000
AXNT20 KNHC 310513
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
205 AM EDT SUN MAR 31 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0445 UTC.

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

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL 
ATLC NEAR 10N13W AND CONTINUES TO 5N17W WHERE THE ITCZ EXTENDS 
ALONG 2N19W 2N39W THEN S OF THE EQUATOR NEAR 45W. CLUSTERS OF  
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM THE ITCZ 
TO 4N BETWEEN 25W-37W AND FROM 3N TO S OF THE EQUATOR BETWEEN 
37W-46W. 

...DISCUSSION...

GULF OF MEXICO...                                                
AN UPPER RIDGE IS OVER MEXICO TO OVER THE CENTRAL PLAIN STATES 
AMPLIFYING AN UPPER TROUGH OVER THE GULF WITH THE AXIS EXTENDING 
ACROSS APALACHICOLA BAY TO THE NE YUCATAN PENINSULA. THE UPPER 
RIDGE IS ADVECTING UPPER LEVEL MOISTURE ACROSS MEXICO AND TEXAS 
INTO THE FAR W GULF. A SURFACE RIDGE CONTINUES TO DOMINATE THE 
GULF ANCHORED IN THE W ATLC. SOUTHERLY RETURN SURFACE FLOW 
COVERS THE N GULF AND IS GENERATING ISOLATED SHOWERS OVER THE NE 
GULF FROM 25N-29N BETWEEN 84W-90W LEAVING THE REMAINDER OF THE 
GULF UNDER CLEAR SKIES TONIGHT. SURFACE RIDGE WILL PREVAIL 
THROUGH TUE. A COLD FRONT WILL CLIP THE N GULF ON MON. A SECOND 
STRONGER COLD FRONT IS EXPECTED TO REACH THE GULF WED AND EXTEND 
FROM FLORIDA BIG BEND TO THE YUCATAN PENINSULA THU NIGHT. 

CARIBBEAN SEA...                                                
A BROAD UPPER RIDGE OVER THE TROPICAL ATLC TO OVER THE E ATLC IS 
GIVING THE CARIBBEAN SW FLOW ALOFT. THE REMNANTS OF A FRONT IS  
ANALYZED AS A SHEAR AXIS EXTENDING ACROSS THE LEEWARD/VIRGIN 
ISLANDS NEAR 18N62W TO SW HAITI NEAR 18N74W. SCATTERED SHOWERS 
ARE N OF THE SHEAR AXIS AND FROM 14N TO THE SHEAR AXIS BETWEEN 
62W-68W. REMNANT MOISTURE WITH POSSIBLE ISOLATED SHOWERS ARE 
OVER THE NW CARIBBEAN FROM 15N-21N BETWEEN 78W-86W INCLUDING 
JAMAICA AND THE CAYMAN ISLANDS. A TIGHT PRESSURE GRADIENT EXISTS 
BETWEEN THE LOWER PRESSURE OF SOUTH AMERICA AND THE SURFACE 
RIDGE OVER THE W ATLC PRODUCING FRESH TO STRONG TRADE WINDS THAT 
WILL PREVAIL OVER THE CENTRAL CARIBBEAN THROUGH MON AS THE W 
ATLC SURFACE RIDGE SHIFTS SLOWLY EASTWARD. 

ATLANTIC OCEAN...                                               
A SURFACE RIDGE COVERS THE W INTO THE CENTRAL ATLC W OF 50W 
ACROSS FLORIDA INTO THE GULF OF MEXICO AND IS ANCHORED BY A 1027 
MB HIGH NEAR 30N71W. A BROAD UPPER TROUGH COVERS THE E ATLC N OF 
THE DISCUSSION AREA SUPPORTING A COLD FRONT THAT ENTERS THE 
REGION NEAR 32N30W AND EXTENDS ALONG 25N38W TO 20N51W THEN 
DISSIPATES TO THE THE LEEWARD/VIRGIN ISLANDS NEAR 18N62W WHERE 
IT BECOMES A SHEAR AXIS AS IT EXTENDS OVER THE GREATER ANTILLES. 
ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM EITHER SIDE OF THE 
FRONT. SCATTERED SHOWERS ARE N OF THE DISSIPATING FRONT/SHEAR 
AXIS ACROSS THE GREATER ANTILLES TO 22N BETWEEN 60W-73W. A BROAD 
UPPER RIDGE DOMINATES THE REMAINDER OF THE ATLC ANCHORED NEAR 
20N28W. W ATLC SURFACE RIDGE WILL PREVAIL ACROSS THE AREA 
THROUGH TUE THEN SHIFT EASTWARD. A COLD FRONT WILL SWEEP PAST 
NORTHERN WATERS TUE AND WED.

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

$$
PAW