000 AXNT20 KNHC 170603 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 103 AM EST Sun Dec 17 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 0545 UTC. ...SPECIAL FEATURES... ...Caribbean Sea Gale Warning... Strong surface pressure centered off the coast of South Carolina tightens the pressure gradient in the south-central Caribbean, thus supporting gale-force winds along the northwest portion of the Colombian coast. These winds will pulse every night through early next week as the ridge builds over SW N Atlc waters. Sea heights will range from 8 to 15 feet in the area of strongest winds. Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough passes through the coast of West Africa near 09N13W to 08N18W. The ITCZ continues from 08N18W to 06N26W to 01N50W. Scattered showers are from 02N-05N between the Prime Meridian and 17W and from 07N to 17N between 18W and 35W. ...DISCUSSION... GULF OF MEXICO... A middle short-wave trough extending from northern Texas SE to a base over the NW Gulf supports a 1012 mb low off the coast of Texas near 28N95W. A cold front extends from this low to the SW basin near 22N96W while a warm front extends NE to E along 30N94W to 29N92W to 28N88W. At the last coordinate, the front transitions to a stationary front continuing SE towards South Florida. Radar imagery show a line of heavy showers and tstms between Galveston Texas and SW Louisiana extending S into the Gulf to near 28N. Scattered to isolated showers are also in the NE basin associated with the frontal system. Fresh to strong winds are also in the vicinity of the low due to a tight pressure gradient between the low and high pressure over the SE CONUS. The low will move NE inland dragging the cold front towards Louisiana and adjacent NW Gulf waters. The front will then weaken gradually and transition into a surface trough to move inland Texas early Monday morning. CARIBBEAN SEA... Gale-force will continue to pulse at night in the south-central Caribbean as strong high pressure builds in the SW N Atlc waters. Please refer to the Special Features section above for details. Fair weather prevails across the remainder of the basin being supported by a broad middle to upper level high and very dry air aloft. Little change is expected through the next 24-48 hours. ...HISPANIOLA... A broad middle to upper level high covering the Caribbean and very dry air aloft support very stable conditions across the Island. Similar conditions are forecast through Monday. Fresh to strong NE to E winds will continue in the Windward Passage through Wednesday. ATLANTIC OCEAN... A broad middle to upper level trough over the NW Atlc supports a cold front that extends from 30N57W SW to 25N77W to Andros Island. No convection is associated with this front. Strong high pressure starts to build west of this front and is forecast to prevail over SW N Atlc waters through the middle of the week. Otherwise, the Azores high continue to extend a ridge axis across the eastern Atlc waters. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos