WTCN31 CWHX 190600 CANADIAN HURRICANE INFORMATION STATEMENT ISSUED BY THE CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 2.00 AM EDT FRIDAY 19 SEPTEMBER 2003. THE NEXT STATEMENT WILL BE ISSUED BY 8.00 AM EDT ... TROPICAL STORM ISABEL BECOMING POST-TROPICAL LATER TODAY... 1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION AT 2.00 AM EDT... TROPICAL STORM ISABEL WAS LOCATED NEAR LATITUDE 38.9 N AND LONGITUDE 78.8 W... ABOUT 50 NAUTICAL MILES OR 90 KM NORTH NORTHWEST OF CHARLOTTESVILLE VIRGINIA. MAXIMUM SUSTAINED WINDS ARE ESTIMATED AT 50 KNOTS... 93 KM/H... AND CENTRAL PRESSURE AT 976 MB. ISABEL IS MOVING NORTH-NORTHWEST AT 20 KNOTS... 38 KM/H. 2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH ISABEL IS EXPECTED TO CONTINUE TO WEAKEN IN THE SHORT TERM WITH SOME SLIGHT RE-INTENSIFICATION TONIGHT. DATE TIME LAT LON MSLP MAX WIND EDT MB KTS KMH SEP 19 2.00 AM 38.9N 78.8W 976 50 93 SEP 19 2.00 PM 43.5N 79.8W 987 35 65 SEP 20 2.00 AM 49.6N 79.6W 990 35 65 POST-TROPICAL SEP 20 2.00 PM 56.0N 77.2W 987 35 65 POST-TROPICAL SEP 21 2.00 AM 60.8N 74.0W 985 35 65 POST-TROPICAL SEP 21 2.00 PM 66.1N 71.2W 984 40 74 POST-TROPICAL 3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY ISABEL IS EXPECTED TO IMPACT THE WEATHER OVER ONTARIO AND QUEBEC TODAY AND SATURDAY. THE LEADING RAINBANDS FROM THE STORM HAVE ALREADY REACHED SOUTHERN ONTARIO AND SOME HEAVIER PRECIPITATION CAN BE EXPECTED LATER THIS MORNING AND THIS AFTERNOON WITH THE APPROACH OF THE STORM. RAINS WILL SPREAD NORTHWARD THIS AFTERNOON AND ACROSS JAMES BAY THIS EVENING. RAINFALL AMOUNTS OF 50 MM ARE EXPECTED ALONG AN AXIS RUNNING FROM LONDON TO SUDBURY BY FRIDAY AFTERNOON WITH LOCALLY HIGHER AMOUNTS POSSIBLE. HEAVY RAINS WILL SPREAD NORTHWARD FROM SUDBURY TO MOOSONEE LATER TODAY AND TONIGHT ...CLOSE TO AND WEST OF THE TRACK OF POST-TROPICAL ISABEL AS IT MERGES WITH ANOTHER LOW CROSSING NORTHERN ONTARIO. LESSER RAINFALLS ARE EXPECTED EAST OF THE TRACK OF THE REMNANTS OF ISABEL FOR SOUTHEASTERN ONTARIO AND THE WESTERN HALF OF QUEBEC. HOWEVER THESE AREAS WILL EXPERIENCE THE STRONGEST WINDS..50 TO 70 KM/H WITH HIGHER GUSTS LOCALLY PARTICULARLY ALONG THE SHORELINES OF THE LOWER GREAT LAKES. AT 11.30 PM EDT LONG POINT ON LAKE ERIE OBSERVED A WIND GUST OF 32 KTS 60 KM/H. WINDS WILL PROBABLY REMAIN STRONG WITH THIS SYSTEM THROUGHOUT AS SOME RE-INTENSIFICATION MAY OCCUR AGAIN FRIDAY NIGHT AS THE SYSTEM TRACKS NORTHWARD TO JAMES BAY CLOSE TO THE ONTARIO QUEBEC BORDER. HEAVY RAINFALL WARNINGS AND WIND WARNINGS ARE IN EFFECT FOR PARTS OF SOUTHERN ONTARIO. WARNINGS MAY BE EXTENDED INTO NORTHERN REGIONS OF ONTARIO AND NORTHWESTERN QUEBEC AS CONDITIONS WARRANT. 