[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211058
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE JUL 21 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.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE EXTENDS FROM 17N35W TO 10N36W
TO 5N37W MOVING WEST 15 TO 20 KT. NO PRECIPITATION REALLY IS
DIRECTLY RELATED TO THIS WAVE. STRONG SHOWERS AND THUNDERSTORMS
ARE ABOUT 480 NM TO THE WEST-SOUTHWEST OF THE WAVE IN THE ITCZ.

AN ATLANTIC OCEAN TROPICAL WAVE EXTENDS FROM 20N52W TO 13N54W
TO WESTERN FRENCH GUIANA NEAR 4N54W...MOVING WEST 15 TO 20 KT.
BROAD CYCLONIC FLOW ON WATER VAPOR IMAGERY COVERS THE ATLANTIC
OCEAN FROM THE EQUATOR TO 10N BETWEEN 45W AND 60W...ENCOMPASSING
FRENCH GUIANA...EXTREME NORTHEASTERN BRAZIL...AND THE EASTERN
HALF OF SURINAME. ITCZ PRECIPITATION IS NEARBY.

A TROPICAL WAVE IS ALONG 66W/67W TO THE SOUTH OF 22N...PASSING
OVER PUERTO RICO INTO CENTRAL VENEZUELA...MOVING WEST ABOUT
20 KT. STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN A 70 NM
RADIUS OF 16N65W.

A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 83W/84W...
MOVING WEST ABOUT 20 KT. SHOWERS AND POSSIBLE THUNDERSTORMS HAVE
BEEN POPPING UP TO THE SOUTH OF 16N BETWEEN 79W AND THE COAST OF
CENTRAL AMERICA. THIS PRECIPITATION ALSO IS BEING SUPPORTED BY
UPPER LEVEL DIFFLUENT FLOW THAT IS ASSOCIATED WITH A BROAD UPPER
LEVEL RIDGE.

...THE ITCZ...

FROM AFRICA NEAR 16N16W TO 15N20W TO 11N30W TO 6N40W TO 4N52W
INTO THE EASTERN COASTAL PLAINS OF FRENCH GUIANA. STRONG SHOWERS
AND THUNDERSTORMS ARE FROM 5N TO 7N BETWEEN 43W AND 50W. POSSIBLE
SHOWERS ARE ELSEWHERE FROM 13N TO 14N BETWEEN AFRICA AND 21W...
AND FROM 3N TO 10N BETWEEN 40W AND 60W.

...DISCUSSION...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH GEORGIA INTO
THE GULF OF MEXICO TO 25N85W TO 22N89W. THE STATIONARY FRONT
APPEARS TO BE DISSIPATING. RETURN SOUTHEASTERLY SURFACE FLOW
ALREADY HAS STARTED. A SURFACE TROUGH GOES FROM NORTH CENTRAL
FLORIDA TO THE WEST CENTRAL FLORIDA COAST...TO A 1014 MB LOW
PRESSURE CENTER AT 21/0900 UTC NEAR 28N86W...TO 26N90W. ISOLATED
MODERATE SHOWERS HAVE DEVELOPED IN THE GULF OF MEXICO TO THE
SOUTHEAST OF THE TROUGH. A SECOND SURFACE TROUGH REMAINS FROM
LAKE OKEECHOBEE TO 25N85W 24N89W.

THE CARIBBEAN SEA...
LOW LEVEL TO MIDDLE LEVEL CYCLONIC FLOW IS TO THE SOUTH-SOUTHWEST
OF AN AREA OF NEWLY-DEVELOPING STRONG SHOWERS AND THUNDERSTORMS
THAT IS WITHIN A 70 NM RADIUS OF 16N65W. UPPER LEVEL
ANTICYCLONIC FLOW IS ON TOP OF THE AREA OF THIS PRECIPITATION.
AN UPPER LEVEL TROUGH IN THE ATLANTIC OCEAN IS JUST TO THE EAST
OF THE AREA...ALLOWING THIS PRECIPITATION TO FLOURISH IN AN
ENVIRONMENT OF UPPER LEVEL DIFFLUENT FLOW. SHOWERS ARE POSSIBLE
FROM THE ATLANTIC OCEAN INTO THE EASTERN CARIBBEAN SEA FROM 14N
TO 18N BETWEEN 55W AND 62W.

THE ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH PASSES THROUGH 31N73W TO 27N74W TO 22N75W
NEAR THE BAHAMAS. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG
THUNDERSTORMS ARE FROM 22N TO 26N BETWEEN 72W AND 78W. ISOLATED
MODERATE SHOWERS ARE ELSEWHERE TO THE NORTH OF 26N BETWEEN 70W
AND 80W. A MIDDLE LEVEL TO UPPER LEVEL TROUGH GOES FROM A 31N62W
CYCLONIC CIRCULATION CENTER TO 20N56W TO 15N58W. ISOLATED
MODERATE SHOWERS ARE TO THE NORTH OF 25N BETWEEN 50W AND 65W.

$$
MT





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