000 AXNT20 KNHC 130004 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 704 PM EST MON DEC 12 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 2345 UTC. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across the African Continent entering the Atlantic Ocean through Sierra Leone near 07N12W to 05N15W. The ITCZ begins from that point and continues along 02N24W to 02N32W. A surface trough is west of the ITCZ extending from 06N35W to 01N36W. Scattered to isolated moderate convection is from 0N to 07N E of 40W. ...DISCUSSION... GULF OF MEXICO... A broad middle to upper level trough with base over central Mexico extends to the NW Gulf of Mexico, thus supporting a stationary front that extends along the coast of Texas. The GOES IFR show medium probability of fog off the coast of Texas and adjacent waters, however surface observations indicate the presence of it N of 26N W of 93W. This traduces to visibility less than 3 miles. Mariners and boaters in this region should exercise caution. A broad surface ridge anchored over the central Atlantic extends an axis SW across the Florida Peninsula and the Gulf to near 93W. This is providing light variable flow E of 93W and gentle SE flow over the remainder western basin. Except for the foggy/hazy area in the NW Gulf, the remainder basin in under fair weather conditions being supported by strong dry air subsidence from aloft. The stationary front along Texas will become a cold front early Wed morning, moving across Florida Thu into early Fri morning. CARIBBEAN SEA... A broad upper level anticyclone centered S of Dominican Republic provides a diffluent environment over the W Caribbean W of 80W. Low to middle level moisture associated with the passage of a center of low pressure across Nicaragua along with the diffluence aloft continue to support scattered heavy showers and isolated tstms S of 20N W of 80W. The convection in the SW basin is also being supported by the monsoonal flow that extends from Costa Rica to northern Colombia. Passing showers are noted over the NE Caribbean over the Leeward Islands, across Puerto Rico and the Mona Passage. Fair weather is across the remainder basin being supported by strong dry air subsidence from aloft. Scatterometer data depicts fresh to near gale force E winds over the central Caribbean between 70W and 78W due in part to the strong high pressure over the central Atlantic. Convection over the W Caribbean is forecast to cease by Wednesday. A center of low pressure is forecast to develop over the SW basin Wed morning with associated trough. ...HISPANIOLA... Passing showers are across the Island associated with a patch of shallow moisture. Fresh to strong winds are over coastal and adjacent waters of the Island due to strong high pressure over the central Atlantic. These showers are forecast to continue through Tue night as another patch of moisture currently over the NE Caribbean makes its way westward. ATLANTIC OCEAN... A diffluent environment aloft between the upper trough across the northern Gulf of Mexico and the NW periphery of the anticyclone anchored in the Caribbean support heavy showers and tstms in the vicinity of a surface trough that extends from 31N75W to the E coast of Florida near 27N80W. This convection concentrates from 27N to 32N between 70W and 80W with isolated showers extending across the Bahamas. A broad surface ridge dominate the remainder SW and central Atlc waters anchored by a 1031 mb high N of the area. Ahead of the ridge a cold front extends from 30N34W to 25N51W where it transitions to a stationary front to 24N61W. No showers associated with it. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos