000 AXNT20 KNHC 191803 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 PM EST MON DEC 19 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...SPECIAL FEATURES... ..GULF OF MEXICO GALE WARNING... A stationary front is along 30N84W 24N93W 18N94W. Expect gale- force NW-to-N winds and sea heights ranging from 10 feet to 17 feet to the south OF 25N to the west of the front. The gale- force winds are forecast to continue for the next 42 hours or so. Please read the Atlantic high seas forecast, that is listed under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC, for more details about each area of gale-force winds. ...CARIBBEAN SEA GALE WARNING... Gale-force winds and sea heights ranging from 11 feet to 15 feet are being observed from 11N to 12.5N between 74W and 76W, off the coast of Colombia. The gale-force winds are forecast to continue for the next 24 hours or so. A tight pressure gradient exists, between high pressure that is building in the Atlantic Ocean, to the north of the Caribbean Sea, and lower pressure that is associated with climatologically lower surface pressure in Colombia. Please read the Atlantic high seas forecast, that is listed under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC, for more details. ...THE ITCZ/THE MONSOON TROUGH... The Monsoon Trough reaches the coastal sections of Liberia near 05N09W to 04N14W. The ITCZ continues from 04N14W to 03N33W, and along 01N between 37W and 50W. Convective precipitation: widely scattered moderate to isolated strong from 03N southward between 44W and 50W. isolated moderate elsewhere from 10N southward from 60W eastward. High level clouds are to the south of the line that passes through 26N14W 25N24W 13N50W 10N60W. The high level clouds are moving northeastward. A surface trough is along 05N32W 03N35W 01N36W. Isolated moderate from 07N southward between 33W and 40W. ...DISCUSSION... ...THE GULF OF MEXICO... Upper level SW wind flow spans the entire Gulf of Mexico. Please refer to the SPECIAL FEATURES section for information about the stationary front and accompanying gale-force wind speeds and sea heights. Convective precipitation: scattered moderate to isolated strong from 19N to 22N between 92W and 95W. Isolated moderate to locally strong within 30 nm to 60 nm on either side of 29N84W 27N87W 26N89W 24N91W 23N93W. Other rainshowers are possible to the west of the stationary 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: KVQT, KMDJ, KIKT, KVOA, KVKY, KMIS and KDLP. IFR: KHQI, KEHC, KGHB, KATP, KGRY, and KSPR. MVFR: KMZG, KBBF, KHHV, KVAF, KEMK, KGUL, KGBK, and KEIR. LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... TEXAS: VFR. LOUISIANA: MVFR in Patterson, Galliano, and Port Fourchon. IFR in Boothville. MVFR in some areas that are immediately around the southern part of Lake Pontchartrain. MISSISSIPPI: MVFR in the southernmost coastal sections of the state. ALABAMA: MVFR in the southernmost coastal sections of the state. IFR at Fort Rucker. LIFR in Dothan. FLORIDA: IFR from Tallahassee westward. LIFR in the NW part of Panama City. IFR in Perry. earlier heavy rain and LIFR in Cross City have improved for the moment. MVFR in Brooksville and at the Tampa Executive Airport. ...THE CARIBBEAN SEA... An upper level ridge extends from the northern Colombia, in the part that is from 10N northward, northwestward, to the Yucatan Channel. High level clouds are curving anticyclonically across the open waters of the Caribbean Sea. Rainshowers are possible in areas of broken low level to middle level clouds, especially just to the SE of Puerto Rico, from 15N to 16N between 67W and 70W, and to the west of the line 14N81W 19N84W. 24-HOUR rainfall totals in inches for the period ending at 19/1200 UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.17 in Guadeloupe, 0.15 in St. Thomas in the U.S.A. Virgin Islands, 0.07 in Curacao, and 0.05 in San Juan in Puerto Rico. ...HISPANIOLA... Upper level NE wind flow is moving across Hispaniola. 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. Rainshowers are possible elsewhere, across the open waters of the Caribbean Sea, 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 and Santo Domingo: VFR/no ceiling. few cumulonimbus clouds. La Romana: VFR/no ceiling. Punta Cana: nearby rainshowers. few cumulonimbus clouds. Santiago: MVFR. ceiling 1400 feet. nearby rainshowers. few cumulonimbus clouds. Puerto Plata: VFR/no ceiling. The GFS MODEL forecast for 250 MB shows that NE wind flow will move across the area for the next 48 hours. An E-to-W oriented Atlantic Ocean-to-Caribbean Sea trough eventually will change its position. It will be a NE-to-SW oriented trough, at the end of the 48-hour forecast period. The GFS MODEL forecast for 500 MB shows that NE wind flow will move across the area, with an Atlantic Ocean-to-Gulf of Mexico ridge. A trough will approach Hispaniola from the NE Caribbean Sea islands. The GFS MODEL forecast for 700 mb shows that E-to-NE wind flow will move across the area, with an an Atlantic Ocean-to-Gulf of Mexico ridge. It is possible that an inverted trough will move across Hispaniola during the first half of day two. ...THE ATLANTIC OCEAN... A stationary front passes through 32N29W to 31N33W. A dissipating stationary front continues from 31N33W to 29N40W 29N46W 28N52W. Convective precipitation: isolated moderate to locally strong within 150 nm to the north of the line that passes through 30N32W 27N45W 26N52W. Rainshowers are possible elsewhere to the north of 19N between 35W and 60W. An upper level trough passes through 32N10W, to 24N33W 14N48W and 12N52W. No significant deep convective precipitation is apparent in satellite imagery. A surface ridge passes through Bermuda, to 28N73W, across the southern part of Florida, to 26N84W in the Gulf of Mexico. Surface anticyclonic wind flow is to the north and northwest of the dissipating stationary front. For additional information please visit http://www.hurricanes.gov/marine $$ MT