000 AXNT20 KNHC 042339 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 639 PM EST WED JAN 4 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 2315 UTC. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa reaching the Atlantic waters near 05N09W to 02N17W. The ITCZ begins from that point to 03N26W to 01N35W to 00N50W. Isolated showers and thunderstorms are observed on either side of these boundaries from the Equator to 04N between 15W-45W. ...DISCUSSION... GULF OF MEXICO... Westerly winds aloft prevail across the entire Gulf early this evening with the strongest winds, up to 80 knots, over the northern half. A cold front enters the Gulf near Sarasota, Florida and continues to 24.5N87W where it becomes a stationary front to 23N92W and into the southwest Bay of Campeche. A pre-frontal trough is located from 60 to 90 nautical miles ahead of the front with scattered showers and isolated thunderstorms located south of the cold front to the Cuba coast and over the Straits of Florida. Another cold front is located from near Gainesville, Florida to 26.5N90W to the upper Mexican coast at 25.5N. The two fronts are expected to merge over the next day or so. CARIBBEAN SEA... A middle/upper level trough is located over the eastern third of the Caribbean and will be replaced by a ridge by Friday. Water vapor imagery shows strong subsidence over the entire area and is especially pronounced over the southern half. No surface features are located over the Caribbean. Strong easterly winds are forecast over the south central Caribbean in 36 to 48 hours due to an intensifying high pressure ridge over the Atlantic. HISPANIOLA... The middle/upper level trough mentioned above is located over Hispaniola and is forecast to move east. Cloudiness and isolated showers are observed over the area and adjacent coastal waters. ATLANTIC OCEAN... A middle/upper level trough axis is located through 32N57W to 18N67W or just west of Puerto Rico and is forecast to move rapidly to the east. A broad middle/upper level trough covers the east Atlantic east of about 45W with a cyclonic circulation forecast to develop near 30N25W in 48 hours. An upper level jet is located from near 05N55W to 17N30W to the African coast at 23N with satellite derived winds indicating speeds of up to 100 knots. A cold front extends through 32N73W to just north of Palm Beach, Florida. Scattered showers and thunderstorms are located up to 4 to 5 degrees ahead of the front east of 75W. Another cold front is located through 32N78W to Gainesville, Florida. The two fronts are forecast to merge. A dissipating cold front enters the forecast discussion area near 32N27W and continues along 26N40W to 27N53W. Isolated showers and thunderstorms are near the frontal boundary. For additional information please visit http://www.hurricanes.gov/marine $$ CAB