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000
AGXX40 KNHC 240759
MIMATS

Marine Weather Discussion
NWS National Hurricane Center Miami FL
259 AM EST Tue Jan 24 2017

Marine Weather Discussion for the Gulf of Mexico, Caribbean Sea,
and Tropical North Atlantic from 07N to 19N between 55W and 64W
and the Southwest North Atlantic including the Bahamas

...GULF OF MEXICO...

MODEL PREFERENCE: Global model consensus. High confidence.

The strong cold front that exited the basin yesterday continues
to pull away from the area. Recent scatterometer data still
showed fresh to strong northwest flow in the eastern Gulf, while
buoys, ships and altimeter data showed seas of 10-17 ft, which is
higher than any available wave model guidance initialized at for
06 UTC. Meanwhile high pressure has arrived in the wake of the
front with the parent high center in the southwest Gulf. Light to
moderate anticyclonic winds and subsiding seas prevail west of
87W.

The high center will move east to over south Florida by early
Wednesday as the next cold front approaches the northwest Gulf.
As the high shifts east, winds and seas will greatly diminish in
the central and eastern Gulf. The pressure gradient will tighten
across the western Gulf with deepening elongated low pressure
troughing ahead of the approaching cold front. Southerly return
flow will increase to fresh to strong west of 94W by late tonight
into early Wednesday, building seas to up to 8 ft. The front
will push into the Texas coastal waters by early Wednesday
afternoon, reaching from the Florida big bend to the central Gulf
near 24N92W to near 18N94W by Thursday morning, then will stall
and weaken from the Straits of Florida to the southwest Gulf,
laying down along 22N by Friday morning. Fresh to strong
northwest winds and building seas of 6-9 ft will fill in behind
the front, except offshore of Veracruz where model guidance is
indicating minimal gale force northwest winds during the daytime
hours of Thursday. Winds and seas diminish slightly throughout
the basin late Thursday night into early Friday as the front
stalls and washes out.

High pressure will build in later Friday through Saturday, and
another cold front may clip the far northeast Gulf. The pressure
gradient looks to tighten, especially in the southwest Gulf,
where the remnants of the old front in the form of a trough will
linger while the high builds in from the northwest.

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

MODEL PREFERENCE: Global model consensus. High confidence.

A Strong cold front continues to march east, extending from
eastern Cuba and central Jamaica to near the Nicaragua/Costa Rica
border. Scatterometer data showed fresh to strong northwest flow
behind the front, however, more recent observations show
diminishing winds. Northwest swell of 8-11 ft spilling in from
the southeast Gulf of Mexico will gradually subside through this
afternoon. Recent ship observations ahead of the front,
including through the Windward Passage, show fresh to strong
southwest flow and seas to 8 ft. The front will reach from the
northeast Caribbean to south of Jamaica to the southwest
Caribbean late tonight where it will stall and gradually
dissipate through Wednesday.

Moderate to fresh trades then prevail for the middle of the week,
increasing to fresh to strong offshore of the northwest coast of
Colombia and south of Hispaniola where the pressure gradient will
be locally tighter. These winds will build seas to 8-10 ft by
early Thursday. Winds will strengthen to up to 30 kt offshore of
Colombia Thursday night and again Friday night with nocturnal
enhancement, and up to 25 kt in the Gulf of Venezuela. Meanwhile,
the next cold front will approach the northwest Caribbean by the
end of the week, but model guidance agrees in stalling it just to
the north of the Yucatan Channel.

Over the tropical north Atlantic waters, expect mainly gentle to
moderate trade winds and seas of 4-7 ft to continue through the
forecast period. The only change will be the decaying southerly
portion of the cold front which will sink south across the waters
to the north of 15N Thursday, causing winds to briefly shift
near the boundary.

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

MODEL PREFERENCE: Global model consensus. High confidence.

A strong cold front continues to move across the central and
eastern portion of the southwest north Atlantic basin, extending
from 31N71W to the southeast Bahamas to eastern Cuba. Lightning
and satellite data shows a persistent line of strong
thunderstorms north of 25N within 120-180 nm ahead of the front.
A reinforcing trough follows the front from 31N73W to the
central Bahamas with scattered thunderstorms accompanying this
boundary. Recent scatterometer data showed southerly gale force
winds north of 23N ahead of the front, with west-northwest winds
up to minimal gale force north of 27N and west of the trough.
Fresh to near gale force winds prevail elsewhere both ahead of
and behind the front. Seas are 10-17 ft across a large portion of
the basin outside of the Bahamas.

The majority of the front will push east of 65W by this evening
with the southern portion reaching from 22N65W to near the
Windward Passage before midnight, clearing 55W by Thursday
evening. High pressure will build in the wake of the front
helping to diminish winds and seas. The high will shift east of
the Bahamas Wednesday night as the next cold front approaches the
northwest portion from the southeast United States.

That front will move into the offshore waters of northern
Florida late Thursday afternoon and evening, extending from
31N70W the Straits of Florida by Friday morning, then from
31N65W to the north central coast of Cuba by Saturday morning.
Fresh to strong winds will accompany this front both ahead of and
behind it across the waters north of 27N. Model guidance even
shows winds just ahead of and behind the front near 35 kt along
31N during the daytime hours Thursday, which will need to be
monitored in case a brief gale warning becomes needed north of
30N. Seas will build to 8-12 ft north of 27N with the passage of
this front.

$$

.WARNINGS...Any changes impacting coastal NWS offices will be
coordinated through AWIPS II Collaboration Chat, or by
telephone:

.GULF OF MEXICO...
.GMZ023...SW GULF S OF 22N W OF 94W...
GALE CONDITIONS POSSIBLE Thu.

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

.SW N ATLANTIC INCLUDING THE BAHAMAS...
.AMZ115...ATLANTIC FROM 27N TO 31N BETWEEN 65W AND 70W...
Gale Warning today.
.AMZ119...ATLANTIC FROM 22N TO 27N E OF BAHAMAS TO 70W...
Gale Warning early today.
.AMZ121...ATLANTIC FROM 22N TO 27N BETWEEN 65W AND 70W...
Gale Warning today.

$$

*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.nhc.noaa.gov/marine

$$

.Forecaster Lewitsky. National Hurricane Center.

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