000 AGXX40 KNHC 111930 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 230 PM EST SUN DEC 11 2016 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... MODEL PREFERENCE: Global model consensus. High confidence. Winds across the southern Gulf are diminishing today as high pressure over the southeastern United States slides east and over the western Atlantic. With the loss of the support of the colder airmass to the north, the stationary front is transitioning into a surface trough over the southern Gulf. This trough will dissipate through tonight. Tonight through Wednesday, a ridge axis will setup across northern Florida to the northeastern Gulf. This will result in the development of a weak return flow pattern over the Gulf basin with seas subsiding down from 3 to 6 ft this afternoon, to 2 to 3 ft on Monday. Latest model guidance continues to forecast a frontal boundary to stall out just north of the northern Gulf coast Wednesday. Then, strong high pressure building southeast over the central United States will force the stationary frontal boundary to the southeast as a cold front early Thursday. This cold front will cross the central and eastern Gulf Thursday into Thursday night. The high building across the northern Gulf behind this mid week front will support moderate to fresh northerly winds over the northeast Gulf and moderate to fresh east to southeast winds over the western Gulf through Thursday night. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: Global model consensus. High confidence. A broad area of low pressure has developed just west of a surface trough over the southwestern Caribbean. This low is moving slowly westward and will reach the coast of southern Nicaragua late tonight. Deep moisture streaming westward on the northern semicircle of this low is already producing very heavy rainfall across Nicaragua and northern Costa Rica. This rainfall will continue through tonight and possibly into the day Monday. Mudslides and flash flooding will likely occur over the rugged terrain due to the persistent heavy rainfall today through tonight. The emphasis of this danger has been conveyed through the Atlantic Tropical Weather Discussion, this MIM, as well as through social media. The pressure gradient between high pressure emerging from the eastern United States over the western Atlantic and the lower pressures over the southwest Caribbean and Colombia will continue to support fresh to strong trades over most of the Caribbean south of 18N until the middle of the week. Winds will pulse to near gale force near the coast of Colombia tonight due to a slight tightening of the pressure gradient due to nocturnal fluctuations. The high to the north is sliding east, and will reach the central Atlantic tonight into Monday night which is helping to expand the strong trade winds across the eastern Caribbean as well as the Atlantic forecast waters. The high will slide even farther east through mid week, helping to somewhat relax the trades over the Caribbean and tropical Atlantic forecast waters. Even so, the combination of another area of high pressure building over the Gulf and western Atlantic waters later this week, and the ongoing presence of lower pressures over the southwest Caribbean and Colombia will continue to support overnight enhancements of trades to around 25 kt within 90 nm of the coast of Colombia Wednesday, Thursday, and probably Friday night. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: Global model consensus. High confidence. A stationary front from around 25N65W to the central Bahamas to the Florida Straits will dissipate through tonight. Strong high pressure north of the front is supporting an expanding area of fresh to strong winds south of 28N across the Atlantic forecast zones. The stronger winds will shift to the east and southeast into Monday as the high to the north also shifts eastward toward the central Atlantic. The area of strong winds and seas 8 ft or greater will begin to diminish across the southeast zones Tuesday as the high continues eastward toward the eastern Atlantic. A cold front will enter the far northwest waters Monday and clip the northern zones through Tuesday. Strong return flow and seas to 8 ft are likely north of 30N ahead of this front. Another cold front will cross the northwestern waters Wednesday night and reach from around 31N65W to the central Bahamas by late Thursday. Current model guidance is forecasting mainly moderate to fresh northerly winds behind this second cold front. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Latto. National Hurricane Center.