Tropical Storm Danny #3

000
WTNT35 KNHC 272035
TCPAT5
BULLETIN
TROPICAL STORM DANNY ADVISORY NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL052009
500 PM EDT THU AUG 27 2009

...CENTER OF DANNY DRIFTING WESTWARD...TROPICAL STORM WATCH ISSUED
FOR PART OF THE NORTH CAROLINA COAST...

AT 5 PM EDT...2100 UTC...A TROPICAL STORM WATCH IS IN EFFECT FOR THE
NORTH CAROLINA COAST FROM CAPE LOOKOUT NORTHWARD TO DUCK...
INCLUDING THE ABLEMARLE AND PAMLICO SOUNDS. A TROPICAL STORM WATCH
MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH
AREA...GENERALLY WITHIN 36 HOURS.

INTERESTS ELSEWHERE FROM THE CAROLINAS NORTHWARD TO NEW ENGLAND
SHOULD MONITOR THE PROGRESS OF DANNY. ADDITIONAL WATCHES AND
WARNINGS MAY BE REQUIRED FOR PORTIONS OF THIS AREA LATER TONIGHT AND
FRIDAY.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY
YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE.

AT 500 PM EDT...2100 UTC...THE CENTER OF TROPICAL STORM DANNY WAS
LOCATED NEAR LATITUDE 27.5 NORTH...LONGITUDE 73.5 WEST OR ABOUT 295
MILES...480 KM...NORTHEAST OF NASSAU AND ABOUT 545 MILES...875 KM...
SOUTH-SOUTHEAST OF CAPE HATTERAS NORTH CAROLINA.

DANNY IS CURRENTLY DRIFTING TOWARD THE WEST AT 2 MPH...3 KM/HR. A
TURN TOWARD THE NORTHWEST AND AN INCREASE IN FORWARD SPEED ARE
EXPECTED LATER TONIGHT...WITH A TURN TOWARD THE NORTH AND AN EVEN
FASTER FORWARD SPEED FORECAST ON FRIDAY.

REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT AND
SATELLITE SCATTEROMETER DATA INDICATE THAT MAXIMUM SUSTAINED WINDS
HAVE DECREASED TO NEAR 50 MPH...85 KM/HR...WITH HIGHER GUSTS. SLOW
STRENGTHENING IS POSSIBLE DURING THE NEXT COUPLE OF DAYS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 205 MILES...335 KM
MAINLY TO THE NORTHEAST OF THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES.

...SUMMARY OF 500 PM EDT INFORMATION...
LOCATION...27.5N 73.5W
MAXIMUM SUSTAINED WINDS...50 MPH
PRESENT MOVEMENT...WEST OR 270 DEGREES AT 2 MPH
MINIMUM CENTRAL PRESSURE...1008 MB

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

$$
FORECASTER BEVEN

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ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM DANNY DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL052009
500 PM EDT THU AUG 27 2009

REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE
THAT THE CIRCULATION OF DANNY HAS BECOME BETTER DEFINED TODAY...
WITH STRONGER WINDS IN THE PREVIOUSLY WEAK SOUTHWESTERN QUADRANT.
ASIDE FROM THAT...THE CYCLONE REMAINS VERY DISORGANIZED. THE MAIN
CONVECTION IS IN A LINE 130-170 N MI EAST THROUGH SOUTH OF THE
CENTER...AND THE STRONGEST WINDS ARE 100 N MI OR MORE FROM THE
CENTER OVER THE NORTHERN SEMICIRCLE. THE AIRCRAFT DATA...AS WELL
AS DATA FROM THE QUIKSCAT AND ASCAT SCATTEROMETERS...SUGGEST THAT
THE MAXIMUM WINDS HAVE DECREASED TO 40-45 KT. THE INITIAL
INTENSITY WILL BE REDUCED TO 45 KT.

