000 AXNT20 KNHC 012320 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0705 PM EST SUN JAN 1 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 2315 UTC. ...SPECIAL FEATURES... ...Caribbean Gale Warning... The nocturnal pressure gradient will tighten tonight and again Monday night between the surface ridge over the west Atlantic and the lower pressure over South America to support gale force winds across the south- central Caribbean mainly from 11N-13N between 73W-76W. Seas to 14 ft are expected. Please see the High Seas Forecast product under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across southwest Africa into the east Tropical Atlantic near 08N13W to 05N21W where the ITCZ begins and continues to 03N40W to the coast of South America near 01N50W. Scattered moderate convection is from 01N to 07N between 40W and 55W. ...DISCUSSION... GULF OF MEXICO... A cold front is just inland over SE Texas. Pre-frontal scattered moderate convection is along the Texas and Louisiana coasts N of 26N and W of 90W. The remainder of the Gulf of Mexico has 10-20 kt high pressure return flow with fair weather. In the upper levels, an upper level trough is over N Mexico and New Mexico with axis along 110W. Upper level diffluence E of the trough axis is enhancing the convection over the NW Gulf. Expect in 24 hours for the cold front to be over the NW Gulf with convection extending E to the Florida Panhandle. Also expect 15-20 kt southerly return flow over the remainder of the Gulf. CARIBBEAN SEA... A gale is expected along the coast of Colombia starting on 02/0600 UTC and ending on 02/1800 UTC. 15-25 kt tradewinds are over the remainder of the Caribbean Sea. Satellite imagery shows a surface trough over the central Caribbean from 18N74W to 14N74W with scattered showers. Another surface trough is just E of the Windward Islands from 16N60W to 11N60W producing scattered showers as far W as 64W. Elsewhere, scattered showers are over the NE tip of the Yucatan Peninsula moving N. In the upper levels, an upper level high is centered over NW Nicaragua with a ridge axis extending NE to beyond E Cuba. The entire Caribbean and Central America has very strong subsidence. HISPANIOLA... Scattered showers are over Hispaniola moving W with the tradewind flow. Expect little change over the next 24 hours. ATLANTIC OCEAN... A 1031 mb high is centered over the central Atlantic near 34N56W. A cold front extends from the central Atlantic near 31N41W to 25N53W. A stationary front continues to 23N70W. Scattered showers are within 60 nm of the fronts. Another cold front is over the E Atlantic from 31N20W to 26N30W. Scattered showers are within 60 nm of this front. In the upper levels a ridge is over the W Atlantic W of 60W with strong subsidence. An upper level trough is over the central Atlantic between 40W-60W N of 15N. A small upper level low is over the E Atlantic near 23N31W. Expect over the next 24 hours for both fronts to move E with showers. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa