000 AXNT20 KNHC 180508 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1207 AM EST Wed Jan 18 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 0000 UTC surface analysis and satellite imagery through 0430 UTC. ...SPECIAL FEATURES... A developing area of low pressure is forecast to strengthen offshore of the mid-Atlc coast by Wednesday into Wednesday night. The associated cold front is expected to extend into the SW North Atlc region generating near gale to gale force SW to W winds generally N of 29N between 63W-68W. See latest NWS High Seas Forecast under AWIPS/WMO headers HSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 07N11W to 02N22W. The Intertropical Convergence Zone continues from 02N22W to the Equator near 32W. Isolated moderate convection is from 04N-06N between 08W-12W...and S of 04N between 19W-28W. ...DISCUSSION... GULF OF MEXICO... A middle to upper level ridge prevails over the Gulf basin this evening with axis extending along 84W. Primarily southwest to westerly flow aloft is noted on the western periphery of the ridging with scattered cloudiness and possible isolated showers occurring across the far NW Gulf waters focused along a stationary front analyzed from SW Louisiana along the SE Texas Gulf coast to NE Mexico near 27N102W. Otherwise...the western periphery of a surface ridge prevails with gentle to moderate SE winds expected through Wednesday night. CARIBBEAN SEA... Overall tranquil conditions persist across the Caribbean basin this evening as water vapor imagery indicates upper level dry air and strong subsidence to the E of a middle to upper level trough over the NE Caribbean with axis extending from 26N60W to a base near 15N68W. Latest scatterometer data depicts generally moderate to fresh trades across the basin with slightly stronger winds occurring within close proximity to the coast of Colombia between S of 14N between 73W-77W. Satellite imagery shows isolated trade wind showers across Hispaniola...Puerto Rico...and the US/UK Virgin Islands...while the remainder of the basin remains generally precipitation-free. Similar weather conditions are forecast through Friday as surface ridging remains anchored to the N across the SW North Atlc region. ...HISPANIOLA... Fresh NE winds prevail across the island and adjacent coastal waters this evening. Winds will diminish slightly on Wednesday into Thursday as the ridging to the N weakens. Isolated showers are forecast to continue through Thursday as the E-NE flow persists. ATLANTIC OCEAN... A broad 1025 mb surface high centered near 30N69W extends influence across much of the SW North Atlc generally W of 50W. A slight weakness in the ridging is evident as a cold front enters the discussion area in the central Atlc near 32N36W and extends W-SW to 28N40W to 25N53W to 24N63W. Scattered showers and isolated tstms are occurring within 120 nm either side of the front N of 30N. Isolated showers are occurring elsewhere within 90 nm either side of the front S of 30N between 36W-63W. Farther east... another weakening boundary is analyzed as a surface trough from 32N28W to 27N33W to 23N36W. Isolated showers are possible within 60 nm either side of the trough axis. Finally...E-SE of the Windward Islands...a surface trough analyzed from 06N57W to 14N55W is providing focus for scattered showers and isolated tstms from 05N-18N between 45W-62W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN