000 AXNT20 KNHC 191751 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1251 PM EST Tue Dec 19 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...SPECIAL FEATURES... ...Gale Warning in the Caribbean Sea... Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. The gale-force wind conditions will start during the early morning hours. They will last for periods of 9 to 12 hours or so, and then the wind speeds will slow down to less than gale-force. Pulsing nocturnal NE-to-E winds to gale-force are expected again from the early morning hours of Wednesday until the middle morning hours of Wednesday. The gale-force conditions are expected from 11N to 13N between 74W and 77W, off the coast of Colombia. Expect sea heights to range from 11 feet to 13 feet. ...ITCZ/MONSOON TROUGH... The monsoon trough passes through the coastal sections of Sierra Leone near 07N12W, to 04N22W and 04N28W. The ITCZ continues from 04N28W to 04N34W 02N37W, and 02N40W. Precipitation: widely scattered moderate to isolated strong from 01N to 06N from 37W eastward. Rainshowers are possible elsewhere from 10N southward from 58W eastward. An upper level trough is along 31N36W 25N34W 22N32W 19N31W, and a shear axis from 19N31W 14N39W 10N50W, to 08N59W at the coast of Guyana. High level clouds are to the south of the line from 21N16W to 16N30W 12N40W 07N58W. ...DISCUSSION... ...THE GULF OF MEXICO... Broad middle level-to-upper level anticyclonic wind flow spans the entire area. Comparatively drier air in subsidence is to the E and SE of the line that runs from the coast of Mexico near 24N, to the Florida Panhandle. Surface anticyclonic wind flow covers much of the Gulf of Mexico. A ridge extends from a 28N81W Florida high pressure center, into the west-central and western sections of the Gulf of Mexico. ...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... LIFR off the coast of Texas near Galveston. LIFR, fog and mist in SE Louisiana coastal areas. mostly VFR/some MVFR conditions elsewhere. CURRENT CONDITIONS AND WEATHER, FOR THE COASTAL PLAINS OF THE U.S.A., FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... TEXAS: LIFR/IFR, haze and mist, from the middle coastal plains and inland areas, toward the S and SW. IFR/MVFR from the Houston metropolitan area to Huntsville. LIFR/IFR from Galveston, to Beaumont/Port Arthur, to Jasper. LOUISIANA: LIFR, fog and mist, from Hammond and Baton Rouge southward. MISSISSIPPI: LIFR/IFR, with fog and mist, from Natchez-to-Hattiesburg southward. ALABAMA: lIFR/IFR, fog and mist, from Evergreen-to- Dothan southward. FLORIDA: MVFR/IFR, from Cross City toward the northwest and west. ...THE CARIBBEAN SEA... A middle level anticyclonic circulation center is about halfway between Jamaica and eastern Honduras. Comparatively drier air in subsidence spans the entire Caribbean Sea. Rainshowers are possible in areas of broken low level clouds, that are spread across the entire Caribbean Sea. 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 15/1200 UTC, according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.09 in Curacao, 0.06 in San Juan in Puerto Rico, 0.03 in Guadeloupe, 0.01 in St. Thomas in the Virgin Islands, and a TRACE in Trinidad. ...HISPANIOLA... Upper level NW wind flow is moving across Hispaniola. NE-to-E wind flow from 400 mb to 800 mb also is present across the island. SURFACE OBSERVATIONS...HAITI, in Port-au-Prince: VFR. in the DOMINICAN REPUBLIC: rainshowers are being reported around the country. MVFR conditions...ceilings from 1600 feet to 2000 feet. few cumulonimbus clouds. The GFS MODEL forecast for 250 mb shows that Hispaniola will be to the east of a ridge. Expect NW wind flow during the next 48 hours. The GFS MODEL forecast for 500 mb shows that N-to-NE wind flow will move across the area during the next 2 days. An anticyclonic circulation center will be near 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 near Andros Island in the Bahamas, and the Florida Keys. ...THE ATLANTIC OCEAN... A deep layer trough in the east-central Atlantic Ocean, passing through 32N42W to 27N36W, and appearing to merge with the rest of the 31N36W-to-08N59W trough and shear axis. The trough supports a stationary front that is along 31N37W 24N50W 21N60W, and then dissipating from 21N60W to 20N72W. Precipitation: isolated moderate from 24N northward between 36W and 41W. Rainshowers are possible elsewhere from 21N northward between 36W and 60W. A surface ridge is along 29N51W, to a 1024 mb high pressure center that is near 26N69, to a Florida 1025 mb high pressure center that is near 28N81W. Surface anticyclonic wind flow covers the Atlantic Ocean to the NW and N of the stationary front. A cold front is along the northern border of the area of this bulletin, from Bermuda to 32N74W and 31N78W. Broken to overcast multilayered clouds and isolated moderate rainshowers are from 28N northward from 55W westward. A surface ridge passes through 32N25W to 28N30W and to 24N46W. For additional information please visit http://www.hurricanes.gov/marine $$ MT