AGXX40 KNHC 270759
Marine Weather Discussion
NWS National Hurricane Center Miami FL
359 AM EDT Mon Mar 27 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...
High pressure northeast of the region will support mainly
moderate to fresh east to southeast winds across the southern
Gulf and moderate southerly winds over the northern Gulf through
Wednesday night. The exception will be attributed to fresh to
strong northeast to east winds associated with a thermal trough
moving westward from the Yucatan Peninsula and over the eastern
Bay of Campeche each night. High pressure will build southward
over the Bahamas by Tuesday night. At the same time, deepening
low pressure will move over the southern plains with a cold front
over the interior of Texas. This pattern will result in a
tightening of the pressure gradient across the western Gulf
beginning on Tuesday afternoon and through Thursday.
The cold front associated with the deepening low pressure over
the southern Plains is forecast to reach the northwest gulf
portion early on Thursday, and move over the northern waters
through Friday while weakening. However, southerly flow ahead
of the front will increase to fresh to strong intensity
mainly over the north-central and northeast gulf waters
Thursday through Friday. Enough instability will be available
in the environment ahead of the front for scattered showers and
thunderstorms to likely form there. Some of them may contain
brief gusty winds and possible frequent lightning at times.
...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N
BETWEEN 55W AND 64W...
A weak pressure pattern with moderate winds will persist across
the Caribbean through Tuesday as broad low pressure north of
Hispaniola slowly moves northward then eastward away from the
forecast waters of the Southwest North Atlantic zones. High
pressure will build across the Bahamas by Tuesday night and
persist there through Thursday before it begins to strengthen
and slide eastward beginning on Thursday night. This will bring
a slight increase in the trades across the Caribbean, with fresh
to locally strong southeast winds developing across the Gulf of
The northerly swell that had been affecting the northern and
central tropical North Atlantic has decayed allowing for seas
to subside to less than 8 ft. Another northerly swell event
associated with the aforementioned broad low press north of
Hispaniola will propagate into the northern tropical North
Atlantic Wednesday through Friday, but it appears that the bulk
of the swell energy should just stay along the far northern
boundary of the tropical North Atlantic zones where the induced
8 ft and greater seas may be seen. This scenario may possibly
change in future forecasts pending on just how much time the low
takes before it pulls far enough away from southwest North
Atlantic forecast waters.
...SW N ATLANTIC INCLUDING THE BAHAMAS...
Latest satellite imagery shows the center of the broad low
pressure near 24N69W, moving slowly northward with a pressure
of 1008 mb. An elongated surface trough extends from near
29N67W, through the low and to just north of Hispaniola. The
pressure gradient between high pressure north of the region and
the low pressure continues to support a large area of strong to
near gale force winds north of the low, with gale force winds
from about 90 nm to 240 nm northwest and north of the low center.
Numerous showers and scattered thunderstorms are observed north
of 25N between 57W and 68W. Recent altimeter data revealed seas
of 12-18 ft within about 300 nm north of the low center, with a
large area of 8-12 ft seas across the Atlantic zones south of
30N, east of the Bahama Islands. The forecast remains on track
with the low continuing to slowly track northward into early this
afternoon, before turning northeast while beginning to
accelerate. The low will exit the northeastern zones Tuesday
morning. Although the low center will be east of the
northeastern zones on Tuesday, strong to near gale winds and seas
of 8 to 14 ft will remain north of 25N, east 70W through at
least Tuesday evening, except for higher seas of 12-18 ft north
of 28N east of 67W. Winds will diminish to less than 25 kt over
the northeast zones by Wednesday morning, with seas of 8-11 ft in
northeast to east swell subsiding to 6-9 ft Wednesday night and
to 5-7 ft on Thursday.
Meanwhile, high pressure will build across the Bahamas by
Tuesday night and remain centered there through Thursday, before
it begins to slide eastward Thursday night through Friday in
response to a weak cold front that is forecast by the models to
move across the southeast United States. Fresh to strong
southerly winds will develop over the northwest waters on Friday
in advance of the front, with seas building to 6-8 ft. Southeast
winds over the remainder of the western waters will increase to
fresh category on Friday. Otherwise, the gradient associated
with the high pressure will allow for generally gentle to
moderate anticyclonic flow throughout the basin Wednesday
through Friday with seas in the range of about 4-6 ft.
.WARNINGS...Any changes impacting coastal NWS offices will be
coordinated through AWIPS II Collaboration Chat, or by
.GULF OF MEXICO...
.CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
.SW N ATLANTIC INCLUDING THE BAHAMAS...
.AMZ115...ATLANTIC FROM 27N TO 31N BETWEEN 65W AND 70W...
Gale Warning through tonight.
*For detailed zone descriptions, please visit:
Note: gridded marine forecasts are available in the National
Digital Forecast Database (NDFD) at:
For additional information, please visit:
.Forecaster Aguirre. National Hurricane Center.