Friday, August 28, 2009

Tropical Storm Danny #5




WOCN31 CWHX 290000
Tropical storm Danny information statement issued by the
Canadian hurricane centre of Environment Canada at 9.00 PM ADT
Friday 28 August 2009.

The next statement will be issued by 3.00 AM ADT

...Danny to bring rain to Atlantic Canada...

1. Current position, strength, central pressure and motion

At 9.00 PM ADT... Tropical storm Danny was located near latitude
30.9 N and longitude 75.1 W... About 260 nautical miles or 480 km
south of Cape Hatteras, nc. Maximum sustained winds are estimated
At 35 knots... 65 km/h... And central pressure at 1006 MB. Danny is
Moving north at 5 knots... 9 km/h.

2. Forecast position, central pressure and strength

Date time lat lon MSLP Max wind
ADT MB kts kmh
Aug 28 9.00 PM 30.9N 75.1W 1006 35 65
Aug 29 9.00 AM 35.1N 74.9W 1003 40 74
Aug 29 9.00 PM 40.0N 71.0W 1002 40 74
Aug 30 9.00 AM 44.6N 65.0W 1002 40 74 transitioning
Aug 30 9.00 PM 47.9N 58.7W 1002 40 74 post-tropical
Aug 31 9.00 AM 49.9N 52.2W 1003 40 74 post-tropical
Aug 31 9.00 PM 51.3N 45.6W 1003 40 74 post-tropical
Sep 01 9.00 AM 52.5N 38.8W 1003 40 74 post-tropical

3. Public weather impacts and warnings summary
Rain should move into the Maritimes later on Saturday and
Pull out Sunday afternoon. Model guidance shows amounts
Of near 70 mm possible for Southwest Nova Scotia and southern
New Brunswick...With amounts of 90 or higher possible locally.
Rainfall warnings will likely be issued by 5 AM Saturday for parts of
Nova Scotia and Southern New Brunswick..And possibly for
Prince Edward Island. Currently wind warnings are not expected.
However the highest winds will be expected south of the storm track.
Heavy swell associated with the storm may cause significant surf
And rip tides along the Atlantic coast of Nova Scotia. Caution
Should be observed by people near the coast.

The rain will move into Southwestern Newfoundland on Sunday. Rainfall
amounts may reach or exceed 50 mm locally. Warnings may be issued as
appropriate Saturday or later.

4. Marine weather impacts and warnings summary
Danny will weaken as it moves through canadian waters.
It has now become less likely that storm force winds will occur
Upon entering the marine district. The winds will diminish as it
continues to move over colder waters. Gale warnings have been
Posted for western Maritimes waters and may be extended to
Eastern maritime waters tonight. If necessary warnings should be
issued overnight tonight or later for Newfoundland waters.

5. Technical discussion for meteorologists

A. Analysis
From the visible satellite images this evening Danny's centre is
still displaced west of the convection. A hurricane hunter aircraft
Measured a 33 knot wind in the se quadrant...Hence Danny is
initialized as a minimal tropical storm for his bulletin.

B. Prognostic
Our track agrees with nhc...Which is similar to our previous track.
Model guidance continues to suggest Danny will move along the
Spine of Nova Scotia and then eastwards across Central Newfoundland.
Most of the dynamical models bring it in somewhere near Yarmouth,
ns..
There is still some potential for some re-strengthening as Danny
Moves through weakening shear...With wind strength forecast to be
40 knots as it passes to the east of Cape Hatteras tonight.
After that Danny will come under the influence of an upper trough
digging over the central us which will steer it in a northeasterly
Direction. Increasing shear..Combined with Danny moving over colder
Waters as it goes north of Cape Hatteras..Should weaken the storm.
Currently the guidance keeps it below hurricane strength with most
Of the models showing about 40 to 45 knots over the Scotian shelf.


C. Public weather
Decaying tropical systems often produce heavy rain over the
Maritimes and past experience indicates that locally higher
Amounts may be produced. Dynamic models are producing the
Expected qpfs of 50 to 100 mm with the location of the maxima
Varying from model to model. The Gem and gfs show possible
Maxima to the left of track into Southern New Brunswick...And both
show a possible maximum over Southwestern Nova Scotia. Danny will
Be monitored very closely..Especially due to the high uncertainty
In its development at this time.

D. Marine weather
Wind radii are initialised consistent with data from the hurricane
hunter aircraft this afternoon with gales only in the southeast
quadrant. Todays quikscat pass only captured the outer edges
Of the wind field. Wind radii are modelled based on slight
intensification and expansion due to extratropical transition.

