000 AXNT20 KNHC 280601 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...SPECIAL FEATURES... An Atlantic Ocean tropical wave is along 54W/55W from 18N southward. A 1008 mb low pressure center is along the wave near 13N, about 250 nm to the east of Barbados. Convective precipitation: widely scattered to scattered moderate and isolated strong from 12N to 14N between 53W and 57W. The precipitation pattern continues to shows 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 on Wednesday morning, and then move across the southeastern Caribbean Sea late Wednesday and Thursday. An Air Force Reserve reconnaissance aircraft is scheduled to investigate the system again on Wednesday 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 national meteorological service, which may include tropical storm warnings or watches. The chance of formation during the next 48 hours is high. Gale wind conditions are imminent, within 240 NM of the center in the N and NE quadrants. Expect the sea heights to range from 10 feet to 16 feet. Please refer to the HIGH SEAS FORECAST... MIAHSFAT2/FZNT02 KNHC for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 25W/26W from 17N southward, moving westward 10 to 15 knots. A 1008 mb low pressure center is along the wave near 07N. Convective precipitation: widely scattered to scattered strong from 07N to 10N between 24W and 29W. A Caribbean Sea tropical wave along 76W/77W 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 16N17W, to 13N20W, to the 1008 mb low pressure center that is along the 25W/26W tropical wave, to 08N35W and 09N43W. Convective precipitation: numerous strong from 12N 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 from 50W eastward. ...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 north-to-south oriented surface trough runs from the NE corner of Florida to the Florida Keys. A surface trough extends from the NW Bahamas to 30N74W. A 1010 mb low pressure center is near 34N74W. A warm front extends from the low center to 32N70W. A surface trough extends from the low center to 32N78W. Convective precipitation: scattered strong from 29N to 32N between 67W and 70W. isolated moderate to locally strong elsewhere from 20N northward between 70W and 80W. A surface trough is in the SW corner of the Gulf of Mexico, along 94W/95W from 27N southward. Convective precipitation: numerous strong is along the Mexico coast from 20N to 22N between 96W and 98W. isolated moderate elsewhere from 28N 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: KVAF. 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 in Brownsville and Hebbronville. LOUISIANA: light rain in New Iberia an hour ago. MVFR in Galliano. rain and thunder at the airports that are on the southern side of Lake Pontchartrain, during the last few hours of observations, have stopped/dissipated. MISSISSIPPI: VFR/no ceilings. ALABAMA: MVFR in Evergreen. FLORIDA: MVFR at the NAS in Key West. ...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 73W. 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 09N83W at the border of Costa Rica and Panama, and westward beyond 10N90W 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: rainshowers are possible between 64W and 73W. SURFACE OBSERVATIONS...FOR PORT-AU-PRINCE IN HAITI: as of 27/2300 UTC: VFR/no ceilings; scattered cumulonimbus clouds. FOR THE DOMINICAN REPUBLIC...Barahona: as of 28/0000 UTC; VFR/no ceilings; few cumulonimbus clouds. Santo Domingo: VFR/no ceilings; few cumulonimbus clouds. rain and thunder from the last few hours have dissipated/stopped. La Romana: VFR/no ceilings. Punta Cana: VFR/no ceilings. rain and thunder from the last few hours have dissipated/stopped. in Santiago and in Puerto Plata: VFR/no ceilings;few cumulonimbus clouds in Puerto Plata. 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 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. No significant deep convective precipitation is apparent. A stationary front passes through 32N42W to 29N48W and 29N56W. Convective precipitation: rainshowers are possible from 26N northward between 40W and 60W. A surface ridge passes through 35N31W, to 32N36W, to 28N42W, 25N58W, and to 25N72W. For additional information please visit http://www.hurricanes.gov/marine $$ MT