000 AXNT20 KNHC 031002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 502 AM 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...GALE-FORCE WINDS IN THE GULF OF MEXICO... Strong high pressure anchored in the southern plains and in the middle Atlantic extends south across the Gulf of Mexico and across eastern Mexico. A strong pressure gradient east of the Sierra Madre Oriental in Mexico supports gale-force N winds near Tampico and Veracruz forecast to end early in the morning on Thursday. Please read the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...STORM-FORCE WINDS IN THE ATLANTIC OCEAN... Strong high pressure anchored over the middle Atlantic extends over a portion of the NW Atlc waters southward to the northern Bahamas adjacent waters. A tight pressure gradient between the ridge and a frontal system associated with a center of low pressure anchored in the straits of Florida support gale force winds N of the front to 30N and E of 80W. The low is forecast to undergo rapid deepening today while it moves N-NE between Florida and the northern Bahamas. This will lead to storm-force winds continuing through early Thursday morning when the winds are forecast to diminish again to gale-force. Please read the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough passes through the coastal border area of Liberia to 07N19W to 02N28W. The ITCZ continues from 02N28W to 01N44W. Scattered moderate convection is from 01N to 07N between 08W and 25W. ...DISCUSSION... GULF OF MEXICO... The Gulf is under the influence of a strong surface ridge anchored by several high centers in the southern plains and in the middle Atlantic. A tight pressure gradient exist east of the Sierra Madre Oriental mountain range in Mexico, which is supporting gale force winds from 22N to 27N W of 96W and fresh to strong northerly winds elsewhere S of 28N W of 95W. Please refer to the special features section for further details. Thereafter, the wind field will gradually diminish tonight into Thursday. CARIBBEAN SEA... Southwesterly flow aloft prevails over the Caribbean basin between a middle to upper level trough over the eastern Gulf of Mexico and Yucatan peninsula and a middle level anticyclone anchored over the SE Caribbean. The troughing supports a stationary front analyzed across western Cuba from 22N81W SW to eastern Honduras near 15N84W. Isolated showers are across the NW Caribbean waters east of the front. In the SW Caribbean waters, a low pressure center is analyzed underneath diffluent flow aloft. The 1009 mb low is located near 10N80W and support scattered heavy showers S of 15N between 74W and 81W. Scattered showers are in the north- central Caribbean waters between 68W and 78W, including Hispaniola, the Windward Passage and eastern Cuba. The low is forecast to remain nearly stationary through tonight and then it will dissipate. This will allow for the continuation of showers in the SW Caribbean waters. Otherwise, the eastern Caribbean remains under fair skies and moderate to occasional fresh trades. The front is forecast to gradually weaken today. However, reinforcing cold air will transition the boundary to a cold front that is forecast to stall over western Hispaniola Friday night. Winds behind the front are forecast to increase to fresh to strong in response to the second push of cold air. ...HISPANIOLA... Diffluent flow between a trough aloft with base near Guatemala and an upper ridge covering the eastern half of the Caribbean support scattered showers across the western half of the Island and the Windward passage. This convection is forecast to continue through Friday as a cold front approaches from the west and stalls over the western island Friday. Otherwise, NE winds will increase to fresh to strong in the Windward Passage starting Thursday night and continuing through the weekend. ATLANTIC OCEAN... Broad middle to upper level troughing supports a cold front extending from 31N54W SW to 26N70W where it transitions to a stationary front to the northern Bahamas and then into a warm front that ends in a 1014 mb low located in the straits of Florida near 24N80W. Diffluent flow aloft between the upper trough and the ridge over the central Atlc support scattered showers between 51W and 74W. A surface trough is NE of the Leeward Islands extending from 21N61W to 17N60W to 15N60W. Isolated showers are likely within 90 nm either side its axis. The cold front is expected to continue sliding eastward through Thursday with strong to gale force NE winds following in wake of the front. The low is forecast to strengthen and quickly move N of the discussion area tonight into Thursday. Storm force winds are forecast to develop this evening as the low deepens. See the special features section for further details. 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. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos