ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM TROPICAL STORM OLGA DISCUSSION NUMBER 35 NATIONAL WEATHER SERVICE MIAMI FL 4 AM EST MON DEC 03 2001 OLGA HAS RE-DEVELOPED A SMALL BURST OF MODERATE TO DEEP CONVECTION OVER AND JUST EAST OF THE LOW-LEVEL CENTER. SHIP KIRF TRAVERSED THE CENTER OF OLGA AROUND 03Z AND REPORTED 28 KT WINDS AND A PRESSURE OF 1009.5 MB ABOUT 70 NM SOUTH-SOUTHEAST OF THE CENTER AT 06Z...OUTSIDE OF ANY CONVECTION. AS SUCH...THE INITIAL INTENSITY IS BEING HELD AT 35 KT SINCE SOME STRONGER WINDS MAY EXIST IN THE CONVECTIVE AREAS CLOSER TO THE CENTER. OUTFLOW IS FAIR TO THE EAST AND RESTRICTED TO THE WEST DUE TO INCREASING UPPER-LEVEL WESTERLY SHEAR. THE INITIAL MOTION ESTIMATE IS 360/04. THERE IS NO SIGNIFICANT CHANGE TO THE PREVIOUS FORECAST TRACK OR REASONING. THE UPPER-LEVEL SHORTWAVE TROUGH THAT HAS BEEN MOVING RAPIDLY EASTWARD OFF THE U.S. EAST COAST THE PAST 12 HOURS IS NOW LOCATED ALMOST DUE NORTH OF OLGA. IT APPEARS UNLIKELY THAT THE TROUGH WILL PICK UP AND RECURVE OLGA NORTHEASTWARD INTO THE FAST POLAR WESTERLIES...AND FINALLY END THE 2001 ATLANTIC HURRICANE SEASON. THE SHORTWAVE TROUGH WILL INSTEAD ONLY ACT TO WEAKEN THE MID-LEVEL STEERING FLOW AND CAUSE OLGA TO BECOME STATIONARY OR MAKE A SMALL ANTICYCLONIC LOOP DURING THE NEXT 24 TO 36 HOURS. AFTER THAT...IF OLGA SURVIVES THE INCREASING WESTERLY TO NORTHERLY UPPER-LEVEL SHEAR...THEN THE CYCLONE SHOULD TURN BACK TO THE WEST OR SOUTHWEST UNDER THE INFLUENCE OF THE STRENGTHENING LOW- TO MID-LEVEL SUBTROPICAL RIDGE TO THE NORTH OF OLGA. SINCE THE NHC MODEL GUIDANCE LOOKS LIKE A SQUASHED SPIDER WITH FORECASTS HEADED IN JUST ABOUT EVERY DIRECTION POSSIBLE...A SLOW FORWARD SPEED FOR THE NEXT 36 TO 48 HOURS APPEARS TO BE IN ORDER. NO ONE PARTICULAR MODEL STANDS OUT AS HAVING A GOOD HANDLE ON THE FUTURE TRACK OF OLGA...INCLUDING THE NOGAPS MODEL WHICH NO LONGER BRINGS OLGA ACROSS THE NORTHERN BAHAMAS AND SOUTH FLORIDA IN 72 HOURS. THEREFORE...THE OFFICIAL FORECAST REMAINS CLOSE TO THE PREVIOUS TRACK AND IS CONSISTENT WITH THE EVOLVING SYNOPTIC PATTERN AND BLOCKING SURFACE TO MID-LEVEL RIDGE PATTERN. WATER VAPOR IMAGERY INDICATES THE APPROACHING SHORTWAVE TROUGH IS PUTTING PRESSURE ON THE WEST SIDE OF OLGA AND IS CREATING A SHEARING PATTERN WITH ALL OF THE CONVECTION BEING DISPLACED TO THE EAST. THERE MAY BE SOME MINOR FLUCTUATIONS IN INTENSITY AND OLGA COULD EVEN WEAKEN BACK TO A DEPRESSION LATER TODAY. BUT FOR THE MOST PART...LITTLE CHANGE IN STRENGTH IS EXPECTED DURING THE PERIOD. IF OLGA SURVIVES THE NEXT 48 HOURS...ALL OF THE GLOBAL MODELS ARE STILL FORECASTING THE UPPER-LEVEL FLOW TO WEAKEN AND ALSO DEVELOP A 200 MB ANTICYCLONE TO THE NORTHEAST OF THE BAHAMAS. THIS WOULD PLACE OLGA IN A MORE FAVORABLE ENVIRONMENT FOR STRENGTHENING BY 48 TO 72 HOURS ...IF THE CYCLONE MOVES WESTWARD FASTER THAN THE CURRENT FORECAST. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 03/0900Z 27.6N 69.9W 35 KTS 12HR VT 03/1800Z 28.2N 69.8W 35 KTS 24HR VT 04/0600Z 28.6N 69.4W 35 KTS 36HR VT 04/1800Z 28.5N 68.8W 35 KTS 48HR VT 05/0600Z 28.0N 69.5W 35 KTS 72HR VT 06/0600Z 27.5N 70.5W 30 KTS NNNN