000
AXNT20 KNHC 232337
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU APR 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N9W 1N20W CROSSING THE EQUATOR NEAR 
23W TO 1S30W AND INLAND OVER NE BRAZIL NEAR 3S40W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 2S-4S BETWEEN 
6W-10W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 3N-2S 
BETWEEN 17W-25W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 2100 UTC...A 1023 MB HIGH IS CENTERED OVER THE NE GULF OF 
MEXICO NEAR 29N85W PRODUCING FAIR WEATHER. 5-10 KT ANTICYCLONIC 
SURFACE WINDS ARE OVER THE NE GULF...WHILE 20 KT E WINDS ARE 
OVER THE STRAITS OF FLORIDA. SIMILAR 20 KT SE WINDS ARE OVER THE 
W GULF W OF 92W. LOW LEVEL HAZE IS ALSO OVER THE BAY OF CAMPECHE 
AND THE W GULF W OF 92 DUE TO SMOKE. IN THE UPPER LEVELS...ZONAL 
FLOW IS OVER THE GULF. STRONG SUBSIDENCE COVERS THE ENTIRE GULF 
ENHANCING THE FAIR WEATHER. EXPECT...THE SURFACE HIGH TO MOVE TO 
THE W ATLANTIC OVER THE NEXT 24 HOURS. THIS WILL GENERATE SE 
SURFACE RETURN FLOW OVER THE ENTIRE GULF. ALSO EXPECT SCATTERED 
SHOWERS ALONG THE COAST OF TEXAS...AND FAIR WEATHER OVER THE E 
GULF AND FLORIDA. FURTHERMORE...WINDS WILL REMAIN STRONG OVER 
THE STRAITS OF FLORIDA WITH 20-25 KT OVER THE NEXT 24 HOURS. 

CARIBBEAN SEA... 
AS OF 2100 UTC...THE TAIL END OF A COLD FRONT IS OVER W 
HISPANIOLA NEAR 20N72W. SCATTERED SHOWERS ARE OVER W HISPANIOLA 
FROM 17N-21N BETWEEN 71W-75W. FRESH TRADES ARE OVER THE 
CARIBBEAN SEA WITH STRONGEST WINDS ALONG THE COAST OF N 
COLOMBIA. SCATTERED SHOWERS ARE OVER THE LEEWARD 
ISLANDS...PUERTO RICO...HONDURAS ...AND THE GULF OF HONDURAS. 
CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE 
ALONG THE COASTS OF PANAMA AND COSTA RICA FROM 7N-12N BETWEEN 
76W-86W. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER THE 
CARIBBEAN WITH AXIS ALONG 70W. CONSIDERABLE UPPER LEVEL MOISTURE 
IS OVER THE SW CARIBBEAN. STRONG SUBSIDENCE IS OVER THE 
REMAINDER OF THE CARIBBEAN. EXPECT...THE COLD FRONT TO MOVE E TO 
N OF PUERTO RICO OVER THE NEXT 24 HOURS WITH CONVECTION. ALSO 
EXPECT SHOWERS AND CONVECTION OVER THE NW CARIBBEAN AND THE 
YUCATAN PENINSULA OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
AS OF 2100 UTC...A COLD FRONT IS OVER THE W ATLANTIC ALONG 
32N61W 26N66W TO W HISPANIOLA NEAR 20N72W. SCATTERED SHOWERS ARE 
WITHIN 60 NM E OF THE FRONT. A DOMINATE 1038 MB HIGH IS OVER THE 
CENTRAL ATLANTIC NEAR 41N41W. THIS HIGH IS PRODUCING FAIR 
WEATHER AND NE SURFACE FLOW OVER THE ATLANTIC FROM 10N-30N E OF 
60W. IN THE UPPER LEVELS...ZONAL FLOW IS OVER THE W ATLANTIC W 
OF 70W. A SHARP UPPER LEVEL RIDGE IS OVER THE CENTRAL ATLANTIC 
WITH AXIS FROM THE LEEWARD ISLANDS NEAR 18N64W TO BEYOND 32N51W. 
A SHARP UPPER LEVEL TROUGH IS FURTHER E OVER THE E ATLANTIC WITH 
AXIS FROM FRENCH GUIANA NEAR 5N53W TO BEYOND 32N32W. AN UPPER 
LEVEL HIGH IS CENTERED OFF THE COAST OF W AFRICA NEAR 7N16W. 
EXPECT... THE FRONT OVER THE W ATLANTIC TO MOVE E WITH 
CONVECTION TO 32N55W OVER THE NEXT 24 HOURS.

$$
FORMOSA