000
AXNT20 KNHC 111727
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT APR 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N10W CROSSING THE EQUATOR NEAR 20W 
TO 3S30W TO E BRAZIL NEAR 5S37W. SCATTERED MODERATE TO STRONG 
CONVECTION IS FROM EQ-4N BETWEEN 11W-23W. WIDELY SCATTERED 
MODERATE CONVECTION IS FROM 1S-5S BETWEEN 23W-29W. SIMILAR 
CONVECTION IS ALONG THE COAST OF BRAZIL FROM 1S-3S BETWEEN 
38W-44W. 

...DISCUSSION...

GULF OF MEXICO...
AS OF 1500 UTC...A COLD FRONT EXTENDS FROM THE FLORIDA PANHANDLE 
TO THE CENTRAL GULF OF MEXICO ALONG 30N83W 29N90W. A STATIONARY 
FRONT CONTINUES W TO S TEXAS TO 27N97W. SCATTERED SHOWERS ARE 
WITHIN 30 NM OF THE FRONTS. 15-20 KT NORTHERLY WINDS ARE N OF 
THE FRONTS WHILE 10 KT SOUTHERLY WINDS DOMINATES THE REMAINDER 
OF THE GULF. MOSTLY FAIR WEATHER IS S OF THE FRONTS. IN THE 
UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER THE GULF WITH AXIS 
ALONG 90W. SIGNIFICANT UPPER LEVEL MOISTURE IS OVER THE N GULF N 
OF 23N. STRONG SUBSIDENCE COVERS THE YUCATAN PENINSULA AND THE 
YUCATAN CHANNEL. EXPECT IN 24 HOURS...THE COLD FRONT TO MOVE TO 
CENTRAL FLORIDA WHILE THE STATIONARY FRONT RETROGRADES BACK 
NORTH TO LOUISIANA WITH CONVECTION.  

CARIBBEAN SEA...
FRESH TRADEWINDS ARE OVER THE CARIBBEAN AND CENTRAL AMERICA WITH 
STRONGEST WINDS ALONG THE COAST OF N COLOMBIA. A SURFACE TROUGH 
EXTENDS FROM JAMAICA TO N COLOMBIA ALONG 78W. SCATTERED SHOWERS 
ARE OVER THE SW CARIBBEAN S OF 13N TO INCLUDE THE COASTS OF 
PANAMA AND COSTA RICA. SCATTERED SHOWERS ARE ALSO OVER 
HISPANIOLA...AND THE WINDWARD ISLANDS S OF 13N. IN THE UPPER 
LEVELS...ZONAL FLOW IS OVER THE CARIBBEAN WITH STRONG 
SUBSIDENCE. EXPECT...THE SURFACE TROUGH TO MOVE W AND PRODUCE 
SHOWERS OVER SOUTHERN CENTRAL AMERICA OVER THE NEXT 24 HOURS.  

ATLANTIC OCEAN...
A 1027 MB HIGH IS OVER THE W ATLANTIC NEAR 36N50W. A SURFACE 
RIDGE AXIS EXTENDS SW TO THE NORTHERN BAHAMA ISLANDS. A FRONTAL 
TROUGH IS FURTHER E FROM 32N49W TO 28N55W. A 1030 MB HIGH IS 
OVER THE E ATLANTIC NEAR 36N29W. IN THE UPPER LEVELS...ZONAL 
FLOW IS OVER THE W ATLANTIC W OF 70W. AN UPPER LEVEL LOW IS OVER 
THE W ATLANTIC NEAR 26N52W. ANOTHER UPPER LEVEL LOW IS OVER THE 
E ATLANTIC NEAR 25N29W. A LARGE UPPER LEVEL HIGH IS OVER THE 
TROPICAL ATLANTIC NEAR 5N36W. ANTICYCLONIC FLOW IS FROM 15N-10S 
BETWEEN 20W-60W.

$$
FORMOSA