000 AXNT20 KNHC 281111 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT WED SEP 28 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 1045 UTC. ...SPECIAL FEATURES... An Atlantic Ocean tropical wave is along 57W from 19N southward. A 1007 mb low pressure center is along the wave near 13N, about 150 nm to the east of Barbados. Convective precipitation: scattered to numerous strong from 12N to 15N between 55W and 59W, and from 11N to 13N between 60W and 63W. Isolated moderate elsewhere from 10N to 20N between 50W and 63W. The precipitation pattern continues to show signs of organization. It is likely that a tropical depression or a tropical storm may form later today if this weather system continues to become more organized. The system is moving westward to west-northwestward 15 to 20 mph, and it is expected to pass over the Windward Islands later today, and then move across the southeastern Caribbean Sea tonight and Thursday. An Air Force Reserve reconnaissance aircraft is scheduled to investigate the system again later this morning. Please monitor the progress of this weather system if you have any interests that are in the Windward and southern Leeward Islands, Bonaire, Curacao, Aruba, and along the northern coast of South America. Please consult any bulletins and/or warnings that are issued by your country's weather bureau, which may include tropical storm warnings or watches. The chance of formation during the next 48 hours is high. Heavy rains and tropical-storm-force winds in squalls are expected to spread over the Windward Islands and sections of the southern Leeward Islands, beginning this morning, and continuing through tonight and early Thursday. Gale-force wind conditions are present, within 150 NM of the center in the N quadrant. Expect the sea heights to range from 10 feet to 15 feet. Please refer to the HIGH SEAS FORECAST, MIAHSFAT2/FZNT02 KNHC, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 26W/27W from 17N southward, moving westward 10 to 15 knots. Convective precipitation: widely scattered moderate to isolated strong from 07N to 10N between 24W and 30W. It is possible that the precipitation may be more related to the monsoon trough. A Caribbean Sea tropical wave along 78W/79W from 16N southward, moving westward 15 knots. The wave is to the south of Jamaica. The wave is moving into the area of an upper level trough that is along 81W. Convective precipitation: isolated moderate in the area of the trough and the cyclonic wind flow from the upper level trough. ...ITCZ/MONSOON TROUGH... The Monsoon Trough passes through coastal sections of Senegal near 15N17W, to 07N26W, to 09N43W. Convective precipitation: widely scattered moderate to isolated strong from 05N to 18N between 10W and 21W to 15N between 16W and 18W. scattered strong from 09N to 12N between 37W and 39W. Isolated moderate to locally strong elsewhere from 04N to 13N between 20W and 50W. ...DISCUSSION... ...THE GULF OF MEXICO... An upper level anticyclonic circulation center is in Mexico near 24N99W. Upper level anticyclonic wind flow spans the Gulf of Mexico. An upper level trough passes through Georgia to Florida. A NE-to-SE oriented surface trough runs from the NE corner of the Gulf of Mexico into N central Florida. A second surface trough is in the Atlantic Ocean, from just to the north of the NW Bahamas beyond 32N76W. Convective precipitation: widely scattered moderate to isolated strong to the west of the line that passes through 32N64W to 27N66W, to the northern part of the Windward Passage. A surface trough is in the SW corner of the Gulf of Mexico, along 94W/95W from 27N southward. Convective precipitation: scattered strong is along the Mexico coast from 20N to 24N between 96W and 99W. isolated moderate elsewhere from 29N southward from 90W westward. ...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, KGHB, KVOA, KVKY, and KMIS. LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... TEXAS: light rain in the easternmost parts of the lower valley of Texas. in LOUISIANA and in MISSISSIPPI: VFR/no ceilings. ALABAMA: MVFR in Evergreen. IFR in Troy. FLORIDA: MVFR in Crestview. light rain in the southern part of the Panama city metropolitan area. IFR in Perry. the sky has been clearing up at the Tampa Executive Airport. ...THE CARIBBEAN SEA... An upper level trough is along 81W, from Cuba into the SW corner of the Caribbean Sea. An upper level cyclonic circulation center is near 16N81W. Convective precipitation: isolated moderate from 77W westward. Broad upper level cyclonic wind flow also accompanies a trough, that passes through an Atlantic Ocean cyclonic circulation center that is about 250 nm to the NE of the center of Hispaniola, across Hispaniola, toward the coast of Colombia near 11N75W. Convective precipitation: rainshowers are possible between 64W and 76W. 24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT 28/0000 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...0.02 in Guadeloupe. The monsoon trough is along 09N/10N between 74W and 85W, in the eastern Pacific Ocean. Any precipitation is mixed with the 81W trough precipitation. ...HISPANIOLA... Upper level cyclonic wind flow is moving around a trough that cuts right through Hispaniola. Convective precipitation: isolated moderate within 120 nm to the southeast of the eastern sections of the Dominican Republic. rainshowers are possible elsewhere from 15N northward between 67W and 75W. SURFACE OBSERVATIONS...FOR THE DOMINICAN REPUBLIC...Santo Domingo: VFR/no ceilings; few cumulonimbus clouds. rain and thunder. La Romana and Punta Cana: VFR/no ceilings. Santiago and Puerto Plata: VFR/no ceilings. The GFS MODEL forecast for 250 MB shows that day one will consist of cyclonic wind flow from the current trough continuing across the Dominican Republic. N wind flow will move across Haiti, related to a SE Cuba anticyclonic circulation center. The anticyclonic circulation center will be across northern sections of Haiti at the end of day one. Expect SW wind flow across the entire area of Hispaniola for day two, as part of a larger-scale area of anticyclonic wind flow. The GFS MODEL forecasts for 500 MB and for 700 MB show that SE wind flow will move across Hispaniola for the first half of day one. NE wind flow will replace the SE wind flow during day one, and then the NE wind flow will cover the area during all of day two. A cyclonic circulation center will end up being about 275 nm to the SSE of the center of Hispaniola at the end of day two. ...THE ATLANTIC OCEAN... A weak upper level trough passes through 32N65W, to the cyclonic circulation center that is about 250 nm to the NE of the center of Hispaniola. Convective precipitation: isolated moderate from elsewhere 20N northward between 60W and 70W. An upper level cyclonic circulation center is near 23N34W. Cyclonic wind flow that is moving around the center covers the area from 16N northward between 25W and 45W. Convective precipitation: rainshowers are possible from 20N to 23N between 30W and 33W. A stationary front passes through 32N41W to 29N47W and 29N53W. Convective precipitation: isolated moderate from 29N to 31N between 55W and 60W. rainshowers are possible elsewhere from 26N northward between 40W and 60W. For additional information please visit http://www.hurricanes.gov/marine $$ MT