Hanna, now a Tropical Storm, sets sights on East Coast

WOCN31 CWHX 041800
TROPICAL STORM HANNA INFORMATION STATEMENT ISSUED BY THE
CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 3.00 PM ADT
THURSDAY 04 SEPTEMBER 2008.

THE NEXT STATEMENT WILL BE ISSUED BY 9.00 PM ADT

... HANNA TO AFFECT MARITIMES ON SUNDAY...

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 3.00 PM ADT... TROPICAL STORM HANNA WAS LOCATED NEAR LATITUDE
25.1 N AND LONGITUDE 74.2 W... ABOUT 175 NAUTICAL MILES OR 330 KM
EAST OF NASSAU BAHAMAS. MAXIMUM SUSTAINED WINDS ARE ESTIMATED AT 55
KNOTS... 102 KM/H... AND CENTRAL PRESSURE AT 989 MB. HANNA IS
MOVING NORTHWEST AT 12 KNOTS... 22 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
ADT MB KTS KMH
SEP 04 3.00 PM 25.1N 74.2W 989 55 102
SEP 05 3.00 AM 27.8N 76.3W 990 55 102
SEP 05 3.00 PM 30.4N 77.8W 990 60 111
SEP 06 3.00 AM 33.6N 77.8W 989 65 120
SEP 06 3.00 PM 37.1N 75.7W 994 55 102 TRANSITIONING
SEP 07 3.00 AM 41.0N 71.7W 997 50 93 TRANSITIONING
SEP 07 3.00 PM 44.6N 66.2W 1000 45 83 POST-TROPICAL
SEP 08 3.00 AM 47.8N 59.2W 1000 45 83 POST-TROPICAL
SEP 08 3.00 PM 50.2N 50.8W 1002 40 74 POST-TROPICAL
SEP 09 3.00 AM 51.4N 41.8W 1002 40 74 POST-TROPICAL
SEP 09 3.00 PM 52.0N 32.5W 1002 40 74 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY
TOO EARLY FOR ANY SPECIFIC DETAILS...BUT IT APPEARS HANNA MAY BRING
WIND AND RAIN TO ATLANTIC CANADA ON SUNDAY AND MONDAY. LONG-PERIOD
WAVES/SURF FROM HANNA AND ANOTHER DISTANT STORM..IKE..SHOULD BEGIN
TO AFFECT THE MARITIMES ON SATURDAY.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY
AGAIN TOO EARLY FOR SPECIFIC DETAILS... BUT BASED ON LATEST
PROJECTIONS HANNA MAY BRING GALES TO MARITIME WATERS ON SUNDAY AND
INTO NEWFOUNDLAND WATERS ON MONDAY. LONG PERIOD SWELL FROM HANNA
AND DISTANT HURRICANE IKE SHOULD BEGIN TO REACH MARITIME WATERS
ON SATURDAY.

5. TECHNICAL DISCUSSION FOR METEOROLOGISTS

A. ANALYSIS
VISIBLE SATELLITE IMAGERY OF HANNA INDICATES A RATHER SUB-TROPICAL
APPEARANCE WITH DRIER AIR INTRUDING INTO THE STORM WHICH SEEMS TO BE
INHIBITING CONVECTION NEAR THE STORM CORE. NOT SURPRISINGLY NHC HAS
REDUCED INITIAL INTENSITY TO 55 KNOTS BASED ON THIS AND FLIGHT LEVEL
WINDS MEASURED DURING A MORNING FLIGHT RECON. HOWEVER NEW CONVECTION
HAS RECENTLY BLOSSOMED IN THE WESTERN SEMICIRCLE AND MW IMAGERY IS
SHOWING SOME IMPROVED ORGANISATION ON THE WEST SIDE AS WELL.

B. PROGNOSTIC
DESPITE THE SLIGHT WEAKENING AND SOMEWHAT UNFAVOURABLE CONDITIONS
FOR STRENGTHENING IN THE SHORT TERM..HANNA IS EXPECTED TO SOON MOVE
INTO A MORE FAVOURABLE SHEAR ENVIRONMENT AND IS STILL EXPECTED TO
INTENSIFY INTO A MARGINAL HURRICANE BEFORE MAKING LANDFALL ALONG THE
NORTH CAROLINA COAST SATURDAY MORNING...WITH POST-TROPICAL TRANSITION
AND WEAKENING OF HANNA WILL LIKELY BEGIN THEREAFTER. PHASE SPACE
PROGNOSTICS GENERALLY AGREE TRANSITIONING WILL TAKE PLACE SOMETIME
BETWEEN THE 6TH TO 7TH...IMPLYING HANNA WILL VERY LIKELY BE
POST-TROPICAL BY THE TIME IT REACHES THE MARITIMES.

CHC TRACK STILL EXPLICITLY FOLLOWING NHC TRACK AT THIS POINT...AND
LATEST TRACK SCENARIO IS UNCHANGED FROM PREVIOUS BULLETIN. MODEL
GUIDANCE ARE ALL SIMILAR IN CURVING HANNA TO THE NORTHEAST AFTER
BRUSHING THE EASTERN US SEABOARD ON SATURDAY. LATEST MODEL SOLUTIONS
ARE NOW SLIGHTLY BETTER CLUSTERED IN BOTH SPEED AND TRACK IN TAKING
HANNA ACROSS THE SOUTHERN MARITIMES ON SUNDAY...HOWEVER EVEN THESE
SLIGHT DIFFERENCES IN TRACK COULD BRING SIGNIFICANT DIFFERENCES
WITH RESPECT TO DISTRIBUTION OF MAXIMUM WINDS AND RAINFALL.

C. PUBLIC WEATHER
NIL.

D. MARINE WEATHER
NIL.

PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
04/18Z 275 200 30 230 90 0 0 90 0 0 0 0
05/06Z 275 200 30 230 90 0 0 90 0 0 0 0
05/18Z 250 200 60 230 90 25 0 80 0 0 0 0
06/06Z 230 190 65 165 75 50 0 75 50 0 0 0
06/18Z 200 200 50 100 75 75 0 0 0 0 0 0
07/06Z 175 220 50 45 60 60 0 0 0 0 0 0
07/18Z 70 225 50 0 0 0 0 0 0 0 0 0
08/06Z 50 210 50 0 0 0 0 0 0 0 0 0
08/18Z 40 200 50 0 0 0 0 0 0 0 0 0
09/06Z 40 200 50 0 0 0 0 0 0 0 0 0
09/18Z 40 200 50 0 0 0 0 0 0 0 0 0


WIND RADII OF TRANSITIONING SYSTEM REFLECTS ENVIRONMENT PLUS
TROPICAL SYSTEM.

END BORGEL/FOGARTY