THE CENTER HAS MOVED SLOWLY WESTWARD SINCE SUNRISE...WITH THE
INITIAL MOTION ESTIMATED AT 270/2. THE TRACK GUIDANCE MODELS
REMAIN IN EXCELLENT AGREEMENT THAT DANNY SHOULD TURN NORTHWARD OVER
THE NEXT 24-36 HR IN ADVANCE OF A COMPLEX DEEP-LAYER TROUGH MOVING
INTO THE EASTERN UNITED STATES. AFTER THAT...THE STORM SHOULD
ACCELERATE NORTHEASTWARD INTO THE WESTERLIES...PASSING NEAR OR OVER
CAPE HATTERAS...SOUTHEASTERN NEW ENGLAND...AND THE CANADIAN
MARITIMES ON ITS WAY INTO THE NORTH ATLANTIC. WITH THE MORE
WESTERLY INITIAL POSITION...THE TRACK GUIDANCE ENVELOPE HAS SHIFTED
SOMEWHAT WESTWARD DURING THE FIRST 48 HR...AND THE NEW FORECAST
TRACK IS ADJUSTED WESTWARD AS WELL. WHILE THE TRACK IS STILL DOWN
THE MIDDLE OF THE GUIDANCE ENVELOPE...THE GFS...UKMET...NOGAPS...
AND CANADIAN MODELS ARE ALL TO THE LEFT OF THE NEW TRACK. SOME
ADDITIONAL ADJUSTMENT TOWARD THE LEFT...TOWARD THE EAST COAST OF
THE U. S....MAY BE REQUIRED IF THIS TREND CONTINUES.

DANNY REMAINS IN AN AREA OF UPPER-LEVEL CONFLUENT FLOW ASSOCIATED
WITH THE PERSISTENT CYCLONIC SHEAR AXIS SEEN IN WATER VAPOR
IMAGERY. IN ADDITION...BOTH WATER VAPOR IMAGERY AND SSM/IS TOTAL
PRECIPITABLE WATER IMAGERY SUGGEST THAT THE ENVIRONMENT NEAR DANNY
IS DRY. THESE FACTORS...COMBINED WITH THE CURRENT LACK OF
ORGANIZATION...SUGGESTS THAT STRENGTHENING WILL BE SLOW AT BEST
DURING THE NEXT 24 HR. THERE IS A WINDOW OF OPPORTUNITY FOR DANNY
TO STRENGTHEN FROM 24-36 HR AS IT IS FORECAST TO MOVE UNDER AN
UPPER-LEVEL ANTICYCLONE. AFTER THAT...IT WILL ENCOUNTER STRONG
SOUTHWESTERLY FLOW ASSOCIATED WITH THE DEEP-LAYER TROUGH...WHICH
SHOULD CAUSE WEAKENING AND EXTRATROPICAL TRANSITION. THE NEW
INTENSITY FORECAST CALLS FOR DANNY TO NOT REACH HURRICANE
STRENGTH...WITH A PEAK INTENSITY OF 60 KT IN 48 HR. IT SHOULD BE
NOTED THAT THE GFDL AND HWRF STILL FORECAST DANNY TO BECOME A
HURRICANE BY 36 HR.

FORECAST POSITIONS AND MAX WINDS

INITIAL 27/2100Z 27.5N 73.5W 45 KT
12HR VT 28/0600Z 28.5N 74.7W 45 KT
24HR VT 28/1800Z 30.7N 75.0W 50 KT
36HR VT 29/0600Z 34.4N 74.1W 55 KT
48HR VT 29/1800Z 38.8N 71.6W 60 KT
72HR VT 30/1800Z 46.5N 61.5W 50 KT...EXTRATROPICAL
96HR VT 31/1800Z 50.0N 49.0W 40 KT...EXTRATROPICAL
120HR VT 01/1800Z 51.0N 32.0W 35 KT...EXTRATROPICAL

$$
FORECASTER BEVEN

NNNN

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WOCN31 CWHX 271800
Tropical storm Danny information statement issued by the
Canadian hurricane centre of Environment Canada at 3.00 PM ADT
Thursday 27 August 2009.

The next statement will be issued by 9.00 PM ADT

... Danny still taking shape ...

1. Current position, strength, central pressure and motion

At 3.00 PM ADT... Tropical storm Danny was located near latitude
27.4 N and longitude 73.5 W... About 400 nautical miles or 740 km
east northeast of Miami . Maximum sustained winds are
Estimated at 50 knots... 93 km/h... And central pressure at 1004
MB. Danny is moving west northwest at 8 knots... 15 km/h.

