Danny Becomes Extratropical off the Coast of Southern New England

WOCN31 CWHX 291800
Post-tropical storm Danny information statement issued by the
canadian hurricane centre of Environment Canada at 3.00 PM ADT
Saturday 29 August 2009.

The next statement will be issued by 9.00 PM ADT

...Post-tropical Danny tracking towards Southern Nova Scotia...

1. Current position, strength, central pressure and motion

At 3.00 PM ADT... Post-tropical storm Danny was located near
Latitude 37.3 N and longitude 71.7 W... About 180 nautical miles
Or 335 km east of Wallops Island . Maximum sustained winds are
Estimated at 40 knots... 74 km/h... And central pressure at 1002
MB. Danny is moving northeast at 41 knots... 76 km/h.

2. Forecast position, central pressure and strength

Date time lat lon MSLP Max wind
ADT MB kts kmh
Aug 29 3.00 PM 37.3N 71.7W 1002 40 74 post-tropical
Aug 29 9.00 PM 40.6N 68.6W 1002 40 74 post-tropical
Aug 30 3.00 AM 43.5N 64.8W 1002 40 74 post-tropical
Aug 30 9.00 AM 46.1N 60.9W 1002 40 74 post-tropical
Aug 30 3.00 PM 47.7N 56.3W 1002 40 74 post-tropical
Aug 30 9.00 PM 49.2N 51.4W 1002 40 74 post-tropical
Aug 31 3.00 AM 49.7N 45.9W 1003 40 74 post-tropical
Aug 31 9.00 AM 49.4N 40.3W 1003 40 74 post-tropical
Aug 31 3.00 PM 49.1N 35.1W 1004 40 74 post-tropical

3. Public weather impacts and warnings summary
Rainfall warnings in effect over Southern New Brunswick
And pei for amounts of 50 mm and for Nova Scotia.. Rainfall
Amounts of 50 to 70 mm with local amounts up to 100 mm.
For Northern New Brunswick.. Rainfall amounts of 20 to 30 mm
Are predicted. Rainfall warnings are in effect for
The Southwestern Newfoundland regions for amounts near 50 mm.
Rainfall warnings may need to be extended to some of the
Other regions.

Rain at times heavy will reduce visibilities..Present driving
Hazards for motorists..And overflow catch basins and ditches.

Winds warnings are not anticipated. However warnings for Les Suetes
over the Cape Breton Highlands of 110 km/h and Wreckhouse winds near
Port aux Basques of 100 km/h are predicted.

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.

4. Marine weather impacts and warnings summary
Gale warnings are in effect for all maritime marine waters
Except the Laurentian fan. Gale warnings are in effect for all
The Newfoundland waters except the Grand Banks.

5. Technical discussion for meteorologists

A. Analysis
Danny ended its transition to a post-tropical storm this morning.
Satellite pictures shows heavy convection in its vicinity
And quickscat shows the circulation expanded the gales far
Away from the centre. Dynamic support from the upper flow
Is driving the system which at this time continues to feed
From the warm sea surface.


B. Prognostic
Nhc in Miami stopped tracking post-tropical storm Danny
Early this morning. CHC forecasters will continue to maintain
Danny as a post-tropical entity until it moves out of the
Response zone on Monday.

Post-tropical storm Danny will move over colder water
Tonight as it passes near the Atlantic coast of Nova Scotia
Then track across Cape Breton Sunday morning.
It will pass over Southeastern Newfoundland late Sunday then
Move away over the Atlantic Sunday night and on Monday.
Canadian models indicate good upper support over the tropical
Airmass associated with Danny which moves ahead of low
Pressure system coming from the Great Lakes.
Past experience indicates that post-tropical storm Danny
Is likely to remain as an entity under those conditions.


C. Public weather
The tropical nature of this system will produce rain at
Times heavy giving significant rainfall in a short period
Of time. Rainfall amounts of 50 mm and up to 100 mm are
Likely to fall over Nova Scotia..Pei and
Southern New Brunswick.

Heavy rainfall warnings are in effect for those regions.

D. Marine weather
Gale force winds are predicted over most of the maritime
And Newfoundland marine district.

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.

Predicted wind radii (NM)
Time gales storms hurricane
Ne se sw nw ne se sw nw ne se sw nw
29/18Z 240 160 100 10 0 0 0 0 0 0 0 0
30/00Z 260 180 120 10 0 0 0 0 0 0 0 0
30/06Z 260 220 120 10 0 0 0 0 0 0 0 0
30/12Z 260 220 120 10 0 0 0 0 0 0 0 0
30/18Z 220 160 120 10 0 0 0 0 0 0 0 0
31/00Z 220 150 120 10 0 0 0 0 0 0 0 0
31/06Z 200 150 100 10 0 0 0 0 0 0 0 0
31/12Z 180 150 60 10 0 0 0 0 0 0 0 0
31/18Z 130 150 60 10 0 0 0 0 0 0 0 0


End campbell/roussel