Blogging About Hurricane Bill #11

WOCN31 CWHX 211800
Hurricane Bill information statement issued by the canadian
Hurricane centre of Environment Canada at 3.00 PM ADT Friday
21 August 2009.

The next statement will be issued by 9.00 PM ADT

... Bill will move into the Maritimes on Sunday and into
Newfoundland on Monday...

1. Current position, strength, central pressure and motion

At 3.00 PM ADT... Hurricane Bill was located near latitude 28.5 N
And longitude 66.8 W... About 255 nautical miles or 475 km
South southwest of Bermuda. Maximum sustained winds are
Estimated at 95 knots... 176 km/h... And central pressure at 957
MB. Bill is moving north northwest at 16 knots... 30 km/h.

2. Forecast position, central pressure and strength

Date time lat lon MSLP Max wind
ADT MB kts kmh
Aug 21 3.00 PM 28.5N 66.8W 957 95 176
Aug 22 3.00 AM 31.2N 68.2W 957 100 185
Aug 22 3.00 PM 34.8N 68.6W 965 95 176
Aug 23 3.00 AM 39.0N 67.2W 970 90 167 transitioning
Aug 23 3.00 PM 43.2N 63.7W 976 80 148 transitioning
Aug 24 3.00 AM 46.7N 57.2W 983 70 130 transitioning
Aug 24 3.00 PM 49.6N 47.9W 987 60 111 post-tropical
Aug 25 3.00 AM 51.5N 37.2W 990 55 102 post-tropical
Aug 25 3.00 PM 54.0N 26.8W 992 45 83 post-tropical
Aug 26 3.00 AM 56.5N 16.2W 996 35 65 post-tropical

3. Public weather impacts and warnings summary
At this point it is too early for warnings to be issued as Bill
remains well to our south.

The main rainfall associated with Bill will move into Nova Scotia..
Southern New Brunswick..And Prince Edward Island on Sunday. Rainfall
amounts of up to 100 to 150 mm will impact these areas with lesser
amounts for Northern New Brunswick. The rain will spread into
Newfoundland late Sunday night into Monday..Giving upwards of 100 mm.

Winds possibly exceeding 90 km/h will impact Nova Scotia on
Sunday..Mainly along the coast. For Monday winds possibly
Exceeding 120 km/h will affect coastal areas of Southeastern
Newfoundland. Warnings for wind and rainfall amounts will be
Issued tonight or tomorrow.

Swell from hurricane Bill will arrive along the Atlantic coast
Of Nova Scotia on Saturday. Swell heights near 2 m
Will generate rough surf and hazardous rip currents along some
beaches. Breaking wave heights on the shoreline may exceed 3 m
Along parts of the Atlantic coast of Nova Scotia Saturday.

Significant waves heights of up to 12 metres will
Move onto the Scotian shelf on Sunday and wave of up 10 metres will
move onto the Grand Banks on Monday. For Atlantic coastal nova
Scotia strong surf and waves possibly exceeding 6 to 8 m will
Impact certain areas. For coastal Newfoundland waves also may
Exceed 6 to 8 m..Especially south to southwest facing coastlines
From the Burin Peninsula to Cape Race.

Residents are advised to exercise caution and to stay well away
From the shore.

Some of the largest spring tides of the year will be occurring
This weekend. This may combine with large waves and storm surge
Over the Atlantic coast of Eastern Nova Scotia late on Sunday..As
well as the South Coast of Newfoundland overnight into Monday.

4. Marine weather impacts and warnings summary
Given the current CHC track hurricane Bill is expected to begin
To impact maritime marine areas Saturday night and Newfoundland
marine areas Sunday night. Winds will rapidly increase on Sunday
Over southern maritime marine areas starting over southwestern
Areas. Over Southern Newfoundland waters winds will rapidly
Increase from west to east Sunday night and Monday. It
Appears very likely that hurricane and storm force winds will
Spread over portions of the southern marine areas of the
Maritimes and Newfoundland as a result of Bill. Marine warnings
Will be issued tonight or tomorrow.

5. Technical discussion for meteorologists

A. Analysis
Following nhc on position and intensity.

Bill's satellite signature has deteriorated since yesterday.
Southerly shear is indicated and the eye is less distinct. Ssmis
imagery indicates either a convective band around a weakened eye
Or an eyewall replacement cycle. Currently it looks like some
Variability in the intensity for the next 24 hours..Followed by
gradual weakening as it moves towards our waters.

B. Prognostic

No change in forecast philosophy for the next 60 hours..But tweaking
track slightly northward as it crosses Newfoundland to account for
Some model guidance showing a more northerly track..And also to
address the chance of significant storm surge and wave activity
For the south coast marine areas.

Bill is tracking northwestward south of Bermuda. Bill is expected
To begin a gradual turn north-northwest today and northward on
Saturday in response to a deep-layer trough forecast to move over
The Eastern United States and an upper-level ridge building
Over the Atlantic. On Sunday Bill will curve and accelerate
northeastward ahead of the trough. Track guidance is tightly
clustered for the first couple of days but then becomes divergent
On both direction and speed later in the forecast period.

Cyclone phase space diagrams indicate Bill will begin to undergo
extra-tropical transition on the 23rd and will be completed
On the 24th.

C. Public weather

As the storm begins transitioning on the 23rd we should be seeing
The rain shield extending to the left and forward of track and
The wind field starting to expand away from the storm centre.
For Northern New Brunswick a predecessor rain band associated with
the hurricane will form tonight and pulses of rain associated
With it may give up to 50 mm into Sunday.

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 250 200 120 200 130 110 60 130 100 45 30 90
22/06Z 250 200 120 200 130 110 60 130 100 45 30 90
22/18Z 250 225 135 190 115 100 60 105 95 45 25 75
23/06Z 245 225 135 190 110 100 65 80 75 50 20 40
23/18Z 235 225 160 190 105 115 85 80 60 50 15 15
24/06Z 230 255 170 150 115 130 90 75 35 35 5 5
24/18Z 235 260 145 120 140 140 85 60 0 0 0 0
25/06Z 245 260 155 120 150 150 95 60 0 0 0 0
25/18Z 255 260 165 120 0 0 0 0 0 0 0 0
26/06Z 265 260 175 120 0 0 0 0 0 0 0 0

End mercer/bowyer




WOCN31 CWHX 211800
HURRICANE BILL INFORMATION STATEMENT ISSUED BY THE CANADIAN
HURRICANE CENTRE OF ENVIRONMENT CANADA AT 3.00 PM ADT FRIDAY
21 AUGUST 2009.

THE NEXT STATEMENT WILL BE ISSUED BY 9.00 PM ADT

... BILL WILL MOVE INTO THE MARITIMES ON SUNDAY AND INTO
NEWFOUNDLAND ON MONDAY...

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 3.00 PM ADT... HURRICANE BILL WAS LOCATED NEAR LATITUDE 28.5 N
AND LONGITUDE 66.8 W... ABOUT 255 NAUTICAL MILES OR 475 KM
SOUTH SOUTHWEST OF BERMUDA. MAXIMUM SUSTAINED WINDS ARE
ESTIMATED AT 95 KNOTS... 176 KM/H... AND CENTRAL PRESSURE AT 957
MB. BILL IS MOVING NORTH NORTHWEST AT 16 KNOTS... 30 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
ADT MB KTS KMH
AUG 21 3.00 PM 28.5N 66.8W 957 95 176
AUG 22 3.00 AM 31.2N 68.2W 957 100 185
AUG 22 3.00 PM 34.8N 68.6W 965 95 176
AUG 23 3.00 AM 39.0N 67.2W 970 90 167 TRANSITIONING
AUG 23 3.00 PM 43.2N 63.7W 976 80 148 TRANSITIONING
AUG 24 3.00 AM 46.7N 57.2W 983 70 130 TRANSITIONING
AUG 24 3.00 PM 49.6N 47.9W 987 60 111 POST-TROPICAL
AUG 25 3.00 AM 51.5N 37.2W 990 55 102 POST-TROPICAL
AUG 25 3.00 PM 54.0N 26.8W 992 45 83 POST-TROPICAL
AUG 26 3.00 AM 56.5N 16.2W 996 35 65 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY
AT THIS POINT IT IS TOO EARLY FOR WARNINGS TO BE ISSUED AS BILL
REMAINS WELL TO OUR SOUTH.

