Marine Interpretation Message
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000
AGXX40 KNHC 241942
MIMATS

Marine Weather Discussion
NWS National Hurricane Center Miami FL
242 PM 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.

Weak high pressure has taken reign over the forecast area, with
a 1016 mb high center analyzed just north of the Yucatan
peninsula near 22N89W. Latest and current buoy and satellite-
derived show winds continuing to diminish throughout, with the
exception of the far western waters from 24N to 28N west of 94W
where southerly return flow is increasing and the buoys there are
reporting south winds of 20-25 kt. The resultant seas with these
winds are in the 6-7 ft. Seas in the remainder of the gulf are
in the range of 3-5 ft elsewhere west of 90W, and 4-7 ft east of
90W except for higher seas in the range of 7-10 ft south of 26N
east of 85W. Lower seas of 2-4 ft are confined to south of 24N
and west of 90W.

The seas of 7-10 ft south of 26N east of 85W will subside to
6-8 ft this evening, to 5-7 ft tonight and to 3-4 ft on
Wednesday. Seas elsewhere will change little through Wednesday,
but continue to build in the far western gulf where the strong
southerly flow there will persist as low pressure deepens over
the central U.S. This low pressure will push a cold front over
the northwest gulf early Wednesday morning. The front will
quickly reach from northeast Florida to the Bay of Campeche
Thursday afternoon, and become stationary over the southern
portion of the gulf on Friday.

Fresh to strong northwest winds and building seas of 6-9 ft will
follow in the wake of 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 across the area Friday through
Sunday. The pressure gradient is expected to tighten in some
sections of the western gulf Friday evening through Sunday,
with possible strong to near gale force northwest to north
winds along the coast of Mexico near Veracruz on Sunday.

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

MODEL PREFERENCE: Global model consensus. High confidence.

The strong cold front of the previous days has weakened today,
and as of 18Z extends from northwest Haiti southwest to 15N78W
to inland across central Costa Rica. Weak high pressure is
present in the wake of the front. The Ascat pass from 1536Z this
morning showed weaker northwest to north winds in the moderate
to fresh range range behind the front over the western Caribbean.
The buoys are reporting lowering seas behind the front. Winds
east of the front have also diminished during the morning and
early afternoon hours.

Models are in pretty good agreement that the front will reach
from from the northeast Caribbean near the Leeward Islands
southwest 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 25-30 kt
offshore of Colombia each night beginning Wednesday through
Sunday night with the aided factor of nocturnal enhancement, and
up to 25 kt in the Gulf of Venezuela. The next cold front will
approach the northwest Caribbean by the end of the week, but
12Z model guidance remains in agreement 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.

The strong cold front of the past few days has reached the
eastern portion of the forecast zones along a position from
near 31N65W to 23N68W to over northwest Haiti. Large seas in the
range of 8-12 ft due to a northwest swell are present west of
the front with a pocket of even larger seas of 10-14 ft in the
far northern waters north of about 29N and east of 77W. Adjusted
seas to higher values of up 11 ft some to the west of 77W from
previous advertised forecast based on an altimeter pass from
early this afternoon. These values are higher than what the
wave model guidances show and even the latest NWPS TAFB wave
guidance values. A gale warning was issued this morning for
those same waters as a secondary push of northwest flow has
surged southeastward in the wake of the front bumping up the
strong to near gale force west to northwest flow behind the front
to minimal gale force winds. Cold air instability west to
northwest flow behind the front in combination with a post-
frontal trough is bringing scattered showers and isolated
thunderstorms to most of zone AMZ115, and the eastern part of
zone AMZ113. The front will move east of the forecast waters
north of 22N tonight, and east of 55W on Thursday. 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
and 34 kt wind speed probabilities from the GFS mean ensemble
indicate gale force winds to pass just north of 31N on Thursday
east and west of this next front. Presently, it appears that
these winds will stay north of the forecast waters. Wave
guidance depicts seas of 8-12 ft sweeping through the far
northern waters of zones AMZ113 and AMZ115 Thursday through
Saturday. By Sunday, the highest seas will be in the range of
7-10 ft in the far northeast part of zone AMZ115. These seas will
diminish late on Sunday.

$$

.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. S OF 20N W OF 95W

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

.SW N ATLANTIC INCLUDING THE BAHAMAS...
.AMZ113...ATLANTIC N OF 29N BETWEEN 70W AND 77W...
    Gale Warning through tonight.
.AMZ115...ATLANTIC N OF 29N BETWEEN 65W AND 70W...
    Gale Warning tonight into Wed.

$$

*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 Aguirre. National Hurricane Center.



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