000
AGXX40 KNHC 281712
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
112 PM EDT WED OCT 28 2015

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: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL
FORECAST. LATEST NWPS FOR WAVE PARAMETERS. HIGH CONFIDENCE.

GREATEST UNCERTAINTY LIES WITH THE FORECAST FOR THE DEEP-LAYERED
TROUGH EXPECTED TO MOVE THROUGH THE SOUTHERN PLAINS OVER THE
WEEKEND. THE GFS HAS BEEN FASTER THAN THE ECMWF ALOFT...WITH THE
ECMWF DIGGING THE MID-LEVEL ENERGY FARTHER S THAN THE GFS. THE 00Z
ECMWF SHOWS 25 KT RETURN FLOW IN THE NW GULF BY 12Z FRI WHILE THE
GFS WAITS UNTIL THE AFTERNOON. THE GFS SEEMS LIKE A REASONABLE
SOLUTION TO USE TO ADJUST THE GRIDS. BY SUN MORNING...THE
UKMET...ECMWF...AND GFS ARE ALL IN GOOD AGREEMENT ON THE COLD
FRONT POSITION FROM THE CENTRAL LOUISIANA COAST TO THE FAR SW
GULF.

...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...

MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL
FORECAST. LATEST NWPS FOR WAVE PARAMETERS. HIGH CONFIDENCE.

BUILDING HIGH PRES OVER THE CENTRAL ATLC WILL ALLOW TRADES TO
BUILD TO A FRESH TO STRONG BREEZE WITH THE ASSISTANCE OF NOCTURNAL
DRAINAGE FLOW ALONG THE COAST OF COLOMBIA TONIGHT AND THU NIGHT.
THE HIGH WILL QUICKLY SHIFT E UNDER THE INFLUENCE OF A PROGRESSIVE
NORTHERN STREAM. WINDS WILL GENERALLY DIMINISH TO A GENTLE TO
MODERATE BREEZE FRI THROUGH THE WEEKEND AS A RESULT. THE MODELS
ARE IN REASONABLE AGREEMENT ON THIS SCENARIO...SO THE GFS WAS USED
TO ADJUST THE PREVIOUS FORECAST. A NEW BATCH OF LONG PERIOD NE
SWELL SHOULD REACH THE TROPICAL N ATLANTIC WATERS THU NIGHT INTO
FRI...BUILDING SEAS TO AROUND 6-8 FT FRI THROUGH THE WEEKEND
BEFORE SUBSIDING. THE NWPS WAS USED TO ADJUST THE SEAS HERE. 

..SW N ATLANTIC INCLUDING THE BAHAMAS...

MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL
FORECAST. LATEST NWPS FOR WAVE PARAMETERS. HIGH CONFIDENCE.
 
A COLD FRONT WILL SWEEP THROUGH MUCH OF THE AREA N OF 27N BY SAT
AFTERNOON. THE MODELS ARE IN REASONABLE AGREEMENT ON THIS
TIMING. NONE OF THE MODELS SHOW WINDS OR SEAS MEETING THE
ADVISORY CRITERIA OF 20-25 KT AND 8 FT...RESPECTIVELY...BUT THE
GFS AND ECMWF ALONG WITH THEIR RESPECTIVE WAVE MODELS SHOW THE
FORECAST APPROACHING THESE CONDITIONS BRIEFLY AT 06Z IN THE AREA
N OF 30N BETWEEN 77W AND 78W. WILL STICK WITH THE GFS BLEND WITH
THE PREVIOUS OFFICIAL FORECAST AS IT IS PREFERRED OVER THE
REMAINDER OF THE AREA. WINDS WEAKEN AND SEAS SUBSIDE FROM THU
THROUGH SAT AS THE FRONT WEAKENS AND EVENTUALLY DISSIPATES. BY
SUN...HIGH PRES BUILDS FROM THE N AND TRADE WINDS PICK UP TO A
MODERATE TO FRESH BREEZE S OF 23N. 

$$

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

.GULF OF MEXICO...
     NONE.

.CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
     NONE.

.SW N ATLANTIC INCLUDING THE BAHAMAS...
     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.HURRICANE WARNINGS.GOV/MARINE

$$

.FORECASTER SCHAUER. NATIONAL HURRICANE CENTER.