000
AGXX40 KNHC 031854
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
254 PM EDT FRI MAY 3 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: ECMWF

COLD FRONT EXTENDING FROM NEAR MOUTH OF MS S ACROSS GULF THEN SW
TO CENTRAL BAY OF CAMPECHE WITH STRONG NLY FLOW BEHIND BOUNDARY.
NW WIND BRIDGING ACROSS THE FRONT AND MAKING IT SOMEWHAT NEBULUS
AND REALLY INSIGNIFICANT FOR MOST OF THE AREA. W AND NW GULF BUOYS
AS WELL AS PEMEX BUOYS RUNNING SEVERAL FEET ABOVE WW3 AND HAVE
ADJUSTED UP 1-3 FT ACROSS W PORTIONS OVER WW3. COMPLEX LOW PRES
ACROSS E GULF WITH CENTRAL LOW JUST OFFSHORE OF KAAF WITH AN
OCCLUDED BOUNDARY WRAPPING INTO N SIDE OF THIS LOW...AND A FEW
VORTICES EMBEDDED IN WNW FLOW ACROSS SE GULF MOVING ESE. MEANWHILE
A SMALL LOW ALONG E COAST OF FLORIDA OFF OF CANAVERAL AIDING IN
STRONG PRES GRADIENT AND GALES THERE. 00Z RUN OF ECMWF SEEMED TO
VERIFY MORE ACCURATELY AND HAVE USED FOR BASIN OF FORECAST.
HOWEVER...AS WE HAVE DISCOVERED THERE ARE ISSUES WITH MOST RECENT
AWIPS2 BUILD INSTALLED YDA...AND HAS LIMITED US WITH AVAILABLE
GRIDDED OUTPUT. ELONGATING LOW TO SHIFT SLOWLY NE ACROSS FL
OVERNIGHT AND SAT WITH FRONT MOVING E AND GRADUALLY MERGING ALONG
E COAST OF FL BY 48 HOURS...WITH ANOTHER WEAK FRONTAL BOUNDARY
THEN DROPPING INTO NW GULF 06-12Z SUN.

GALES BEHIND CURRENT FRONT EXPECTED TO END AROUND 00Z WITH WINDS
AND SEAS GRADUALLY SUBSIDING THROUGH EARLY SUN. MODEL IN
REASONABLE AGREEMENT...BUT WITH COMPLEX NATURE OF LOW PRES ACROSS
E GULF...PRECISE PLACEMENT OF LOW CENTERS AND FRONT IS CRUCIAL.

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

ANOMALOUSLY LIGHT WINDS AND VERY CALM SEAS PREVAIL ACROSS THE
BASIN WITH SEAS 3 FT OR LESS. LLVL TROUGH EXTENDING S OUT OF E
GULF SWINGING E ACROSS WRN GULF AND AIDED WITH UPPER LEVEL WLY
SUPPORT CONTINUES TO INDUCE CLUSTER OF DEEP CONVTN...PERSISTING IN
AN AREA OF UPPER DIVERGENCE OFF OF NICARAGUA AND HONDURAS.
FRESHENING NW FLOW MOVING THROUGH YUCATAN CHANNEL ATTM WILL SPREAD
S NEXT 24 HOURS TO NEAR GULF OF HONDURAS WITH SEAS BUILDING TO 5
TO 7 FT...WHILE LLVL TROUGH SHIFTS FURTHER E TO E CUBA.
OTHERWISE...LIGHT AND VARIABLE WINDS AND MILD CONDITIONS TO
PREVAIL THROUGH 72 HRS.

...SW N ATLANTIC INCLUDING THE BAHAMAS...                   
MODEL PREFERENCE: ECMWF

SMALL LOW PRES CENTER EMERGED OUT OF EVENING CNVTN BETWEEN S FL
AND BAHAMAS THIS PAST EVENING AND HAS WOUND UP OVERNIGHT AND MOVED
N INTO OLD FRONTAL ZONE EXTENDING FROM NE FL SE INTO CENTRAL ATLC.
HIGH PRES BUILDING SW TOWARDS THIS AREA HAS INCREASED PRES
GRADIENT YIELDING GALES N THROUGH NE OF LOW...NOW CURRENTLY NEAR
28.2N79.3W...EXTENDING E TO 77W AS VERIFIED BY RECENT ASCAT-A AND
B PASSES. COASTAL BUOYS JUMPED UP AS HIGH AS 16-18 FT WHICH WAS
EVEN ABOVE WW3 ENSEMBLE MAX VALUES...AND HAD TO INCREASE WAVE
HEIGHTS BY 2-5 FT ACROSS THIS REGION FOR PACKAGE. ENTIRE LOW
COMPLEX TO SHIFT NE OVERNIGHT AS LOW LIFTS N THEN NW...AND
CAPTURED WITHIN BROADER CYCLONIC CIRCULATION...SHIFTING GALES N
THROUGH 00Z BEFORE ENDING AND SHRINKING IN AREAL COVERAGE.
ELONGATED FRONTAL ZONE TO LIFT GRADUALLY N NEXT FEW DAYS...WITH
PRE GRADIENT ALONG AND TO N OF BOUNDARY MAINTAINING FRESH WINDS
PARALLEL TO BOUNDARY AS IT LIFTS. ANOMALOUS PATTERN YIELDING W TO
SW FLOW ACROSS BAHAMAS ATTM THAN WILL BACK TO WLY OVER NEXT 24
HOURS AND INCREASE TO 10-15 KT...AN UNUSUAL PATTERN FOR THE
ISLANDS.

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

.GULF OF MEXICO...
GMZ011...GALE WARNING TODAY INTO TONIGHT. 
GMZ013...NONE.
GMZ015...NONE.
GMZ017...GALE WARNING TODAY INTO TONIGHT. 
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...GALE WARNING TODAY INTO TONIGHT. 
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 STRIPLING. NATIONAL HURRICANE CENTER.