000
AXNT20 KNHC 201738
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED MAR 20 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.

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

THE MONSOON TROUGH PASSES THROUGH COASTAL GUINEA NEAR 10N13W TO 
4N21W. THE ITCZ CONTINUES FROM 4N21W TO 1N30W TO THE COAST OF 
BRAZIL NEAR 2S45W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 
2N-5N BETWEEN 27W-45W. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION IS ALONG THE COAST OF BRAZIL FROM 2S-4N BETWEEN 45W-
52W.  
 
...DISCUSSION...

THE GULF OF MEXICO...
                                                
AS OF 1500 UTC...A 1014 MB LOW IS CENTERED OVER THE NE GULF OF 
MEXICO NEAR 28N85W. A COLD FRONT EXTENDS W FROM THE LOW TO 
26N90W TO N OF TAMPICO MEXICO NEAR 24N98W. A WARM FRONT EXTENDS 
E FROM THE LOW ACROSS CENTRAL FLORIDA TO 28N80W. A REINFORCING 
FORMING COLD FRONT IS OVER THE NW GULF FROM 28N85W TO 
BROWNSVILLE TEXAS NEAR 26N97W. 20-25 KT N WINDS AND A COLDER 
AIRMASS IS N OF THIS FORMING FRONT. RADAR IMAGERY AND LIGHTNING 
DETECTION SHOWS WIDELY SCATTERED MODERATE CONVECTION OVER MOST 
OF THE N GULF AND CENTRAL FLORIDA N OF 25N BETWEEN 80W-94W. IN 
THE UPPER LEVELS...THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE 
N GULF N OF 27N. A 90-110 KT JETSTREAM IS FURTHER S OVER THE S 
GULF. UPPER LEVEL DIFFLUENCE E OF THE TROUGH IS ENHANCING 
CONVECTION OVER FLORIDA. IN CONTRAST STRONG SUBSIDENCE IS S OF 
25N WITH MOSTLY FAIR WEATHER. EXPECT IN 24 HOURS FOR A COLD 
FRONT TO EXTEND FROM W CUBA AT 23N80W TO TAMPICO MEXICO WITH 
SHOWERS AND SOME COLD AIR ADVECTION.  

THE CARIBBEAN SEA...
                                                 
A 1008 MB LOW IS CENTERED OVER N COLOMBIA NEAR 5N70W. A 
RELATIVELY LAX SURFACE PRESSURE GRADIENT IS OVER THE CARIBBEAN 
SEA AND CENTRAL AMERICA PRODUCING 10-15 KT TRADEWINDS. SCATTERED 
SHOWERS ARE NOTED OVER E CUBA...HISPANIOLA...PUERTO RICO...AND 
THE E CARIBBEAN E OF 65W. MOSTLY FAIR WEATHER IS OVER THE 
REMAINDER OF THE CARIBBEAN. EXPECT IN 24 HOURS FOR ADDITIONAL  
SCATTERED SHOWERS TO BE OVER THE YUCATAN PENINSULA...THE YUCATAN 
CHANNEL...AND W CUBA DUE TO A COLD FRONT. ALSO EXPECT CONTINUED 
SCATTERED SHOWERS OVER THE E CARIBBEAN. 

THE ATLANTIC OCEAN...
 
A COLD FRONT IS OVER THE W ATLANTIC FROM 32N64W TO 29N75W. A 
STATIONARY FRONT CONTINUES TO CENTRAL FLORIDA NEAR 28N80W. 
SCATTERED SHOWERS ARE WITHIN 45 NM OF THE FRONT. A PREFRONTAL 
TROUGH EXTENDS FROM 30N67W TO 25N73W. A 1020 MB HIGH IS CENTERED 
OVER THE CENTRAL ATLANTIC NEAR 31N51W. A COLD FRONT IS FURTHER E 
OVER THE E ATLANTIC FROM 32N30W TO 27N40W TO 27N46W MOVING E. 
SCATTERED SHOWERS ARE WITHIN 45 NM OF THE FRONT. EXPECT IN 24 
HOURS FOR BOTH COLD FRONTS TO MOVE E WITH SHOWERS OVER THE E 
ATLANTIC FRONT AND CONVECTION OVER THE W ATLANTIC FRONT BETWEEN 
60W-67W.

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

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FORMOSA