000
AXNT20 KNHC 091712
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SAT MAR 09 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH COASTAL SIERRA LEONE NEAR 
8N13W TO 2N21W. THE ITCZ CONTINUES FROM 2N21W TO 0N37W TO THE  
COAST OF NORTHEASTERN BRAZIL NEAR 2S45W. ISOLATED MODERATE 
CONVECTION IS S OF THE MONSOON TROUGH FROM 1N-5N BETWEEN 1W-6W. 
WIDELY SCATTERED MODERATE CONVECTION IS ALONG THE ITCZ FROM 
5S-3N BETWEEN 22W-38W.

...DISCUSSION...

THE GULF OF MEXICO...
A 1026 MB HIGH IS CENTERED OVER GEORGIA NEAR 33N83W. 15-20 KT SE 
SURFACE FLOW IS OVER THE ENTIRE GULF OF MEXICO. THE SURFACE 
RETURN FLOW IS PRODUCING OVERCAST LOW CLOUDS OVER THE NW GULF 
WITH SCATTERED RAIN AND SHOWERS ALONG THE LOUISIANA AND TEXAS 
COASTS. IN THE UPPER LEVELS...WESTERLY DIFFLUENT FLOW IS OVER 
THE GULF PRODUCING BROKEN TO OVERCAST HIGH CLOUDS OVER THE N 
GULF N OF 25N. FAIR WEATHER IS S OF 25N. EXPECT IN 24 HOURS FOR 
A COLD FRONT TO BE INLAND OVER S TEXAS WITH MORE RAIN AND 
SHOWERS. ALSO EXPECT THE SURFACE PRESSURE GRADIENT TO INCREASE 
OVER THE GULF WITH 20-25 KT SW WINDS THROUGHOUT.   

THE CARIBBEAN SEA...
THE TAIL END OF A COLD FRONT IS OVER THE NE CARIBBEAN FROM 
20N63W TO PUERTO RICO AT 18N67W. SCATTERED SHOWERS ARE OVER 
PUERTO RICO AND HISPANIOLA FROM 17N-20N BETWEEN 65W-74W. 10-25 
KT TRADEWINDS ARE OVER THE REMAINDER OF THE CARIBBEAN WITH 
HIGHEST WINDS ALONG THE COAST OF N COLOMBIA. A 1008 MB LOW IS 
CENTERED OVER N COLOMBIA NEAR 9N75W. SCATTERED SHOWERS ARE OVER 
THE SW CARIBBEAN...PANAMA...COSTA RICA...AND NICARAGUA FROM 
7N-14N BETWEEN 76W-85W. THE REMAINDER OF THE CARIBBEAN SEA HAS 
MOSTLY FAIR WEATHER. IN THE UPPER LEVELS...THE WESTERN END OF AN 
UPPER LEVEL RIDGE IS PRODUCING SW UPPER LEVEL FLOW OVER THE 
ENTIRE AREA. EXPECT IN 24 HOURS FOR MORE ZONAL UPPER LEVEL FLOW 
TO OCCUR. ALSO EXPECT THE SURFACE FRONT IN 24 HOURS TO BE NE OF 
THE LEEWARD ISLANDS. ELSEWHERE...THE TRADEWINDS WILL PERSIST 
WITH THE ADDITION OF SCATTERED SHOWERS ALONG THE COAST OF 
VENEZUELA.    

THE ATLANTIC OCEAN...
A 988 MB LOW IS N OF THE AREA OVER THE W ATLANTIC NEAR 36N64W. A 
TIGHT SURFACE PRESSURE GRADIENT S OF THE LOW IS PRODUCING A GALE 
N OF 29N BETWEEN 60W-68W. A COLD FRONT ENTERS THE CENTRAL 
ATLANTIC NEAR 31N45W AND EXTENDS SW TO THE LEEWARD ISLANDS AT 
20N63W. SCATTERED SHOWERS ARE WITHIN 120 NM N OF THE FRONT. A 
PREFRONTAL TROUGH ALSO EXTENDS FROM 31N43W TO 23N50W TO 20N55W. 
SCATTERED SHOWERS ARE WITHIN 45 NM OF THIS TROUGH. A 1023 MB 
HIGH IS CENTERED OVER THE E ATLANTIC W OF THE CANARY ISLANDS 
NEAR 28N30W. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER 
THE W ATLANTIC N OF 20N BETWEEN 50W-80W. AN UPPER LEVEL RIDGE IS 
N OF 20N E OF 50W TO WEST AFRICA. EXPECT OVER THE NEXT 24 HOURS 
FOR THE COLD FRONT TO MOVE E AND BE FROM 31N38W TO 18N60W WITH 
SHOWERS AND THUNDERSTORMS.   

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

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FORMOSA