2. Forecast position, central pressure and strength

Date time lat lon MSLP Max wind
ADT MB kts kmh
Aug 27 3.00 PM 27.4N 73.5W 1004 50 93
Aug 28 3.00 AM 29.4N 74.3W 1003 55 102
Aug 28 3.00 PM 31.8N 74.6W 998 60 111
Aug 29 3.00 AM 35.3N 73.3W 982 65 120
Aug 29 3.00 PM 39.7N 70.2W 982 65 120
Aug 30 3.00 AM 43.5N 66.3W 986 60 111 transitioning
Aug 30 3.00 PM 47.2N 61.1W 994 55 102 post-tropical
Aug 31 3.00 AM 49.7N 54.7W 992 45 83 post-tropical
Aug 31 3.00 PM 51.5N 47.1W 998 40 74 post-tropical
Sep 01 3.00 AM 52.8N 39.5W 1000 35 65 post-tropical
Sep 01 3.00 PM 54.2N 30.5W 1002 30 56 post-tropical

3. Public weather impacts and warnings summary
Eventually Danny will produce rain over the late weekend
But it is too early to determine amounts.

4. Marine weather impacts and warnings summary
Danny will weaken as it moves through canadian waters
Though it may produce hurricane winds upon first entering
The marine district.. The winds will diminish as it
Continues to move over colder waters.

5. Technical discussion for meteorologists

A. Analysis
Visual satellite imagery shows a low level circulation centre
That is removed to the west of the convection. As a result..
Danny is reanalysed further west than previously noted.

B. Prognostic
Despite being removed from the area of convection.. Danny
Looks more more organised on the satellite imagery.
The model guidance continues to show Danny developing
Into a marginal hurricane as it tracks northward
And passes the Carolina coast. Such a track is based on the
System coming under southerly winds ahead of an upper
Low near the Mississippi delta. Thereafter Danny
Comes under the influence of the westerlies over Canada.
Phase space diagrams indicate Danny will begin extra
Tropical transition once it passes Cape Cod and become post
Tropical as it moves through the Maritimes and Newfoundland.

It must be emphasized that there is still a lot of uncertainty
With respect to the track and intensity of Danny once it
Reaches canadian waters. We are in agreement with the guidance
From Miami so far.

C. Public weather
Decaying tropical systems often produce heavy rain over the
Martimes and past experience indicates that locally higher
Amounts may be produced. Dynamic models are producing the
Expected qpfs but with the maximums in various locations
As can be expected with decaying tropical systems .

D. Marine weather

Wind radii initialised on this mornings quickscat overpass
And modelled thereafter.

Predicted wind radii (NM)
Time gales storms hurricane
Ne se sw nw ne se sw nw ne se sw nw
27/18Z 200 200 0 200 120 0 0 0 0 0 0 0
28/06Z 200 200 0 200 120 0 0 0 0 0 0 0
28/18Z 200 200 30 180 100 30 0 30 0 0 0 0
29/06Z 200 200 75 100 90 75 30 45 0 20 0 0
29/18Z 200 200 75 100 90 90 45 45 0 20 0 0
30/06Z 200 200 75 100 90 90 45 30 0 0 0 0
30/18Z 200 200 90 100 90 90 45 0 0 0 0 0
31/06Z 200 200 90 90 0 0 0 0 0 0 0 0
31/18Z 200 200 90 90 0 0 0 0 0 0 0 0
01/06Z 200 200 90 90 0 0 0 0 0 0 0 0
01/18Z 200 200 90 90 0 0 0 0 0 0 0 0


End campbell




WOCN31 CWHX 271800
TROPICAL STORM DANNY INFORMATION STATEMENT ISSUED BY THE
CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 3.00 PM ADT
THURSDAY 27 AUGUST 2009.

THE NEXT STATEMENT WILL BE ISSUED BY 9.00 PM ADT

... DANNY STILL TAKING SHAPE ...

