000
AXNT20 KNHC 121028
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE MAY 12 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.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N8W 2N20W CROSSING THE EQUATOR 
NEAR 33W AND CONTINUES TO NE BRAZIL NEAR 3S40W. SCATTERED 
MODERATE CONVECTION IS FROM 6N-7N BETWEEN 12W-14W. ISOLATED 
MODERATE CONVECTION IS FROM 3N-4N BETWEEN 20W-28W. WIDELY 
SCATTERED MODERATE CONVECTION IS FROM 1N-3N BETWEEN 33W-36W... 
AND FROM 1S-4S BETWEEN 21W-25W. 

...DISCUSSION...

GULF OF MEXICO...
AS OF 0900 UTC...A 1014 MB LOW IS CENTERED OVER N FLORIDA NEAR 
27N83W. A COLD FRONT EXTENDS FROM 31N77W TO THE LOW CENTER TO SE 
LOUISIANA NEAR 30N90W. PRECIPITATION NEAR THE FRONT HAS RECENTLY 
DISSIPATED OVER FLORIDA AND THE GULF OF MEXICO. ELSEWHERE... 
SCATTERED MODERATE CONVECTION IS INLAND OVER NE MEXICO FROM 
25N-27N BETWEEN 98W-100W. WINDS S OF THE FRONT REMAIN 10-15 KT 
FROM THE SE. A PATCH OF OVERCAST LOW CLOUDS ARE OVER THE S BAY 
OF CAMPECHE S OF 19N. SCATTERED TO BROKEN HIGH CLOUD HAS 
ADVECTED OVER THE W GULF W OF 90W FROM N MEXICO. FAIR SKIES 
PERSIST OVER THE SE GULF. IN THE UPPER LEVELS...A RIDGE IS 
MOVING INTO THE W GULF W OF 90W PRODUCING NW UPPER LEVEL FLOW 
AND CLOUDINESS. STRONG SUBSIDENCE REMAINS OVER THE SE GULF. 
EXPECT...THE SURFACE LOW AND COLD FRONT TO DRIFT TO CENTRAL 
FLORIDA OVER THE NEXT 24 HOURS WITH CONVECTION.  

CARIBBEAN SEA...
FRESH TRADES CONTINUE OVER THE CARIBBEAN SEA WITH STRONGEST 
WINDS ALONG THE COAST OF N COLOMBIA. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION IS OVER PANAMA AND COSTA RICA FROM 
6N-10N BETWEEN 79W-86W. ELSEWHERE...A SURFACE TROUGH IS OVER THE 
LEEWARD ISLANDS FROM 19N65W TO 13N60W. RAIN AND SHOWERS ARE OVER 
THE LEEWARD ISLANDS...PUERTO RICO...AND HISPANIOLA N OF 15N AND 
E OF 74W. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS 
PRODUCING SW-W FLOW OVER THE CARIBBEAN. CONSIDERABLE UPPER LEVEL 
MOISTURE IS OVER THE CARIBBEAN EXCEPT OVER THE NW CARIBBEAN 
WHERE STRONG SUBSIDENCE PERSISTS. EXPECT...THE SURFACE TROUGH TO 
MOVE W OVER THE NEXT 24 HOURS WITH SHOWERS. 

ATLANTIC OCEAN...
PREFRONTAL ACTIVITY IS PRODUCING SCATTERED MODERATE CONVECTION 
OFF THE COAST OF N FLORIDA FROM 29N-31N BETWEEN 77W-79W. A LARGE 
1025 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 31N43W PRODUCING 
MAINLY FAIR WEATHER. A SURFACE RIDGE AXIS EXTENDS W TO 28N65W.  
IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER THE W 
ATLANTIC N OF 20N BETWEEN 55W-65W. AN UPPER LEVEL LOW IS 
CENTERED OVER THE CENTRAL ATLANTIC NEAR 24N42W. IN THE TROPICS 
...A LARGE UPPER LEVEL HIGH IS CENTERED NEAR 4N35W WITH A RIDGE 
AXIS EXTENDING W TO 4N55W. EXPECT...THE COLD FRONT OVER N 
FLORIDA TO DRIFT E OVER THE NEXT 24 HOURS WITH CONVECTION. 

$$
FORMOSA