000 AGXX40 KNHC 161937 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 237 PM EST Sat Dec 16 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 stationary front extends from Tampa Florida to 26N88W to 26N93W where it transitions to warm front to 23N95W to 21N95W. A coastal surface trough set up just offshore NE Mexico and southern Texas this morning. Strong high pressure is over the far northern waters of the central gulf and over the NE waters. The pressure gradient between the high pressure and the frontal boundary as well as with the trough has increased leading to mostly fresh E to SE winds over much of the NW Gulf. The buoys indicate seas in the range of 4-6 ft over the NW Gulf, and 3-4 ft elsewhere except 4-5 ft far SE waters and Straits of Florida. The gale force NW-N winds that were indicated by the Ascat pass from the 0400Z Ascat pass from last night over the far SW Gulf near the coast of Veracruz have diminished to 15-20 kt per scatterometer data from this morning. The 9-12 ft seas that were developed by the recent gale force winds are subsiding and should lower to around 6-8 ft during the afternoon. Models suggest that low pressure will developing along the trough as the warm front lifts northward across the western this afternoon and evening. The warm front will extent into the low by late this afternoon or early evening as the low nears the central Texas coast. The gradient will increase slightly this evening over the NW gulf N of the warm front as the low reaches a position of near 28N97W with a pressure of 1017 mb and warm front to extend from the low to 28N92W to near 26N89W. Expect fresh to strong E to SE winds within 90 nm N of the front, with seas of 5-8 ft. By late Sunday night, the low is presently forecast to reach near 29N95W with a pressure of 1016 mb, and with warm front extending from it to 30N92W to 27N91W. Fresh to strong S to SW winds are expected within 60 nm of the low in the SE quadrant, and within 60 nm S of the warm front between 93W- 94W with seas of 7-8 ft. The low will quickly move inland near the SW Louisiana/NE Texas border by early on Sunday and begin to weaken further. The warm front will lifting N of the forecast waters early Sunday. The pressure gradient will relax at that time allowing for the fresh to strong winds to become moderate to fresh SE to S winds ahead of a trough that will trail from the low to 27N94W to 24N96W. High pressure will settle in over the area Sunday evening through Monday night, then move eastward Tuesday evening through Wednesday as a weak cold front moves across the northern waters. This front will reach the NE Gulf Wednesday night and weaken. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... The western Caribbean trough of the past several days has moved to just inland the Yucatan Peninsula, Belize and NW Honduras as of early this afternoon. High pressure will continue to build to the N of the basin through the rest of this weekend, and leading to a tightening of pressure gradient across the central Caribbean, where highest winds will reach minimal gale each night through Monday and possibly early Tuesday morning. Winds will diminish slightly to 25-30 kt during the day. Seas will build to 10-15 ft near the coast of Colombia late Sunday night and up 14 ft during the other times. The fresh to strong trades will expand in coverage this weekend through Monday night. These winds will then become more confined to the central Caribbean Tue through Wed night. Plumes of fresh to strong NE to E winds will develop to the lee of Cuba and through and near the Windward Passage beginning late Saturday night and diminish some on Tuesday and to 15-20 kt on Wednesday through Thursday. ...SW N ATLANTIC INCLUDING THE BAHAMAS... As of early this afternoon, a cold front extends from near 31N68W to 28N77W to just S of MLB. The latest visible satellite imagery nicely depicts the leading narrow line of low clouds that marks the front. A pre- frontal trough extends from 31N65W to 27N71W to the central Bahamas. Scattered showers are along and SE of the trough. A partial Ascat pass from this afternoon revealed strong W-NW winds to the W of the front to 69W and N of 28N, with seas of 9-11 ft. Winds elsewhere NW of the front are lighter, NW-N 15-20 kt except for N winds of 10-15 kt W of about 75W. Seas elsewhere W of the front are 8-10 ft in NW swell, except for 5-8 ft seas W of 75W. A stronger cold front is right on the heels of the aforementioned one crossing 31N between 70W-79W as of 18Z this afternoon. Ship with caller ID "CQGZ" is right along the front at a position of 31N73W at 18Z with N winds of 20 kt and seas of 10 ft. The second cold front will catch up with the northern portion of the first front this afternoon, and the merged front will quickly move across the rest of the northern waters tonight as high pressure builds east-southeastward in its wake. The associated ridging will slide southward to along 29N Monday and Monday night, to 28N Tuesday and Tuesday night, to 27N Wednesday and to 26N Thursday. With this synoptic pattern setting up, expect fairly tranquil marine conditions across the entire basin. The only other impact to a small part of the area will be the southern portion of another cold front that will quickly brush the far northern waters Wednesday, preceded by strong SW winds and seas of around 7-10 ft. Northerly winds behind the boundary will be mostly moderate as latest model run depict. Uncertainty with the forecast comes into play late Wednesday night into as models differ on position of low pressure and its intensity as it tracks offshore the SE United States, with an attendant cold front that moves off the SE Georgia and NE Florida coasts to over the NW waters of the forecast area. Despite the differences in the models, nevertheless, it does appear that strong SW winds will impact much of the NW and N central waters on Thursday. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ031...CARIBBEAN FROM 11N TO 15N BETWEEN 72W AND 80W INCLUDING COLOMBIA BASIN... Gale Warning tonight into Sun night. GALE CONDITIONS POSSIBLE Mon into Mon night. GALE CONDITIONS POSSIBLE Tue night. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Aguirre. National Hurricane Center.