000
AGXX40 KNHC 020758
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
358 AM EDT THU MAY 2 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...
MODEL PREFERENCE: GFS/ECMWF/PERSISTENCE BLEND WITH AVERAGE
CONFIDENCE.

A MID TO UPPER LEVEL SHORT WAVE TROUGH PERSISTS OVER THE LOWER
MISSISSIPPI VALLEY AHEAD OF A MAJOR TROUGH DIGGING INTO THE
CENTRAL PLAINS. CONVECTION REMAINS ACTIVE OVER THE N CENTRAL GULF
THIS MORNING...WHERE 1010 MB SURFACE HAS FORMED NEAR THE MOUTH OF
THE MISSISSIPPI RIVER. BUOYS AND CMAN STATIONS ARE REPORTING E
WINDS TO 25 KT NEAR MOBILE BAY ATTM. THE LOW WILL SHIFT SE INTO
THE E CENTRAL GULF THROUGH LATE TODAY...AHEAD OF COLD FRONT
ASSOCIATED WITH MAIN TROUGH THAT WILL MOVE OFF THE TEXAS COAST
THIS AFTERNOON. GIVEN A TIGHT PRES GRADIENT AND DECENT CAA EXPECT
WINDS TO REACH GALE FORCE OFF THE COAST OF TAMAULIPAS IN GMZ017
BY EARLY FRI. IN ADDITION...GIVEN WARMER SST OFF S TEXAS...EXPECT
ENOUGH POST FRONTAL BOUNDARY LAYER INSTABILITY TO PROMOTE
FREQUENT GUSTS TO GALE FORCE OVER SOUTHERN PORTIONS OF
GMZ011...AND NE PORTIONS OF GMZ017 IN THE OVERNIGHT HOURS OF THU
NIGHT INTO FRI MORNING. WHILE CONFIDENCE IS REMAINS HIGH ON THE
GALE FRI MORNING NEAR TAMPICO IN GMZ017...THERE IS STILL SOME
UNCERTAINTY ABOUT THE PROSPECTS FOR GALE FARTHER SOUTH OFF
VERACRUZ BEHIND THE FRONT ON FRI. SREF OUTPUT STILL FAVORS A
GALE...BUT GEFS AND ALL OPERATIONAL MODELS DISAGREE. THIS MAY BE
DUE TO HIGHER SUN ANGLES AND GREATER AIRMASS MODIFICATION THIS
LATE IN THE SEASON. WILL BET AGAINST THE SREF AND NOT ISSUE A GALE
FOR VERACRUZ ATTM. THE FRONT DRIFTS E AND WEAKENS THROUGH SAT.
WINDS AND SEAS DIMINISH RAPIDLY BEHIND THE FRONT LATE FRI INTO SAT
AS HIGH PRES BUILDS ACROSS THE WESTERN GULF. FOR THE WEEKEND INTO
EARLY NEXT WEEK...MODELS ARE FORMING A CONSENSUS REGARDING THE LOW
PRES MOVING THROUGH THE EASTERN GULF AHEAD OF THE WEAKENING FRONT
SAT...AND ACROSS THE FLORIDA PENINSULA...THEN WEAKENING SUN AND
MON OVER THE BAHAMAS.

...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
MODEL PREFERENCE: GFS/ECMWF BLEND WITH GOOD CONFIDENCE.

CURRENT OBSERVATIONS INDICATE GENTLE TO MODERATE TRADES PREVAIL
ACROSS THE FORECAST AREA...EXCEPT TO FRESH ACROSS THE GULF OF
HONDURAS. SEAS ARE GENERALLY IN THE 4-6 FT RANGE. A WEAKENING
BOUNDARY WILL PUSH THROUGH THE YUCATAN CHANNEL FRI...AND DELIVER
NW WINDS OF 15 TO 20 KT TO THE NW GULF.THE FRONTAL BOUNDARY WILL
DISSIPATE RAPIDLY BUT THE MOVEMENT OF LOW PRES ACROSS S FLORIDA
THROUGH SAT WILL ALLOW DIMINISHING NW FLOW TO DOMINATE THE WESTERN
GULF THROUGH THE WEEKEND...WITH LIGHT E TO SE WINDS OVER THE TROP
N ATLC AND EASTERN CARIBBEAN. FAVORED EC WAVE OUTPUT OVER THE NW
CARIBBEAN WITH THE ONSET OF STRONGER WINDS FRI...BUT BLENDED WITH
MWW3 OUTPUT OVER THE WESTERN CARIBBEAN THROUGH THE WEEKEND WITH
SUBSIDING SEAS AS WINDS DIMINISH. LIGHT FLOW WILL LIMIT SEAS
FROM THE TROP N ATLC TO THE CENTRAL CARIBBEAN THROUGH EARLY NEXT
WEEK.

...SW N ATLANTIC INCLUDING THE BAHAMAS...
MODEL PREFERENCE: GFS/ECMWF BLEND WITH AVERAGE CONFIDENCE.

LATEST SHIP AND BUOY OBSERVATIONS HIGHLIGHT AN ELONGATED SURFACE
TROUGH PARALLEL TO THE NE FLORIDA COAST ABOUT 90 NM OUT. THIS WILL
WEAKEN TODAY AS HIGH PRES BUILDS N OF THE AREA...AND LOW PRES
MOVES INTO THE SE GULF. THIS COMBINATION WILL RESULT IN A TIGHT
PRESSURE GRADIENT OVER OVER THE WATERS OFF NE FLORIDA AN N OF THE
NORTHERN BAHAMAS STARTING TODAY...AND WILL STRENGTHEN WINDS OVER
THIS AREA WITH SEAS BUILDING TO 10 FT BY AFTERNOON. THERE IS MORE
CONSENSUS IN THE MODELS CONCERNING THE DEVELOPMENT AND MOVEMENT OF
THE LOW PRES IN THE GULF TODAY THROUGH SAT...SHOWING THE LOW
MIGRATING E ACROSS S FLORIDA THROUGH SAT AND WEAKENING INTO A
TROUGH OVER THE BAHAMAS SUN. THE FRESH TO STRONG WINDS AND SEAS 8
FT OR GREATER WILL PREVAIL THROUGH MUCH IF NOT ALL OF THE
FORECAST PERIOD IN THE WATERS OFF NE FLORIDA AND N OF THE NORTHERN
BAHAMAS. MODERATE WINDS AND SEAS WILL PREVAIL OVER THE REMAINDER
OF THE FORECAST AREA.

.WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE
COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE:

.GULF OF MEXICO...
GMZ011...GALE WARNING FOR FREQUENT GUSTS TO GALE FORCE TONIGHT
INTO FRI. 
GMZ013...NONE. 
GMZ015...NONE. 
GMZ017...GALE WARNING FRI. 
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 CHRISTENSEN. NATIONAL HURRICANE CENTER.