marine weather discussion NWS National Hurricane Center Miami FL 235 am 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...
As of 0600 UTC, a 1012 mb low pressure system is located near 28n86w. A stationary front extends from the low across northern Florida into the SW N Atlantic. A cold front also stretches from the low SW across the Eastern Bay of Campeche. A vigorous short- wave trough rotating through a very well pronounced longwave trough that enters the Gulf across se Louisiana, and extends to near Tuxpan, Mexico supports these features. High pressure is building southward over the western Gulf behind the front cold front with a 1027 mb center near tmpico, Mexico. A very tight pressure gradient between the high pressure and the cold front has resulted in a large swath of strong to gale force northerly winds overtaking the waters to the W of the cold front. The most recent scatterometer data confirmed the presence of these winds. In addition, an altimeter pass indicated seas of near 15 ft over the Western Bay of Campeche. Doppler radar shows scattered showers and thunderstorms over the NE Gulf waters in association with the low while similar convective activity is now approaching SW Florida and the Florida Keys. Winds and seas could be higher near tstms. The low pressure will move across northern Florida today reaching the SW N Atlantic by this evening dragging the associated cold front, forecast to cross the Yucatan Channel by early Fri morning. Minimal gale force winds are expected to persist over the SW Gulf through early this morning, then winds and seas will begin to gradually dimisnish across the Gulf region as the front exits the area. High pressure in the wake of the front will dominate the Gulf on Fri with gentle to moderate northerly winds and seas of 3 to 5 ft. Southerly return flow will briefly set-up over the western Gulf on Sat, then a ridge will build again across the Gulf waters on sun, producing mainly gentle to moderate northerly winds and seas of 2 to 3 ft.
...Caribbean Sea and tropical N Atlantic from 07n to 19n between 55w and 64w...
A persistent surface trough is analyzed along 81w from 11n to 22n. Scattered showers and isolated thunderstorms are seen near this feature. The trough is forecast to drift eastward over the next couple of days as a cold front reaches the NW Caribbean. Gentle to moderate trades and seas of 4 to 5 ft are noted E of the trough axis over the east and central Caribbean while mainly gentle northerly winds and seas of 2 to 3 ft prevail west of the trough axis over the western Caribbean. The cold front, currently moving across the Gulf of Mexico, is forecast to enter the NW Caribbean by early Fri morning, reaching from western Cuba to Belize by Fri evening, and 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 should bring an increase in northerly winds of mostly 20 kt with possible pockets of 25 kt within about 120 nm off the Nicaragua coast tonight through Monday night along with Max combined seas of 6 or 7 ft. There is a possibility that seas may reach 8 ft on Monday as suggest by latest marine guidance.
...SW N Atlantic including the Bahamas...
A ridge is now confined to the extreme se waters. A 1008 mb low pressure is over the NE waters near 30n67w with a cold front extending southwestward to the se Bahamas. Latest satellite imagery shows a large area of showers, with embedded tstms on the se semicircle of the low center. The most recent ascat pass provided observations of minimal gale force winds within about 150 nm on the se quadrant of the low, with a swath of fresh to strong southerly winds covering the waters N of 23n between 63w and 67w. An altimeter pass indicated seas up to 14 ft within the area of gale force winds. These conditions will exit forecast zone amz115 late this morning as the low pressure moves north of area.
Another low pressure system, currently over the eastern Gulf of Mexico, will move across northern Florida today reaching the SW N Atlantic by this evening. The associated cold front will move across the western and central waters trough early Sunday morning, and across the eastern and se waters late Sunday through Monday as it weakens to a frontal trough. Scattered showers and thunderstorms with possible gusty winds are expected with both the low and the cold front. Model guidance suggests that a reinforcing cold front will reach the north waters by sun evening and move southward through Mon night, than stall near 27n on Tue.
.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 Warning early today.
.Caribbean Sea and tropical N Atlantic from 07n to 19n between 55w and 64w... none.
.SW N Atlantic including the Bahamas... .amz115...Atlantic from 27n to 31n between 65w and 70w... Gale Warning early today.
*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 gr. National Hurricane Center.