTED RIDGE SUPPORTS A GENERALLY WEST-NORTHWEST MOTION. DUE TO THE UNCERTAINTY SURROUNDING THE CENTER LOCATION THE OFFICIAL FORECAST TRACK IS IDENTICAL TO THE PACKAGE FROM 12Z. THIS SEEMS TO BE THE PATH OF LEAST REGRET UNTIL WE CAN GET A MORE CLEAR-CUT CENTER POSITION AND SUBSEQUENT MOTION. BASED ON THE SIZE OF FRANCES THE GOVERNMENT OF MEXICO HAS ISSUED A TROPICAL STORM WARNING FROM THE TEXAS/MEXICAN BORDER TO TAMPICO MEXICO. ALL OTHER TROPICAL STORM WARNINGS REMAIN UNCHANGED. GUINEY FORECAST POSITIONS AND MAX WINDS INITIAL 09/2100Z 25.6N 94.7W 35 KTS 12HR VT 10/0600Z 25.9N 95.5W 40 KTS 24HR VT 10/1800Z 26.2N 96.6W 50 KTS 36HR VT 11/0600Z 26.5N 97.6W 35 KTS...INLAND 48HR VT 11/1800Z 26.8N 98.7W 25 KTS...INLAND 72HR VT 12/1800Z 27.0N 100.0W 20 KTS...INLAND NNNN