ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM HURRICANE GEORGES DISCUSSION NUMBER 16 NATIONAL WEATHER SERVICE MIAMI FL 5 AM EDT SAT SEP 19 1998 DVORAK T-NUMBERS ARE STILL 5.0...SO 90 KT REMAINS THE ESTIMATED WIND SPEED. IT APPEARS...THE HURRICANE HAS UNDERGONE SOME EYE STRUCTURE CHANGES AS REFLECTED IN THE SSM/I SATELLITE IMAGERY DURING THE PAST 12 HRS AND THE EYE DIAMETER IS NOW MUCH LARGER. THE SYSTEM MAY BE ADJUSTING ITS HORIZONTAL WIND FIELD...A SHIP LOCATED ABOUT 175 NMI MILES NORTH OF THE CENTER REPORTED 40 KTS AND 16 FOOT SEAS AT OOZ. HOWEVER...THE CONDITIONS FOR ADDITIONAL STRENGTHENING ARE STILL PRESENT AND THE FORECAST CALLS FOR THIS. THE HEADING IS 280/16 KT WHICH IS A DECREASE FROM 24 HOURS AGO WHERE IT WAS 275/20 KT. THIS SUGGESTS THAT THE BASIC CURRENT WHICH IS DEPENDENT ON THE RIDGE TO THE NORTH IS DECREASING WHICH ALSO SUGGESTS THAT THE RIDGE TO THE NORTH IS NOT AS STRONG AS IT WAS 24 HOURS AGO. WHILE THE RIDGE TO THE NORTH IS FORECAST TO HOLD THROUGH THE FORECAST PERIOD...SOME ADDITIONAL NORTHWARD COMPONENT IN THE TRACK COULD OCCUR. THE TRACK MODELS SHOW A LARGE DIVERGENCE ON EITHER SIDE OF THE OFFICIAL EXTRAPOLATED FORECAST TRACK AND THE GFDL FORECAST TRACK. NOGAPS...UKMET...AND AVN TO THE NORTH AND BAM MODELS AND A98 TO THE SOUTH. THE OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS ONE BUT SLIGHTLY NORTH AT THE 48 AND 72 HOUR FORECAST POSITIONS. BASED ON THIS A HURRICANE WARNING WILL BECOME NECESSARY LATER THIS MORNING FOR ALL OR A PORTION OF THE WATCH AREA. INTERESTS IN THE CARIBBEAN SHOULD NOT FOCUS ON THE EXACT NHC FORECAST TRACK FOR TWO REASONS. FIRST...THE AVERAGE NHC TRACK ERROR FOR A 48 HOUR FORECAST IS AROUND 200 MILES. SECOND...THE HURRICANE IS NOT A POINT. GEORGES IS LIKELY TO AFFECT AN AREA SEVERAL HUNDRED MILES ACROSS. ALL AREAS WITHIN THE HURRICANE WATCH ARE POTENTIAL TARGETS OF HURRICANE FORCE WINDS OVER THE WEEKEND. THE 34 KT WIND RADII HAVE BEEN ADJUSTED SLIGHTLY BASED ON ANALYSIS OF SSM/I DATA MADE BY THE AIR FORCE WEATHER AGENCY AND THE SHIP OBSERVATION AT 00Z. JARVINEN FORECAST POSITIONS AND MAX WINDS INITIAL 19/0900Z 14.2N 51.5W 90 KTS 12HR VT 19/1800Z 14.7N 54.1W 95 KTS 24HR VT 20/0600Z 15.2N 57.4W 100 KTS 36HR VT 20/1800Z 15.6N 60.7W 105 KTS 48HR VT 21/0600Z 16.2N 63.6W 110 KTS 72HR VT 22/0600Z 17.0N 69.0W 115 KTS NNNN