000 AXNT20 KNHC 121152 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT MON SEP 12 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 24N49W 21N49W 10N52W. A 1007 mb low pressure center is along the wave near 21N. Convective precipitation: scattered to numerous strong from 20N to 25N between 45W and 50W, and from 10N to 13N between 50W and 54W. The current high seas forecast consists of gale-force winds from 20N to 23.5N between 45W and 51W, and sea heights ranging from 10 feet to 15 feet. Please read the high seas forecast, that is listed under MIAHSFAT2/FZNT02 KNHC, for more details. Visible satellite images show that the circulation associated with the low pressure system located about 695 nm east-northeast of the northern Leeward Islands is becoming better defined. Gale force winds are already associated with this system, and if the current development trend continues, a tropical storm could form later today. Due to this, the system has a high chance of tropical formation within the next 48 hours as it moves northwestward or north-northwestward at 10 to 15 kt over the central Atlantic Ocean. Please read the high seas forecast, that is listed under MIAHSFAT2/FZNT02 KNHC, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 20W/21W. The wave has been re-positioned in order to agree with current satellite imagery. Convective precipitation: Scattered strong from 11N to 17N between Africa and 20W. Isolated to widely scattered moderate from 06N to 11N between Africa and 20W. An Atlantic Ocean tropical wave is along 30W/31W from 13N southward. Convective precipitation: Isolated moderate from 06N to 14N between 28W and 32W. A western Caribbean Sea tropical wave is along 86W, from 20N southward. The wave cuts through Honduras, Nicaragua, and the northwestern coastal sections of Costa Rica. Convective precipitation: Isolated moderate from 18N southward from 83W westward. ...ITCZ/MONSOON TROUGH... The Monsoon Trough passes through the coastal sections of Mauritania near 18N16W, to 14N20W, to 09N30W and 09N41W. Convective precipitation: widely scattered moderate to isolated strong elsewhere from 02N to 16N between Africa and 48W. ...DISCUSSION... ...THE GULF OF MEXICO... Upper level cyclonic wind flow covers the western two-thirds of the Gulf of Mexico. A surface trough is in the north central Gulf of Mexico, and another surface trough is in the northeastern corner of the area. Convective precipitation: Widely scattered moderate to isolated strong from 24N northward from 91w eastward. Isolated moderate from 24N southward from 90W eastward. A 1013 mb low pressure center is near 23N85W in the southeastern corner of the Gulf of Mexico. ...FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N NORTHWARD AND FROM 88W WESTWARD... LIFR: KEHC. IFR: none. MVFR: KHHV. 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 Victoria and Bay City, and in Tomball. LOUISIANA: MVFR in Lafayette. MISSISSIPPI: LIFR in Natchez, and at the Hattiesburg Public Airport. Rain during the last observations at the Chain Municipal Airport in Hattiesburg. ALABAMA: VFR/no ceilings. FLORIDA: light rain in Milton. Drizzle and rain have ended for the moment in Perry. ...THE CARIBBEAN SEA... Broad upper level cyclonic wind flow covers the Caribbean Sea that is from 80W eastward. Much of the cyclonic wind flow has to do with the 19N74W Haiti cyclonic circulation center. Upper level anticyclonic wind flow covers the rest of the area. An upper level trough passes through 22N63W in the Caribbean Sea, to a 19N74W cyclonic circulation center that is just to the west of Haiti, to 12N78W in the southwestern corner of the Caribbean Sea. Convective precipitation: Isolated moderate in the Caribbean Sea from 14N northward between Puerto Rico and 80W. Widely scattered moderate to isolated strong is elsewhere from 17N southward between 80W and 83W. Scattered strong from 11N to 13N between 75W at the coast of Colombia and 80W. 24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT 12/0000 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...0.78 in Bermuda, 0.11 in Curacao and in Havana. The monsoon trough is along 09N74W in northern Colombia, to Panama along 80W, beyond northwestern Costa Rica. Convective precipitation: Scattered strong from 11N to 13N between 75W at the coast of Colombia and 80W. ...HISPANIOLA... Upper level cyclonic wind flow spans the island. An upper level cyclonic circulation center is near 19N74W, just to the west of Haiti. Convective precipitation: Isolated moderate in the Caribbean Sea from 14N northward between Puerto Rico and 80W. SURFACE OBSERVATIONS...FOR PORT-AU-PRINCE IN HAITI: rainshowers and thunder at 12/0100 UTC. FOR THE DOMINICAN REPUBLIC... Barahona: rainshowers and thunder at 12/0000 UTC. Santo Domingo/La Romana/Punta Cana: VFR/no ceilings. Few cumulonimbus clouds in La Romana at 12/0300 UTC. Santiago/Puerto Plata: VFR/no ceilings. FOR HISPANIOLA: The GFS MODEL forecast for 250 MB shows that cyclonic wind flow and a trough will cover the area for the next 48 hours. The GFS MODEL forecast for 500 MB shows that anticyclonic wind flow will move across Hispaniola during the next 48 hours. The GFS MODEL forecast for 700 MB shows that NE wind flow will be moving across the area during the next 48 hours, with a large-scale Atlantic Ocean-to-Caribbean Sea ridge. ...THE ATLANTIC OCEAN... Upper level cyclonic wind flow covers parts of the Atlantic Ocean from Cuba northward from 70W westward, away from the Atlantic Ocean-to-Caribbean Sea trough. A surface trough is along 29N75W 21N76W. A second surface trough is along 31N76W 28N80W. Convective precipitation: Isolated to widely scattered moderate elsewhere from Cuba to 32N between 70W and 80W. The surface pressures remain high in the area, and there are still no signs of a closed surface circulation. Conditions do not appear conducive for significant development of this disturbance while it moves west-northwestward 10 to 15 mph. Locally heavy rainfall is possible in parts of the central and northwestern Bahamas today, and in parts of the Florida peninsula on Tuesday. An upper level trough extends from 32N52W, to an upper level cyclonic circulation center that is near 27N57W, to 22N63W, to a 19N74W cyclonic circulation center that is just to the west of Haiti, to 12N78W in the southwestern corner of the Caribbean Sea. Convective precipitation: Isolated moderate from 20N northward between 56W and 72W. Isolated moderate in the Caribbean Sea from 14N northward between Puerto Rico and 80W. Widely scattered moderate to isolated strong is elsewhere from 17N southward between 80W and 83W. Scattered strong from 11N to 13N between 75W at the coast of Colombia and 80W. An upper level trough extends from a Canary Islands cyclonic circulation center, to 19N27W. Convective precipitation: widely scattered moderate from 26N to 28N between 14W and 19W. Broad surface anticyclonic wind flow covers the Atlantic Ocean from 26N northward between Africa and 70W. One 1022 mb high pressure center is near 30N39W. A second 1022 mb high pressure center is near 32N55W. For additional information please visit http://www.hurricanes.gov/marine $$ MT/ERA