000
AGXX40 KNHC 041813
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
213 PM EDT SUN AUG 4 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: HIGH CONFIDENCE THROUGH DAY 3 THEN MODERATE
CONFIDENCE. LATEST GFS/ECMWF BLENDED WITH OFFICIAL FORECAST. NWPS
USED FOR WAVE PARAMETERS.

RIDGING EXTENDS FROM SW FLORIDA THROUGH THE NORTHERN TEXAS COAST.
THIS HAS SHIFTED SOUTH FROM YESTERDAY IN RESPONSE TO DEEP LAYER
TROUGHING OVER THE EASTERN SEABOARD. THE HIGH PRES STAYS CENTERED
OVER THE CENTRAL GULF THROUGH MIDWEEK KEEPING WINDS AND SEAS
MINIMAL OVERALL. THE PATTERN STARTS TO CHANGE SLIGHTLY LATER IN
THE WEEK AS A TROUGH OFF THE EAST COAST OF FLORIDA MIGRATES ACROSS
THE PENINSULA INTO THE EASTERN GULF. THE ECMWF FOLLOWED BY THE
CMC SHOW THIS FEATURE MORE DISTINCTLY THAN THE GFS...UKMET OR
NAVGEM. THE UKMET SHOWS THE TROUGH MIGRATING W THROUGH
FLORIDA BY WED...BUT THEN SHOWS IT DEAMPLIFYING WITH THE RIDGE
AGAIN BUILDING FROM THE WESTERN ATLC TO THE CENTRAL GULF. THE
OFFICIAL FORECAST FOLLOWS THE ECMWF SHOWING THE TROUGH...BUT
MODERATING IT WITH THE GFS BLENDED IN. THE TROUGH IS EXPECTED TO
MOVE W ACROSS THE SOUTHERN GULF THROUGH LATE IN THE WEEK. THE MAIN
IMPACT WILL BE AN SLIGHT INCREASE SE WINDS OVER THE SE GULF LATE
IN THE WEEK WITH INCREASED SHOWERS AND THUNDERSTORMS.

...CARIBBEAN SEA AND TROPICAL N ATLANTIC...                    
MODEL PREFERENCE: HIGH CONFIDENCE. LATEST GFS/ECMWF BLENDED WITH
OFFICIAL FORECAST. NWPS USED FOR WAVE PARAMETERS.

RIDGING OVER THE N CENTRAL ATLC WILL MAINTAIN FRESH TO STRONG
WINDS OVER THE S CENTRAL CARIBBEAN...WITH NEAR 30 KT OFF COLOMBIA
PARTICULARLY DURING THE OVERNIGHT AND EARLY MORNING HOURS. SEAS OF
8-12 FT ARE EXPECTED ACROSS THIS SAME AREA OF THE STRONGEST WINDS. 
GENERALLY MODERATE FLOW PERSISTS ELSEWHERE WITH 3 TO 5 FT SEAS.
THE PATTERN WILL GRADUALLY TRANSITION THROUGH MID WEEK AS A
TROPICAL WAVE APPROACHES FROM THE TROPICAL EASTERN ATLC. THIS
WILL COINCIDE WITH THE PUSH OF A MID LATITUDE TROUGH THROUGH THE
U.S. EAST COAST INTO THE WESTERN ATLC. TOGETHER...THESE FEATURES
WILL SERVE TO SIGNIFICANTLY WEAKEN THE ATLC RIDGE AND THUS ALLOW
WINDS AND SEAS TO DIMINISH ACROSS THE CARIBBEAN BASIN AND THE
TROPICAL ATLC WATERS W OF 55W.

...SW N ATLANTIC W OF 55W INCLUDING THE BAHAMAS...
MODEL PREFERENCE: HIGH CONFIDENCE. LATEST GFS/ECMWF BLENDED WITH
OFFICIAL FORECAST. WW3 USED FOR WAVE PARAMETERS.

1022 MB HIGH PRES IS CENTERED IN THE N CENTRAL ATLC NEAR 29N58W
WITH A RIDGE EXTENDING TO THE SW-W TO SE FLORIDA. LIGHT WINDS ARE
PRESENT ALONG THE IMMEDIATE RIDGE...WITH MODERATE WINDS
ELSEWHERE. THIS ATLC RIDGE WILL PREVAIL INTO EARLY NEXT
WEEK...MAINTAINING GENERALLY LIGHT TO MODERATE FLOW N OF 22N...AND
FRESH FLOW S OF 22N. THE RIDGE WILL SHIFT S TO 26N EARLY NEXT
WEEK...AHEAD OF A FRONTAL TROUGH BOUNDARY APPROACHING THE AREA.
THE FRONTAL TROUGH IS FORECAST TO BREACH S OF 31N MON...STALLING
FROM NEAR BERMUDA TO 28N80W BY TUE MORNING. MODEL GUIDANCE KEEPS
THIS TROUGH AROUND LATE TUE INTO WED...PUSHING W ACROSS FLORIDA BY
LATE WED. ANOTHER TROUGH WILL MIGRATE W ACROSS THE WATERS S OF 24N
FROM THE CENTRAL ATLC WED...REACHING THE BAHAMAS BY LATE THU. THE
RIDGE WILL BUILD BEHIND THE TROUGH OVER THE CENTRAL ATLC BY
FRI...ALLOWING A RESURGENCE OF TRADE WINDS OVER THE WATERS S OF
22N E OF 70W.

$$

.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 CHRISTENSEN. NATIONAL HURRICANE CENTER.