000
AGXX40 KNHC 210704
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
305 AM EDT SUN APR 21 2013

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN
SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND
64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS.

GULF OF MEXICO...                                                
THE UPPER LEVEL TROUGH SUPPORTING THE COLD FRONT IN THE GULF OF 
MEXICO HAS LIFTED OUT LEAVING A STATIONARY FRONT EXTENDING FROM 
SW FLORIDA TO THE E BAY OF CAMPECHE. WINDS AND SEAS HAVE COME 
DOWN CONSIDERABLY FROM LAST NIGHT...AND WINDS AND SEAS HAVE 
FALLEN BELOW ADVISORY CRITERIA. LATEST SURFACE OBSERVATIONS 
DEPICT MODERATE TO FRESH WINDS AND SEAS IN THE 4-6 FT RANGE 
PREVAILING OVER THE MAJORITY OF THE GULF WATERS...EXCEPT FOR A 
SMALL PORTION IN THE CENTRAL GULF WITH SEAS TO 7 FT. THE 
STATIONARY FRONT WILL DISSIPATE TODAY LEAVING A SURFACE TROUGH 
OVER THE SW GULF AND BAY OF CAMPECHE. THIS TROUGH WILL LINGER 
THROUGH AT LEAST MON BEFORE DISSIPATING. WINDS AND SEAS WILL 
FURTHER DECREASE OVER THE FIRST HALF OF THE WEEK.

HIGH PRESSURE BUILDING OVER THE SE UNITED STATES WILL HELP FOR 
ANTICYCLONIC FLOW ACROSS THE GULF WATERS WITH SE RETURN FLOW 
SETTING UP OVER THE WESTERN GULF BY TUE MORNING. ALL THE MODELS 
ARE IN AGREEMENT WITH A COLD FRONT WILL SHIFT INTO THE NW GULF 
WATERS ON WEDNESDAY. THERE WAS SOME DISAGREEMENT IN PREVIOUS 
MODEL RUNS AS TO HOW FAR THE FRONT WILL MAKE IT ACROSS THE GULF 
WATERS. NOW THE MODEL GUIDANCE IS COMING INTO MORE OF AN 
AGREEMENT THAT THE FRONT WILL NOT MAKE IT VERY FAR INTO THE GULF 
WATERS...LIKELY STALLING OVER THE FAR NORTHERN GULF WATERS BY 
THU. 
 
CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W...       
HIGH PRESSURE RIDGE N OF THE AREA CONTINUES TO WEAKEN. IN 
RESPONSE...THE PRESSURE GRADIENT OVER ALL FORECAST WATERS HAS 
WEAKENED. AS A RESULT WINDS AND SEAS HAVE FALLEN BELOW ADVISORY 
CRITERIA OVER THE CARIBBEAN WATERS. LATEST OBSERVATIONS DEPICT 
MODERATE TO FRESH WINDS ACROSS THE EASTERN AND CENTRAL 
CARIBBEAN...AND LIGHT TO GENTLE WINDS OVER THE WESTERN 
CARIBBEAN. SEAS ARE IN THE 5-7 FT RANGE OVER THE EASTERN AND 
CENTRAL CARIBBEAN...AND 3-4 FT OVER THE WESTERN CARIBBEAN. 
MODERATE TO FRESH WINDS WITH SEAS IN THE 6-9 FT RANGE IN NE 
SWELL PREVAILS OVER THE TROPICAL N ATLC WATERS. THE NE SWELLS 
ACROSS THE TROPICAL N ATLC WILL SUBSIDE TO 6-7 FT BY TONIGHT 
THROUGH MOST OF WED...THEN LOWER TO 5-6 FT INTO THU.

THE SURFACE RIDGE WILL CONTINUE TO WEAKEN TODAY...AND IS NOT 
EXPECTED TO BUILD N OF THE AREA THROUGH THE FORECAST PERIOD. 
THIS WILL KEEP WINDS AND SEAS BELOW ADVISORY CRITERIA THROUGH 
THU. 

SW N ATLC S OF 31N W OF 55W...                                   
A STATIONARY FRONT EXTENDS FROM 31N75W TO SOUTH FLORIDA. LATEST 
OBSERVATIONS DEPICT MODERATE N WINDS AND SEAS IN THE 4-6 FT 
RANGE W OF THE FRONT. A WEAK SURFACE RIDGE EXTENDS FROM 31N61W 
TO NEAR 27N73W. LATEST OBSERVATIONS SHOW MODERATE TO FRESH 
TRADES AND SEAS 6-8 FT OVER THE SE PART OF THE FORECAST 
AREA...AND GENTLE TO MODERATE E TO SE WINDS WITH SEAS 4-7 FT 
OVER THE REMAINDER OF THE FORECAST AREA...EXCEPT W OF THE 
BAHAMAS WHERE SEAS ARE IN THE 2-4 FT RANGE. 

THE STATIONARY FRONT WILL WEAKEN TO A TROUGH TODAY. HIGH 
PRESSURE BUILDING W OF THE TROUGH AXIS WILL STRENGTHEN WINDS 
OVER THE NW PART OF THE FORECAST AREA WITH SEAS BUILDING TO 10 
FT BY MON. MODELS COMING INTO AGREEMENT THAT THE TROUGH WILL 
DRIFT WESTWARD THROUGH MON...THEN WEAKEN AND SHIFT EASTWARD 
THROUGH WED. WITH THE TROUGH WEAKENING...WINDS WILL DIMINISH 
WEST OF THE TROUGH AXIS BY TUE. 
                                 
.WARNINGS...ANY CHANGES WILL BE COORDINATED THROUGH AWIPS 12
PLANET CHAT OR BY TELEPHONE:

.GULF OF MEXICO...                                             
GMZ011...NONE.                                        
GMZ013...NONE.                                        
GMZ015...NONE.                                          
GMZ017...NONE.                                      
GMZ019...NONE.                                     
GMZ021...NONE.                                       
GMZ023...NONE.                        
GMZ025...NONE.

.CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
AMZ011...NONE.
AMZ013...NONE.
AMZ015...NONE.
AMZ017...NONE.
AMZ019...NONE.
AMZ021...NONE.
AMZ023...NONE.
AMZ025...NONE.
AMZ027...NONE.
AMZ029...NONE.
AMZ031...NONE.
AMZ033...NONE.
AMZ035...NONE.
AMZ037...NONE.
AMZ039...NONE.

.SW N ATLANTIC INCLUDING THE BAHAMAS...
AMZ111...NONE.
AMZ113...NONE.
AMZ115...NONE.
AMZ117...NONE.
AMZ119...NONE.
AMZ121...NONE.
AMZ123...NONE.
AMZ125...NONE.
AMZ127...NONE.

*FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT:
HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF

NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE
NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT:
HTTP://PREVIEW.WEATHER.GOV/GRAPHICAL

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

$$
FORECASTER AL