000 AXNT20 KNHC 162350 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 750 PM EDT Mon Oct 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 2330 UTC. ...SPECIAL FEATURES... ...Gale Warning... As of 2100 UTC the frontal boundary that extends across the Gulf of Mexico has become stationary, extending from 30N84W to 19N96W. A tight pressure gradient and cool dry air associated with the front is supporting northerly winds to continue to funnel along the coast of Mexico reaching gale force from Tampico to Veracruz through late today, with seas reaching 8 to 16 ft. The front will gradually lose identity across the southeast Gulf of Mexico through mid week and these conditions will subside. ...TROPICAL WAVES... A tropical wave extending from 14N50W to 06N49W, moving west at about 15-20 kt. There remains good continuity of this wave on various satellite imagery. Scattered moderate convection is from 06N-13N between 42W-52W. A tropical wave a little farther west, reaching from 14N58W to 06N58W, moving west at 10-15 kt. This wave is not as well defined, with drier air is impinging on the northern extent of it. No significant convection is observed with this wave at this time. A tropical wave is analyzed over the central Caribbean, from eastern Cuba to the central coast of Colombia. There is good continuity in various satellite data and satellite derived winds showing a broad wave axis traversing the central Caribbean. No significant convection is noted currently in the area of the tropical wave axis, largely due to dry subsident air aloft moving into the northwest and north central Caribbean at the base of an upper- level trough north of the area. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 12N16W to 06N27W, where it transitions to the ITCZ and continues to 07N46W. Aside from the convection related to the tropical wave along 50W, scattered showers are noted along the monsoon trough mainly east of 21W. ...DISCUSSION... GULF OF MEXICO... As of 2100 UTC, the frontal boundary that extends across the Gulf of Mexico has become stationary, extending from 30N84W to 19N96W. A Gale Warning is in effect for the area west of the front. See the section above for details. Scattered moderate convection prevails along and in the vicinity of the frontal boundary covering most of the basin. Seas are building to 10 ft over the northwest Gulf in the area of strong winds west of the front. Gentle breezes and slight seas are noted elsewhere. High pressure building north of the area in the wake of the front will allow fresh to strong winds across the basin late in the week. CARIBBEAN SEA... The pressure gradient generated between the high pressure over the central Atlantic and an approaching tropical wave east of Barbados is supporting fresh to locally strong southeast winds are noted over the eastern Caribbean. Showers and thunderstorms are active from north of 14N and east of 69W affecting mostly Puerto Rico and adjacent waters. Deep dry air is noted elsewhere, related in part to dry subsident air aloft filtering over the Caribbean on the south side of an upper-level trough northeast of the Bahamas. Moderate winds and seas prevail currently. High pressure building north of the area will allow strong winds to pulse over the south central Caribbean mainly at night and in the wake of passing short waves through mid week. This trend will persist late in the week, with strong winds and building seas forecast for across the eastern Caribbean. ...HISPANIOLA... A negatively tilted upper-level trough is reaching from off the Carolinas through the southern Bahamas and into central Hispaniola. Divergence aloft is interacting with local sea breezes enhancing convection over the island. This activity will continue through the next 24 hours. A tropical wave moving across Hispaniola mid week will bring additional potential for showers, ending by late week as drier deep layer moisture moves into the region. ATLANTIC OCEAN... Two tropical waves are moving across the basin. Refer to the section above for details. A 1012 mb low is centered north of Hispaniola near 25N71W. A surface trough extends north from the low to beyond 31N70W. Scattered moderate convection is north of 23N between 64W-70W. A 1030 mb high is centered over the central Atlantic near 34N40W, enhancing fresh trade winds in the deep tropics. Elsewhere, the tail end of a weakening frontal boundary is producing scattered showers over the Canary Islands and areas of Saharan dust continue to move off northeastern Africa into adjacent Atlantic waters as far west as 40W. For additional information please visit http://www.hurricanes.gov/marine $$ ERA