510 AXNT20 KNHC 251718 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Dec 25 2021 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough remains mostly inland along the Guinean Forests of West Africa. The ITCZ extends from 05N10W near the coast of Liberia through 06N20W to 01N45W near the coast of Brazil. Scattered moderate to isolated strong convection is noted in the eastern Atlantic from the equator to the monsoon trough/ITCZ and between the Gulf of Guinea and 23W. Scattered moderate convection is also noted in the western Atlantic from the equator to 05N and between 40W and the coast of South America. GULF OF MEXICO... A surface ridge extends from the western Atlantic across the northern Gulf. This pattern is supporting a fresh southerly breeze over the northwest Gulf with buoys reporting 6 to 8 ft seas. Gentle to moderate breezes with 3 to 5 ft seas dominate the central basin with a gentle breeze and 1 to 2 ft seas in the northeast Gulf. No shower or thunderstorm activity is currently observed in the basin. For the forecast, the ridge extending from high pressure over the western Atlantic will lift northward through early next week, supporting moderate to fresh southeast winds over the central and western Gulf. Looking ahead, the high pressure will move eastward through mid week, allowing winds and seas to diminish over the central and western Gulf by Wed night. Mostly gentle winds and slight seas will persist over the eastern Gulf into Mon, followed by moderate winds and seas through mid week. CARIBBEAN SEA... A 1022 mb high pressure in the NW Atlantic continues to support enhanced easterly flow in the Caribbean. A recent scatterometer pass indicates moderate NE winds in the eastern Caribbean with buoys reporting 3-5 ft seas. Winds are moderate to fresh in the central Caribbean with the strongest winds near the coast of Colombia. Seas in the area are 5-7 ft. In the northwestern Caribbean, a gentle to moderate breeze dominates with 3-5 ft seas. There are two weak surface troughs noted on the analysis. One in the eastern Caribbean and the other between Jamaica and Central America. Neither of these features are producing significant convection, but isolated showers are possible. For the forecast, fresh to strong winds will pulse mainly during overnight hours off Colombia starting tonight. Elsewhere, winds and seas will diminish through Sun across the basin as high pressure north of the area shifts eastward. This pattern will return late Mon as high pressure again builds north of the area following a cold front moving across the western Atlantic. This will support moderate to fresh NE to E winds across the basin through mid week. ATLANTIC OCEAN... The main feature in the tropical north Atlantic is the tail end of a cold front extending from 31N43W to 22N60W. A shear line then continues from 22N60W to 20N73W along the coast of Hispaniola. Behind this boundary, anticyclonic flow rotates around a 1022 mb high pressure centered near 31N67W. A recent scatterometer satellite pass showed moderate to fresh northeast winds extend from the boundary to 25N with 6-8 ft seas. South of 25N and ahead of the front, winds are gentle to moderate with 4-6 ft seas. The strongest winds in the basin are found on both sides of the cold front north of 25N. Scatterometer data reveals strong NW winds extend roughly 300 nm behind the front and strong SW winds extend roughly 300 nm ahead of the front. Seas are 9-11 ft in these areas. Farther east, a 1022 mb high pressure centered near 28N24W is maintaining a gradient with lower pressure near the ITCZ to generate fresh to locally strong NE winds and 8-10 ft seas in the eastern Atlantic south of 25N and in the central Atlantic south of 15N. Winds are gentle to moderate elsewhere. For the forecast, the shearline will remain stationary and dissipate through tonight. High pressure building behind the front will move to the south of Bermuda today, ahead of another front that will move across the waters between Bermuda and northeast Florida Sun. Looking ahead, the front will move southeast of the region early next week as high pressure builds northeast of the northern Bahamas behind the front. Large N swell with building seas will follow the front east of 70W Sun through mid week. $$ FLYNN