000
AXNT20 KNHC 201053
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON JUL 20 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...
A NEW TROPICAL WAVE IS ALONG 27W TO THE SOUTH OF 14N...BASED
ON SATELLITE IMAGERY. POSSIBLE SHOWERS ARE FROM 5N TO 10N
BETWEEN 24W AND 30W.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 45W TO THE SOUTH
OF 16N MOVING WESTWARD 15 KT. NO NEARBY PRECIPITATION.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 55W TO THE SOUTH OF 17N
MOVING WESTWARD 15 TO 20 KT. STRONG SHOWERS AND THUNDERSTORMS
IN CLUSTERS COVER THE AREA FROM 12N TO 14N BETWEEN 56W AND 58W...
JUST TO THE EAST OF BARBADOS. OTHER SHOWERS ARE POSSIBLE FROM
10N TO 12N BETWEEN 46W AND 50W...AND FROM 10N TO 20N BETWEEN 50W 
AND 60W. AN UPPER LEVEL TROUGH GOES FROM A CYCLONIC CIRCULATION
CENTER NEAR 29N58W TO 17N58W TO 13N57W.
 
A TROPICAL WAVE GOES FROM THE ATLANTIC OCEAN INTO THE CARIBBEAN 
SEA...FROM 24N73W...TO 17N74W...8N74W IN NORTHERN COLOMBIA. THIS 
WAVE IS MOVING WESTWARD 15 TO 20 KT. UPPER LEVEL ANTICYCLONIC
FLOW COVERS THE CARIBBEAN SEA.

...THE ITCZ...
FROM AFRICA NEAR 14N17W TO 6N35W TO 7N54W. STRONG SHOWERS AND
THUNDERSTORMS ARE FROM 13N TO 14N BETWEEN 17W AND 18W...AND 
FROM 5N TO 8N BETWEEN 31W AND 33W. ISOLATED MODERATE SHOWERS
ARE ELSEWHERE FROM 4N TO 7N BETWEEN 33W AND 48W.

...DISCUSSION...

THE GULF OF MEXICO...
A MIDDLE LEVEL TO UPPER LEVEL PASSES THROUGH CENTRAL ALABAMA
TO 25N90W IN THE CENTRAL GULF OF MEXICO. ANY PRECIPITATION
THAT WAS ACCOMPANYING THIS TROUGH SIX HOURS OR MORE EARLIER HAS 
DISSIPATED AT THIS TIME. CLOUDS ARE TO THE NORTH OF 24N98W 
22N90W 27N83W. A STATIONARY FRONT PASSES THROUGH THE FLORIDA 
PANHANDLE INTO SOUTHEASTERN LOUISIANA AND BEYOND EAST TEXAS.

THE CARIBBEAN SEA...
THE BASE OF A MIDDLE LEVEL TO UPPER LEVEL TROUGH REACHES JUST
TO THE EAST OF BARBADOS. UPPER LEVEL ANTICYCLONIC FLOW MOVES
FROM THE GULF OF HONDURAS TO JAMAICA AND BEYOND THE WINDWARD
PASSAGE. THE SOUTHERN END OF AN UPPER LEVEL TROUGH THAT STARTS
FROM AN ATLANTIC OCEAN 27N75W CYCLONIC CIRCULATION CENTER 
REACHES THE NORTHWESTERN CARIBBEAN SEA JUST TO THE SOUTH OF 
CUBA. ISOLATED MODERATE SHOWERS IN CLUSTERS ARE FROM 16N TO 18N 
BETWEEN 80W AND THE GULF OF HONDURAS. MIDDLE LEVEL TO UPPER 
LEVEL CYCLONIC FLOW COVERS THE AREA FROM 10N TO NORTHEASTERN 
NICARAGUA BETWEEN 80W AND 85W. SHOWERS AND THUNDERSTORMS ARE
IN THE WATERS TO THE SOUTH OF 12N BETWEEN 80W AND LAND. 
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE FROM 3N TO 9N
BETWEEN 73W AND 80W...INCLUDING IN THE EASTERN PACIFIC OCEAN
ALONG THE COLOMBIA COAST AND IN NORTHERN COLOMBIA. THIS 
PRECIPITATION IS OCCURRING IN AN AREA OF BROAD SURFACE LOW 
PRESSURE...THE ITCZ...AND AN ADVANCING TROPICAL WAVE.

THE ATLANTIC OCEAN...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 27N75W
CYCLONIC CIRCULATION CENTER INTO THE NORTHWESTERN CARIBBEAN SEA
JUST TO THE SOUTH OF CUBA. WIDELY SCATTERED TO SCATTERED 
MODERATE SHOWERS AND ISOLATED STRONG THUNDERSTORMS COVER THE 
AREA TO THE NORTH OF 20N BETWEEN 63W AND 80W ALONG THE FLORIDA 
COAST MOSTLY. THIS PRECIPITATION IS OCCURRING BETWEEN THE 27N75W
CYCLONIC CENTER AND THE 29N58W 13N57W TROUGH THAT REACHES JUST TO
THE EAST OF BARBADOS. AN UPPER LEVEL TROUGH PASSES FROM THE 
MADEIRA ARCHIPELAGO TO 28N26W TO 20N30W...NO PRECIPITATION 
ACCOMPANIES THIS TROUGH. BROAD SURFACE ANTICYCLONIC FLOW COVERS 
THE AREA. A SURFACE RIDGE EXTENDS FROM 28N77W BEYOND BERMUDA.

$$
MT