000 AXNT20 KNHC 170002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 702 PM EST Thu Nov 16 2017 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 2345 UTC. ...SPECIAL FEATURES... A 996 mb low is centered near 34N48W with the associated cold front extending SW from the low to 31N50W. The low is supported aloft by a middle to upper level trough with axis extending S to a base near 30N. A surface trough follows the tail of the front extending SW along 25N60W to the Windward Passage. Gale force S-SW winds are N of 28.5N E of the trough to 46W with seas from 9 to 15 ft. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 08N13W to 07N27W. The Intertropical Convergence Zone axis extends from 07N27W to 07N40W to 06N53W. Scattered moderate convection is from 03N-15N E of 41W. ...DISCUSSION... GULF OF MEXICO... Generally, stable conditions prevail basin-wide being supported by dry air subsidence from aloft and broad surface high pressure anchored over Illinois state and extending SSW across the northern half of the Gulf. This ridge provides NE light to moderate flow E of 90W and NE-E light to gentle flow elsewhere. In the SW basin, a surface trough extends from 22N92W to the Bay of Campeche near 17N94W with possible isolated showers. The next cold front is expected to emerge off the Texas and Louisiana coasts Saturday night. Fresh to strong N-NE winds will follow in wake of the front as it sweeps southeastward. CARIBBEAN SEA... A middle level trough extends from the SW N Atlc SSW to a base near Panama. This trough continues to support a 1007 mb low over SW Haiti adjacent waters or to the SE of Jamaica near 17N74W. A surface trough extends from the Windward Passage to the low to 09N80W. Scattered heavy showers and isolated tstms are S of 19N between 67W-82W. Isolated showers are occurring across Hispaniola and portions of Puerto Rico, the Windward Passage and the Mona Channel. Otherwise, moderate to occasional fresh northerly winds are noted across the western Caribbean waters generally W of 79W while SW flow of the same magnitude is E of the low pressure system to 71W. Variable light to gentle winds are elsewhere. The low is expected to remain nearly stationary S-SW of Hispaniola through early Monday. ...HISPANIOLA... Scattered showers and tstms persist across the island and will continue through the weekend as deep moisture advects NE over the region due to a middle to upper level trough. Convection will likely be heaviest in the afternoon and evening hours during maximum heating. Localized flooding and life-threatening mud slides are also possible during this time. ATLANTIC OCEAN... Aside from the special features section above highlighting the area of low pressure and associated gale-force winds, the remnants of a dissipating cold front are analyzed as a surface trough in the SW N Atlc waters from 29N72W to 24N75W. The surface trough associated with the region discussed in special features supports scattered heavy showers and tstms N of Puerto Rico and Hispaniola to 23N and isolated showers N of 23N between 50W-60W. Scattered showers are N of 28N between 40W-50W. The frontal troughing is expected to persist across the central Atlc through Saturday night as ridging builds in off the SE CONUS and into the SW North Atlc. Otherwise, surface ridging will prevail in the E Atlc. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos