670 AXNT20 KNHC 161805 TWDAT 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 33W from 03N-20N, moving W at 15 kt. Scattered moderate convection is along and within 480 nm E of the wave axis. The tropical wave that was analyzed along 57W at 16/0600 UTC has been adjusted E to 55W at 16/1200 UTC based on the latest TPW loop, long-term satellite imagery and tropical wave model diagnostics. The tropical wave is moving W at 10 kt. Scattered moderate convection is from 09N-13N between 51W-57W. A Caribbean Sea tropical wave is along 68W, from 04N-20N, moving W at 10-15 kt. Scattered moderate convection is from 13N-20N between 60W-72W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of The Gambia near 13N17W to 07N32W. The ITCZ is from 05N35W to 06N44W to 09N51W. Scattered moderate convection is from 03N-14N between 20W and the coast of Africa. A surface trough extends from 15N47W to 09N53W. Scattered moderate convection is from 09N-16N between 46W-51W. GULF OF MEXICO... As of 16/1500 UTC, a cold front extends across the Gulf of Mexico from Tallahassee Florida to just S of the Mouth of the Mississippi River near 29N89W to 28N95W to Port Mansfield Texas near 26.5N97.5W to 24N99W over N Mexico to 26N103W. Strong NE winds are occurring N of the front. Isolated to scattered light showers are within 120 nm north of the front. The cold front will extend from northern Florida to Tampico Mexico tonight, then stall and dissipate in the SE Gulf. Fresh to strong NE winds and building seas are expected north of the front through Sat. Elsewhere, an area of upper-level divergence and enhanced moisture seen on TPW imagery over the SE Gulf of Mexico is leading to scattered moderate convection from 21N-26N between 81W-89W, including the Yucatan Channel and the SW coast of Florida, south of Marco Island. A weak surface trough is producing scattered showers and isolated tstorms near Veracruz Mexico. CARIBBEAN SEA... An area of upper-level divergence and enhanced moisture over the western Caribbean is causing scattered moderate isolated strong convection off the coast of Honduras from 14.5N-18N between 82W-89W. Scattered moderate convection is also seen in the Yucatan Channel as well as in the far SW Caribbean from 10N-11N between 77.5W-81.5W. Shower and tstorm activity over the E Caribbean east of 72W is related to the tropical wave along 68W and to an upper-level trough over the NE Caribbean. This precipitation is affecting areas from the Leeward Islands to the Dominican Republic and extends as far south as 13N between 63W-67W. A recent ASCAT pass shows moderate winds across most of the basin, except for fresh winds seen in the south-central Caribbean, south of 14N between 71W-79W, and in the eastern Caribbean between 62W-65W. For the forecast, the tropical wave south of the Mona Passage will reach the Windward Passage on Sat. A broad area of low pressure is expected to form early next week in the SW Caribbean Sea. Some gradual development of the system is possible thereafter, as it remains nearly stationary. See the NHC Tropical Weather Outlook for more details. ATLANTIC OCEAN... A surface trough extends from 30N77W to the Florida Keys. Scattered moderate isolated strong convection is from 26N-31N between 75W-80W. Similar convection is over portions of South Florida. Farther southeast, a tropical wave and an upper-level trough are enhancing showers south of 20N between 56W-70W. A 1013 mb surface low is near 31N54W. Scattered moderate convection is from 24N-32N between 49W-53W. Gradual tropical or subtropical development of this system is possible through the middle of next week while the low meanders over the central Atlantic well to the southeast of Bermuda. This system has a low chance of becoming a tropical or subtropical cyclone during the next 48 hours. The gradient between the low center and high pressure to the north will increase winds and seas across the waters north of 25N between 50W-70W by Sun evening. A cold front will move off the SE U.S. coast tonight, extend from 31N69W to the central Florida Keys Sat night, then stall and dissipate on Sun. Fresh to strong NE winds and building seas are expected north of the front this weekend. Farther east, a surface trough is along 41W from 25N-31N. Scattered showers are within 180 nm east of the trough. A 1016 mb low is near 31N26W. A 1020 mb high is near 27N29W. $$ Hagen