WTCN31 CWHX 191200 CANADIAN HURRICANE INFORMATION STATEMENT ISSUED BY THE CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 8.00 AM EDT FRIDAY 19 SEPTEMBER 2003. THE NEXT STATEMENT WILL BE ISSUED BY 2.00 PM EDT ... ISABEL BECOMING A POST-TROPICAL STORM... 1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION AT 8.00 AM EDT... TROPICAL STORM ISABEL WAS LOCATED NEAR LATITUDE 40.5 N AND LONGITUDE 79.2 W... ABOUT 45 NAUTICAL MILES OR 85 KM EAST OF PITTSBURG. MAXIMUM SUSTAINED WINDS ARE ESTIMATED AT 45 KNOTS... 83 KM/H... AND CENTRAL PRESSURE AT 986 MB. ISABEL IS MOVING NORTH NORTHWEST AT 20 KNOTS... 37 KM/H. 2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH ISABEL IS FORECAST TO FURTHER WEAKEN IN THE SHORT TERM BECOMING A POST-TROPICAL STORM TONIGHT WITH SOME SUBSEQUENT RE-INTENSIFICATION. ISABEL IS LIKELY TO INCREASE ITS SPEED DURING THE NEXT 24 HOURS AND TURN SOMEWHAT TO THE RIGHT. DATE TIME LAT LON MSLP MAX WIND EDT MB KTS KMH SEP 19 8.00 AM 40.7N 79.4W 995 45 83 SEP 19 8.00 PM 46.6N 79.5W 996 35 65 POST-TROPICAL SEP 20 8.00 AM 52.9N 78.3W 986 35 65 POST-TROPICAL SEP 20 8.00 PM 59.8N 75.9W 985 40 74 POST-TROPICAL SEP 21 8.00 AM 64.6N 75.4W 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 RAINBAND FROM THE STORM HAS ALREADY REACHED ACROSS MUCH OF GEORGIAN BAY AND LAKE HURON. THE FOLLOWING MAIN AREA OF PRECIPITATION WHICH IS HEAVIER COVERS LAKE ERIE AND EXTENDS SOUTH TO THE STORM. RAINS WILL SPREAD NORTHWARD THROUGH NORTHEASTERN ONTARIO 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 AND FURTHER NORTH TO TIMMINS BY MIDNIGHT...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. HEAVY RAINS WILL CONTINUE FROM THERE TO MOOSONEE FRIDAY NIGHT AS THE REMAINS OF ISABEL BEGIN MERGING WITH ANOTHER LOW OVER NORTHWESTERN ONTARIO. LESSER RAINFALLS ARE EXPECTED FOR SOUTHEASTERN ONTARIO AND THE WESTERN HALF OF QUEBEC ...EAST OF THE TRACK OF ISABEL. HOWEVER THESE AREAS WILL EXPERIENCE THE STRONGEST WINDS..WITH MEAN SPEEDS OF 50 TO 70 KM/H WITH LOCALLY HIGHER GUSTS PARTICULARLY ALONG THE SHORELINES OF THE LOWER GREAT LAKES. AT 05.30 AM EDT LONG POINT ON LAKE ERIE OBSERVED GALE FORCE WINDS WITH A WIND GUST OF 42 KTS...78 KM/H. WINDS WILL PROBABLY REMAIN STRONG WITH THIS SYSTEM THROUGHOUT AS GALES ARE PRESENTLY BEING REPORTED OVER COASTAL EXPOSED AREAS AND OVER INLAND HIGHER TERRAIN SOME DISTANCE TO THE NORTHEAST OF THE CENTRE...AND SOME RE-INTENSIFICATION MAY OCCUR AGAIN TONIGHT 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 AND FOR SOUTHERN SECTIONS OF NORTHERN ONTARIO. WARNINGS MAY BE EXTENDED INTO NORTHERN REGIONS OF NORTHERN ONTARIO AND WESTERN QUEBEC AS CONDITIONS WARRANT. 4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY ISABEL IS EXPECTED TO TRANSITION TONIGHT INTO A POST-TROPICAL SYSTEM AND IS LIKELY TO STILL BE A TROPICAL STORM AS IT CROSSES THE LOWER GREAT LAKES. GALE WARNINGS ARE IN EFFECT FOR LAKE ERIE LAKE ONTARIO AND FOR GEORGIAN BAY AND GUSTS TO GALE FORCE ARE ALREADY BEING REPORTED BY THE BUOYS THERE. THE WARNINGS ARE ALSO IN EFFECT FOR THE GREAT LAKES IN THE WESTERLIES DEVELOPING TONIGHT IN THE WAKE OF THE SYSTEM. ALSO..MODERATE SURF CONDITIONS ALONG THE ATLANTIC COAST OF NOVA SCOTIA WILL PRESIST TODAY AND WILL DECAYING 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 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 OVERNIGHT AS HAVE THE INTENSITY OF RETURNS FROM RADARS CLOSEST TO THE STORM. THE CLOUD AROUND THE STORM HAS BECOME VERY ASYMMETRIC MAKING ITS CENTRE SOMEWHAT HARD TO PINPOINT. VISUAL IMAGERY WHICH WILL BE AVAILABLE SHORTLY MAY MAKE THIS JOB EASIER! LITTLE PRECIPITATION IS SHOWING UP SOUTH OF THE STORM DUE TO THE ENTRAINMENT OF DRY AIR IN THE SOUTHWESTERN QUADRANT OF THE STORM COMING DOWN FROM THE APPALACHIANS. B. PROGNOSTIC TROPICAL STORM ISABEL WILL CONTINUE TO WEAKEN THIS MORNING AS IT TRACKS NORTH NORTHWEST TOWARDS THE CANADIAN BORDER. WE FOLLOW NHC TRACK CLOSELY WHICH IS IN FAIRLY GOOD AGREEMENT WITH THE 00Z MODEL RUNS OF THE GEM AND THE GLOBAL ALTHOUGH SLIGHLY TO THE EAST AND SLIGHTLY FASTER. THE SYSTEM IS STILL EXPECTED TO BE TROPICAL IN NATURE AS IT CROSSES EXTREME EASTERN LAKE ERIE AND WESTERN LAKE ERIE AROUND NOON BUT THEREAFTER IT WILL INTERACT WITH THE WEAKENING SHORT WAVE TROUGH TO THE WEST. SOME RE-INTENSIFICATION MAY OCCUR THEREAFTER AS THE SYSTEM TRACKS NORTHWARD UNDER SOMEWHAT LOWERING HEIGHTS BUT THE TROUGH IS ALSO LIFING NORTHWARD AT THIS POINT...SO DEEPENING WILL BE SLOW. AFTER 20 00Z THE SYSTEM WILL HAVE SPED UP SOMEWHAT AND COLD AIR WILL BE FLOODING ITS SOUTHWESTERN FLANK AS IT BEGINS TO MERGE WITH THE EXTRATROPICAL LOW CROSSING NORTHERN ONTARIO. END/PARKES/MCILDOON