000 AXNT20 KNHC 052252 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 552 PM EST THU JAN 5 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 2230 UTC. ...SPECIAL FEATURES... A cold front is currently analyzed across the NW Gulf waters from the SW Louisiana coast near 30N93W SW to the Texas coast near the Matagorda Bay. The front will begin to move eastward quickly through the overnight hours into Friday across the basin...and position itself SE of the Gulf waters by Saturday night. Near gale to gale force northerly winds are expected to materialize by 07/0600 UTC from 21N-28N W of 90W and persist through early Sunday morning. See 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 09N13W to 04N19W. The Intertropical Convergence Zone axis extends from 04N19W to 01N30W to the Equator near 38W. Isolated moderate convection is S of 04N between 37W-45W. ...DISCUSSION... GULF OF MEXICO... Nearly zonal westerly flow aloft prevails over much of the Gulf basin this evening with an upper level trough and middle level energy noted on water vapor imagery over the Intermountain West. This trough and energy is forecast to drive a cold front... currently analyzed offshore of the Texas and Louisiana coasts... across the basin through Saturday night. As mentioned above...near gale to gale force northerly winds are expected across portions of the western Gulf with fresh to strong N-NE winds expected through Monday morning. Strong high pressure will remain anchored across the southern plains and move eastward to the mid-Atlc coast by Sunday night. Otherwise...a weak 1015 mb high centered near 28N87W continues to provide mostly tranquil conditions this evening. CARIBBEAN SEA... Water vapor imagery continues to indicate strong subsidence over the entire basin. A dissipating stationary front is analyzed across the Yucatan Channel region supporting isolated showers N of 20N between 83W-88W. Otherwise...a fairly weak pressure gradient is noted across the basin with gentle to moderate trades expected to persist through the overnight hours. Slightly stronger trades...moderate to fresh...are expected within close proximity to the coast of Colombia and NW Venezuela. By Saturday night...a cold front is expected to move into the NW Caribbean resulting in strong to near gale northerly winds that will spread southeastward to 74W by Monday morning. ...HISPANIOLA... Conditions remain mostly fair with partly cloudy skies this evening and the a possible isolated shower occurring across interior portions of the island. Dry air and strong subsidence aloft however are providing an overall stable environment that is expected to persist the next several days keeping overall conditions tranquil. ATLANTIC OCEAN... A middle to upper level trough is noted on water vapor imagery in the vicinity of 34N68W with axis extending SW to over the NW Bahamas near 26N77W. This troughing supports a cold front analyzed from 32N65W SW to the central Bahamas near 25N76W to the northern coast of western Cuba near 23N81W. Widely scattered showers and isolated tstms are occurring N of 26N between 61W-70W...with isolated showers occurring elsewhere within 90 nm either side of the front W of 70W. Otherwise...a 1011 mb low centered off the coast of Georgia near 32N80W is forecast to move quickly NE and away from the discussion area. By Saturday morning...another low is expected to develop in nearly the same location off the coast of Georgia and South Carolina with a strong cold front moving across the SW North Atlc ushering in a round of strong to near gale force northerly winds Saturday night late through Monday morning. Farther east...a ridge continues to influence much of the central Atlc anchored by a 1024 mb high centered near 32N47W. Within the southern periphery of the ridge to the E of the Lesser Antilles...scattered showers and tstms are occurring from 07N-16N between 47W-60W. This activity is likely supported by an upper level trough axis noted on water vapor imagery extending from 22N54W SW to a base over the eastern Caribbean Sea near 15N65W. Finally...across the eastern Atlc...a complex surface low is centered on a 1007 mb low centered near 32N28W with surface trough axis extending SE to 30N26W then S-SW to 25N30W to 23N34W. This low is supported aloft by a middle to upper level low centered near 32N28W. Scattered showers and tstms are occurring mainly east of the surface trough axis from 26N-34N between 20W-26W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN