marine weather discussion NWS National Hurricane Center Miami FL 219 PM EDT sun may 28 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 1017 mb high is centered just offshore of Sanibel is this morning with associated anticyclonic flow across the E Gulf and generally moderate sly flow W half. 12z swh analysis showed seas slight seas across NE third of basin at 3 ft or less, and 3-5 ft elsewhere, with peak of 6 ft NW of Yucatan, where wind surge accompanying thermal trough last night kept seas up overnight.
Little change in the overall pattern expected through late Mon before the high begins to drift N and into NE Gulf for Tue. A thermal trough will develop late each afternoon over the Yucatan Peninsula, and shift WNW across the southwestern Gulf waters, generally to S of 24n between 90w and 93w, during the overnight and early daylight hours, and gradually lose identity along about 94w by late each morning. Expect a NE-E-se 15-20 kt wind shift along the trough axis, except 20 to 25 kt along the N coast of the Yucatan Peninsula this evening and again on Mon evening, with guidance hinting that these brief strong conditions will not develop again till Fri evening. Expect seas to build briefly to 6 ft just W of these peak winds.
...Caribbean Sea and tropical N Atlantic from 07n to 19n between 55w and 64w...
Atlc ridge is centered on a 1024 mb high in central Atlc near 29n45w and extending WSW to old frontal zone just E of central Bahamas. A second weak 1017 mb high is over the E Gulf of mex, with resultant pressure gradient across the Carib basin weak today. Ascat passes show moderate to fresh trades across central portions with seas generally 5-6 ft and likely Max of 8 ft this morning that may now be slightly lower. Gulf of Honduras winds and seas have abated from fresh to strong last night. Pair of tropical waves moving through E part of basin attm, one along 63-64w and interacting with broad upper trough for scattered cnvtn, and a second low lat wave along 51-52w and mainly producing weather near the ITCZ. Sal appears to follow this wave. Moderate to fresh Ely trades across the Atlc only producing 5-7 ft seas across tropical Atlc waters.
High pressure will support fresh E trades, with 5-8 ft seas, across the central Caribbean through Tue morning, with strong nocturnal trades within about 90 nm of the NW coast of Colombia and across the Gulf of Venezuela. The pressure gradient will tighten on Tue, with strong E winds expanding N from the Colombian coast to along 15n between about 70w and 77w on Wed, and expanding further N and further W on Thu with seas building to 11 ft near 13n75w. Strong nocturnal E to se trades forecast across the Gulf of Honduras through Thu night. Tropical waves over the E Caribbean and over the tropical waters E of the windwards, will continue westward accompanied by a moderate to fresh NE-E-se wind shift and only a slight enhancement of convection.
The Atlc ridge will build wwd along 27-28n next few days and tighten pres gradient by Tue-Wed, as 2 tropical waves are moving through central Carib. This should yield much enhanced winds and seas across the central Carib and models suggest wind wax a bit N of typical climo position. Seas to build to 8-10 ft in this zone on Wed.
...SW N Atlantic including the Bahamas...
Frontal remnants extend from near 31n60w to the central Bahamas and have almost dissipated W of 65w. Atlc ridge to the E extends WSW to the frontal boundary and will begin to build W along 27-28n next few days and freshen the trades S of 23n, with diurnal heating inducing the typical area of strong winds along the N coast of Hispaniola during the late afternoon and evenings beginning on Mon. Moderate SW flow is forecast N of the ridge. Tropical wave moisture and energy remain embedded in tropics and not expected to impact Greater Antilles or Atlc waters.
.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 stripling. National Hurricane Center.