000 AXNT20 KNHC 172318 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 618 PM EST Sun Dec 17 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 2245 UTC. ...SPECIAL FEATURES... ...Gale Warning in the Caribbean Sea... NE-to-E gale-force winds will start again during the early morning hours of Monday, in about 12 hours, from 11N to 13N between 73W and 76W, in the waters that are off the coast of Colombia. Expect sea heights to range from 10 feet to 15 feet. The wind speeds will be less than gale-force by Monday afternoon. The gale-force NE-to-E winds will start again during the early morning hours of Tuesday, and eventually be continuing at gale-force again by Tuesday afternoon. Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough passes through the coastal sections of Sierra Leone near 07N12W, to 07N20W and 06N26W. The ITCZ continues from 06N26W to 05N29W, 07N42W, and to 06N46W. Precipitation: isolated moderate within 240 nm on either side of 10N36W 06N41W 03N51W. An upper level trough is along 31N35W 24N35W 20N38W 12N45W 07N50W 04N54W. Broken-to-overcast multilayered clouds and possible rainshowers are within 480 nm to the SE of the 31N35W-to-04N54W line. ...DISCUSSION... THE GULF OF MEXICO... A cold front extends from a SW Louisiana 1018 mb low pressure center, to 28N92W and 25N94W. A stationary front continues from 25N94W, to the coast of Mexico near 21N97W. Scattered moderate to strong rainshowers are from 27N to 29N between 89W and 91W, in the waters that are off the coast of SE Louisiana. A surface ridge passes through Florida near 29N81W, to 24N86W in the SE corner of the Gulf of Mexico, to Honduras. ...CURRENT CONDITIONS AND WEATHER, FOR THE OFFSHORE OIL PLATFORM SITES, THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N NORTHWARD AND FROM 88W WESTWARD... Mostly MVFR, and a few cases of IFR, at the platforms. CURRENT CONDITIONS AND WEATHER, FOR THE COASTAL PLAINS OF THE U.S.A., FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... TEXAS: MVFR in the Deep South/the Lower Valley. IFR from the Middle Texas Gulf coast toward Laredo. LOUISIANA: IFR/LIFR from Baton Rouge-to-Patterson east and southeastward. LIFR, light rain, and fog in Boothville. MISSISSIPPI: IFR/LIFR, with rain and fog, from Natchez-to-Hattiesburg southward. ALABAMA: IFR in Evergreen and in Dothan. IFR/LIFR from Mobile to Gulf Shores, and areas of rain. FLORIDA: IFR/LIFR and rain in the Florida Panhandle. MVFR in parts of the Pensacola metropolitan area. THE CARIBBEAN SEA... Broad middle level-to-upper level anticyclonic wind flow, and comparatively drier air in subsidence, span the entire Caribbean Sea. Rainshowers are possible in areas of broken low level clouds, from 70W eastward, from 11N to 18N between 70W and 80W, and from 80W westward. Please refer to the SPECIAL FEATURES section for more details about the gale-force winds for the coast of Colombia during the next two days. 24-hour rainfall totals in inches, for the period that ended at 17/1200 UTC, according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.18 in Curacao, 0.10 in St. Thomas in the Virgin Islands, 0.08 in San Juan in Puerto Rico, 0.06 in Guadeloupe, 0.04 in Montego Bay in Jamaica, 0.02 in Trinidad, and a TRACE in Freeport in the Bahamas. ...HISPANIOLA... Upper level N-to-NW wind flow is moving across Hispaniola. NE-to-E wind flow from 400 mb to 800 mb also is present across the island. Broad middle level-to-upper level anticyclonic wind flow spans the entire Caribbean Sea. SURFACE OBSERVATIONS...HAITI, in Port-au-Prince: VFR. in the DOMINICAN REPUBLIC: VFR at all the observation sites. The GFS MODEL forecast for 250 mb shows that Hispaniola will be to the east of a ridge. Expect N-to-NW wind flow during the next 48 hours. The GFS MODEL forecast for 500 mb shows that NE wind flow will move across the area during the next 2 days. An anticyclonic circulation center will move from the Bahamas near Andros Island toward NW Cuba. The GFS MODEL forecast for 700 mb shows that NE wind flow will move across the area. An anticyclonic circulation center will be in the area from the NW Bahamas to the Straits of Florida. THE ATLANTIC OCEAN... A deep layer central Atlantic Ocean trough is supporting a cold front, that passes through 32N48W to 25N60W and 24N65W. The cold front is dissipating from 24N65W and 23N73W. Precipitation: scattered moderate to strong rainshowers are from 31N to 33N between 42W and 44W. rainshowers are possible elsewhere within 180 nm on either side of the line that passes through 32N40W to 29N46W to 26N51W to 24N55W, and elsewhere from 20N northward from 55W westward. This cold front is ready to merge with a cold front that passes through 32N45W to 31N47W. A surface ridge passes through 32N29W to 25N42W and to 23N55W. For additional information please visit http://www.hurricanes.gov/marine $$ MT