marine weather discussion NWS National Hurricane Center Miami FL 254 am EDT Wed Aug 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...
The remnant low pressure center of Harvey is currently off the northwest coast of the Yucatan Peninsula near 21n 91w with an estimated minimum pressure of 1009 mb, moving northwest at 10 kt. Numerous showers and thunderstorms are observed within 180 nm north of the center of the low pressure. A scatterometer pass from 03 UTC indicated winds of 20 to 25 kt in this area as well. While there is currently strong south to southwest shear impacting the low pressure, environmental conditions will be favorable over the next day or two and there is still a high chance of the low pressure will redevelop into a tropical cyclone. A Gale Warning remains in effect for the central and northwest portions of the Gulf, where seas are expected to build to 8 to 14 ft through late Fri/early Sat before the possible tropical cyclone makes landfall. Please see hurricanes.Gov for information on the development of the remnants of Harvey.
Weak low pressure may forming in Florida Bay in the southeast Gulf, on the southern end of a surface trough reaching through east central Florida. Global models have been indicating rather broad and disorganized weak low pressure over the southeast Gulf through Thu, becoming more distinct by late Thu as it moves northeast across central Florida. This low pressure will have minimal impact on winds and seas, but may serve as a focus for scattered showers and thunderstorms over the southeast Gulf.
...Caribbean Sea and tropical N Atlantic from 07n to 19n between 55w and 64w...
Recent scatterometer data showed moderate to fresh trade winds in the south central Caribbean, with gentle to moderate trade winds elsewhere. Buoy observations and altimeter data indicated 3 to 5 ft seas across the Basin. A tropical wave analyzed from the Windward Passage to the central coast of Colombia will shift west across the western Caribbean through Fri. Strong trades will pulse off the coast of northwest Venezuela and northeast Colombia in the wake of the tropical wave, but will be restricted to within 90 nm of the coast mainly during the late evening and overnight hours starting tonight. A weak surface trough will move across the Leeward Islands tonight then dampen out, have little impact marine weather other than a few more showers. Little change is expected elsewhere through the next several days.
...SW N Atlantic including the Bahamas...
1018 mb high pressure is centered near 29n72w, between a weak trough off the coast of Florida, and another weak trough between 27n and Bermuda. Scattered showers are observed within 120 nm of both troughs, including much of the Bahamas. The weak pressure pattern in maintaining light to gentle winds north of 27n and moderate trade winds south of 27n, pulsing to 15 to 20 kt off the north coast of Hispaniola. The subtropical ridge will gradually build along 28n into Fri with little change in winds or seas. The main forecast issue going into Sat continues to be the emergence of weak low pressure off the coast of northeast Florida, where it will deepen over the Gulf Stream Sat in an area of weak upper level shear. Global models continue to show this scenario, with the developing low pressure continuing north of the area through sun. The main marine impacts will likely be north of the discussion area by sun if this scenario pans out.
.Warnings...Any changes impacting coastal NWS offices will be coordinated through AWIPS ii collaboration chat, or by telephone:
.Gulf of Mexico... .gmz011...NW Gulf including Stetson bank... Gale Warning Thu night. Gale conditions possible Thu night into Fri night. .Gmz013...N central Gulf including Flower Garden banks marine Sanctuary... Gale Warning Thu into Thu night. Gale conditions possible Thu night into Fri. .Gmz017...W central Gulf from 22n to 26n W of 94w... Gale Warning Thu night. Gale conditions possible Thu night into Fri. .Gmz019...Central Gulf from 22n to 26n between 87w and 94w... Gale Warning Thu into Thu night. Gale conditions possible Thu night into Fri.
.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 Christensen. National Hurricane Center.