000
AXNT20 KNHC 281052
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON SEP 28 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 IS ALONG 33W/34W TO THE SOUTH OF 
17N MOVING WESTWARD 10 TO 15 KT. ITCZ PRECIPITATION FROM 10N TO 
13N BETWEEN 32W AND 36W. 

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 81W/82W TO THE SOUTH OF
18N MOVING WEST 10 TO 15 KT. THE WAVE IS MOVING THROUGH THE BASE
OF A MIDDLE LEVEL TO UPPER LEVEL TROUGH. THE STRONG SHOWERS AND
THUNDERSTORMS FROM COLOMBIA'S GULF OF URABA TO 12N BETWEEN 76W
AND 79W EASILY PROBABLY ARE MORE RELATED TO THE ITCZ AND THE
MIDDLE LEVEL TO UPPER LEVEL TROUGH.

...THE ITCZ...

FROM SIERRA LEONE TO 8N12W 8N20W 11N32W 8N46W TO 10N62W IN 
NORTHEASTERN VENEZUELA. STRONG SHOWERS AND THUNDERSTORMS FROM
9N TO 10N BETWEEN AFRICA AND 16W. ISOLATED MODERATE SHOWERS AND 
POSSIBLE THUNDERSTORMS COVER THE REST OF THE AREA FROM 5N TO 8N
BETWEEN 14W AND 20W...AND FROM 6N TO 12N BETWEEN 30W AND 48W.
ISOLATED MODERATE SHOWERS FROM 10N TO 14N BETWEEN 50W AND 63W.

...DISCUSSION...

THE GULF OF MEXICO...
CYCLONIC FLOW FROM A DEEP LAYER TROUGH COVERS THE U.S.A. TO THE 
EAST OF 90W. THIS TROUGH SUPPORTS A CURRENT COLD FRONT THAT 
PASSES THROUGH 32N74W TO THE FLORIDA EAST COAST AT 28N INTO THE 
EASTERN GULF OF MEXICO NEAR 27N88W. HIGH CLOUDS ARE WITHIN 60 NM 
ON EITHER SIDE OF 26N98W 27N90W 28N82W BEYOND 30N76W WITH THE 
UPPER LEVEL SOUTHWESTERLY WIND FLOW. POSSIBLE SHOWERS ARE TO THE 
SOUTH OF THE HIGH CLOUDS TO THE EAST OF 94W. AN UPPER LEVEL 
CYCLONIC CIRCULATION CENTER IS MOVING ACROSS THE ISTHMUS OF 
TEHUANTEPEC.  

THE CARIBBEAN SEA...
THE SOUTHERN END OF THE DEEP LAYER ATLANTIC OCEAN TROUGH PASSES 
ON TOP OF THE EASTERN DOMINICAN REPUBLIC TO 15N74W AND 12N81W...
SLICING THROUGH CENTRAL NICARAGUA...TOWARD THE UPPER LEVEL 
CYCLONIC CENTER THAT IS MOVING ACROSS THE ISTHMUS OF 
TEHUANTEPEC. THE STRONG SHOWERS AND THUNDERSTORMS FROM 
COLOMBIA'S GULF OF URABA TO 12N80W PROBABLY ARE MORE RELATED
TO THE ITCZ AND THE MIDDLE LEVEL TO UPPER LEVEL TROUGH.
ISOLATED MODERATE SHOWERS ARE TO THE SOUTH OF 14N TO THE
EAST OF 68W...RELATED TO THE ITCZ.

THE ATLANTIC OCEAN...
CYCLONIC FLOW FROM A DEEP LAYER TROUGH COVERS THE U.S.A.
TO THE EAST OF 90W. THIS TROUGH SUPPORTS A CURRENT COLD FRONT 
THAT PASSES THROUGH 32N74W TO THE FLORIDA EAST COAST AT 28N
INTO THE EASTERN GULF OF MEXICO NEAR 27N88W. ISOLATED MODERATE 
SHOWERS AND POSSIBLE THUNDERSTORMS IN THE ATLANTIC OCEAN ARE
WITHIN 30 NM TO 60 NM ON 32N72W 28N76W...TO THE BAHAMAS NEAR
26N79W...TO THE UPPER FLORIDA KEYS. A DEEP LAYER CENTRAL 
ATLANTIC OCEAN TROUGH PASSES THROUGH 32N39W TO 30N46W TO 
A 30N60W CYCLONIC CENTER AND TO 24N65W...ACROSS THE EASTERN
DOMINICAN REPUBLIC...INTO THE CARIBBEAN SEA. A COLD FRONT PASSES 
THROUGH 31N40W TO 29N45W TO 28N50W. A STATIONARY FRONT CONTINUES
FROM 28N50W TO 30N60W. ISOLATED MODERATE SHOWERS AND POSSIBLE 
THUNDERSTORMS ARE WITHIN 120 NM TO 180 NM TO THE SOUTH AND 
SOUTHEAST OF THE TROUGH. A MIDDLE LEVEL TO UPPER LEVEL TROUGH 
GOES FROM 24N36W TO 16N39W TO 8N43W. A SURFACE TROUGH FROM 
23N42W TO 17N41W TO 12N44W IS THE REMNANT OF T.D. EIGHT.
SHOWERS AND THUNDERSTORMS FROM 19N TO 20N BETWEEN 40W AND 41W.
AN EASTERN ATLANTIC OCEAN MIDDLE LEVEL TO UPPER LEVEL TROUGH 
PASSES ON TOP OF THE MADEIRA ARCHIPELAGO TO 26N23W TO 20N29W.
NO SURFACE FRONT OR TROUGH IS ACCOMPANIES THIS TROUGH.

$$
MT