000 AXNT20 KNHC 111118 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT SUN SEP 11 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 46W/47W from 21N southward. A 1009 mb low pressure center is along the wave near 15N. The 06-hour forecast consists of a 1009 mb low pressure center near 17N 47.5W...a possible tropical cyclone. Expect gale- force winds and sea heights ranging from 10 feet to 14 feet, from 60 nm to 240 nm in the northern quadrant of the low center. Convective precipitation: widely scattered to scattered moderate and isolated strong from 06N to 22N between 40W and 55W. Environmental conditions are conducive for development. It is likely that a tropical depression may form later today or on Monday. This feature is forecast to move northwestward to north- northwestward in the central Atlantic Ocean. The chance of formation through 48 hours is high. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 19W from 20N southward. This position agrees with current satellite imagery. Convective precipitation: widely scattered moderate to isolated strong from 09N to 18N between Africa and 25W. An Atlantic Ocean tropical wave was added to the 11/0600 UTC surface map analysis, along 27W/28W, in agreement with the current satellite imagery. Convective precipitation: isolated moderate from 05N to 11N between 25W and 33W. A Caribbean Sea tropical wave is along 82W/83W, along the coast of Central America. Convective precipitation: widely scattered moderate to isolated strong from 17N southward from 78W westward to Central America. A Gulf of Mexico tropical wave is along 96W from 20N southward. Convective precipitation: numerous strong is inland in Mexico, and in the coastal waters, from 18N to 20N between 93W and 96W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough passes through the coastal border sections of Mauritania and Senegal, to 10N28W, to the 1009 mb low pressure center that is along the 46W/47W tropical wave, continuing to 10N52W. Convective precipitation: Widely scattered moderate to isolated strong from 05N to 11N between 11W and 17W, and from 04N to 07N between 32W and 38W. ...DISCUSSION... ...THE GULF OF MEXICO... An upper level cyclonic circulation center is along the upper south central Louisiana coast. Cyclonic wind flow covers the Gulf of Mexico to the west of the line 29N90W 20N97W. Upper level anticyclonic wind flow covers the rest of the area. A surface trough is along 91W/92W from 24N to 29N, in the central Gulf of Mexico. Convective precipitation: isolated moderate from 22N to 30N between 87W and 91W. A 1013 mb low pressure center is near 24N84W in the southeastern corner of the Gulf of Mexico. A surface trough is along the Florida west coast near 28N, to the 1013 mb low center, to 23N85W. Convective precipitation: widely scattered moderate to isolated strong from 20N in the northwestern corner of the Caribbean Sea to 24N in the Gulf of Mexico between 80W and 87W. Upper level winds are not favorable, and development of this system is not expected. The low is forecast to weaken while it moves westward to west-southwestward 5 to 10 mph into the central Gulf of Mexico during the next day or two. ...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... TEXAS: LIFR in Edinburg. Heavy rain in Robstown and at the Naval Air Station in Corpus Christi. MVFR in Bay City. Lightning is being reported near Rockport. LOUISIANA: IFR in Patterson. MVFR in Galliano. MISSISSIPPI: VFR/no ceilings. ALABAMA: light rain at the Mobile Downtown General Airport. FLORIDA: MVFR at the Tampa Executive Airport. Rain and thunder are close to Natchez. Light rain is at the Key West Naval Air Station and at the Key West International Airport. ...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 20N72W Hispaniola cyclonic circulation center. Upper level anticyclonic wind flow covers the rest of the area. 24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT 11/0000 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...0.34 in Guadeloupe, and 0.19 in Tegucigalpa in Honduras. The monsoon trough is along 10N between northern Colombia and beyond northern Costa Rica, into the eastern Pacific Ocean. Broad upper level cyclonic wind flow is in the southwestern corner of the Caribbean Sea. Convective precipitation: Numerous strong from 03N to 07N between the coast of Colombia and 80W in the eastern Pacific Ocean. ...HISPANIOLA... Upper level cyclonic wind flow spans the island. An upper level cyclonic circulation center is near 20N72W. A surface trough is in the Atlantic Ocean, along 24N70W 20N71W. Convective precipitation: scattered moderate to isolated strong from 21N to 24N between 70W and 72W. isolated moderate elsewhere from 17N to 24N between 66W and 73W. There are no signs of a surface circulation associated with this system. Conditions are not conducive for development of this disturbance, while it moves generally west-northwestward about 15 mph. SURFACE OBSERVATIONS...FOR PORT-AU-PRINCE IN HAITI: rain and thunder at 11/0100 UTC. FOR THE DOMINICAN REPUBLIC...Santo Domingo/La Romana/Punta Cana: rain and thunder. Santiago: MVFR. Puerto Plata: rain and thunder. FOR HISPANIOLA: The GFS MODEL forecast for 250 MB shows that cyclonic wind flow will cover the area for day one and for day two. The GFS MODEL forecast for 500 MB: the current cyclonic circulation center is forecast to spread cyclonic wind flow across Hispaniola, as the cyclonic center moves westward during day one. The cyclonic circulation center will reach the Windward Passage, spreading southerly wind flow across the area for the rest of day one. Day two will start with southerly wind flow, switching to variable, from the northeast, and finally from the southeast again. The GFS MODEL forecast for 700 MB shows that the wind flow will be from the E and SE at the start of day one, followed by NE wind flow. NE wind flow will span Hispaniola for day two. ...THE ATLANTIC OCEAN... Upper level cyclonic wind flow covers the Atlantic Ocean from Cuba northward from 70W westward, away from the 20N72W cyclonic circulation center. A surface trough is along 78W from the northwestern Bahamas northward. Convective precipitation: Isolated moderate to locally strong elsewhere from Cuba northward between 70W and 80W. An upper level cyclonic circulation center is near 24N52W. Cyclonic wind flow covers the area from 18N to 32N between 45W and 62W. Convective precipitation: isolated moderate in the area of cyclonic wind flow. An upper level cyclonic circulation center is near 28N23W. Cyclonic wind flow covers the Atlantic Ocean from 23N northward between 19W and 30W. Convective precipitation: rainshowers are possible from 24N northward between 20W and 30W. Broad surface anticyclonic wind flow covers the Atlantic Ocean from 24N northward between Africa and the southeastern U.S.A. coastal areas. For additional information please visit http://www.hurricanes.gov/marine $$ MT