000
AXNT20 KNHC 181715
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
205 PM EDT MON APR 18 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION
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.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N10W EQ20W 1S30W 3S40W. 
SCATTERED MODERATE TO STRONG CONVECTION IS FROM 5N-2S E OF 4W... 
AND FROM 2N-7N BETWEEN 9W-13W. SCATTERED MODERATE CONVECTION IS 
FROM 1N-3N BETWEEN 13W-23W. WIDELY SCATTERED MODERATE CONVECTION 
IS FROM EQ-5S BETWEEN 30W-48W.

...DISCUSSION...

THE GULF OF MEXICO...
10-15 KT SE RETURN FLOW WITH FAIR WEATHER DOMINATES FLORIDA AND 
THE GULF OF MEXICO. IN THE UPPER LEVELS...ZONAL FLOW PREVAILS 
WITH STRONG SUBSIDENCE. EXPECT...SOME AIR MASS SHOWERS OVER S 
FLORIDA AND THE WESTERN BAY OF CAMPECHE IN THE AFTERNOON AND 
EVENING HOURS...OTHERWISE EXPECT LITTLE CHANGE OVER THE NEXT 24 
HOURS.  

THE CARIBBEAN SEA...
10-20 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH HIGHEST 
WINDS ALONG THE COAST OF N COLOMBIA. SCATTERED SHOWERS ARE OVER 
PANAMA...N COLOMBIA...AND VENEZUELA S OF 12N BETWEEN 60W-80W. 
MOSTLY FAIR WEATHER IS OVER THE REMAINDER OF THE CARIBBEAN. IN 
THE UPPER LEVELS...ZONAL FLOW DOMINATES THE AREA. UPPER LEVEL 
MOISTURE IS OVER S AMERICA... AND THE S CARIBBEAN S OF 12N. 
STRONG SUBSIDENCE IS OVER THE REMAINDER OF THE SEA. EXPECT 
LITTLE CHANGE OVER THE NEXT 24 HOURS.   

THE ATLANTIC OCEAN...
A SLOW MOVING COLD FRONT IS OVER THE W ATLANTIC FROM 32N70W TO 
29N75W TO 27N80W. SCATTERED MODERATE CONVECTION IS FROM 28N-30N 
BETWEEN 70W-74W. A SURFACE TROUGH IS E OF THE LEEWARD ISLANDS 
FROM 24N59W TO 20N57W TO 13N57W. SCATTERED SHOWERS ARE E OF THE 
TROUGH FROM 19N-26N BETWEEN 52W-57W. SURFACE RIDGING IS OVER THE 
CENTRAL ATLANTIC N OF 20N BETWEEN 37W-52W. A 1012 MB LOW IS OVER 
THE E ATLANTIC NEAR 32N31W. A COLD FRONT EXTENDS S FROM THE LOW 
TO 2831N27W TO 26N30W TO 24N35W. SCATTERED SHOWERS ARE WITHIN 45 
NM OF THE FRONT. A 1002 MB LOW IS ALSO NEAR THE MADEIRA ISLANDS 
AT 34N17W. A SURFACE TROUGH EXTENDS S TOWARDS THE CANARY ISLANDS 
ALONG 30N16W 27N19W. THE TROUGH IS VOID OF ANY PRECIPITATION. IN 
THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE W ATLANTIC 
N OF 25N BETWEEN 60W-80W SUPPORTING THE W ATLANTIC FRONT. 
ANOTHER UPPER LEVEL TROUGH IS OVER THE E ATLANTIC N OF 25N 
BETWEEN 20W-40W SUPPORTING THE E ATLANTIC SURFACE SYSTEMS. 
EXPECT OVER THE NEXT 24 HOURS FOR...THE W ATLANTIC FRONT TO 
DISSIPATE...FOR THE SURFACE TROUGH E OF THE LEEWARD ISLANDS TO 
GENERATE CONVECTION OVER THE CENTRAL ATLANTIC...AND FOR THE LOW 
AT 32N31W TO MOVE SE TO 26N24W WITH SHOWERS.    

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

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FORMOSA