THE MAIN RAINFALL ASSOCIATED WITH BILL WILL MOVE INTO NOVA SCOTIA..
SOUTHERN NEW BRUNSWICK..AND PRINCE EDWARD ISLAND ON SUNDAY. RAINFALL
AMOUNTS OF UP TO 100 TO 150 MM WILL IMPACT THESE AREAS WITH LESSER
AMOUNTS FOR NORTHERN NEW BRUNSWICK. THE RAIN WILL SPREAD INTO
NEWFOUNDLAND LATE SUNDAY NIGHT INTO MONDAY..GIVING UPWARDS OF 100 MM.

WINDS POSSIBLY EXCEEDING 90 KM/H WILL IMPACT NOVA SCOTIA ON
SUNDAY..MAINLY ALONG THE COAST. FOR MONDAY WINDS POSSIBLY
EXCEEDING 120 KM/H WILL AFFECT COASTAL AREAS OF SOUTHEASTERN
NEWFOUNDLAND. WARNINGS FOR WIND AND RAINFALL AMOUNTS WILL BE
ISSUED TONIGHT OR TOMORROW.

SWELL FROM HURRICANE BILL WILL ARRIVE ALONG THE ATLANTIC COAST
OF NOVA SCOTIA ON SATURDAY. SWELL HEIGHTS NEAR 2 M
WILL GENERATE ROUGH SURF AND HAZARDOUS RIP CURRENTS ALONG SOME
BEACHES. BREAKING WAVE HEIGHTS ON THE SHORELINE MAY EXCEED 3 M
ALONG PARTS OF THE ATLANTIC COAST OF NOVA SCOTIA SATURDAY.

SIGNIFICANT WAVES HEIGHTS OF UP TO 12 METRES WILL
MOVE ONTO THE SCOTIAN SHELF ON SUNDAY AND WAVE OF UP 10 METRES WILL
MOVE ONTO THE GRAND BANKS ON MONDAY. FOR ATLANTIC COASTAL NOVA
SCOTIA STRONG SURF AND WAVES POSSIBLY EXCEEDING 6 TO 8 M WILL
IMPACT CERTAIN AREAS. FOR COASTAL NEWFOUNDLAND WAVES ALSO MAY
EXCEED 6 TO 8 M..ESPECIALLY SOUTH TO SOUTHWEST FACING COASTLINES
FROM THE BURIN PENINSULA TO CAPE RACE.

RESIDENTS ARE ADVISED TO EXERCISE CAUTION AND TO STAY WELL AWAY
FROM THE SHORE.

SOME OF THE LARGEST SPRING TIDES OF THE YEAR WILL BE OCCURRING
THIS WEEKEND. THIS MAY COMBINE WITH LARGE WAVES AND STORM SURGE
OVER THE ATLANTIC COAST OF EASTERN NOVA SCOTIA LATE ON SUNDAY..AS
WELL AS THE SOUTH COAST OF NEWFOUNDLAND OVERNIGHT INTO MONDAY.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY
GIVEN THE CURRENT CHC TRACK HURRICANE BILL IS EXPECTED TO BEGIN
TO IMPACT MARITIME MARINE AREAS SATURDAY NIGHT AND NEWFOUNDLAND
MARINE AREAS SUNDAY NIGHT. WINDS WILL RAPIDLY INCREASE ON SUNDAY
OVER SOUTHERN MARITIME MARINE AREAS STARTING OVER SOUTHWESTERN
AREAS. OVER SOUTHERN NEWFOUNDLAND WATERS WINDS WILL RAPIDLY
INCREASE FROM WEST TO EAST SUNDAY NIGHT AND MONDAY. IT
APPEARS VERY LIKELY THAT HURRICANE AND STORM FORCE WINDS WILL
SPREAD OVER PORTIONS OF THE SOUTHERN MARINE AREAS OF THE
MARITIMES AND NEWFOUNDLAND AS A RESULT OF BILL. MARINE WARNINGS
WILL BE ISSUED TONIGHT OR TOMORROW.

5. TECHNICAL DISCUSSION FOR METEOROLOGISTS

A. ANALYSIS
FOLLOWING NHC ON POSITION AND INTENSITY.

BILL'S SATELLITE SIGNATURE HAS DETERIORATED SINCE YESTERDAY.
SOUTHERLY SHEAR IS INDICATED AND THE EYE IS LESS DISTINCT. SSMIS
IMAGERY INDICATES EITHER A CONVECTIVE BAND AROUND A WEAKENED EYE
OR AN EYEWALL REPLACEMENT CYCLE. CURRENTLY IT LOOKS LIKE SOME
VARIABILITY IN THE INTENSITY FOR THE NEXT 24 HOURS..FOLLOWED BY
GRADUAL WEAKENING AS IT MOVES TOWARDS OUR WATERS.

B. PROGNOSTIC

NO CHANGE IN FORECAST PHILOSOPHY FOR THE NEXT 60 HOURS..BUT TWEAKING
TRACK SLIGHTLY NORTHWARD AS IT CROSSES NEWFOUNDLAND TO ACCOUNT FOR
SOME MODEL GUIDANCE SHOWING A MORE NORTHERLY TRACK..AND ALSO TO
ADDRESS THE CHANCE OF SIGNIFICANT STORM SURGE AND WAVE ACTIVITY
FOR THE SOUTH COAST MARINE AREAS.

BILL IS TRACKING NORTHWESTWARD SOUTH OF BERMUDA. BILL IS EXPECTED
TO BEGIN A GRADUAL TURN NORTH-NORTHWEST TODAY AND NORTHWARD ON
SATURDAY IN RESPONSE TO A DEEP-LAYER TROUGH FORECAST TO MOVE OVER
THE EASTERN UNITED STATES AND AN UPPER-LEVEL RIDGE BUILDING
OVER THE ATLANTIC. ON SUNDAY BILL WILL CURVE AND ACCELERATE
NORTHEASTWARD AHEAD OF THE TROUGH. TRACK GUIDANCE IS TIGHTLY
CLUSTERED FOR THE FIRST COUPLE OF DAYS BUT THEN BECOMES DIVERGENT
ON BOTH DIRECTION AND SPEED LATER IN THE FORECAST PERIOD.

CYCLONE PHASE SPACE DIAGRAMS INDICATE BILL WILL BEGIN TO UNDERGO
EXTRA-TROPICAL TRANSITION ON THE 23RD AND WILL BE COMPLETED
ON THE 24TH.

C. PUBLIC WEATHER

AS THE STORM BEGINS TRANSITIONING ON THE 23RD WE SHOULD BE SEEING
THE RAIN SHIELD EXTENDING TO THE LEFT AND FORWARD OF TRACK AND
THE WIND FIELD STARTING TO EXPAND AWAY FROM THE STORM CENTRE.
FOR NORTHERN NEW BRUNSWICK A PREDECESSOR RAIN BAND ASSOCIATED WITH
THE HURRICANE WILL FORM TONIGHT AND PULSES OF RAIN ASSOCIATED
WITH IT MAY GIVE UP TO 50 MM INTO SUNDAY.

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 250 200 120 200 130 110 60 130 100 45 30 90
22/06Z 250 200 120 200 130 110 60 130 100 45 30 90
22/18Z 250 225 135 190 115 100 60 105 95 45 25 75
23/06Z 245 225 135 190 110 100 65 80 75 50 20 40
23/18Z 235 225 160 190 105 115 85 80 60 50 15 15
24/06Z 230 255 170 150 115 130 90 75 35 35 5 5
24/18Z 235 260 145 120 140 140 85 60 0 0 0 0
25/06Z 245 260 155 120 150 150 95 60 0 0 0 0
25/18Z 255 260 165 120 0 0 0 0 0 0 0 0
26/06Z 265 260 175 120 0 0 0 0 0 0 0 0

END MERCER/BOWYER

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000
WTNT33 KNHC 211735
TCPAT3
BULLETIN
HURRICANE BILL INTERMEDIATE ADVISORY NUMBER 25A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
200 PM AST FRI AUG 21 2009

...HURRICANE BILL EXPECTED TO TURN TOWARD THE NORTH-NORTHWEST LATER
TODAY...

