000 AXNT20 KNHC 271200 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 700 AM EST TUE DEC 27 2016 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 FEATURE... Please refer to the METEO-FRANCE High Seas Forecast, that is listed under the following links: MARINE...BULLETINS EXPERTISES...GRAND LARGE...METAREA II...or on the website: WWW.METEOFRANCE.COM/PREVISIONS-METEO-MARINE/BULLETIN/ GRANDLARGE/METAREA2. Gale-force winds are forecast for the area that is called: IRVING. The OUTLOOK, for the 24 hours that follow the forecast that is valid until 28/1200 UTC, consists of: the persistence of a cyclonic gale or near gale in IRVING. ...THE ITCZ/THE MONSOON TROUGH... The Monsoon Trough reaches the coastal sections of Liberia near 06N10W to 04N16W. The ITCZ continues from 04N16W to 02N24W 02N32W 02N40W. The surface trough of six hours ago has weakened and dissipated. Convective precipitation: widely scattered moderate to isolated strong from 01N to 07N from 20W eastward, and from 07N southward between between 20W and 36W. Isolated moderate elsewhere from 10N southward from 60W eastward. High level clouds are to the south of 27N15W 26N22W 19N40W 16N50W 15N60W, moving northeastward. ...DISCUSSION... ...THE GULF OF MEXICO... A surface trough is along 92W/93W from 17N in the Isthmus of Tehuantepec to 23N in the SW corner of the Gulf of Mexico. Convective precipitation: scattered moderate to isolated strong from 17N to 21N between 95W and 96W. The easternmost 20 percent of the area is covered with upper level anticyclonic wind flow. This anticyclonic wind flow is part of the larger-scale upper level ridge that is in the Caribbean Sea. An ill-defined upper level trough passes through the eastern part of the Gulf of Mexico, from 90W eastward. A separate area of upper level anticyclonic wind flow is moving from interior sections of Mexico into the central Gulf of Mexico. A surface ridge passes through the Florida Panhandle, to the middle Texas coastal waters/deep south of Texas, into the SW corner of the Gulf of Mexico. Convective precipitation: Rainshowers are possible from 90W eastward, from 23N southward from 90W westward, from 88W eastward, and from 25N northward from 90W westward, in areas of scattered/broken low level clouds. ...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: KBBF, KBQX, KXIH, KGRY, and KDLP. IFR: KHHV, and KSPR. MVFR: KMZG, KVAF, KEMK, KEIR, and KVQT. LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... TEXAS: LIFR, nearly everywhere, from the Lower Rio Grande Valley to Houston and to Huntsville, and from Galveston to Beaumont/Port Arthur and Jasper. LOUISIANA: LIFR, pretty much everywhere, in the southern sections/coastal plains. MISSISSIPPI: IFR from Natchez-to-Hattiesburg. LIFR in the coastal plains/southernmost sections. ALABAMA: LIFR, mostly, from Dothan and Evergreen southward. FLORIDA: LIFR from Cross City westward, at the Tampa Executive Airport, and in Punta Gorda. ...THE CARIBBEAN SEA... Upper level anticyclonic wind flow, from South America and Central America, toward the north and northeast, is related to an upper level ridge that extends from northern Colombia beyond NW Cuba. Comparatively drier air in subsidence is apparent in water vapor imagery, to the north and northeast of the line that passes through La Peninsula de la Guajira of northern Colombia, to the eastern coast of Jamaica, beyond NW Cuba. Upper level NE wind flow has been pushing the comparatively drier air into this part of the Caribbean Sea. Upper level southerly wind flow covers the area that is from 80W westward, in the area of upper level anticyclonic wind flow, with the Colombia-to-NW Cuba ridge. Convective precipitation: isolated moderate from 18N southward from 80W westward, in the coastal waters and coastal plains of Central America. It is possible that speed convergence may be a contributing factor to the precipitation. The monsoon trough is along 09N between 73W and beyond 84W in Costa Rica. Convective precipitation: isolated moderate from 11N southward from 76W westward. 24-HOUR rainfall totals in inches for the period ending at 27/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.19 in Curacao, and 0.13 in Guadeloupe. ...HISPANIOLA... Upper level NW wind flow is moving across Hispaniola. Comparatively drier air in subsidence is apparent in water vapor imagery, across the entire area. Convective precipitation: Rainshowers are possible across Hispaniola, and in the coastal waters and coastal plains, in areas of broken low level to middle level clouds. SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR/no ceiling. for the DOMINICAN REPUBLIC: Barahona: VFR. Santo Domingo/La Romana/Punta Cana: VFR/no ceiling. Santiago: light rain. MVFR. ceiling 1200 feet. Puerto Plata: MVFR. ceiling 1600 feet. The GFS MODEL forecast for 250 MB shows that NW wind flow will move across the area during the next 48 hours. A NW-to-SE oriented ridge is forecast to be along the line from the Yucatan Channel to Colombia. The GFS MODEL forecast for 500 MB shows that NE wind flow will move across the area during the next 48 hours, with a Gulf of Mexico-to-central Caribbean Sea ridge. The GFS MODEL forecast for 700 mb shows that NE wind flow will move across the area during the next 48 hours. It is possible that an inverted trough may move across Hispaniola during each day of the two-day forecast period. ...THE ATLANTIC OCEAN... A central Atlantic Ocean upper level trough is supporting a cold front that 32N40W to 29N44W and 27N50W. Convective precipitation: isolated moderate within 90 nm on either side of 25N44W 28N40W beyond 32N36W. Rainshowers are possible elsewhere from 23N northward between 32W and 74W. An upper level trough extends from 32N26W to 25N35W 19N48W and 14N60W. Convective precipitation: isolated moderate from 28N northward between Africa and 16W. Rainshowers are possible within 250 nm on either side of 32N27W 24N34W 16N41W 15N60W. A surface ridge passes through 32N20W to 28N26W 23N47W, to the east of the cold front. Surface anticyclonic wind flow covers the Atlantic Ocean from 20N northward between 51W and 79W, to the west of the cold front. For additional information please visit http://www.hurricanes.gov/marine $$ MT