000 AGXX40 KNHC 301829 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 229 PM EDT Thu Mar 30 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... The pressure gradient associated with high pressure extending from the SW N Atlc to the central gulf and low pressure in the western basin associated with a cold front support moderate to fresh winds E of 90W. SE winds are fresh to strong NW of the Yucatan Peninsula to 24W and over the eastern Bay of Campeche just to the east of a 1006 mb low located near 21N94W. The cold front that extends from SW Louisiana to NE Mexico is preceded by a squall line that extends from SE Louisiana to near 25N93W. Lighting density data show strong convection and numerous tstms along and in the vicinity of the squall line about N of 25N. The cold front will quickly move to central waters this afternoon and the eastern waters late tonight while it weakens. Fresh to strong NW winds will be W of the front through tonight, then mainly fresh southerly winds will precede the front across NE waters. However, atmospheric instability associated with upper level dynamics is expected to continue to bring numerous showers and thunderstorms, some capable of producing strong gusty winds and tough seas ahead of the front through Friday. Another area of low pressure will develop over the southern Plains Friday, and move over the southern United States during the weekend. The pressure gradient between the low and Atlantic high pressure ridging extending to the eastern waters will once again increase the southeast winds to fresh to strong W of 85W. The cold front associated with this second area of low pressure is forecast to move off the Texas coast early Monday morning and reach from west-central Florida to the northeast Yucatan Peninsula at night. Mostly strong southerly winds are likely to precede the front. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Generally, gentle to moderate trades dominate over the Caribbean waters with the exception of SE of Hispaniola and the Gulf of Honduras where fresh winds are noted. High pressure building over the SW N Atlc will allow for the trades to become mainly fresh at night while fresh to strong winds are forecast for the Gulf of Honduras and along the coast of Colombia. This pattern of moderate to fresh trades over the majority of the Caribbean and fresh to strong winds over the Gulf of Honduras and Colombia coast will persist through the upcoming weekend. Over the tropical Atlantic waters, a weakening cold front extends from 19N55W across the Leeward Islands to 15N65W and sustains gentle to light easterly flow over just about the entire Tropical North Atlantic zones, except for moderate trades in the southeast portion of these zones. The front is forecast to continue to move SE while gradually dissipating through tonight. Northerly swell is decaying in the Tropical North Atlantic, however wave model guidance is suggesting that quite an impressive and extensive batch of long period northerly swell will begin to infiltrate the Tropical North Atlantic waters starting on Saturday. This northerly swell will propagate through all of the Tropical North Atlantic zones into Monday while inducing combined sea state of 8-11 ft. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A long-period northerly swell will move into the northeast portion of zone AMZ115 beginning this tonight with seas of 6-9 ft. This swell will propagate through all of the eastern portion of the basin into Sunday afternoon, with combined sea state peaking to around 10 ft. Weak high pressure prevails over the basin as a weak cold front extends across the northern waters from near 28N65W to 27N73W then becoming stationary northwest to 30N79W. The front is followed by generally moderate northwest to north winds. The cold front will move off the area late Friday, while the stationary front becomes diffuse tonight. The next cold front will emerge off the southeast U.S. coast on Friday night and move over the north-central waters Saturday. A tight gradient between the front and former high pressure in the area will develop fresh to strong southerly winds over much of zone AMZ113 on Saturady with seas of 8-9 ft. This strong southerly flow will shift to the northeast zone Saturday night through Sunday. High pressure in the wake of the front will slide eastward to the northeast part of the forecast waters by late Monday. A strengthening pressure gradient between a low pressure system forecast to be over the SE CONUS on Monday afternoon and the high pressure over the SW N Atlc will lead to a significant increase of southerly flow over the northwest waters beyond Monday night. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.nhc.noaa.gov/marine $$ .Forecaster Ramos. National Hurricane Center.