000 AGXX40 KNHC 071944 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 244 PM EST Sun Jan 7 2018 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 weak surface trough extends from N to S along 93W, while ridging dominates the rest of the basin. Fresh to strong winds are E of the trough to 87W, as well as in the SE Gulf through the Straits of Florida where the pressure gradient is tight. The 1532Z Ascat along with the latest and current buoy observations depict these winds. The buoys show that seas are in the 6-8 ft range under the strongest winds, with lower seas of 3-5 ft elsewhere except for 2-3 ft seas in the far NE and NW gulf portions. The trough will dissipate by this evening as it shifts to the W-NW while ridging builds in its wake. Return flow will dominate the basin until early Mon when the next cold front will enter the NW Gulf. Fresh to strong winds are likely on either side of the front N of 26N. An area of low pres associated with the front is forecast to move into the N central waters Monday afternoon and evening. The low will then shift to the SE Gulf Tue into early Wed. while gradually weakening. The low should become a remnant trough by Wed night while return flow becomes re- established into the end of the week ahead of the next cold front to affect the forecast waters. Models have come more into agreement with timing of the cold front into the NW Gulf on Thu evening, and with its forecast positions across the central and eastern gulf waters Fri and Fri night. The 12Z ECMWF now depicts strong to near gale force W-NW behind the front similar to the UKMET, whereas the 12Z GFS and Canadian model runs are slightly weaker. The ECMWF and UKMET track the attendant low pres farther S across the southern U.S. from Thu night through Fri. For this forecast will weigh winds for behind the front very near the ECMWF/UKMET guidance. Gale force northerly winds are very possible to occur over the far SW gulf along the coast Veracruz early on Fri NW-N winds to near gale force are possible over the far W central gulf western gulf early on Fri. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A stationary front extends from near 25N65W southwestward to the Windward Passage and continues to across Jamaica to 15N80W and to near 10N81W where it appears a weak low may be present. A very tight pressure gradient between the front and strong high pres building ESE over the NW Caribbean has induced a large swath of gale force NE winds between the front and 81W N of 18N, and fresh to strong NE winds are elsewhere W of the front N of 17N. Seas are 8-12 ft behind the front, with highest seas near 19N80W. The Ascat pass from this morning nicely depicted these winds. Scattered showers and isolated thunderstorms are N of 18N between Haiti and Jamaica NE to eastern Cuba. Isolated showers and thunderstorms are noted within 180 nm W of the boundary, except for scattered showers and thunderstorms within 120 nm to its E from 10N-11N. To the E of front, a surface trough is analyzed from S central Hispaniola to near 13N72W. Isolated showers are possible along and near this trough. The Ascat data from this morning showed mainly moderate E-SE trades to the E and SE of the stationary front. The stationary front is forecast to gradually weaken and dissipate through Tuesday afternoon, with the remnants drifting westward through the period. The gale force winds between front and 81W N of 18N will diminish to strong winds early this evening. On the other end, strong NE gale force winds have recently begin through the approach to the Windward Passage. These winds will continue through tonight, then diminish to strong NE winds late tonight. Winds will then diminish across the western Caribbean Mon with a weak pres gradient persisting there through the week. Moderate to fresh trades will prevail through the next several days across the eastern Caribbean, except pulsing to strong NW of the coast of Colombia. In the tropical N Atlantic, moderate to fresh trades will prevail through the next several days. Northerly swells of 8-11 ft will persist through the early part of the week, subsiding to 6-9 ft thereafter. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A stationary front extends from near 25N65W to just SE of eastern Cuba early this afternoon, high pressure ridging stretches from mid-Atlc region southward to the far western waters of the area. The Ascat pass from this morning highlighted a swath of NE gale force winds W of the front S of 25N, and fresh to strong NE winds elsewhere W of the front S of about 28N. The gale force winds W of the stationary front are forecast to persist through part of tonight, then diminish to strong NE-E late tonight as the front gradually weakens to a trough by Tue and eventaully dissipates afterwards. Wind and sea conditions across the region will improve Monday through Tuesday night as the high shifts eastward and weakens. A N to S oriented trough will set up between the Bahamas and Florida waters Wed, and shift to the far NW waters early on Thu. The trough is expected to move inland NE Florida and SE Georgia during Thu. Moderate return flow will become established over the area on Thursday night, with fresh to locally strong E winds over the far southern waters from the SE the Bahamas and eastward from there through Fri. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ013...CARIBBEAN N OF 18N BETWEEN 76W AND 85W INCLUDING CAYMAN BASIN... Gale Warning today. .AMZ015...CARIBBEAN APPROACHES TO THE WINDWARD PASSAGE... Gale Warning today into tonight. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ117...BAHAMAS INCLUDING CAY SAL BANK... Gale Warning today. .AMZ119...ATLANTIC FROM 22N TO 27N E OF BAHAMAS TO 70W... Gale Warning today into tonight. .AMZ121...ATLANTIC FROM 22N TO 27N BETWEEN 65W AND 70W... Gale Warning today. .AMZ123...ATLANTIC S OF 22N W OF 70W INCLUDING APPROACHES TO THE WINDWARD PASSAGE... Gale Warning today into tonight. .AMZ125...ATLANTIC S OF 22N BETWEEN 65W AND 70W INCLUDING PUERTO RICO TRENCH... Gale Warning today. $$ *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 Aguirre. National Hurricane Center.