000 AXNT20 KNHC 080003 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 702 PM EST SAT JAN 7 2017 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...SPECIAL FEATURES... A cold front is currently analyzed across NW portions of the SW North Atlc, the Florida Keys, and Gulf of Mexico from 25N80W to western Cuba near 22N84W to the NE Yucatan Peninsula near 20N87W. The front continues moving eastward and will clear the Gulf of Mexico tonight and remain impacting the SW North Atlc waters through the remainder of the weekend into Monday. Gale force winds are in the Gulf of Mexico S of 22N W of 93W with seas from 15 to 23 ft. In the Atlantic, fresh to near gale force winds with frequent gusts to gale force are W of the front. Near gale to gale force SW winds are N of 30N within 60 nm E of the front with seas building to 11 ft. Both gale events are forecast to end by Sunday afternoon. See latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 07N13W to 07N16W where the Intertropical Convergence Zone axis begins and continues along 02N22W to 0N32W to the NE coast of Brazil near 01S44W. Scattered to isolated showers are from 01S to 07N between 17W-35W. ...DISCUSSION... GULF OF MEXICO... The main impact across the basin tonight continue to be the Special Features cold front that extends from 25N80W to western Cuba near 22N84W to the NE Yucatan Peninsula near 20N87W. The front continues to be supported aloft by a middle to upper level trough noted on water vapor imagery with axis extending over the Great Lakes SW to a base over the Bay of Campeche. Shallow moisture along with upper level diffluence support scattered showers across the Florida Straits and the Yucatan Channel. A strong pressure gradient between the front and strong high pressure building behind it support gale force winds S of 22N W of 93W with seas from 15 to 23 ft. Also, frequent gusts to gale force winds are possible in the north-central basin. Otherwise, the strong ridge anchored by a 1044 mb high centered over Texas will continue to slide eastward to the mid-Atlc coast by Monday morning. As this occurs, the current wind field will gradually diminish from west to east Sunday night into Monday as SE return flow establishes across the NW Gulf. CARIBBEAN SEA... Water vapor imagery continues to indicate strong subsidence over most regions of the basin with the exception of the SE and SW Caribbean where abundant low to middle level moisture support widespread scattered to isolated showers. Scattered showers are also in the Yucatan Channel associated with a cold front moving across the Florida Straits, the Yucatan Channel and the Yucatan Peninsula. This front will move over NW Caribbean waters later tonight with fresh to strong winds behind it that will increase to near gale force by Sunday afternoon as the front continue to move E-SE across the NW basin waters. A fairly weak pressure gradient across the basin maintain moderate trades across the E basin. Fresh to strong trades are over the south-central basin with the strongest winds along the coast of Colombia. This area of winds will expand to the remainder SW basin Sunday where it will merge with the area of strong to near gale force winds associated with the cold front. ...HISPANIOLA... Dry air and strong subsidence aloft are providing an overall stable environment that is expected to persist through Sunday evening. However, a cold front entering the NW Caribbean later tonight will slide E-SE to the eastern tip of Cuba by late Sunday where it will stall through Monday night. The front will then move across Hispaniola and Puerto Rico Tuesday through Wednesday morning. This will support showers across the Island from Sunday evening through Wednesday evening. ATLANTIC OCEAN... Southwesterly flow aloft prevails over the SW North Atlc region as a middle to upper level trough approaches from the west. This upper trough with axis extending from the Great Lakes to a base over the Bay of Campeche supports a 1006 mb low centered off the mid-Atlantic coastal waters. A cold front extends from this low SW to 30N75W to the northern Bahamas to the Straits of Florida. Fresh to near gale force winds with frequent gusts to gale force are W of the front. Near gale to gale force SW winds are N of 30N within 60 nm E of the front with seas building to 11 ft. Enhanced satellite imagery and GOES lighting density data show scattered showers and tstms within 210 nm SE-E of the front and isolated showers W of the boundary. As the front passes...winds will shift northerly ranging from strong to near gale strength. This N-NE wind field will quickly move southeastward across the region through Monday as strong high pressure anchors to the north across the mid-Atlc coast. Otherwise, surface high pressure anchored N of the area extends a ridge axis S-SW across the remainder SW N Atlc and the central Atlc, thus providing fair weather conditions. Across the eastern Atlc, a 1006 mb low is centered near 29N26W with a surface trough axis extending S-SW to 26N25W. This low is supported aloft by a broad cut-off middle to upper level low centered near 29N26W. Widely scattered showers and isolated tstms are occurring generally east of the surface low N of 25N between 17W-25W. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos