Tropical Depression Danny #6

WOCN31 CWHX 291200
Tropical storm Danny information statement issued by the
Canadian hurricane centre of Environment Canada at 9.00 AM ADT
Saturday 29 August 2009.

The next statement will be issued by 3.00 PM ADT

... Danny a weak tropical storm ...

1. Current position, strength, central pressure and motion

At 9.00 AM ADT... Remnants of tropical storm Danny was located
Near latitude 35.0 N and longitude 73.6 W... About 100 nautical
Miles or 180 km east of Cape Hatteras . Maximum sustained winds
Are estimated at 40 knots... 74 km/h... And central pressure
At 1004 MB. Danny is moving north northeast at 27 knots... 50 km/h.

2. Forecast position, central pressure and strength

Date time lat lon MSLP Max wind
ADT MB kts kmh
Aug 29 9.00 AM 35.0N 73.6W 1004 40 74 remnant
Aug 29 9.00 PM 39.6N 69.8W 1002 40 74 post-tropical
Aug 30 9.00 AM 43.8N 64.6W 1002 40 74 post-tropical
Aug 30 9.00 PM 47.0N 58.6W 1002 40 74 post-tropical
Aug 31 9.00 AM 49.5N 52.0W 1003 40 74 post-tropical
Aug 31 9.00 PM 51.2N 44.8W 1004 40 74 post-tropical
Sep 01 9.00 AM 52.5N 37.2W 1004 40 74 post-tropical

3. Public weather impacts and warnings summary
Rainfall warnings in effect over Southwestern New Brunswick
For amounts of 75 mm and over Southern Nova Scotia for 50 mm.
Elsewhere across the Maritimes.. Forecast amounts will be less
Than the 50 mm warning criteria. A rainfall warning will be
Posted over the Newfoundland south coast region for amounts
Just above 50 mm. The heavy rainfall will present driving hazards
For motorists.. Overflowing 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 is anticipated.

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
The western waters of the Newfoundland marine district.

5. Technical discussion for meteorologists

A. Analysis
Aircraft can not find any circulation nor gale force
Winds. Hence Miami has discontinued messaging as Danny becomes
absorbed by the extra-tropical low generated by the advancing
Upper trough from the deep south. Convection has become
Notable in the area off the Carolina coast where cyclogenesis
Will likely occur.

B. Prognostic

In their final message.. Miami carries an absorbed Danny
With the newly formed extra tropical low hence their final
Track is snapped westward.

At the CHC.. We will maintain Danny as a separate entity
For now based on the reasoning suggested in our previous
Message and repeated below. As well.. We prefer to see the
Latest quickscat and visual satellite imagery before
Discontinuing our messages.

Of note.. Even if we no longer reference Danny.. All
Of our public and marine forecasts were constructed last
Night based on dynamical modelling taking the influence
Of Danny into account. We doubt that there will be little
Change in the forecasts for the Maritimes and Newfoundland
Other than tweaking numbers based on newer dynamic models.

As mentioned in the previous message..
There are 3 separate weather entities.. A very marginal tropical
Storm.. The approaching upper trough from the american deep
South and the upper trough moving in from Ontario. Unfortunately
The Gem combined Danny and the southern upper trough hence it
generated an unrealistically deep and fast moving low that
Was west of our chosen track. One suspects that latent
Heating feedback is also an issue so the Gem was rejected.
The nam kept Danny as a weakening entity that can be followed
By the 576 thickness warm pool and the 500 MB vorticity
Through Newfoundland. As a result.. The nam provides the
Best template for the public and marine forecasts. The gfs
Resolution is too coarse to offer much help.

C. Public weather
The effect of rainfall from Danny will mostly be confined
To Nova Scotia and Newfoundland. The very heavy rain over
New Brunswick is mostly caused by a moisture laden gulf
Of Mexico airmass carried by an upper trough from the
American deep south which rides over a warm frontal zone.
The nam model hints at local amounts of 100 mm there.

D. Marine weather
Wind radii are initialised with the latest quikscat pass
And then modelled thereafter.

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
29/12Z 240 240 5 5 0 0 0 0 0 0 0 0
30/00Z 240 240 20 35 0 0 0 0 0 0 0 0
30/12Z 240 220 45 150 0 0 0 0 0 0 0 0
31/00Z 240 200 60 240 0 0 0 0 0 0 0 0
31/12Z 240 190 75 270 0 0 0 0 0 0 0 0
01/00Z 240 180 90 300 0 0 0 0 0 0 0 0
01/12Z 240 180 90 300 0 0 0 0 0 0 0 0



End campbell/roussel

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000
WTNT35 KNHC 290842
TCPAT5
BULLETIN
TROPICAL DEPRESSION DANNY ADVISORY NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL052009
500 AM EDT SAT AUG 29 2009

...DANNY RAPIDLY BECOMING ABSORBED BY AN EXTRATROPICAL LOW...

AT 5 AM EDT...0900 UTC...THE TROPICAL STORM WATCH FOR THE NORTH
CAROLINA COAST FROM CAPE LOOKOUT NORTHWARD TO DUCK...INCLUDING THE
PAMLICO AND ALBEMARLE SOUNDS HAS BEEN DISCONTINUED.

SATELLITE IMAGES AND DATA FROM AN AIR FORCE RECONNAISSANCE PLANE
INDICATE THAT DANNY IS RAPIDLY BECOMING ABSORBED BY AN
EXTRATROPICAL LOW OVER NORTH CAROLINA. AT 500 AM EDT...0900
UTC...THE REMNANTS OF DANNY WERE LOCATED NEAR LATITUDE 34.3
NORTH... LONGITUDE 74.6 WEST OR ABOUT 80 MILES...130 KM...SOUTHEAST
OF CAPE HATTERAS NORTH CAROLINA AND ABOUT 540 MILES...875
KM...SOUTH-SOUTHWEST OF NANTUCKET MASSACHUSETTS.

THE EXTRATROPICAL LOW IS FORECAST TO MOVE RAPIDLY TOWARD THE
NORTH-NORTHEAST AND THEN NORTHEAST NEAR 30 TO 35 MPH DURING THE NEXT
DAY OR SO.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER
GUSTS.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB...29.74 INCHES.

LARGE SWELLS FROM THE EXTRATROPICAL LOW 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 500 AM EDT INFORMATION...
LOCATION...34.3N 74.6W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...NORTH-NORTHEAST OR 20 DEGREES AT 30 MPH
MINIMUM CENTRAL PRESSURE...1007 MB

THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON THIS SYSTEM. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE
FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER
SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

$$

FORECASTER AVILA

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

000
WTNT45 KNHC 290843
TCDAT5
TROPICAL DEPRESSION DANNY DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL052009
500 AM EDT SAT AUG 29 2009

SATELLITE IMAGES...SURFACE OBSERVATIONS AND DATA FROM AN AIR FORCE
RECONNAISSANCE PLANE INDICATE THAT DANNY IS RAPIDLY BECOMING
ABSORBED BY A FRONTAL LOW WHICH IS DEVELOPING OVER NORTH CAROLINA.
IN FACT...THE PLANE TRAVERSED THE POSSIBLE LOCATION OF DANNY A
COUPLE TIMES AND DID NOT FIND ANY SIGNIFICANT CYCLONIC WIND
SHIFT NOR DID IT MEASURE TROPICAL STORM FORCE WINDS AT THE SURFACE.
THEREFORE...ADVISORIES ON DANNY HAVE BEEN TERMINATED AND THE
TROPICAL STORM WATCH HAS BEEN DISCONTINUED. THE EXTRATROPICAL LOW
WILL MOVE TOWARD THE NORTH-NORTHEAST AND THEN NORTHEAST AND ITS
POTENTIAL IMPACTS WILL BE HANDLED WITH GALE WARNINGS AND OTHER
PRODUCTS ISSUED BY LOCAL NWS OFFICES IN THAT REGION. ADDITIONAL
INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS
ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER
NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.


FORECAST POSITIONS AND MAX WINDS

INITIAL 29/0900Z 34.3N 74.6W 30 KT...BECOMING ABSORBED
12HR VT 29/1800Z 38.0N 73.0W 35 KT...EXTRATROPICAL
24HR VT 30/0600Z 41.2N 69.2W 40 KT...EXTRATROPICAL
36HR VT 30/1800Z 46.2N 62.8W 40 KT...EXTRATROPICAL
48HR VT 31/0600Z 49.5N 56.0W 40 KT...EXTRATROPICAL
72HR VT 01/0600Z 54.5N 43.5W 40 KT...EXTRATROPICAL
96HR VT 02/0600Z 56.5N 27.0W 45 KT...EXTRATROPICAL
120HR VT 03/0600Z 57.0N 10.1W 50 KT...EXTRATROPICAL

$$
FORECASTER AVILA