Marine Interpretation Message
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064
AGXX40 KNHC 231911
MIMATS

Marine Weather Discussion
NWS National Hurricane Center Miami FL
211 PM EST Thu Nov 23 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...

A 1012 mb low pressure system is centered over the far NE Gulf
near 29N84W. A cold front extends SW from the low to the Bay of
Campeche near 18N62W. An amplified trough extending southward
from the Mississippi Valley through the Bay of Campeche supports
these features. High pressure ridges southward over the western
gulf and eastern Mexico from Texas. The pressure gradient between
the high pressure and the cold front continues to maintain a
large swath of strong to gale force northerly winds over the
waters W of the cold front. Surface observations from
Coatzacoalcos Veracruz Mexico indicated sustained winds remained
above gale force along the Veracruz coast of Mexico, so exceeded
all of the model guidance for the wind forecast during the first
6 hours. Used NWPS guidance value of 10 to 13 ft for seas in the
gale area. After 12Z expect winds and seas to rapidly diminish
as the high pressure ridge shifts rapidly eastward and weakens.
Low pressure over the Florida Big Bend will cross northern
Florida and reach the SW N Atlantic by this evening and drag the
associated cold front across the Yucatan Channel by early Fri
morning and across the Straits of Florida by early Saturday
morning. Broad but weak high pressure overspreading the Gulf in
the wake of the front will maintain gentle to moderate winds
through Sat night. Seas across the basin are expected to subside
to between 2 and 4 ft by Sun morning, when a weak cold front will
introduce more cold air to the NW Gulf.

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

A persistent surface trough crosses the western Caribbean along
82W from western Cuba to Costa Rica. Isolated thunderstorms are
noted near this feature. The trough is forecast to be nudged
eastward during the next couple of days as a cold front enters
the NW Caribbean from the Gulf of Mexico. Another much weaker
surface trough crosses the far eastern Caribbean from near St
Lucia to the Virgin Islands near 18N64W. This trough possesses no
significant convection. Low pressure systems currently near
Florida and Bermuda have weakened the ridge to the north. As a
result, gentle to moderate trades and seas of 3 to 5 ft prevail
over the Caribbean. The cold front forecast to enter the NW
Caribbean will do so by early Fri morning, then reach from
western Cuba to Belize by Fri evening. The front will dissipate
after it reaches from central Cuba to the Gulf of Honduras on Sat
evening while dissipating. The pressure gradient between
building high pressure over Central America and the frontal
boundary will cause northerly winds of 20 to 25 kt to funnel
along the Nicaragua coast tonight through Monday night. Seas are
expected to peak around 8 ft on Monday night.

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

Deepening low pressure is centered just NE of the forecast zones
near 31.5N64.5W. This system will continue to pull away toward
the NE during the next couple of days. Winds and seas in Zone 115
will subside below advisory levels this evening. Another low
pressure system, currently over the far NE Gulf of Mexico, will
move across northern Florida today and reach the SW N Atlantic by
this evening. The associated cold front will enter the NW
Bahamas on Sat night, enter the central Bahamas early Sunday
morning, then finally cross the SE waters Sunday night and Monday
morning as it weakens to a frontal trough. Showers and
thunderstorms could produce gusty winds in the vicinity of the
low and cold front. Model guidance suggests that a reinforcing
surge of cold air following the front will reach the north waters
by Sun evening and move southward through Mon night.

$$

.WARNINGS...Any changes impacting coastal NWS offices will be
coordinated through AWIPS II Collaboration 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.nhc.noaa.gov/marine

$$

.Forecaster McElroy. National Hurricane Center.



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