000
AGXX40 KNHC 261810
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
210 PM EDT THU SEP 26 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 BLENDED WITH OFFICIAL FORECAST WITH 
GOOD CONFIDENCE.

WEAK FRONTAL BOUNDARY TROUGHING CONTINUES ACROSS NORTHERN GULF. 
THE MAIN PORTION OF THE TROUGH WILL SHIFT EASTWARD TONIGHT WHILE 
LINGERING WESTERN PORTION DISSIPATES. HIGH PRES WILL BUILD SE  
FROM THE GREAT LAKES REGION ACROSS THE SOUTHEASTERN U.S. FRI 
THROUGH SAT AND ALLOW E-NE WINDS TO STRENGTHEN IN THE NE GULF 
THIS WEEKEND. EXPECT SLIGHTLY COOLER DRY AIR TO SPREAD ACROSS 
THE EASTERN HALF OF THE GULF BY FRI NIGHT.

...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 65W...

MODEL PREFERENCE: GFS/ECMWF BLENDED WITH OFFICIAL FORECAST WITH 
MODERATE CONFIDENCE.

HIGH PRES RIDGE N OF THE AREA WILL MAINTAIN GENTLE TO MODERATE 
TRADES ACROSS MOST OF THE REGION THROUGH MON. A PAIR OF TROPICAL 
WAVES IN THE WESTERN ATLC ARE EXPECTED TO DRIFT NE TOWARD THE 
VIRGIN ISLANDS THROUGH SAT. SCATTEROMETER DATA AT 1410 UTC SHOWS 
SMALL AREA OF FRESH TRADE WINDS NEAR THE COAST OF VENEZUELA BUT 
GENTLE TO MODERATE WINDS ELSEWHERE. MODEL GUIDANCE IN GOOD 
AGREEMENT MAINTAINING SIMILAR FLOW PATTERN THROUGH FRI NIGHT... 
THEN A SIGNIFICANT CHANGE IN WEST-CENTRAL CARIBBEAN AFTER SAT AS 
WEAK LOW FORMING IN SW CARIBBEAN NEAR 12N80W SAT MORNING DRIFTS 
N THROUGH SUN...THEN TRANSITIONS TO A N-S ORIENTED TROUGH ALONG 
80W MON THROUGH TUE. MODELS ARE IN GENERAL AGREEMENT WITH BROAD 
TROUGHING DEVELOPING ALONG 80W WHICH WILL SIGNIFICANTLY WEAKEN 
AND DISRUPT TRADE WIND FLOW BETWEEN 75W AND 85W. STILL TOO EARLY 
TO HAVE GOOD CONFIDENCE IN SUCH AN ATYPICAL DEVELOPMENT AS THIS.

...SW N ATLANTIC INCLUDING THE BAHAMAS...

MODEL PREFERENCE: GFS/ECMWF BLENDED WITH OFFICIAL FORECAST WITH 
MODERATE CONFIDENCE.

FRONTAL BOUNDARY WITHOUT MUCH TEMPERATURE CONTRAST EXTENDS W 
FROM 1002 MB LOW PRES NEAR 31N68W TO NEAR JACKSONVILLE FLORIDA. 
THE LOW WILL MOVE EASTWARD S OF BERMUDA TONIGHT AND DRAG THE 
FRONT ACROSS THE ATLC WATERS N OF 27N. MODEL GUIDANCE INDICATES 
STRONG TO NEAR GALE SW WINDS CAN BE EXPECTED WITHIN 240 NM SE OF 
THE FRONT TONIGHT WITH SEAS BUILDING TO AROUND 10-11 FT. THE 
MOST HAZARDOUS MARINE CONDITIONS WILL SHIFT E OF THE AREA FRI. 
GFS MODEL SHOWS TRAILING AREA OF LOW PRES EXPECTED TO DEVELOP 
NEAR 30N76W TONIGHT....WHICH WILL DRIFT SE IN WEAK STEERING FLOW 
THROUGH SAT NIGHT...THEN ACCELERATE NE SUN AND MON. TIGHT PRES 
GRADIENT BETWEEN THE LOW AND HIGH PRESSURE BUILDING ACROSS THE 
SOUTHEASTERN U.S. WILL INCREASE NE WINDS TO AROUND 25 KT WITH 
SEAS BUILDING TO 8-9 FT ALONG THE NORTH FLORIDA COAST N OF 27N 
FRI NIGHT AND SAT. FRONT BECOMES DIFFUSE SUN AND WEAKENS TO A 
TROUGH WITH WINDS AND SEAS. MODELS ARE ROUGHLY IN AGREEMENT WITH 
THIS SCENARIO. PRIMARY DIFFERENCES ARE IN PRECISE LOCATION AND 
MOVEMENT OF THE LOWS EXPECTED TO FORM ALONG THE FRONTAL BOUNDARY 
BUT OVERALL PATTERN APPEARS CONSISTENT BETWEEN VARIOUS MODELS.

$$

.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 MUNDELL. NATIONAL HURRICANE CENTER.