000 AXNT20 KNHC 210543 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1243 AM EST Sun Jan 21 2018 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...SPECIAL FEATURES... Broad strong high pressure extending from the western Atlantic into the Gulf of Mexico is creating a gradient tight enough to support winds to gale force off the coast of Colombia through tonight. The gale force winds will diminish early Sunday, but remain strong to near gale-force through Monday. See the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean near 08N13W and continues to 04N20W. The ITCZ begins near 04N20W and extends to 00N35W and terminates near 00N48W. No significant convection is observed. ...DISCUSSION... ...GULF OF MEXICO... Ridging extends across the western Atlantic 30N, across northern Florida and into the Deep South States. Fresh southeast return flow is observed over the northwest Gulf between the ridge and lower pressure over the central Plains. Fresh easterlies are also noted over the Straits of Florida and Yucatan Channel. Elsewhere moderate east to southeast winds persist across the northern Gulf, with lighter flow over the southwest Gulf. A mid to upper level trough is digging eastward across the lower Mississippi Valley, supporting showers over the eastern Gulf and a surface trough from the southeast Gulf through northeast Florida. Patch fog is being reported off the central coast of Louisiana, but otherwise visibility remains good. The moderate to fresh SE winds will continue across the western Gulf through this evening ahead of a cold front moving southeast off the Texas coast around sunrise on Mon. The cold front will extend from the mouth of the Mississippi to Veracruz Mexico late Mon, and then stall from southwest Florida to near Veracruz Mexico on Tue night. Remnants of the front will lift N on Wed and Thu. ...CARIBBEAN SEA... Clusters of showers and thunderstorms are ongoing across the northwest Caribbean, related to divergence aloft at the base a sharp upper trough extending from the northeast Gulf of Mexico to the Yucatan peninsula. Elsewhere, in addition to the gale force winds mentioned in the Special Feature section off Colombia, fresh to strong trade winds are noted in latest scatterometer data and buoy observations over much of the central Caribbean, lee of Cuba and Windward Passage. Seas are reaching 9 to 11 ft over the south central Caribbean with highest seas off Colombia. Moderate to fresh trades and 5 to 7 ft seas are noted in the eastern Caribbean and east of the Windward and Leeward Islands. Persistent ridging north of the area will allow strong to near gale force trades to pulse along the northwest coast of Colombia through Thu night. Strong east winds are forecast across the Central Caribbean waters on Sun, diminishing slightly on Mon as the ridge weakens. Moderate to fresh trades will continue across the tropical Atlc waters E of the Windwards through Thu night. ...ATLANTIC OCEAN... Ridging extends along roughly 30N, anchored by a 1026 mb high pressure area centered near 30N70W. Divergence aloft on the east side of an upper trough over the Gulf of Mexico is supporting a few showers off the Florida coast and northern Bahamas. A cold front reaches from 31N43W to 21N65W. A recent scatterometer pass showed fresh trade winds across the Turks/Caicos and southern Bahamas, along the dissipating stationary front trailing the end of the cold front. A few showers are noted within 210 nm east of the front north of 25N. Farther east, 1035 mb high pressure is centered off Portugal, with an associated ridge extending over the region north of 20N, supporting fresh to strong NE winds off the coast of North Africa between the Canary Islands and Cabo Verde. Farther south, moderate to fresh trade persist across the deep tropics. The High pressure will shift east to just southwest of Bermuda through Mon, then shift north of Bermuda Mon night allowing a cold front to move off the northeast Florida coast Tue morning. The cold front will reach from near Bermuda to Straits of Florida Wed night and from 27N65W to Central Cuba on Thu night. Strengthening high pres in the wake of the front will support strong NE wind W of 73W. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen