000
AXNT20 KNHC 152355
TWDAT 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL 
805 PM EDT MON APR 15 2013

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...WEATHER
OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...THE ITCZ/THE MONSOON TROUGH... 

THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST OF SIERRA 
LEONE NEAR 7N12W TO 4N13W. THE INTERTROPICAL CONVERGENCE ZONE 
AXIS EXTENDS FROM 4N13W TO 2N20W TO 1S30W TO THE COAST OF BRAZIL 
NEAR 3S40W. ISOLATED MODERATE CONVECTION IS FROM 3S-4N BETWEEN 
18W-25W...AND FROM 6S-1S BETWEEN 25W-32W.

...DISCUSSION...

THE GULF OF MEXICO...

AS OF 2100 UTC...THE TAIL END OF A COLD FRONT EXTENDS FROM THE W 
ATLANTIC TO S OF ST AUGUSTINE FLORIDA AT 30N81W TO THE GEORGIA 
BORDER AT 31N83W. RADAR IMAGERY SHOWS NO PRECIPITATION ALONG THE 
FRONT. THERE IS HOWEVER A WIND SHIFT AND A TEMPERATURE DROP OF 
15 DEGREES ALONG THE FRONT. ELSEWHERE OVER S FLORIDA AND THE 
STRAITS OF FLORIDA RADAR IMAGERY DOES SHOW SCATTERED SHOWERS AND 
SCATTERED THUNDERSTORMS S OF 27N. THE REMAINDER OF THE GULF OF 
MEXICO HAS 10-15 KT SOUTHERLY SURFACE WINDS AND MOSTLY FAIR 
WEATHER. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS PRODUCING 
SW FLOW OVER THE GULF. STRONG SUBSIDENCE IS ALSO OVER MOST OF 
THE GULF. EXPECT IN 24 HOURS FOR THE COLD FRONT TO BE ENTIRELY 
OVER THE W ATLANTIC. ALSO EXPECT CONTINUES 10-15 KT SE SURFACE 
FLOW OVER THE ENTIRE GULF AND MOSTLY FAIR WEATHER. 

THE CARIBBEAN SEA...                                             
   
A 1004 MB LOW IS CENTERED OVER N COLOMBIA NEAR 7N73W. SCATTERED 
MODERATE CONVECTION IS INLAND OVER N COLOMBIA AND W VENEZUELA. 
ISOLATED MODERATE CONVECTION IS OVER PANAMA AND COSTA RICA DUE 
TO THE MONSOON TROUGH. 15-20 KT TRADEWINDS ARE OVER THE 
CARIBBEAN SEA. STRONGEST WINDS ARE OVER THE CENTRAL CARIBBEAN S 
OF JAMAICA BETWEEN 70W-80W. MORE SCATTERED SHOWERS ARE NOTED 
OVER THE HIGHER ELEVATIONS OF PUERTO RICO...HISPANIOLA AND CUBA. 
IN THE UPPER LEVELS... AN UPPER LEVEL HIGH IS CENTERED OVER N 
COLOMBIA NEAR 11N75W. A BAND OF SCATTERED HIGH CLOUDS ARE NOTED 
OVER THE W CARIBBEAN AND CENTRAL AMERICA W OF 70W MOVING AROUND 
THE UPPER LEVEL HIGH. EXPECT IN 24 HOURS FOR AN AREA OF SHOWERS  
TO ADVECT OVER THE E CARIBBEAN E OF 63W. EXPECT LITTLE CHANGE 
OVER THE REMAINDER OF THE CARIBBEAN.  

THE ATLANTIC OCEAN...                                 
              
A 1016 MB LOW IS OFF THE COAST OF SOUTH CAROLINA NEAR 32N75W. A 
COLD FRONT EXTENDS SW FROM THE LOW TO S OF ST AUGUSTINE FLORIDA 
NEAR 30N81W. SCATTERED SHOWERS ARE WITHIN 240 NM E OF THE LOW.  
A 1023 MB HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 
28N58W. ANOTHER 1023 MB HIGH IS OVER THE E ATLANTIC NEAR 29N30W. 
OF NOTE IN THE UPPER LEVELS...TWO UPPER LEVEL LOWS ARE CENTERED 
OVER THE TROPICAL ATLANTIC NEAR 25N53W...AND 23N34W. UPPER LEVEL 
DIFFLUENCE AND SCATTERED SHOWERS ARE E OF THE LOW AT 23N34W FROM 
13N-27N BETWEEN 15W-33W. EXPECT IN 24 HOURS FOR THE SURFACE LOW 
TO MOVE SE TO NEAR 29N68W WITH CONVECTION. ALSO EXPECT SCATTERED 
SHOWERS OVER THE BAHAMAS. 

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

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FORMOSA