[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291058
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT AUG 29 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...SPECIAL FEATURES...

TROPICAL STORM DANNY HAS WEAKENED INTO TROPICAL DEPRESSION
DANNY DURING THE LAST FEW HOURS. THE CENTER OF DANNY WAS NEAR
34.3N 74.6W...OR ABOUT 80 MILES/130 KM TO THE SOUTHEAST OF CAPE
HATTERAS NORTH CAROLINA AND ABOUT 540 MILES/875 KM TO THE
SOUTH-SOUTHWEST OF NANTUCKET MASSACHUSETTS. DANNY RAPIDLY IS
BECOMING ABSORBED BY AN EXTRATROPICAL LOW PRESSURE CENTER THAT
IS OVER NORTH CAROLINA. 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. THE 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.A. EAST COAST DURING THE NEXT DAY OR TWO. PLEASE CONSULT
STATEMENTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE FOR MORE DETAILS. STRONG SHOWERS AND
THUNDERSTORMS ARE WITHIN 15 NM TO 30 NM ON EITHER SIDE
OF 72W FROM 25N BEYOND 32N.

A STRONG TROPICAL WAVE IS ALONG 16N37W 11N39W 6N41W. A 1010 MB
LOW PRESSURE CENTER IS NEAR 11N39W ALONG THE WAVE. ISOLATED
MODERATE SHOWERS FROM 3N TO 16N BETWEEN 33W AND 51W.
THIS SYSTEM MAY BECOME A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

...TROPICAL WAVES...
THE NEWEST TROPICAL WAVE IS ALONG 21W/22W TO THE SOUTH OF 18N
MOVING WESTWARD 10 TO 15 KT. MODERATE SHOWERS TO ISOLATED
STRONG THUNDERSTORMS FROM 10N TO 17N BETWEEN AFRICA AND 28W.

A TROPICAL WAVE IS ALONG 57W/58W TO THE SOUTH OF 17N MOVING WEST
15 TO 20 KT. MIDDLE LEVEL DRY AIR IN SUBSIDENCE IS IN THE AREA
FROM 10N TO 20N BETWEEN 50W AND 60W. NO DEEP CONVECTIVE
PRECIPITATION IS CLOSE TO THE WAVE.

A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 87W/88W TO THE
SOUTH OF 18N MOVING WESTWARD NEAR 20 KT. THIS WAVE IS MOVING
THROUGH AND/OR ALREADY MOVED THROUGH THE AREA OF AN UPPER LEVEL
TROUGH THAT COVERS THE WESTERN CARIBBEAN SEA FROM 8N TO 22N
BETWEEN 78W AND 90W.

...THE ITCZ...

12N23W 12N36W 9N45W 9N56W. ISOLATED MODERATE SHOWERS
ELSEWHERE FROM 2N TO 16N BETWEEN AFRICA AND 60W.

...DISCUSSION...

THE GULF OF MEXICO...
THE MIDDLE LEVEL TO UPPER LEVEL TROUGH FROM GEORGIA INTO THE
NORTHEASTERN GULF OF MEXICO FROM SIX HOURS AGO HAS BECOME EVEN
MORE AND MORE STRETCHED ALONG A NORTHEAST-TO-SOUTHWEST LINE...
STILL ENDING IN THE NORTHEASTERN GULF OF MEXICO. UPPER LEVEL
SOUTHWESTERLY-TO-WESTERLY WIND FLOW MOVES FROM MEXICO ACROSS
90W...UNDER BROAD UPPER LEVEL ANTICYCLONIC FLOW. A STATIONARY
FRONT GOES FROM EAST TEXAS INTO SOUTH CENTRAL TEXAS. ISOLATED
MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE IN THE UPPER
TEXAS COASTAL AREA...DECREASING IN QUANTITY MORE AND MORE ALONG
THE ENTIRE TEXAS COAST TO THE SOUTH OF THE UPPER TEXAS COAST.
MODERATE SHOWERS ARE IN THE SOUTHWESTERN CORNER OF THE AREA
UNDER UPPER LEVEL ANTICYCLONIC FLOW.

THE CARIBBEAN SEA...
MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW AROUND A 17N82W
CYCLONIC CIRCULATION CENTER COVERS THE AREA FROM 8N TO 25N
BETWEEN 77W AND 90W. SCATTERED MODERATE SHOWERS TO ISOLATED
STRONG THUNDERSTORMS ARE TO THE SOUTH OF 11N BETWEEN THE
GULF OF URABA OF COLOMBIA TO CLOSE TO THE COAST OF COSTA
RICA...AT THE SOUTHERN END OF THE TROUGH. UPPER LEVEL
ANTICYCLONIC WIND FLOW AND DRY AIR IN SUBSIDENCE MOVE FROM
THE ATLANTIC OCEAN...TOWARD THE CENTRAL CARIBBEAN SEA...AND
NORTHWESTWARD ACROSS HAITI AND BEYOND.

THE ATLANTIC OCEAN...
MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW AROUND A 30N46W
CENTER COVERS THE AREA FROM 23N TO 35N BETWEEN 40W AND 52W.
MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW AROUND A 27N23W
CENTER COVERS THE AREA FROM 23N TO 33N BETWEEN AFRICA AND 30W.

$$
MT





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