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 3.00 PM ADT... TROPICAL STORM DANNY WAS LOCATED NEAR LATITUDE
27.4 N AND LONGITUDE 73.5 W... ABOUT 400 NAUTICAL MILES OR 740 KM
EAST NORTHEAST OF MIAMI . MAXIMUM SUSTAINED WINDS ARE
ESTIMATED AT 50 KNOTS... 93 KM/H... AND CENTRAL PRESSURE AT 1004
MB. DANNY IS MOVING WEST NORTHWEST AT 8 KNOTS... 15 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
ADT MB KTS KMH
AUG 27 3.00 PM 27.4N 73.5W 1004 50 93
AUG 28 3.00 AM 29.4N 74.3W 1003 55 102
AUG 28 3.00 PM 31.8N 74.6W 998 60 111
AUG 29 3.00 AM 35.3N 73.3W 982 65 120
AUG 29 3.00 PM 39.7N 70.2W 982 65 120
AUG 30 3.00 AM 43.5N 66.3W 986 60 111 TRANSITIONING
AUG 30 3.00 PM 47.2N 61.1W 994 55 102 POST-TROPICAL
AUG 31 3.00 AM 49.7N 54.7W 992 45 83 POST-TROPICAL
AUG 31 3.00 PM 51.5N 47.1W 998 40 74 POST-TROPICAL
SEP 01 3.00 AM 52.8N 39.5W 1000 35 65 POST-TROPICAL
SEP 01 3.00 PM 54.2N 30.5W 1002 30 56 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY
EVENTUALLY DANNY WILL PRODUCE RAIN OVER THE LATE WEEKEND
BUT IT IS TOO EARLY TO DETERMINE AMOUNTS.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY
DANNY WILL WEAKEN AS IT MOVES THROUGH CANADIAN WATERS
THOUGH IT MAY PRODUCE HURRICANE WINDS UPON FIRST ENTERING
THE MARINE DISTRICT.. THE WINDS WILL DIMINISH AS IT
CONTINUES TO MOVE OVER COLDER WATERS.

5. TECHNICAL DISCUSSION FOR METEOROLOGISTS

A. ANALYSIS
VISUAL SATELLITE IMAGERY SHOWS A LOW LEVEL CIRCULATION CENTRE
THAT IS REMOVED TO THE WEST OF THE CONVECTION. AS A RESULT..
DANNY IS REANALYSED FURTHER WEST THAN PREVIOUSLY NOTED.

B. PROGNOSTIC
DESPITE BEING REMOVED FROM THE AREA OF CONVECTION.. DANNY
LOOKS MORE MORE ORGANISED ON THE SATELLITE IMAGERY.
THE MODEL GUIDANCE CONTINUES TO SHOW DANNY DEVELOPING
INTO A MARGINAL HURRICANE AS IT TRACKS NORTHWARD
AND PASSES THE CAROLINA COAST. SUCH A TRACK IS BASED ON THE
SYSTEM COMING UNDER SOUTHERLY WINDS AHEAD OF AN UPPER
LOW NEAR THE MISSISSIPPI DELTA. THEREAFTER DANNY
COMES UNDER THE INFLUENCE OF THE WESTERLIES OVER CANADA.
PHASE SPACE DIAGRAMS INDICATE DANNY WILL BEGIN EXTRA
TROPICAL TRANSITION ONCE IT PASSES CAPE COD AND BECOME POST
TROPICAL AS IT MOVES THROUGH THE MARITIMES AND NEWFOUNDLAND.

IT MUST BE EMPHASIZED THAT THERE IS STILL A LOT OF UNCERTAINTY
WITH RESPECT TO THE TRACK AND INTENSITY OF DANNY ONCE IT
REACHES CANADIAN WATERS. WE ARE IN AGREEMENT WITH THE GUIDANCE
FROM MIAMI SO FAR.

C. PUBLIC WEATHER
DECAYING TROPICAL SYSTEMS OFTEN PRODUCE HEAVY RAIN OVER THE
MARTIMES AND PAST EXPERIENCE INDICATES THAT LOCALLY HIGHER
AMOUNTS MAY BE PRODUCED. DYNAMIC MODELS ARE PRODUCING THE
EXPECTED QPFS BUT WITH THE MAXIMUMS IN VARIOUS LOCATIONS
AS CAN BE EXPECTED WITH DECAYING TROPICAL SYSTEMS .

D. MARINE WEATHER

WIND RADII INITIALISED ON THIS MORNINGS QUICKSCAT OVERPASS
AND MODELLED THEREAFTER.

PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
27/18Z 200 200 0 200 120 0 0 0 0 0 0 0
28/06Z 200 200 0 200 120 0 0 0 0 0 0 0
28/18Z 200 200 30 180 100 30 0 30 0 0 0 0
29/06Z 200 200 75 100 90 75 30 45 0 20 0 0
29/18Z 200 200 75 100 90 90 45 45 0 20 0 0
30/06Z 200 200 75 100 90 90 45 30 0 0 0 0
30/18Z 200 200 90 100 90 90 45 0 0 0 0 0
31/06Z 200 200 90 90 0 0 0 0 0 0 0 0
31/18Z 200 200 90 90 0 0 0 0 0 0 0 0
01/06Z 200 200 90 90 0 0 0 0 0 0 0 0
01/18Z 200 200 90 90 0 0 0 0 0 0 0 0


END CAMPBELL