000 AXNT20 KNHC 190006 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 705 PM EST SUN DEC 18 2016 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 2315 UTC. ...SPECIAL FEATURES... As of 2100 UTC, a strong cold front extends from the Florida Panhandle at 31N85W to 26N92W to Veracruz Mexico at 19N96W. Northerly gale-force winds are over the western Gulf of Mexico behind the front with seas 8 to 11 feet. A considerable amount of cold air advection is also associated with the front. Please read the Atlantic high seas forecast, that is listed under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC, for more details. The tightening pressure gradient between high pressure building north of the Caribbean and lower pressure associated with climatological low pressure over Colombia will support gale- force winds over portions of the south central Caribbean beginning shortly at 19/0000 UTC, persisting until 20/1800 UTC. Please read the Atlantic high seas forecast, that is listed under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC, for more details. ...THE ITCZ/MONSOON TROUGH... The monsoon trough extends westward from the African coast near 06N11W to 03N20W. The ITCZ continues from 03N20W to 02N30W to 03N40W to the coast of South America near 03N51W. Scattered showers are within 120 nm of the axis west of 35W. ...DISCUSSION... ...THE GULF OF MEXICO... A strong cold front with gale conditions are over the NW Gulf of Mexico. See above. Scattered moderate convection is within 90 nm north of the front, north of 23N. 5-10 kt southerly winds are south of the front, where air temperatures remain in the 70's and 80's. Expect the cold front in 24 hours to extend from Central Florida to the Bay of Campeche near 18N94W, with gale conditions persisting over the SW Gulf, together with convection. ...THE CARIBBEAN SEA... Near gale force winds are along the coast of Colombia. See above. Moderate to fresh trades cover much of the central and Eastern Caribbean. Moderate to fresh trades are elsewhere over the Caribbean. No deep convection is currently observed over the basin. Scattered showers are embedded in the trades streaming across the Leeward Islands. In the upper levels, ridging is over the Caribbean Sea with Strong subsidence. ...HISPANIOLA... Deep-layer high pressure will maintain a relatively quiet weather pattern over the island for the next several days. Subsident air aloft will produce drying over the area through Tuesday with only a few passing showers in the tradewind flow. ...THE ATLANTIC OCEAN... A weakening stationary front extends SW from 31N39W to 26N54W. Isolated moderate convection is within 120 nm north of the front, east of 50W. High pressure centered near the Azores will be reinforced by a new high pressure ridge moving eastward from the northwest Atlantic. The resultant ridge will continue to dominate the remainder of the Central and Eastern Atlantic through the early part of the week. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa