000
AGXX40 KNHC 291900
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
300 PM EDT MON APR 29 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... 
RIDGING PERSISTS FROM A 1026 MB HIGH OFF NEW ENGLAND...DOWN THE
EASTERN SEABOARD...ACROSS THE FLORIDA PENINSULA TO THE TEXAS
COAST. LOWEST PRESSURE IS LOCATED IN THE SW GULF. BUOY AND THE
1456Z SCATTEROMETER DATA SHOW ONLY GENTLE TO MODERATE BREEZE
PREVAILING IN E TO SE FLOW OVER ENTIRE GULF THIS AFTERNOON. SEAS
ARE RUNNING 2 TO 4 FT OVERALL. LITTLE CHANGE IS EXPECTED THROUGH
WED. A DEEP LAYER TROUGH DIGS INTO THE PLAINS WITH AN ATTENDANT
COLD FRONT PUSHING INTO THE NW GULF WATERS BY LATE THU. 12Z GFS
AND 00Z ECMWF REMAIN IN DECENT AGREEMENT WITH THE TIMING OF THE
FRONT. GIVEN THE COLD AIR BEHIND THE FRONT AND THE RELATIVELY WARM
WATERS OVER THE WESTERN GULF...IT IS LIKELY THAT STRONG GRADIENT
FLOW WILL MIX TO THE SURFACE OVER THE FAR WESTERN GULF FRI. THE
12Z GFS CONTINUES TO SHOW A SMALL AREA OF GALES IN THE CENTRAL
WESTERN GULF FRI MORNING. HOWEVER...THE PAST TWO RUNS OF THE GEFS
INDICATE THE CHANCE FOR GALES HAVE DROPPED TO 20% PROBABILITIES BY
FRI MORNING NEAR TAMPICO AND NONE OF THE OTHER DETERMINISTIC
GLOBAL MODELS ARE CALLING FOR GALE FORCE WINDS. A BLEND OF
GFS/ECMWF IN THE GRIDS HAS WINDS PEAKING JUST BELOW GALE FORCE ON
FRIDAY...THOUGH OF COURSE THIS MAY CHANGE AS WE GET CLOSER TO THE
EVENT.  LOOKING AHEAD TO THE WEEKEND...THE FRONT SAGS SE AND
STALLS OVER THE SE GULF BY SAT. WINDS AND SEAS DIMINISH RAPIDLY
FROM W TO E AS WEAK HIGH PRES BUILDS OVER THE NW GULF COASTAL
AREA.

...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
HIGH PRES N OF REGION MAINTAIN MODERATE TO FRESH BREEZE ACROSS
TROPICAL N ATLC AND CENTRAL CARIBBEAN WITH GENTLE TO MODERATE E
FLOW THROUGH MID WEEK. FRESH BREEZE EXPECTED ACROSS GULF OF
HONDURAS TUE THROUGH THU AS RIDGE STRENGTHENS BEFORE DRIFTING E.
LONG PERIOD NE SWELL 5-6 FT SEEP THROUGH ATLC PASSAGES TODAY AND
TONIGHT THEN BEGINNING SUBSIDING THROUGH WED. WINDS DIMINISH
ACROSS THE BASIN LATER IN THE WEEK AS THE HIGH PRES N OF THE AREA
SHIFTS E AND IS REPLACED BY LOW PRES...THUS WEAKENING THE PRES
GRADIENT OVER THE REGION. A BLEND OF GFS/ECMWF IS THE BASIS FOR
THE UPDATED GRIDS.

...SW N ATLANTIC INCLUDING THE BAHAMAS...
WEAK RIDGING IS IN PLACE OVER THE SW N ATLC WATERS THIS
MORNING...WITH GENTLE TO MODERATE RETURN FLOW PREVAILING. BUOYS
41047 AND 41043 INDICATE SEAS 6 TO 8 FT IN NE SWELL OVER MUCH OF
THE AREA OUTSIDE THE BAHAMAS. THIS IS SLIGHTLY HIGHER THAN THE
MWW3 GUIDANCE IS INITIALIZES. MODEL GUIDANCE IS IN DECENT
AGREEMENT THROUGH MIDWEEK SHOWING A GRADUAL EASTWARD SHIFT OF THE
RIDGE...AHEAD OF A TROUGH SAGGING SE FROM THE CAROLINAS TO THE
OFFSHORE WATERS OF NE FLORIDA AND N OF GRAND BAHAMA. BY
FRI...HOWEVER...THE MODELS SHOW SIGNIFICANT DIFFERENCES.  THE 12Z
GFS/06Z GEFS INDICATING BROAD TROUGHING FROM THE CENTRAL GULF OF
MEXICO EASTWARD TO ACROSS THE BAHAMAS WITH FRESH TO STRONG BREEZE
E OF NORTHERN FL AND GA. IN CONTRAST...THE 00Z ECMWF/NAVGEM INDICATE
A MORE COHERENT LOW CENTERED OVER THE FL PENINSULA. AND
FINALLY...THE 12Z UKMET SHOWS A SINGLE LOW OVER LA ALONG THE
FRONTAL BOUNDARY. AS MOST OF THE SOLUTIONS ARE AHEAD OF THE
FRONT...THERE IS A SLIGHT POSSIBILITY FOR THE SYSTEM TO DEVELOP
AS A SUBTROPICAL CYCLONE. GIVEN THE WIDE VARIETY OF
POSSIBILITIES...THE CONFIDENCE CURRENTLY IS LOW IN THE SOLUTION
PROVIDED...WHICH IS A BLEND OF PERSISTENCE...GFS...AND ECMWF.

.WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES 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://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP

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

$$
.FORECASTER LANDSEA. NATIONAL HURRICANE CENTER.