000 AXNT20 KNHC 031721 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1221 PM EST Wed Jan 3 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 1200 UTC surface analysis and satellite imagery through 1615 UTC. ...SPECIAL FEATURES... As of 03/1500 UTC...a vigorous middle to upper level trough is noted on water vapor imagery over the NE Gulf of Mexico and Florida panhandle supporting a developing area of low pressure focused on a pair of 1010 mb lows...one centered off the coast of SE Florida near 26N80W and the other farther N offshore near 30N80W. A forming cold front extends from the southern-most low across western Cuba and into the NW Caribbean Sea. A warm front also extends E from the low across the NW Bahamas and SW North Atlc waters to 27N71W. With respect to the northern-most low...a stationary front extends N paralleling the Florida coast along 80W. With the middle to upper level trough energy focused near 29N85W and becoming negatively tilted this afternoon...the northern-most low pressure is expected to deepen rapidly during the next 24 hours and move N of the area generating storm-force winds within 90 nm of center in the southern semicircle in the discussion waters and eventually develop hurricane-force winds off the east coast of the US north of the discussion area. A recent scatterometer pass around 03/1428 UTC captured near gale to gale force easterly wind N of the warm front to 31N W of 73W. The low is forecast to move north offshore of the east coast of the US reaching Nova Scotia Canada by Thursday night. See the latest NWS NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC and NWS OPC High Seas Forecast under AWIPS/WMO headers HSFAT1/FZNT01 KWBC for more details. A strengthened pressure gradient and reinforcing cold air filtering in across the western Gulf of Mexico continues to support near gale to gale force N-NW winds generally S of 26N W of 95W. The wind field is forecast to translate southward along the coast of Mexico through late Wednesday night and diminish below gale force by Thursday. See the 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 04N08W to 06N16W. The Intertropical Convergence Zone axis extends from 06N16W to the Equator near 33W. Widely scattered moderate convection is from the Equator to 03N between the Prime Meridian and 06W...and from 01N-06N between 09W-26W. ...DISCUSSION... GULF OF MEXICO... Aside from the near gale to gale force conditions mentioned above...a surface ridge prevails across the Gulf this afternoon anchored by a 1036 mb high centered across northern Mexico near 28N101W. Fresh to strong northerly winds are expected to persist through Thursday afternoon. Thereafter...the ridging will weaken gradually relaxing the pressure gradient and winds will diminish into moderate breeze levels for the upcoming weekend. CARIBBEAN SEA... Southwesterly flow aloft prevails over the Caribbean basin this afternoon between an upper level trough over the eastern Gulf of Mexico and Florida peninsula and an upper level ridge anchored over northern Venezuela. The troughing supports a forming cold front analyzed across western Cuba from 23N82W to the Gulf of Honduras near 17N87W. Isolated showers are possible across the NW Caribbean waters in the vicinity of the front as the cooler and drier airmass NW of the front filters southward across the western Caribbean through tonight. Farther SE...broad surface troughing and a 1009 mb low centered offshore of central Panama near 10N80W continues to provide focus for scattered to numerous showers and scattered tstms S of 17N between 74W-81W...and S of 12N between 81W-84W. Otherwise...the eastern Caribbean remains under fair skies within moderate to occasional fresh trades. As the Special Features low pressure area across the SW North Atlc waters moves northward...the associated cold front will move across the western Caribbean to 78W and become stationary across the Windward Passage and Hispaniola Thursday into Friday with fresh to strong winds expected W of the boundary through the upcoming weekend. ...HISPANIOLA... Increased cloudiness and isolated showers are expected through tonight across Hispaniola as broad surface troughing and lower pressure focuses on the Bahamas...Greater Antilles...and central Caribbean Sea. A cold front currently across western Cuba and the NW Caribbean Sea will begin to approach from the west on Thursday with NE winds increasing through the Windward Passage region and persisting through early next week. ATLANTIC OCEAN... Outside of the Special Features developing area of low pressure across the SW North Atlc...a cold front enters the discussion area across the central Atlc near 32N50W to 31N53W becoming stationary to 30N62W to 27N73W and linking up with the Special Features warm front boundary. Scattered showers and isolated tstms are occurring within 240 nm either side of the boundary. The remainder of the central and eastern Atlc is under the influence of a surface ridge anchored by a 1037 mb high centered W-SW of the Iberian peninsula near 37N15W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN