000 AGXX40 KNHC 111017 AAA MIMATS Marine Weather Discussion...updated NWS National Hurricane Center Miami FL 517 AM EST SUN DEC 11 2016 updated Gulf of Mexico section for forecast cold front position 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...updated MODEL PREFERENCE: Global model consensus. High confidence. The 06Z surface analysis has a stationary front draped from northwest Cuba southwest to inland the northern Yucatan peninsula. A trough extends from 24N96W southeast to 18N93W. Strong high pressure ridging is sliding eastward over the northern gulf east of 93W. The tight pressure gradient along the coast of Mexico south of 21N, and within 60 nm of the coast of Veracruz is relaxing. Northwest to north winds there have diminished to 20-25 kt with seas in the 9-11 ft range as depicted in the 0318Z Ascat pass. This Ascat pass also showed a swath of fresh to strong northeast winds roughly from 22N to 25N east of 93W, including the Straits of Florida. Seas with these winds are in the 8-9 ft range per recent altimeter data, except for higher seas of 9-10 ft in the Straits of Florida where northeast flow counter to the loop current is helping to maintain these seas. Seas elsewhere are in the range of 4-7 ft, except for lower seas of 2-3 ft in the far northern waters. Water vapor imagery continues shows ample upper-level moisture streaming eastward across much of the southern portion of central gulf, and the southeast part of the eastern gulf in broad upper level southwest flow. Upper-level jet stream energy riding along this flow is helping to trigger off scattered showers across these area. Scattered showers and isolated tstms are confined to the Bay of Campeche. The strong high pressure will continue to shift eastward and weaken through early on Monday. A weaker gradient will set up over the area through the next few days allowing for seas to considerably subside to 2-3 ft throughout by late MOnday, except for 3-5 ft seas in the approach to the Yucatan channel, and in the Yucatan channel. The 3-5 ft seas then subside to 2-3 ft Wednesday through Thursday. A cold front is forecast to approach the northern gulf Tuesday night, then become stationary through Wednesday. Models indicate that strong high pressure surges south over the southeast U.S. pushing the cold front across the northern and eastern gulf Wednesday night through Thursday night. Northerly flow will increase behind the front during this time as the high pressure broadens, and increases the pressure gradient over much of the northern and eastern gulf. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: Global model consensus. High confidence. The 0136 Ascat pass showed fresh northeast winds between 67W and 79W and also south of 16N between 79W and 82W. Similar winds are in the windward passage where a ship earlier again confirmed these winds as well. A small pocket of strong northeast to east winds is along the coast of Colombia, and in the Gulf of Venezuela. Seas are in the 8-11 ft range over the central Caribbean, except for 10-12 ft within 90 nm of coast of Colombia. Both buoy and Ascat data show moderate to fresh northeast to east winds elsewhere, with seas in the 5-7 ft range, except for 3 to 4 ft west of 79W and higher seas of 5-7 ft in the windward passage. A well-defined surface trough, resembling an easterly wave, is analyzed at 06Z along 78W from the coast of Panama north to 17N. It is moving westward at 10-15 kt. A tight gradient in the wake of the trough is helping to contribute to the aforementioned fresh northeast winds over the central Caribbean. Numerous showers and thunderstorms are occurring within 180 nm east of the trough south of 15N. Scattered showers and isolated thunderstorms are elsewhere south of 17N between 74W and 83W. The surface trough will move across the western Caribbean sea through Monday night before moving inland central America. A stationary front extending from the northern Yucatan peninsula northeastward to western Cuba will dissipate this afternoon as strong high pressure behind it continues to slide eastward. The fresh northeast winds in the central Caribbean will become mostly strong, and expand in coverage through Monday night, then diminish on Tuesday. Strong northeast to east trades are expected to materialize across the tropical north Atlantic zone AMZ127 Sunday night through most of Tuesday. Combined seas up to 12 ft in zone AMZ031 will continue through Monday before subsiding thereafter. Seas are forecast to build to 8-10 ft in the tropical north Atlantic zone Monday and Monday night before they begin to subside on Tuesday. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: Global model consensus. High confidence. Strong high pressure is sliding eastward from the Carolinas into the western Atlantic in the behind a slow moving cold front currently extending from near 25N65W to 25N70W where it becomes stationary to northwest Cuba. A tight gradient between the ridge and front is producing strong northeast winds from 24N to 27N west of 71W, with seas of 8-10 ft. The highest of these seas is west of 78W, including the Straits of Florida. The cold front will weaken through tonight as it moves east-southeastward, and while at the same time the stationary portion dissipates. The strong northeast winds will then response by diminishing to fresh category, but at the same time veer around to a southerly component as the high pressure slides eastward. The high will shift to the eastern part of the basin by Tuesday in response to a cold front that approaches the southeast U.S. East to southeast winds will increase to strong intensity over much of the central and eastern waters tonight through early on Monday, then diminish later on Monday. By that time, a tight gradient will be confined to the southeast portion of the basin where fresh to strong east winds will materialize. These winds and associated seas then diminish on Tuesday as a weaker pressure gradient becomes establised over the area. The previously mentioned cold front is expected to brush the far northern waters Monday through Tuesday night. Presently, model guidance highlights mainly fresh south to southwest winds ahead of this front, and gentle to moderate west to northwest winds behind it becoming light and variable Tuesday night and Wednesday. Seas of 5-7 ft are expected east of the front within the fresh to south to southwest winds, and 4-5 ft behind the front. A stronger cold front is expected to move into the far northwest corner late Wednesday night, and reach the eastern waters late Thursday. This front is forecast to be preceded by fresh to strong southerly winds, and seas possibly up to 8 ft. Northerly winds behind the front are forecast to be mainly in the fresh range, but this is subject to change based on guidance from future model runs. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.hurricanes.gov/marine $$ .Forecaster Aguirre. National Hurricane Center.