000 AXNT20 KNHC 112350 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... Tropical wave extends from 23N44W through a 1009 mb low near 17N47W to 11N52W moving north-northwest near 15 kt over the past 24 hours. Gale force winds are occurring over the north semicircle of the low. Please see the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. Shower activity associated with this system has increased and become a little better organized during the past several hours, and a tropical depression is likely to form later tonight or on Monday. There is a high chance of tropical development over the next 48 hours. Please see the latest NWS Tropical Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for more details. Scattered moderate to isolated strong convection is within 150 nm east of the wave axis north of 17N and within 150 nm west of the wave axis north of 20N. Clusters of scattered moderate to isolated strong convection are within 300 nm east of the remainder of the wave axis. ...TROPICAL WAVES... Tropical wave in the far east Tropical Atlantic extends from 20N20W along 13N24W to 8N24W moving west-southwest 10 to 15 kt over the past 24 hours. Wave coincides with a 700 mb trough based on the global models and is embedded within a surge of moisture as seen on the Total Precipitable Water Imagery. No associated deep convection. Tropical wave southwest of the Capo Verde Islands extends along 30W from 6N-12N moving southwest near near 10 kt over the past 12 hours. Wave is to the west of a 700 mb trough based on the global models and is embedded within a low amplitude surge of moisture as seen on the Total Precipitable Water Imagery. No associated deep convection. Tropical wave in the Caribbean extends along 83W/84W from 10N- 20N moving west 5 to 10 kt over the past 24 hours. Wave coincides with a 700 mb trough based on the global models and is embedded within a large area of moisture as seen on the Total Precipitable Water Imagery. Wave is also located beneath northerly upper flow. No associated deep convection. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 16N17W and continues along 16N19W 12N22W 9N33W to 10N38W. The remainder of the monsoon trough and the ITCZ are being disrupted by the low and wave in the Special Features. Scattered moderate to isolated strong convection is within 30/45 nm of a line from 8N32W to 10N34W. Small clusters of scattered moderate convection dot the area within 250 nm south and 120 nm north of the monsoon trough between 20W-30W. ...DISCUSSION... ...GULF OF MEXICO... A broad upper trough over the eastern CONUS dips south over the Gulf of Mexico supporting a frontal boundary that remains inland over the southeast CONUS. This front is generating scattered to numerous showers and scattered thunderstorms across central Georgia and Alabama to southern Mississippi and Louisiana. These showers and thunderstorms are along the coastal waters of Louisiana and along the Texas coast north of Galveston. A surface trough extends from the coast of Louisiana near 29N91W along 27N90W to 24N90W with isolated showers and possible isolated thunderstorms within 90 nm east of the trough. An upper ridge is anchored over south Mexico near Veracruz extending a ridge axis over the Yucatan peninsula then northeast across the Florida peninsula into the west Atlantic. A weak 1014 mb low remains in the southeast Gulf near 24N85W with isolated showers and thunderstorms south of 26N between 82W-86W to over west Cuba and into the Yucatan Channel. A weak surface ridge extends from over the central CONUS into the Gulf of Mexico anchored by a 1021 mb high over central Texas and a stronger 1025 mb high over Illinois. The surface ridge will shift north and merge with an area of high pressure north of the area Monday. The 1014 mb low will weaken to an open trough as it reaches the south/central Gulf Monday night. ...CARIBBEAN SEA... An upper ridge over the Gulf of Mexico covers the west Caribbean west of 81W. An upper low is centered over Hispaniola extending an upper trough west to 19N78W and covering the central Caribbean. A second upper ridge, anchored in the east Atlantic extends across the west Tropical Atlantic over the Windward Islands to northwest Venezuela. This is creating a diffluent environment across the west Caribbean to generate scattered to numerous showers and scattered thunderstorms inland over Puerto Rico, Hispaniola, and Cuba with scattered showers and isolated thunderstorms north of a line from Hispaniola near 18N71W to 16N83W. Isolated showers and thunderstorms dot the remainder of the Caribbean west of 78W leaving the east Caribbean under mostly clear skies this evening. The tropical wave will move over Central America tonight. ...HISPANIOLA... Scattered to numerous showers and scattered thunderstorms have developed over the island this evening. The upper low/trough currently over the island will persist through midweek. This could continue to bring showers and thunderstorms to the island, especially in the afternoon and evening hours through Wednesday. ...ATLANTIC OCEAN... An upper ridge axis extends from the Gulf of Mexico across the Florida peninsula near Cape Canaveral to near Wilmington, North Carolina. A narrow upper trough extends through 32N77W to over the Bahamas near 22N76W. A surface trough extends from the Windward Passage near 20N74W across the southern Bahamas to 26N72W. Scattered showers and isolated thunderstorms are from the Bahamas to 30N between 71W-78W. The remainder of the Atlantic is dominated by a surface ridge north of 23N east of 75W anchored by a pair of 1023 mb highs near 32N44W and 33N55W. The surface trough across the southeast Bahamas will move west- northwest through the remainder of the Bahamas tonight through Thursday. The tropical wave in the Special Features will move northwestward for the next few days possibly as a tropical cyclone. For additional information please visit http://www.hurricanes.gov/marine $$ PAW