Blogging About Hurricane Bill #18

WOCN31 CWHX 230000
HURRICANE BILL INFORMATION STATEMENT ISSUED BY THE CANADIAN
HURRICANE CENTRE OF ENVIRONMENT CANADA AT 9.00 PM ADT SATURDAY
22 AUGUST 2009.

THE NEXT STATEMENT WILL BE ISSUED BY 3.00 AM ADT

...LARGE HURRICANE BILL TO IMPACT NOVA SCOTIA AND PORTIONS OF PEI...

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 9.00 PM ADT... HURRICANE BILL WAS LOCATED NEAR LATITUDE 37.8 N
AND LONGITUDE 68.3 W... ABOUT 376 NAUTICAL MILES OR 696 KM SOUTH
SOUTHWEST OF YARMOUTH NOVA SCOTIA. MAXIMUM SUSTAINED WINDS ARE
ESTIMATED AT 75 KNOTS... 139 KM/H... AND CENTRAL PRESSURE AT 961
MB. BILL IS MOVING NORTH NORTHEAST AT 20 KNOTS... 37 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
ADT MB KTS KMH
AUG 22 9.00 PM 37.8N 68.3W 961 75 139
AUG 23 3.00 AM 40.0N 67.5W 965 75 139
AUG 23 9.00 AM 42.2N 65.4W 965 75 139
AUG 23 3.00 PM 44.2N 62.8W 970 70 130
AUG 23 9.00 PM 46.1N 59.5W 980 65 120 TRANSITIONING
AUG 24 3.00 AM 47.8N 54.9W 985 60 111 TRANSITIONING
AUG 24 9.00 AM 48.7N 50.0W 990 50 93 TRANSITIONING
AUG 24 3.00 PM 49.9N 44.0W 990 50 93 POST-TROPICAL
AUG 24 9.00 PM 50.5N 37.6W 995 45 83 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY
TROPICAL STORM WARNINGS ARE IN EFFECT FOR ATLANTIC COASTAL NOVA
SCOTIA WITH WIND SPEEDS OF 65 KM/H WITH GUSTS TO 90.

HURRICANE WATCHES ARE CONTINUED FOR EASTERN MAINLAND NOVA SCOTIA
AND SOUTHERN CAPE BRETON WITH POTENTIAL WIND SPEEDS OF 120 KM/H
WITH GUSTS TO 140.

TROPICAL STORM WATCHES REMAIN IN EFFECT FOR THE REMAINDER OF NOVA
SCOTIA.. EASTERN PRINCE EDWARD ISLAND AND THE SOUTHERN HALF OF
NEWFOUNDLAND WITH POTENTIAL WIND SPEEDS OF 70 KM/H WITH GUSTS TO 100.

STORM IMPACTS:

RAINFALL...
ON SUNDAY THE CENTRE OF HURRICANE BILL IS EXPECTED TO PASS JUST SOUTH
OF NOVA SCOTIA GIVING RAINFALL AMOUNTS OF 75 TO 100 MM OVER NOVA
SCOTIA..PEI AND NEWFOUNDLAND EXCEPT FOR NOVA SCOTIA WHERE LOCAL
AMOUNTS UP TO 150 MM ARE POSSIBLE. AS A RESULT.. LOCAL FLOODING
CAN BE EXPECTED IN FLOOD-PRONE AREAS. HEAVY DOWNPOURS WILL REDUCE
VISIBILITIES AND LEAD TO STANDING WATER PRESENTING A HAZARD TO
MOTORISTS. HEAVY RAINFALL HAS THE POTENTIAL TO CAUSE STREET
FLOODING..ROAD WASHOUTS AND FLOODED BASEMENTS.

WINDS...
WITH STRONG EAST TO NORTHEASTERLY WINDS OVER NOVA SCOTIA WE ARE
LIKELY TO SEE SOME TREE BRANCHES BREAKING AND POSSIBLE DOWNED
UTILITY LINES. PLEASE STAY TUNED IN THE EVENT THAT THE STORM
BEHAVIOR CHANGES WHERE THE WIND THREAT COULD INCREASE.

COASTAL SURF AND SURGE...
A COMBINATION OF STORM SURGE (OF 0.5 TO 1.0 METRES) AND HEAVY
SURF ALONG THE ATLANTIC COAST OF NOVA SCOTIA AND SOUTHERN
NEWFOUNDLAND (FROM LARGE WAVES RANGING FROM 5 TO 10 METRES)
IS EXPECTED. THESE CONDITIONS MAY LEAD TO SHORELINE EROSION
AND DAMAGE TO DOCKS AS WELL AS GENERATE DANGEROUS RIP CURRENTS
AT LOCAL BEACHES. IT IS WORTHY TO NOTE THAT SPRING TIDES ARE
OCCURRING OVER THE WEEKEND..INCREASING THE THREAT OF
COASTAL FLOODING.

SPECTATORS ARE ADVISED TO KEEP A SAFE DISTANCE FROM THE SHORELINE
DUE TO THE RAPID APPROACH OF LARGE WAVES.

FURTHER DETAILS ARE AVAILABLE IN THE PUBLIC FORECAST BULLETINS.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY
HURRICANE FORCE WIND WARNINGS ARE IN EFFECT NEAR AND SOUTH OF
THE HURRICANE TRACK WITH WIND SPEEDS IN THE RANGE OF 65 TO 75 KNOTS.
STORM WARNINGS ARE IN EFFECT FOR AREAS JUST NORTH OF THE TRACK.
LARGE WAVES GENERATED BY BILL OVER OFFSHORE WATERS WILL RANGE FROM
10 TO 14 METRES SOUTH OF THE TRACK. FURTHER DETAILS ARE AVAILABLE IN
THE LOCAL SEA STATE FORECASTS.

5. TECHNICAL DISCUSSION FOR METEOROLOGISTS

A. ANALYSIS

SATELLITE PICTURES INDICATE THAT THE HIGHEST WINDS IN BILL HAVE
DECREASED.. BUT THE OVERALL CLOUD PATTERN REMAINS VERY IMPRESSIVE.
ACCORDING TO THE NATIONAL HURRICANE CENTRE ASSESSMENT.. THE
INTENSITY IS 75 KNOTS OR 140 KMH.

THE FAVOURABLE FACTORS DRIVING BILL INDICATE THAT IT WILL
MAINTAIN ITS INTENSITY THIS EVENING BUT A GRADUAL WEAKENING IS
ANTICIPATED ON SUNDAY. THE TRACK IS MAINTAINED CLOSE TO THE NATIONAL
HURRICANE CENTRE TRACK AS WELL AS ITS INTENSITY.


B. PROGNOSTIC
HURRICANE BILL WILL MAINTAIN ITS INTENSITY FOR THE NEXT
12 HOURS THEN WEAKEN GRADUALLY AS IT MOVES NORTHEASTWARD
OVER COLDER WATER ON SUNDAY. WE CONTINUE TO FOLLOW
THE NHC TRACK WHICH IS CONSISTENT WITH THE PREVIOUS TRACKS.
OUR CONFIDENCE IN THE TRACK AND INTENSITY IS ENHANCED BY
THE NUMERICAL MODELS CONSISTENT TRACK AND INTENSITY AS WELL.

WE EXPECT EXTRA TROPICAL TRANSITION TO BE DELAYED UNTIL SUNDAY
NIGHT GIVEN THAT THE HURRICANE WILL REMAIN EMBEDDED IN THE AMBIENT
TROPICAL AIRMASS THAT HAS BEEN PRESENT OVER EASTERN CANADA FOR
SEVERAL DAYS. THIS IMPLIES THAT BILL WILL RETAIN TROPICAL
CHARACTERISTICS LONGER THAN USUAL. IT IS ALSO WORTHY OF NOTE THAT
BILL HAS A LARGE CIRCULATION BASED ON QUIKSCAT IMAGERY.

C. PUBLIC WEATHER ASSOCIATED
THE ANTICIPATED TROPICAL NATURE OF BILL AND ITS DELAYED TRANSITION
TO POST TROPICAL WILL LIKELY DICTATE A CLOSE-TO-TRACK RAINFALL
MAXIMUM OVER NOVA SCOTIA.

D. MARINE WEATHER

PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
23/00Z 260 225 145 190 105 105 60 85 85 40 25 30
23/06Z 245 230 140 175 100 105 65 80 75 45 25 35
23/12Z 235 235 140 160 100 105 75 75 70 50 30 40
23/18Z 220 235 160 160 95 110 75 65 55 55 35 35
24/00Z 210 240 180 160 90 115 75 60 45 60 45 0
24/06Z 210 240 180 160 95 95 55 50 0 0 0 0
24/12Z 210 240 180 160 100 75 40 45 0 0 0 0
24/18Z 210 245 180 160 50 35 20 20 0 0 0 0
25/00Z 210 250 180 160 0 0 0 0 0 0 0 0

END ROUSSEL/FOGARTY/BOWYER/CAMPBELL/BORGEL




WOCN31 CWHX 221800
Hurricane Bill information statement issued by the canadian
Hurricane centre of Environment Canada at 3.00 PM ADT Saturday
22 August 2009.

The next statement will be issued by 9.00 PM ADT

...Large hurricane Bill to impact Nova Scotia and portions of pei...

1. Current position, strength, central pressure and motion

At 3.00 PM ADT... Hurricane Bill was located near latitude 36.0 N
And longitude 68.8 W... About 296 nautical miles or 548 km
Northwest of Bermuda . Maximum sustained winds are estimated at
85 knots... 157 km/h... And central pressure at 965 MB. Bill is
Moving north at 20 knots... 37 km/h.

2. Forecast position, central pressure and strength

Date time lat lon MSLP Max wind
ADT MB kts kmh
Aug 22 3.00 PM 36.0N 68.8W 965 85 157
Aug 22 9.00 PM 38.0N 68.0W 965 85 157
Aug 23 3.00 AM 40.1N 67.1W 970 80 148
Aug 23 9.00 AM 42.1N 65.3W 980 75 139
Aug 23 3.00 PM 44.2N 62.6W 983 70 130
Aug 23 9.00 PM 46.1N 59.5W 987 65 120 transitioning
Aug 24 3.00 AM 47.4N 54.8W 990 60 111 transitioning
Aug 24 9.00 AM 48.7N 50.0W 997 50 93 transitioning
Aug 24 3.00 PM 49.5N 43.8W 997 50 93 post-tropical
Aug 24 9.00 PM 50.3N 37.5W 988 45 83 post-tropical
Aug 25 3.00 AM 51.0N 32.5W 993 40 74 post-tropical

3. Public weather impacts and warnings summary
Tropical storm warnings are in effect for Atlantic coastal Nova
Scotia with wind speeds of 65 km/h with gusts to 90.

Tropical storm warnings have been extended to include eastern
mainland Nova Scotia and Southern Cape Breton with wind speeds
Of 65 km/h with gusts to 90.

Hurricane watches are continued for eastern mainland Nova Scotia
And Southern Cape Breton with potential wind speeds of 120 km/h
With gusts to 140.

Tropical storm watches have been issued for the remainder of nova
Scotia.. Eastern Prince Edward Island and the southern half of
Newfoundland with potential wind speeds of 70 km/h with gusts to 100.

Storm impacts:

Rainfall...
On Sunday the centre of hurricane Bill is expected to pass just south
of Nova Scotia giving rainfall amounts of 75 to 100 mm over nova
Scotia..Pei and Newfoundland except for Nova Scotia where local
Amounts up to 150 mm are possible. As a result.. Local flooding
Can be expected in flood-prone areas. Heavy downpours will reduce
visibilities and lead to standing water presenting a hazard to
motorists. Heavy rainfall has the potential to cause street
Flooding..Road washouts and flooded basements.

Winds...
With strong east to northeasterly winds over Nova Scotia we are
likely to see some tree branches breaking and possible downed
Utility lines. Please stay tuned in the event that the storm
Behavior changes where the wind threat could increase.

Coastal surf and surge...
A combination of storm surge and heavy surf along the Atlantic coast
of Nova Scotia and Southern Newfoundland (from large waves
Ranging from 2 to 5 metres) is expected. Waves could reach 8 metres
over Southeastern Newfoundland. These conditions may lead to
shoreline erosion and damage to docks as well as generate dangerous
rip currents at local beaches. It is worthy to note that spring
Tides are occuring over the weekend..Increasing the threat of
Coastal flooding.

Spectators are advised to keep a safe distance from the shoreline
Due to the rapid approach of large waves.

Further details are available in the public forecast bulletins.

4. Marine weather impacts and warnings summary
Hurricane force wind warnings are in effect near and south of
The hurricane track with wind speeds in the range of 65 to 75 knots.
Storm warnings are in effect for areas just north of the track.
Large waves generated by Bill over offshore waters will range from
10 to 14 metres south of the track. Further details are available in
the local sea state forecasts.

5. Technical discussion for meteorologists

A. Analysis

Satellite pictures indicate that the highest winds in Bill have
Decreased.. But the overall cloud pattern remains very impressive.
According to the national hurricane centre assessment.. The
Intensity is 85 knots or 157 kmh.

An airforce plane is scheduled to fly through Bill later today
For more accurate data to determine the latest intensity and wind
radii. The favourable factors driving Bill indicate that it will
maintain its intensity today but a gradual weakening is anticipated
tonight and Sunday. The track is maintained close to the national
hurricane centre track as well as its intensity.


B. Prognostic
Hurricane Bill will maintain its intensity for the next
12 hours then weaken gradually as it moves northeastward
Over colder water on Sunday. We continue to follow
The nhc track which is consistent with the previous tracks.
Our confidence in the track and intensity is enhanced by
The numerical models consistent track and intensity as well.

We expect extra tropical transition to be delayed until Sunday
Night given that the hurricane will remain embedded in the ambient
tropical airmass that has been present over Eastern Canada for
several days. This implies that Bill will retain tropical
characteristics longer than usual. It is also worthy of note that
Bill has a large circulation based on quikscat imagery.

C. Public weather associated
The anticipated tropical nature of Bill and its delayed transition
To post tropical will likely dictate a close-to-track rainfall
maximum over Nova Scotia.

D. Marine weather

Predicted wind radii (NM)
Time gales storms hurricane
Ne se sw nw ne se sw nw ne se sw nw
22/18Z 265 215 140 190 105 105 55 80 85 40 25 30
23/00Z 260 225 145 190 105 105 60 85 85 40 25 30
23/06Z 245 230 140 175 100 105 65 80 75 45 25 35
23/12Z 235 235 140 160 100 105 75 75 70 50 30 40
23/18Z 220 235 160 160 95 110 75 65 55 55 35 35
24/00Z 210 240 180 160 90 115 75 60 45 60 45 30
24/06Z 210 240 180 160 95 95 55 50 0 0 0 0
24/12Z 210 240 180 160 100 75 40 45 0 0 0 0
24/18Z 210 245 180 160 50 35 20 20 0 0 0 0
25/00Z 210 250 180 160 0 0 0 0 0 0 0 0
25/06Z 210 250 180 160 0 0 0 0 0 0 0 0


End roussel/fogarty/bowyer