ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM HURRICANE BONNIE DISCUSSION NUMBER 21 NATIONAL WEATHER SERVICE MIAMI FL 5 PM EDT MON AUG 24 1998 A SLOW MOTION TOWARD THE NORTHWEST IS EVIDENT...ESTIMATED TO BE 325/05. OBJECTIVE GUIDANCE IS...SHALL I SAY...DIVERGENT. AT 72 HOURS THERE IS NEARLY A 1200 N MI SPREAD BETWEEN THE MEDIUM BAM...NEAR THE GEORGIA COAST...AND THE GFDL WHICH RECURVES BONNIE OUT TO SEA. THE 12Z AVN SHOWS A 500 MB SHORTWAVE NEARING THE NORTHEASTERN U.S. IN A COUPLE OF DAYS...BREAKING DOWN THE RIDGE NEAR MID-ATLANTIC COAST AND ALLOWING BONNIE TO RECURVE OFFSHORE OF THE NORTH CAROLINA OUTER BANKS. HOWEVER THE NOGAPS AND U.K. MET. OFFICE GLOBAL MODELS COMPLICATE THE FORECAST SINCE THEY DO NOT RECURVE THE HURRICANE AND TAKE IT NEAR TO..OR ACROSS...THE U.S. SOUTHEAST COAST. SINCE THE LATTER TWO MODELS ARE RESPECTABLE ONES...THE OFFICIAL FORECAST IS STILL NOT COMMITTED TO A RECURVATURE. WITH SUCH DIVERSE GUIDANCE...OBVIOUSLY OUR CONFIDENCE IN THE 72 HOUR POINT IS NOT THAT HIGH. THE FORECAST TRACK COUPLED WITH THE LARGE SIZE OF BONNIE...TROPICAL STORM FORCE WINDS EXTENDING 200 NM OVER THE NORTHWEST QUADRANT... DICTATE THE ISSUANCE OF A HURRICANE WATCH FOR A PORTION OF THE U.S. SOUTHEAST COAST. STRONG WINDS ARE POSSIBLE ON THE COAST IN 36 HOURS OR LESS. INTENSITY REMAINS UNCHANGED...NEAR 100 KNOTS. EVEN THOUGH BONNIE APPEARS TO BE IN AN ENVIRONMENT OF MODEST WESTERLY SHEAR...THE HURRICANE HAS SUCH A LARGE AND POWERFUL CIRCULATION SO AS TO BE RESILIENT TO THE SHEARING. ALSO...THE HURRICANE WILL LIKELY MOVE OVER SLIGHTLY WARMER WATERS DURING THE NEXT DAY OR SO. LITTLE CHANGE IN STRENGTH IS PREDICTED UNTIL THE END OF THE FORECAST PERIOD WHEN CONDITIONS WILL PROBABLY BECOME A LITTLE MORE HOSTILE. NOTE...THE NHC INTERNET SITE IS BEING OVERLOADED...FORCING OCCASIONAL SHUTDOWNS. SOME OF ITS HURRICANE INFORMATION CAN BE OBTAINED FROM THE FEDERAL EMERGENCY MANAGEMENT AGENCY AT WWW.FEMA.GOV/HLT/TROP.HTML PASCH FORECAST POSITIONS AND MAX WINDS INITIAL 24/2100Z 26.3N 72.9W 100 KTS 12HR VT 25/0600Z 27.1N 73.5W 100 KTS 24HR VT 25/1800Z 28.9N 74.5W 100 KTS 36HR VT 26/0600Z 30.7N 75.3W 100 KTS 48HR VT 26/1800Z 32.5N 76.0W 100 KTS 72HR VT 27/1800Z 36.5N 76.0W 85 KTS NNNN