000 AXNT20 KNHC 230001 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 646 PM EST Sun Jan 22 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 2300 UTC. ...SPECIAL FEATURES... ...GULF OF MEXICO GALE WARNING... A strong cold front is crossing the eastern Gulf of Mexico this evening. Gale force winds to 35 kt are occurring north of 25N east of the front with seas to 13 ft. Gale force winds to 40 kt are occurring north of 23N west of the front with seas building to 19 ft. For more information, please refer to the latest High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC. ...ATLANTIC GALE WARNING... The same cold front noted above will sweep eastward into the southwest Atlantic with southwest winds increasing to 30-35 kt north of 29N west of 77W this evening and seas building to 16 ft. These conditions will spread east ahead of the front for the next 48 hours with winds increasing to 30 to 40 kt by Monday afternoon north of 23.5N within 150 nm east of the front. Please refer to the latest High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough passes across the coast of Africa near 05N09W to 04N18W. The ITCZ begins from that point and extends to 00N27W to 03S35W. Isolated moderate convection is south of 06N between 26W and 44W. ...DISCUSSION... ...THE GULF OF MEXICO... A vigorous upper level trough over the southern United States supports a strong cold front that as of 2100 UTC extended from 31N84W to 18N94W. A squall line is just ahead of the front north of 27N. Gale force winds are occurring both ahead of and behind the front mainly north of 23N over the Gulf basin this evening. Please refer to the special features section for more details. The cold front will continue to move rapidly southeastward and exit the eastern Gulf Monday morning. Winds and seas will gradually subside beginning Monday afternoon. ...THE CARIBBEAN SEA... A 1016 mb surface high is centered to the north of Jamaica and extends across most of the basin. The tail end of a surface trough, formerly a stationary front, extends over the Virgin Islands with isolated showers. The latest scatterometer data indicates gentle to moderate trades across the basin east of 78W, and south of 15N west of 78W. Fresh to strong southerly winds are north of 15N west of 78W, ahead of an approaching cold front over the Gulf of Mexico. The cold front will enter the northwestern Caribbean late tonight and reach from eastern Cuba to the Honduras/Nicaragua border by Monday evening. Strong northwest winds will occur north of the front. ...HISPANIOLA... Dry air in subsidence prevails over island at this time. These conditions will prevail through Monday morning. A cold front approaching from the northwest will bring increasing southerly winds Monday afternoon through Tuesday, with showers possible Tuesday through Tuesday night as the front crosses the island. ...THE ATLANTIC OCEAN... A 1016 mb surface high prevails across the west Atlantic centered near 25N65W. A strong cold front is approaching the southeastern United States supporting clusters of thunderstorms over the Atlc waters north of 29N west of 76W with strong to near gale southwesterly winds. A stationary front extends from 31N43W to 24N50W, then transitions to a surface trough to 18N64W. Scattered moderate convection is north of 24N between 37W and 45W. A 1018 mb area of high pressure centered near 33N23W dominates the eastern Atlc. Over the next 24 hours thunderstorms and winds will increase over the Florida offshore waters ahead of the approaching cold front with gale force winds developing this evening. Please see the special features section for more details regarding this gale. For additional information please visit http://www.hurricanes.gov/marine $$ ASL