000 AXNT20 KNHC 151801 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 101 PM EST TUE NOV 15 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 1745 UTC. ...THE ITCZ/THE MONSOON TROUGH... The Monsoon Trough reaches the coastal areas of Sierra Leone near 08N13W. The ITCZ continues from 08N13W to 07N22W 10N35W 07N45W, and 07N55W. Convective precipitation: isolated to widely scattered moderate and locally strong from 13N southward from 53W eastward. Broad upper level cyclonic wind flow covers the area that is from 10N southward between 54W and South America. Convective precipitation: isolated moderate to locally strong from 06N to 08N between 55W and 59W. A surface trough curves along 20N56W 16N60W, to Trinidad. Convective precipitation: widely scattered moderate to isolated strong from 08N to 13N between 57W and 62W. ...DISCUSSION... ...THE GULF OF MEXICO... An upper level trough is moving through the eastern sections of the U.S.A., through the Florida Panhandle, into the north central Gulf of Mexico, and toward NE coastal Mexico. One cold front is passing through the Atlantic Ocean, along 32N73W, across the NW Bahamas, to the Florida Keys, to the northern coast of the Yucatan Peninsula. A stationary front curves from the northern coast of the Yucatan Peninsula to the northern part of the Isthmus of Tehuantepec, and to a 1013 mb low pressure center that is inland near 18N93W. Convective precipitation: broken to overcast multilayered clouds and possible rainshowers are to the south of the line 29N83W 26N87W 26N97W, and from 27N to 28N between 86W and 88W. A second cold front is inland, moving through central Texas. Upper level W and SW wind flow covers the rest of the Gulf of Mexico. A surface ridge passes through the deep south of Texas, through the coastal plains of Mexico, into the Isthmus of Tehuantepec of southern Mexico. Gale-force winds are forecast to start to be experienced later tonight, in the Gulf of Tehuantepec on the eastern Pacific Ocean side of southern Mexico. Please read the Eastern Pacific Ocean HIGH SEAS FORECAST...MIAHSFEP2/FZPN03 KNHC...and the Eastern Pacific Ocean TROPICAL WEATHER DISCUSSION...MIATWDEP/AXPZ20 KNHC...for more details. ...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: none. LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... in TEXAS and LOUISIANA: VFR/no ceilings. MISSISSIPPI: MVFR in Natchez. FLORIDA: VFR/no ceilings. ...THE CARIBBEAN SEA... A surface trough that is in the SW corner of the area, curves from 16N80W to 13N79W, to a 1009 mb low pressure center that is near 11N77W, and to the coast of Colombia near 10N76W. Convective precipitation: scattered strong from 14N to 16N between 77W and 79W, and from 10N to 12N between 78W and 81W. Environmental conditions are expected to be conducive for slow development of this area of low pressure during the next several days. It is likely that a tropical depression may form by late this week or during the weekend while the low drifts northward or northeastward. The chance of formation into a tropical cyclone is low. Upper level anticyclonic wind flow spans the entire area, except for the SW corner of the Caribbean Sea. An upper level ridge extends from northern Colombia, toward Jamaica, toward the Yucatan Channel. Comparatively drier air in subsidence is apparent in water vapor imagery from 15N southward between 70W and 73W, and mostly from 70W eastward. Middle level NW wind flow is in the area of the comparatively drier air. 24-HOUR rainfall totals in inches for the period ending at 15/1200 UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.02 in St. Thomas in the Virgin Islands, and 0.01 in Guadeloupe. ...HISPANIOLA... Upper level NW wind flow is moving across the entire area. A surface trough extends from the Atlantic Ocean along 21N64W, to the eastern part of the Dominican Republic. Convective precipitation: rainshowers are possible from 15N to 21N between 64W and 70W, including in the coastal waters/coastal areas of the eastern part of the Dominican Republic. Isolated moderate to locally strong also from 16N northward between 71W and 76W in the southern coastal waters. SURFACE OBSERVATIONS...for Port-au-Prince in Haiti, VFR/no ceiling. for the DOMINICAN REPUBLIC: Barahona: VFR. few cumulonimbus clouds. Santo Domingo: VFR. La Romana: rain is in the area. MVFR, ceiling at 1800 feet. Punta Cana: VFR/no ceiling. Santiago: VFR. Puerto Plata: VFR. The GFS MODEL forecast for 250 MB shows that NW wind flow will move across the area during the first 6 to 12 hours or so, followed by SW wind flow for the rest of the 48-hour forecast period, as an anticyclonic circulation center moves directly to the south of Hispaniola. The GFS MODEL forecast for 500 MB shows that day one will start with an anticyclonic circulation center directly on top of Hispaniola at the start of day one. The wind flow will be from the SE and S as the anticyclonic center moves eastward, away from Hispaniola. Expect S wind flow for the rest of day one, as the anticyclonic center moves toward the NE corner of the Caribbean Sea. Expect SW wind flow across the area as the anticyclonic center remains in the NE corner of the Caribbean Sea. The GFS MODEL forecast for 700 mb shows that anticyclonic wind flow will cover the area for the first 12 hours to 18 hours, followed by SE and S wind flow, as the anticyclonic circulation center moves to the east of Hispaniola. Expect southerly wind flow during day two, with the anticyclonic circulation center remaining just outside the NE corner of the Caribbean Sea. ...THE ATLANTIC OCEAN... A cold front is passing through the Atlantic Ocean, along 32N73W, across the NW Bahamas, to the Florida Keys, to the northern coast of the Yucatan Peninsula. Convective precipitation: broken to overcast multilayered clouds and possible rainshowers are within 180 nm on either side of the line that passes through 32N69W to 28N73W, beyond 27N80W, along the SE Florida coast. A deep layer central Atlantic Ocean trough is supporting a 1012 mb low pressure center and an occluded frontal boundary. The 1014 mb low pressure center is near 30N55W. The triple point for the occlusion is near 35N53W. The cold front is along 35N53W 32N50W 27N50W 23N54W. A surface trough continues from 23N54W to 22N65W. A separate surface trough extends from the 1012 mb low pressure center to 27N55W 24N61W 24N70W. The upper level cyclonic circulation center is near 30N55W. Convective precipitation: Isolated moderate to locally strong from 18N to 30N between 45W and 55W. Isolated moderate from 30N northward between 47W and 58W. An upper level trough curves from a 28N22W cyclonic circulation center, to 22N32W and 16N36W. Upper level cyclonic wind flow covers the area from 16N northward 40W eastward. Convective precipitation: isolated moderate from 26N northward between 19W and 26W. Surface anticyclonic wind flow covers the Atlantic Ocean from 14N northward between Africa and 48W. 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