marine weather discussion NWS National Hurricane Center Miami FL 116 PM EDT Sat Aug 19 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 is centered in the NW Gulf near 28n87w with a ridge extending from E to W, while a surface trough extends from southern Georgia into the NE Gulf. An upper level low is in the se Gulf near 24n84w. This upper low and the surface trough are supporting scattered thunderstorms in the NE Gulf toward se Louisiana. Otherwise, mainly light to gentle flow prevails across the basin around the high along with 1 to 3 ft seas.
The upper level low will move WNW while the northern extent of a tropical wave, currently moving toward The Straits of Florida approaches the basin. The tropical wave will enter the se Gulf tonight, moving across the basin through early next week.
Meanwhile, Tropical Storm Harvey currently well se of the area in the eastern Caribbean Sea is forecast to approach the NW Caribbean early next week, with the center forecast to be just offshore of Belize by early Tue. Harvey is forecast to emerge into the Bay of Campeche Tue night into Wed. While Harvey will weaken to some extent overland, it is forecast to regain minimal tropical storm strength as it moves across the far SW Gulf through mid week. Please refer to http://hurricanes.Gov for more information on Harvey.
...Caribbean Sea and tropical N Atlantic from 07n to 19n between 55w and 64w...
Tropical Storm Harvey is near 13.9n 68.1w, or about 125 nm NNE of Curacao or about 878 nm E of Cabo Gracias a Dios, and continues to move westward through the eastern Caribbean. Sustained winds are 35 kt with gusts to 45 kt. Minimum central pressure is 1007 mb. Harvey remains poorly organized under moderate vertical shear. Numerous moderate and scattered thunderstorms are within 240 nm in the NW semicircle of Harvey. Harvey is forecast to continue westward across the central Caribbean through sun, moving into the NW Caribbean Mon, and nearing the coast of Belize by Tue morning as a strong Tropical Storm. Harvey will remain a relatively compact system, with an envelope of strong winds and seas 8 to 12 ft within 60-90 nm of the center on the northern semicircle. Please refer to http://hurricanes.Gov for more information on Harvey.
Ahead of Harvey, a tropical wave currently moving across the western Caribbean is following an upper level low in the se Gulf of Mexico. The upper low and tropical wave will result in isolated thunderstorms near the wave axis, mainly in the NW Caribbean, through sun.
The pressure gradient will tigthen across the central portion of the basin by mid week increasing trades to fresh to strong with seas building to 8 ft.
...SW N Atlantic including the Bahamas...
A large and well defined upper level low has exited the basin now in the se Gulf of Mexico. The northern extent of a tropical wave is moving across the Gulf Stream between the western Bahamas and Florida Peninsula with scattered thunderstorms across the western Bahamas. Moderate to fresh easterly winds follow the tropical wave over the waters S of 22n and W of 70w. Meanwhile, a ridge extends along roughly 30n. Fresh easterly winds will expand across the waters S of 25n, with locally stronger winds near the coast of Hispaniola as Tropical Storm Harvey passes S of the region through early next week.
A second feature, a strong tropical wave in the tropical N Atlantic NE of the Leeward Islands will move WNW, eventually reaching the southern and central Bahamas by Sun night. Environmental conditions are not conducive for tropical cyclone development due to strong upper level winds. Even so, the low will bring strong winds and building seas to the area S of 25n from sun through mid week. The ridge will move little through sun, then will shift slowly northward early next week, maintaining light to gentle breezes into early next week N of 28n, with short period southeast swell of 4 to 6 ft.
.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... .Amz019...Caribbean from 15n to 18n between 80w and 85w... Tropical Storm Warning Sun night into Mon. .Amz021...Caribbean from 15n to 18n between 72w and 80w... Tropical Storm Warning tonight into Sun night. .Amz029...W central Caribbean from 11n to 15n W of 80w... Tropical Storm Warning Sun night. .Amz031...Caribbean from 11n to 15n between 72w and 80w including Colombia basin... Tropical Storm Warning tonight into Sun night. .Amz033...Caribbean S of 15n between 64w and 72w including Venezuela basin... Tropical Storm Warning today into tonight.
.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 lewitsky. National Hurricane Center.