ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM HURRICANE OLGA DISCUSSION NUMBER 9 NATIONAL WEATHER SERVICE MIAMI FL 4 PM EST MON NOV 26 2001 AFTERNOON SATELLITE IMAGERY INDICATES AN INTERMITTENT EYE AT THE CENTER OF OGLA...WHICH AS OF THIS WRITING IS BECOMING BETTER DEFINED. SATELLITE INTENSITY ESTIMATES ARE 65 KT FROM SAB AND AFWA...AND 77 KT FROM TAFB. ON THIS BASIS...OLGA IS UPGRADED TO A 65 KT HURRICANE. OLGA HAS TURNED MORE TOWARD THE NORTH DURING THE PAST SIX HOURS. THE INITIAL MOTION IS NOW 350/5...AND THE SORT-TERM MOTION MAY EVEN BE TO THE RIGHT OF THAT. THIS MOTION IS LIKELY IN RESPONSE TO AN UPPER LEVEL TROUGH AND SURFACE FRONT JUST OFFSHORE OF THE EASTERN UNITED STATES....WHICH HAS WEAKENED THE RIDGE NORTHWEST OF THE HURRICANE. SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE THE SYSTEM IS NOT THAT STRONG...AND LARGE-SCALE MODELS SUGGEST IT SHOULD PASS TO THE NORTH OF OLGA. THE LARGE-SCALE MODELS MOVE OLGA NORTHWARD FOR 12-18 HR IN RESPONSE TO THE TROUGH...THEN THEY TURN IT SOUTHWARD AND EVEN SOUTHWESTWARD AFTER 36-48 HR. THIS LOOKS REASONABLE IN LIGHT OF THE EVOLVING SYNOPTIC PATTERN. HOWEVER... SEVERAL NHC HURRICANE GUIDANCE MODELS...INCLUDING THE GFDL... CONTINUE MOVING OLGA TO THE NORTH FOLLOWED BY ACCELERATION TO THE EAST. THIS SCENARIO COULD HAPPEN IF OLGA'S INITIAL NORTHWARD MOTION CONTINUES FOR MORE THAN ABOUT 24 HR OR IS FASTER THAN CURRENTLY FORECAST. GUIDANCE DIVERGENCE OF THIS MAGNITUDE INDICATES A LOW CONFIDENCE FORECAST. THE GLOBAL MODELS HAVE BEEN HANDLING THIS SYSTEM FAIRLY WELL...SO THE OFFICIAL TRACK FORECAST WILL LEAN MORE TOWARD THEM THAN TOWARD THE NORTHEASTWARD MODELS. THE FORECAST CALLS FOR SLOW NORTHWARD MOTION FOR 12-24 HR...FOLLOWED BY A SLOW TURN TOWARD THE WEST-SOUTHWEST. THIS TURN IS NEITHER AS FAR SOUTH OR AS FAST AS THOSE SHOWN BY THE GLOBAL MODELS. OLGA IS CURRENTLY OVER 22C-23C SEA SURFACE TEMPERATURES...AND THIS IS NOT LIKELY TO CHANGE MUCH ON THE CURRENT FORECAST TRACK. THE BIGGEST QUESTION FOR THE INTENSITY FORECAST IS THE EVOLUTION OF THE UPPER LEVEL TROUGH NEAR THE STORM AND HOW MUCH SHEAR WILL THUS IMPACT THE SYSTEM. THE GLOBAL MODELS ARE NOT IN GOOD AGREEMENT ON THE EVOLUTION AND THE LOCATION OF THE MOST FAVORABLE ENVIRONMENT...AND SATELLITE IMAGERY IS NOT GIVING OBVIOUS CLUES JUST YET AS TO WHICH ONE IS RIGHT. THUS...THE INTENSITY FORECAST WILL FOLLOW THE TRENDS FROM THE PREVIOUS PACKAGE...WHICH ASSUMES THAT OLGA WILL REMAIN IN AT LEAST A SOMEWHAT FAVORABLE ENVIRONMENT THROUGH 48 HR. ALTHOUGH THE OUTER WIND FIELD IS CONTRACTING...SHIP REPORTS CONTINUE TO INDICATE A VERY LARGE FIELD OF 12 FT OR GREATER SEAS ASSOCIATED WITH OLGA. SWELLS FROM THE STORM ARE REACHING BERMUDA AND PORTIONS OF THE MID-ATLANTIC STATES. THE SWELLS WILL REACH THE BAHAMAS AND THE ISLANDS OF THE NORTHERN CARIBBEAN LATER TODAY OR TONIGHT...AND REACH THE REMAINDER OF THE EASTERN COAST OF THE UNITED STATES OVER THE NEXT DAY OR TWO. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 26/2100Z 31.5N 56.0W 65 KTS 12HR VT 27/0600Z 32.0N 56.1W 70 KTS 24HR VT 27/1800Z 32.3N 56.5W 70 KTS 36HR VT 28/0600Z 32.3N 56.9W 70 KTS 48HR VT 28/1800Z 32.2N 57.3W 70 KTS 72HR VT 29/1800Z 31.5N 58.0W 65 KTS NNNN