WOCN31 CWHX 211800 HURRICANE HELENE INFORMATION STATEMENT ISSUED BY THE CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 3.30 PM NDT THURSDAY 21 SEPTEMBER 2006. THE NEXT STATEMENT WILL BE ISSUED BY 9.30 PM NDT ... GALES FROM HELENE MAY MISS SOUTHEASTERN GRAND BANKS... 1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION AT 3.30 PM NDT... HURRICANE HELENE WAS LOCATED NEAR LATITUDE 30.5 N AND LONGITUDE 57.0 W... ABOUT 405 NAUTICAL MILES OR 755 KM EAST SOUTHEAST OF BERMUDA . MAXIMUM SUSTAINED WINDS ARE ESTIMATED AT 70 KNOTS... 130 KM/H... AND CENTRAL PRESSURE AT 970 MB. HELENE IS MOVING NORTH NORTHEAST AT 13 KNOTS... 24 KM/H. 2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH DATE TIME LAT LON MSLP MAX WIND NDT MB KTS KMH SEP 21 3.30 PM 30.5N 57.0W 970 70 130 SEP 22 3.30 AM 33.4N 55.8W 970 70 130 SEP 22 3.30 PM 36.1N 52.8W 972 70 130 SEP 23 3.30 AM 38.8N 48.3W 973 70 130 SEP 23 3.30 PM 41.8N 42.9W 970 65 120 POST-TROPICAL SEP 24 3.30 AM 44.4N 37.9W 968 60 111 POST-TROPICAL SEP 24 3.30 PM 49.0N 32.0W 968 60 111 POST-TROPICAL 3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY ROUGH SURF FROM 2 TO 3 METRE BREAKING SWELLS COULD AFFECT THE SOUTH COAST OF NEWFOUNDLAND ON FRIDAY AND SATURDAY...PARTICULARLY THE EASTERN SECTIONS BETWEEN THE BURIN AND AVALON PENINSULAS. OTHERWISE, NO IMPACTS OVER CANADIAN LAND REGIONS ARE EXPECTED. 4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY IT APPEARS THAT HURRICANE HELENE MAY TURN MORE NORTHEASTWARD BEFORE IT PUSHES NORTH TO NORTHEAST GALES INTO THE OUTER REACHES OF THE SOUTHEASTERN GRAND BANKS. HOWEVER MARINERS ARE ADVISED TO MONITOR FUTURE FORECASTS IN THE EVENT THAT WARNINGS ARE REQUIRED. 5. TECHNICAL DISCUSSION A. ANALYSIS SATELLITE IMAGERY SHOWS HELENE MOVING ALMOST DUE NORTHWARD OVER THE LAST FEW HOURS. CLOUD COVER IS OBSCURING THE EYE HOWEVER THERE IS SUFFICIENT ROTATION IN THE OVERALL STORM TO MAKE A REASONABLE ESTIMATE OF THE CENTRE. WE ARE FOLLOWING THE NHC GUIDANCE REGARDING INTENSITY. B. PROGNOSTIC THE STORM SHOULD BEGIN A DEFINITE TURN NORTHEASTWARD OVER THE NEXT 24 HOURS AS IT COMES UNDER THE INFLUENCE OF THE APPROACHING TROUGH THAT WE HAVE BEEN TALKING ABOUT. BEYOND THAT WE HAVE PUSHED OUR TRACK FARTHER EASTWARD FROM OUR PREVIOUS TRACK BASED ON THE PREPONDERANCE OF DYNAMICAL MODELS... MANY OF WHICH TAKE HELENE ON AN ENE TRACK BETWEEN 36-60 HOURS. THE UKMET REMAINS THE STRONGEST EASTERNMOST OUTLIER AND KEEPS HELENE FROM EVEN PASSING NORTH OF 40N. THE GFDL REMAINS THE WESTERNMOST SOLUTION BEING A BIT WEST OF OUR PREVIOUS TRACK. OUR TRACK REFLECTS THE NHC SOLUTION WITH RECOGNITION THAT IT MAY STILL HAVE A WESTERN BIAS AND WE WOULD NOT BE SURPRISED TO SEE THE STORM TURN EVEN FARTHER RIGHT OF OUR TRACK.THE MAIN IMPACT ON CANADA WITH THIS FORECAST WOULD BE TO DIMINISH THE EXPECTATION OF GALES IN THE SOUTHEASTERN GRAND BANKS. DESPITE THE DEEPENING BEYOND 36 HRS SHOWN ON THE CANADIAN MODEL IT APPEARS THAT THERE IS LITTLE INTERACTION WITH THE TROUGH OTHER THAN INCREASING SHEER AND BAROCLINICITY OVER HELENE. ALL MODELS SHOW THE FINAL STORM IN 3-5 DAYS TO BE A MAJOR MID-LATITUDE LOW HOWEVER THE EXACT NATURE OF THE BAROCLINIC FORCING REMAINS UNCLEAR. FSU CPS DIAGNOSTICS WERE UNAVAILABLE PRIOR TO FORECAST TIME. C. PUBLIC WEATHER SEE ABOVE. D. MARINE WEATHER PREDICTED WIND RADII (NM) TIME GALES STORMS HURRICANE NE SE SW NW NE SE SW NW NE SE SW NW 21/18Z 180 180 180 180 70 70 60 60 30 30 25 25 22/06Z 180 180 180 180 70 70 60 60 30 30 25 25 22/18Z 180 180 180 180 70 70 60 60 30 30 25 25 23/06Z 180 180 210 180 70 70 60 60 30 30 25 25 23/18Z 210 210 240 210 80 90 90 70 25 25 10 10 24/06Z 215 240 270 210 100 120 120 80 0 0 0 0 24/18Z 240 300 300 210 120 150 150 90 0 0 0 0 END BOWYER