AGXX40 KNHC 231834
Marine Weather Discussion
NWS National Hurricane Center Miami FL
234 PM EDT Thu Mar 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 1022 MB surface high is analyzed near 28N91W this morning and will
shift N and inland today and become absorbed in strong ridge
building toward the region from the NE. Ensuing pressure
gradient will tighten across the entire gulf this evening through
Fri as this ridge builds across the basin and pushes a dry
backdoor front across NE portions of gulf. Fresh to strong
easterly breezes will develop tonight with an embedded swath of
30 kt se winds...and seas to 9-10 ft...near 27N96W near sunrise
on Fri. The pressure gradient will relax on Fri as the parent
high shifts E into the Atlc with fresh se to s flow forecast
everywhere by Sat morning. A moderate to locally fresh easterly
breeze forecast across the southern gulf waters on Sun. Small
patches of strong southerly flow is forecast along the coast of
Central Mexico on Sun afternoon, as well as developing along the
n coast of the Yucatan Peninsula on Sun evening. The pressure
gradient should relax some more on Mon, with only a fresh breeze
expected along the n coast of the Yucatan on Mon evening.
...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
Fresh NE winds continue in the lee of Cuba and have even backed
slightly as cold front approaches region from the N and inverted
trough sharpens N of Hispaniola. Fresh to strong NE winds will
developing this evening in and downstream of the Windward
Passage on Thu. Expect this strong ne flow to continue across the
n-central and the nw Caribbean on Fri. The pressure gradient is
forecast to relax on Sat, but still expect strong ne pulses to
the lee of Cuba on Sat and Sun nights. Large n swell will reach
the NE Caribbean Passages late Fri night, and continue through
early Sun before subsiding.
Strong ne nocturnal winds expected within 90 nm of the nw coast
of Colombia tonight.
Fresh trades will continue across the tropical waters e of the
Antilles Leewards with seas generally remaining 6-8 ft next 48
hours in mix of NNW swell and ENE tradewind swell. Development of
low pres N of Hispaniola over the weekend and its motion will
strongly influence winds across Nrn waters Sat night and beyond.
...SW N ATLANTIC INCLUDING THE BAHAMAS...
Old frontal boundary nearly stationary from 26.5N65W TO THE SE
BAHAMAS will meander today as strong cold front sinks SSE across
NW half of area today. Morning ASCAT pass showed N to NE winds
20-25 kt behind front from 30N to to front and SW to FL E coast.
Seas behind front in strongest swath of winds NE of Bahamas are
about 2-3 ft above WW3 guidance and 1-2 ft above ECWave. Front
will continue SSE and nearly merge with old boundary through Fri
night-Sat...laying nearly W to E along 24N. Meanwhile, models in
agreement that a sfc low will develop along inverted trough
currently SE of old boundary, and N of Hispaniola, but location
and shape of low still evolving with each new run. Have followed
the GEFS for low placement which is good average between global
models. Strong to near gale force post-frontal ne winds will
spread se across the entire area with 10 to 15 ft seas
propagating S across the waters E of the Bahamas late tonight
into Fri. Models indicate large area of 25-30 kt winds and
frequent gusts to gale force would seem likely, but have yet to
issue Gale Warning. Pres gradient will tighten further across N
semicircle of low and at that time it appears sustained gales
are more likely, Sat evening through Sun. Have been hesitant to
issue gale with 5 degree difference in low location between
models, but 12Z runs coming in now a bit closer, and will
consider for 18-21Z updates.
.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...
*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 Stripling. National Hurricane Center.