Storm surge should not be an issue due to neap
Tides this weekend and insufficient winds. Waves should be less than
8 metres offshore of Nova Scotia and less than 6 into Newfoundland
waters. Coastal waves should be of order 5 metres or less.

Predicted wind radii (NM)
Time gales storms hurricane
Ne se sw nw ne se sw nw ne se sw nw
29/00Z 0 150 0 0 0 0 0 0 0 0 0 0
29/12Z 75 150 40 40 0 0 0 0 0 0 0 0
30/00Z 100 170 55 55 0 0 0 0 0 0 0 0
30/12Z 160 240 90 90 0 0 0 0 0 0 0 0
31/00Z 220 300 150 130 0 0 0 0 0 0 0 0
31/12Z 235 300 170 160 0 0 0 0 0 0 0 0
01/00Z 240 300 180 180 0 0 0 0 0 0 0 0
01/12Z 240 300 180 180 0 0 0 0 0 0 0 0

End campbell/hatt/mercer

-------------------------------------------------------------------------------------

000
WTNT35 KNHC 282342
TCPAT5
BULLETIN
TROPICAL STORM DANNY INTERMEDIATE ADVISORY NUMBER 10A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL052009
800 PM EDT FRI AUG 28 2009

...DANNY NOW MOVING NORTH-NORTHEASTWARD WITH NO CHANGE IN
ORGANIZATION...

A TROPICAL STORM WATCH IS IN EFFECT FOR THE NORTH CAROLINA COAST
FROM CAPE LOOKOUT NORTHWARD TO DUCK...INCLUDING THE PAMLICO AND
ALBEMARLE SOUNDS. A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM
CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...IN THIS CASE...
WITHIN 24 HOURS. A TROPICAL STORM WARNING MAY BE REQUIRED FOR
PORTIONS OF THIS AREA TONIGHT.

INTERESTS ELSEWHERE FROM THE CAROLINAS NORTHWARD TO NEW ENGLAND AND
THE CANADIAN MARITIMES SHOULD MONITOR THE PROGRESS OF DANNY.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...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 800 PM EDT...0000 UTC...THE CENTER OF TROPICAL STORM DANNY WAS
LOCATED NEAR LATITUDE 30.9 NORTH...LONGITUDE 75.1 WEST OR ABOUT
300 MILES...480 KM...SOUTH OF CAPE HATTERAS NORTH CAROLINA AND ABOUT
765 MILES...1230 KM...SOUTH-SOUTHWEST OF NANTUCKET MASSACHUSETTS.

DANNY IS MOVING TOWARD THE NORTH-NORTHEAST NEAR 8 MPH...13 KM/HR.
A GENERAL NORTHWARD TO NORTH-NORTHEASTWARD MOTION IS EXPECTED WITH
AN INCREASE IN FORWARD SPEED DURING THE NEXT COUPLE OF DAYS. ON
THIS TRACK...THE CENTER OF DANNY IS EXPECTED TO PASS OFFSHORE OF
THE OUTER BANKS OF NORTH CAROLINA EARLY SATURDAY...PASS OFFSHORE OF
SOUTHEASTERN NEW ENGLAND ON SATURDAY NIGHT AND MOVE NEAR THE
CANADIAN MARITIMES SUNDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 40 MPH...65 KM/HR...WITH HIGHER
GUSTS. SOME SLIGHT STRENGTHENING IS POSSIBLE TONIGHT...WITH LITTLE
CHANGE IN INTENSITY EXPECTED ON SATURDAY. DANNY IS EXPECTED TO
BECOME EXTRATROPICAL ON SATURDAY NIGHT.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175 MILES...280 KM
MOSTLY TO THE SOUTHEAST OF THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.

LARGE SWELLS FROM DANNY ARE EXPECTED TO PRODUCE DANGEROUS SURF
CONDITIONS AND LIFE-THREATENING RIP CURRENTS ALONG THE U.S. EAST
COAST DURING THE NEXT DAY OR TWO. PLEASE CONSULT STATEMENTS ISSUED
BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE FOR MORE
DETAILS.

...SUMMARY OF 800 PM EDT INFORMATION...
LOCATION...30.9N 75.1W
MAXIMUM SUSTAINED WINDS...40 MPH
PRESENT MOVEMENT...NORTH-NORTHEAST OR 30 DEGREES AT 8 MPH
MINIMUM CENTRAL PRESSURE...1006 MB


THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL
HURRICANE CENTER AT 1100 PM EDT.

$$
FORECASTER BEVEN

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