000 AXNT20 KNHC 151208 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 708 AM EST Wed Feb 15 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 0600 UTC surface analysis and satellite imagery through 1115 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE GULF OF MEXICO... The 9-hour forecast, that starts at 15/0600 UTC, consists of a cold front from 30N86W to 23N90W to 18.5N95W. Expect NW-to-N gale- force winds, and sea heights ranging from 8 feet to 10 feet, to the south of 20.5N to the west of 95W. Please read the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...GALE WARNING FOR THE ATLANTIC OCEAN... The 12-hour forecast, that starts at 15/0600 UTC, consists of a cold front that will be approaching the area from the west. Expect SW gale-force winds and sea heights ranging from 9 feet to 12 feet, to the north of 30N between 75W and 80W. Please read the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough reaches the coastal sections of Sierra Leone near 07N12W, to the equator along 20W. The ITCZ continues from the equator along 20W, to 03S28W, crossing the equator along 34W, to 01N37W. One surface trough is along 02N34W 03N38W. A second surface trough is along 06N37W 03N40W. Convective precipitation: Widely scattered moderate to isolated strong from 07N southward between 10W and 52W. ...DISCUSSION... ...THE GULF OF MEXICO... A middle level-to-upper level trough extends from a Kentucky cyclonic circulation center, through SE Louisiana, into the SW corner of the Gulf of Mexico. The trough is supporting the current cold front that passes through SE Louisiana, into the north central Gulf of Mexico, to the SW corner of the Gulf of Mexico near 19N97W at the coast of Mexico, and then curving northwestward inland to 25N102W. Comparatively drier air in subsidence is apparent in water vapor imagery, everywhere in the Gulf of Mexico, except for the area near the cold front. Convective precipitation: widely scattered moderate within 60 nm on either side of the line, from the Florida Big Bend to 29N86W 26N89W, and from 20N to 22N between 96W and 98W along the coast of Mexico. Upper level SW wind flow covers the rest of the Gulf of Mexico that is to the east of the trough and cold front. The upper level SW wind flow is part of a larger-scale area of anticyclonic wind flow, that spans the Atlantic Ocean from 60W westward, the Caribbean Sea from the Windward Passage westward, and the remaining part of the Gulf of Mexico that is to the east of the upper level trough and cold front. ...LOW LEVEL CLOUD CEILINGS AND WEATHER FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N NORTHWARD AND FROM 88W WESTWARD... LIFR: none. IFR: none. MVFR: KMZG, KBQX, KXIH, KVAF, KEMK, KGUL, KHQI, KEHC, KVQT, KGHB, KEIR, KSPR, KGRY, KATP, KMDJ, KIKT, KVOA, KVKY, KMIS, and KDLP. LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... TEXAS: MVFR from Bay City to Huntsville, and from Beaumont/Port Arthur to Jasper. LOUISIANA: MVFR/IFR from Baton Rouge and Hammond southward, to the coastal plains. MISSISSIPPI: MVFR to the south of the line that runs from Natchez to Hattiesburg. ALABAMA: MVFR in Dothan, and between MISSISSIPPI and the Florida Panhandle. FLORIDA: MVFR and light rain from Destin westward. IFR/MVFR from Perry southward. LIFR in Punta Gorda. MVFR in Naples. ...THE CARIBBEAN SEA... Upper level anticyclonic wind flow covers the NW corner of the area. This anticyclonic wind flow is related to the upper level ridge whose anticyclonic wind flow also covers the Atlantic Ocean from 60W westward. Upper level anticyclonic wind flow is from 15N southward from 75W eastward. Middle level-to-upper level cyclonic wind flow covers the area that is from 15N northward from 70W eastward. This wind flow is part of the larger-scale central Atlantic Ocean trough, that is driving the central Atlantic Ocean frontal boundary. Comparatively drier air in subsidence is apparent in water vapor imagery across the area. Rainshowers are possible to the north of the line that extends from 17N60W to 16N70W to 13N83W at the coast of Nicaragua. 24-HOUR rainfall amounts, for the period ending at 15/0000 UTC... according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.01 in Guadeloupe. ...HISPANIOLA... Middle level to upper level NW wind flow is present across the area. Southerly wind flow is from 600 mb to 800 mb. Comparatively drier air in subsidence is apparent in water vapor imagery across Hispaniola. Convective precipitation: rainshowers are possible inland, and in the waters that surround Hispaniola. SURFACE OBSERVATIONS...for the DOMINICAN REPUBLIC: Santo Domingo: VFR. few cumulonimbus clouds. ceiling 1600 feet. La Romana/Punta Cana: VFR. Santiago: MVFR. ceiling 1600 feet. Puerto Plata: VFR. The GFS MODEL forecast for 250 MB shows that the 48-hour forecast period will start with NW wind flow. The wind flow will be from the SW for the rest of the forecast period, with a ridge. The GFS MODEL forecast for 500 MB shows that day one will start with an anticyclonic circulation center about 100 nm to the southwest of the SW coast of Haiti. The anticyclonic circulation center is forecast to move across the eastern extreme of Hispaniola, and then to Puerto Rico, and then about 60 nm to the SSE of Puerto Rico, and finally to a position that is about 90 nm to the west of Guadeloupe at the end of day one. The wind flow on day one will start as anticyclonic, followed by SW for the rest of day one. Expect NW wind flow across Hispaniola during day two, as Hispaniola is forecast to be on the northern side of a Caribbean Sea ridge. The GFS MODEL forecast for 700 mb shows that broad anticyclonic wind flow will cover Hispaniola during the next 48 hours. At least one anticyclonic circulation center will be on top of Hispaniola or close enough to Hispaniola, in order to create the nearly-constant anticyclonic wind flow across the island. ...THE ATLANTIC OCEAN... A cantral Atlantic Ocean deep-layer trough is supporting a cold front that passes through 32N45W to 25N61W. The front becomes stationary from 25N61W to 25N73W. The front becomes dissipating stationary, and shifting northward a bit with the surface wind flow, from 25N73W to 30N79W. Convective precipitation: rainshowers are possible from 24N northward between 40W and the SE U.S.A. A 1018 mb high pressure center is near 28N66W. Surface anticyclonic wind flow covers the Atlantic Ocean to the north of the frontal boundary. An upper level trough is inland in Africa. That trough is supporting a cold front that is lagging behind, from a 1011 mb low pressure center that is near 33N19W, to 28N20W, 27N25W, to 27N30W. Convective precipitation: rainshowers are possible from 22N northward between Africa and 36W. A surface trough is along 29N40W 24N50W 20N56W 19N64W. Convective precipitation: rainshowers are possible elsewhere from 18N to 26N between 40W and 65W. A 1020 mb high pressure center is near 23N35W. Surface anticyclonic wind flow covers the Atlantic Ocean from 10N to 27N between 30W and 44W. For additional information please visit http://www.hurricanes.gov/marine $$ MT