000 AXNT20 KNHC 130549 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1249 AM EST Wed Dec 13 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...SPECIAL FEATURES... A cold front extends across the SW North Atlc from 32N76W SW to the Florida peninsula near Cape Canaveral and into the Gulf of Mexico. Near gale to gale force winds are occurring N of 30N on either side of the front as depicted on the latest scatterometer passes from 13/0144 UTC and 13/0240 UTC. The front is forecast to sweep eastward through Wednesday and eventually lift N of the discussion area 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 07N12W to 06N14W. The Intertropical Convergence Zone axis extends from 06N14W to 05N30W to 02N51W. Widely scattered moderate convection is within 210 nm N of the axis between 24W-52W. ...DISCUSSION... GULF OF MEXICO... The Special Features cold front mentioned above extends across the central Florida peninsula and into the basin near 27N82W extending W to 25N90W to the NE Mexico coast near 25N97W. A relatively dry and convection-free front...it is providing moderate to fresh N-NW winds E of 90W and gentle to moderate N winds W of 90W this evening. A surface ridge influences much of the remainder of the basin anchored by a 1025 mb high centered near Tuxpan and a 1026 mb high centered across western Texas. As the cold front shifts eastward through Wednesday night...ridging will follow and provide light and variable winds on Wednesday and the re-establishment of southerly return flow Thursday. CARIBBEAN SEA... A stationary front extends from the Windward Passage S-SW to the coast of western Panama near 10N82W. Widely scattered showers and tstms are occurring generally within 120 nm either side of the front. Much of this convection is supported aloft by a divergent upper level pattern on the northern periphery of an upper level anticyclone anchored over eastern Panama near 09N78W. East of the anticyclonic circulation...dry northerly flow prevails providing overall stability to the central and eastern Caribbean this evening. Overall gentle to occasional moderate trades are expected through the overnight period into Wednesday E of the front...while the front is forecast to gradually weaken through Thursday. ...HISPANIOLA... Isolated showers are possible across western portions of the island this evening as a stationary front lies to the W across the Turks and Caicos through the Windward Passage to Jamaica. The front is expected to remain stationary and begin weakening through Thursday. ATLANTIC OCEAN... Water vapor imagery indicates middle to upper level troughing over the eastern CONUS and western North Atlc waters supporting the Special Features cold front extending from 32N76W SW to Cape Canaveral Florida. The reinforcing cold front is expected to merge with a stationary front on Thursday that is currently analyzed to the east from 32N58W to the Turks and Caicos islands to the Windward Passage region. The reinforcing cold front remains relatively convection-free...while isolated showers are occurring within 120 nm either side of the stationary front. Farther east...a surface ridge influences much of the central and eastern Atlc...anchored by a 1034 mb high centered S of the Azores near 36N27W. However...within the southeastern periphery of the ridge nearing the Cape Verde Islands...a cold front extends from the coast of Africa near 19N16W to 22N34W. Primary area of concern with the front is the large area of strong to near gale force NE winds generally N of the front E of 33W. The pressure gradient associated with this wind field is expected to relax by Friday. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN