000
AXNT20 KNHC 310550
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI JUL 31 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0445 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 38W/40W TO THE SOUTH
OF 25N MOVING WEST ABOUT 20 KT. ISOLATED MODERATE SHOWERS FROM 
27N TO 28N BETWEEN 37W AND 38W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 69W TO THE SOUTH OF 20N
MOVING WEST ABOUT 20 KT. ISOLATED MODERATE SHOWERS ARE FROM 12N
TO 21N BETWEEN 65W AND 73W.

...THE ITCZ...

FROM THE AFRICA COAST NEAR 14N17W TO 11N25W TO 13N38W
TO 9N50W TO TRINIDAD. ISOLATED MODERATE SHOWERS AND POSSIBLE 
THUNDERSTORMS ARE WITHIN 60 NM TO 90 NM ON EITHER SIDE OF
14N17W 11N23W 10N29W 8N37W 8N50W 8N53W...AND FROM 10N TO 12N
BETWEEN 60W AND 63W.

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL TROUGH GOES FROM 29N83W TO 27N87W. ISOLATED 
MODERATE SHOWERS...SOME DISSIPATING AND SOME DEVELOPING...
ARE WITHIN 30 NM TO 60 NM ON EITHER SIDE OF THE TROUGH.
A SECOND UPPER LEVEL TROUGH GOES FROM 25N91W TO 24N93W TO 22N96W.
UPPER LEVEL MOISTURE MOVES SOUTHWESTWARD FROM THE ATLANTIC 
OCEAN...CROSSING 30N TO THE WEST OF 74W TOWARD FLORIDA AND THE 
STRAITS OF FLORIDA...INTO THE GULF OF MEXICO TO 86W. BROAD UPPER 
LEVEL CYCLONIC FLOW COVERS MEXICO TO THE NORTH OF 21N. A COLD 
FRONT MOVES FROM SOUTH CENTRAL TEXAS INTO MEXICO JUST TO THE 
SOUTH OF THE TEXAS BIG BEND AND THEN THE FRONT CURVES TO FAR 
WEST TEXAS NEAR EL PASO. ISOLATED STRONG SHOWERS AND
THUNDERSTORMS ARE TO THE NORTH OF 24N TO THE WEST OF 100W.

THE CARIBBEAN SEA...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM THE ATLANTIC 
OCEAN NEAR 30N70W TO 26N74W TO SOUTHEASTERN CUBA NEAR 20N78W TO
17N86W TOWARD THE GULF OF HONDURAS. ISOLATED SHOWERS HAVE POPPED 
UP FROM HAITI TO THE WATERS BETWEEN CUBA AND THE CAYMAN ISLANDS.
THE SOUTHERN END OF AN UPPER LEVEL TROUGH FROM 31N57W IN THE 
ATLANTIC OCEAN REACHES NEAR 17N66W JUST TO THE SOUTH OF PUERTO 
RICO. A TROPICAL WAVE THAT IS ALONG 69W IS SPREADING ISOLATED 
MODERATE SHOWERS FROM 12N TO 21N BETWEEN 65W AND 73W.
ISOLATED STRONG SHOWERS AND THUNDERSTORMS COVER CENTRAL AMERICA 
FROM MEXICO TO THE SOUTH OF 20N TO THE WEST OF 100W...TO THE 
GULF AND ISTHMUS OF TEHUANTEPEC...TO SOUTHWESTERN COASTAL
EL SALVADOR TO NICARAGUA. THIS PRECIPITATION IS OCCURRING
IN AN AREA OF UPPER LEVEL DIFFLUENT WIND FLOW.

THE ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH EXTENDS FROM A 31N57W CYCLONIC CIRCULATION 
CENTER TO 27N57W 25N61W 23N63W 20N64W INTO THE CARIBBEAN SEA 
NEAR 17N66W JUST TO THE SOUTH OF PUERTO RICO AND THE VIRGIN 
ISLANDS. POSSIBLE SHOWERS ARE WITHIN 120 NM TO THE NORTH OF
THE 31N57W CYCLONIC CENTER AND WITHIN 60 NM TO THE SOUTH OF IT.
AN UPPER LEVEL TROUGH PASSES THROUGH 33N28W TO 30N37W 28N38W
TO 24N46W. A SEPARATE UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC 
CIRCULATION CENTER NEAR 28N45W TO 25N50W. AN EASTERN ATLANTIC 
OCEAN UPPER LEVEL TROUGH IS ALONG 18N17W 22N20W TO 25N24W
WITHOUT ANY DEEP LAYER CONVECTIVE PRECIPITATION. 

$$
MT