4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY ISABEL IS EXPECTED TO TRANSITION FRIDAY NIGHT INTO A POST-TROPICAL SYSTEM BUT MAY WELL STILL BE A TROPICAL STORM AS IT CROSSES THE LOWER GREAT LAKES. GALE WARNINGS ARE IN EFFECT FOR LAKE ERIE AND LAKE ONTARIO GALE WARNINGS ARE ALSO IN EFFECT FOR THE ST LAWRENCE RIVER BECAUSE OF CONCERNS FOR WIND CHANNELLING. ADDITIONALLY GALE WARNINGS WILL PROBALY BE ISSUED FOR GEORGIAN BAY. ALSO..MODERATE SURF CONDITIONS ALONG THE ATLANTIC COAST OF NOVA SCOTIA WILL PRESIST TODAY AND WILL DECAY ON SATURDAY. SWELL OF 2 TO 3 METRES TODAY IN THE GULF OF MAINE AND THE MOUTH OF THE BAY OF FUNDY WILL CREATE ROUGH CONDITIONS THERE ESPECIALLY WITH THE EBBING TIDE. NO WIND IMPACTS ARE EXPECTED OVER MARITIME WATERS WITH THIS SYSTEM. 5. TECHNICAL DISCUSSION A. ANALYSIS AS EXPECTED ISABEL HAS WEAKENED STEADILY SINCE MAKING LANDFALL AND AT 9 PM EDT THURSDAY ISABEL WAS DOWNGRADED BY THE NATIONAL HURRICANE CENTRE FROM A HURRICANE TO A TROPICAL STORM. CONVECTION HAS WEAKENED CONSIDERABLY AS HAVE THE INTENSITY OF RETURNS FROM RADARS CLOSEST TO THE STORM. LITTLE PRECIPITATION IS SHOWING UP SOUTH OF THE STORM DUE TO THE ENTRAINMENT OF DRY AIR COMING DOWN FROM THE APPALACHIANS IN THE SOUTHWESTERN QUADRANT OF THE STORM. B. PROGNOSTIC TROPICAL STORM ISABEL WILL CONTINUE TO WEAKEN THIS MORNING AS IT TRACKS NORTH NORTHWESTWARDS TOWARDS THE CANADIAN BORDER. WE FOLLOW NHC TRACK VERY CLOSELY WHICH IS IN GOOD AGREEMENT WITH THE NEW 00Z MODEL RUNS THAT WE HAVE SEEN SO FAR...ALTHOUGH SLIGHTLY FASTER. THE SYSTEM IS STILL EXPECTED TO BE TROPICAL IN NATURE AS IT CROSSES LAKE ERIE NEAR NOON BUT THEREAFTER IT WILL INTERACT WITH THE WEAKENING SHORT WAVE TROUGH TO THE WEST. PHASE SPACE ANALYSIS FROM FLORIDA STATE BASED ON THE ETA MODEL AND PARTICULARLY THE MM5 MODEL ALSO DELAYS THE EXTRATROPICAL TRANSITION FROM PREVIOUS RUNS. SOME RE-INTENSIFICATION MAY OCCUR THEREAFTER AS THE SYSTEM TRACKS NORTHWARD UNDER SOMEWHAT LOWERING HEIGHTS BUT THE TROUGH IS ALSO LIFTING NORTHWARD AT THIS POINT...SO ANY DEEPENING WILL BE SLOW. AFTER 20 00Z THE SYSTEM WILL HAVE SPED UP SOMWHAT AND COLD AIR WILL BE FLOODING ITS SOUTHWESTERN FLANK AS IT BEGINS TO MERGE WITH THE EXTRATROPICAL LOW TO THE WEST AND THE SCALE OF THE SYSTEM EXPANDS. END/PARKES