000 AXNT20 KNHC 030605 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...GALE-FORCE WINDS IN THE GULF OF MEXICO... Strong high pressure anchored in the southern plains and in the Ohio Valley extends south across the Gulf of Mexico and across eastern Mexico. A weakness in the ridge is analyzed as a surface trough over the SW Gulf waters extending from 24N96W to the western Bay of Campeche near 18N94W. A strong pressure gradient between the trough and the strong high pressure east of the Sierra Madre Oriental in Mexico will support the development of gale- force winds starting at 0600 UTC today, Wednesday and ending early morning 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 Ohio Valley extends over the NW Atlc waters and south to the northern Bahamas adjacent waters. A tight pressure gradient between the high 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 within the next 24 hours while it moves NE across 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 Sierra Leone to 07N19W. The ITCZ continues from 07N19W to 06N23W to 02N29W to 03N50W. Scattered moderate convection is from 03N to 07N between 07W and 24W. ...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 Ohio Valley. A tight pressure gradient exist between the Sierra Madre Oriental mountain range in Mexico and a surface trough over the SW Gulf of Mexico. This is leading to fresh to strong NW to N winds from 24N to 28N E of 96W and the entire area W of 96W. The pressure will further intensify, thus leading to the development of gale force winds starting at 0600 UTC today near Tampico and Veracruz. Please refer to the special features section for further details. Thereafter, the wind field will gradually diminish Wednesday night into Thursday. CARIBBEAN SEA... Southwesterly flow aloft prevails over the Caribbean basin between an upper level trough over the eastern Gulf of Mexico and Yucatan peninsula and an upper level anticyclone anchored over the SE Caribbean. The troughing supports a stationary front analyzed across western Cuba from 22N80W SW to eastern Honduras near 15N84W. Isolated showers are across the NW Caribbean waters associated with the front. In the SW Caribbean waters, two centers of low pressure are analyzed underneath diffluent flow aloft. One low pressure is located near 10N80W and the second low is near 11N77W, both providing focus for scattered showers in the central Caribbean waters between 71W and 80W, including Hispaniola, the Windward Passage and eastern Cuba. These lows are forecast to remain nearly stationary, which will continue to support showers in this region. Otherwise, the eastern Caribbean remains under fair skies within moderate to occasional fresh trades. The front is expected to gradually weaken today. However, reinforcing cold air will increase northerly winds tonight into Thursday generally W of 75W. ...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 Thursday night as the upper level wind pattern is forecast to prevail. Otherwise, NE winds will increase to fresh to strong in the Windward Passage staring Thursday night and continuing through the weekend. ATLANTIC OCEAN... Broad middle to upper level troughing supports a cold front entering into the SW North Atlc discussion area near 30N59W SW to 24N73W where it transitions to a stationary front. The stationary front then extends to a 1015 mb low centered in the straits of Florida and then into NW Caribbean waters. Widely scattered showers are within 53W and 75W. To the SE, a surface trough extends from 20N60W to 15N60W providing focus for isolated showers. The cold front is expected to continue sliding eastward through Thursday with strong to near 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. 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