A TROPICAL STORM WARNING AND A HURRICANE WATCH ARE IN EFFECT FOR
BERMUDA.

INTERESTS ALONG THE COAST OF NEW ENGLAND AND IN THE CANADIAN
MARITIMES SHOULD MONITOR THE PROGRESS OF BILL.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER
SERVICE FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR
AREA OUTSIDE OF THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR NATIONAL METEOROLOGICAL SERVICE.

AT 200 PM AST...1800 UTC...THE CENTER OF HURRICANE BILL WAS LOCATED
NEAR LATITUDE 28.5 NORTH...LONGITUDE 66.8 WEST OR ABOUT 290 MILES...
465 KM...SOUTH-SOUTHWEST OF BERMUDA AND ABOUT 695 MILES...1115 KM...
SOUTHEAST OF CAPE HATTERAS NORTH CAROLINA.

BILL IS MOVING TOWARD THE NORTHWEST NEAR 18 MPH...30 KM/HR. A
GRADUAL TURN TO THE NORTH-NORTHWEST AND THEN NORTH IS EXPECTED
LATER TODAY AND SATURDAY. ON THE FORECAST TRACK...THE CORE OF
HURRICANE BILL IS EXPECTED TO PASS OVER THE OPEN WATERS BETWEEN
BERMUDA AND THE EAST COAST OF THE UNITED STATES ON SATURDAY.

DATA FROM AN AIR FORCE PLANE CURRENTLY INVESTIGATING BILL SUGGEST
THAT THE MAXIMUM SUSTAINED WINDS HAVE DECREASED TO NEAR 110
MPH...175 KM/HR...WITH HIGHER GUSTS. BILL IS NOW A CATEGORY TWO
HURRICANE ON THE SAFFIR-SIMPSON SCALE. SOME FLUCTUATIONS IN
INTENSITY ARE LIKELY TODAY AND SATURDAY.

BILL REMAINS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND
OUTWARD UP TO 115 MILES...185 KM...FROM THE CENTER...AND TROPICAL
STORM FORCE WINDS EXTEND OUTWARD UP TO 290 MILES...465 KM. RADAR
FROM BERMUDA SHOWS MORE RAINBANDS APPROACHING THE ISLAND.

THE LATEST MINIMUM CENTRAL PRESSURE RECENTLY REPORTED BY AN AIR
FORCE HURRICANE HUNTER AIRCRAFT IS 957 MB...28.26 INCHES.

BILL IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF 1 TO 3
INCHES OVER BERMUDA...WITH MAXIMUM AMOUNTS OF 5 INCHES.

THE BERMUDA WEATHER SERVICE FORECAST THAT THE STORM TIDE WILL RAISE
WATER LEVELS BY AS MUCH AS 3 FEET ABOVE GROUND LEVEL ALONG THE
COAST...ALONG WITH LARGE AND DANGEROUS BATTERING WAVES...IN ADVANCE
OF BILL.

LARGE SWELLS GENERATED BY THIS HURRICANE ARE AFFECTING PUERTO
RICO...HISPANIOLA...THE BAHAMAS...AND BERMUDA...AND SHOULD BEGIN
AFFECTING MOST OF THE U.S. EAST COAST AND THE ATLANTIC MARITIMES OF
CANADA DURING THE NEXT DAY OR TWO. THESE SWELLS WILL LIKELY CAUSE
EXTREMELY DANGEROUS SURF AND LIFE-THREATENING RIP CURRENTS.

...SUMMARY OF 200 PM AST INFORMATION...
LOCATION...28.5N 66.8W
MAXIMUM SUSTAINED WINDS...110 MPH
PRESENT MOVEMENT...NORTHWEST OR 325 DEGREES AT 18 MPH
MINIMUM CENTRAL PRESSURE...957 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
500 PM AST.

$$
FORECASTER AVILA