455 AXNT20 KNHC 281558 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Dec 28 2022 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 1600 UTC. ...MONSOON TROUGH/ITCZ... The ITCZ crosses the Prime Meridian at 05N, continuing through 05N20W to 02N46W. Scattered moderate convection is observed from 03N to 08N, between 15W and 30W. GULF OF MEXICO... A ridge extends across the Gulf of Mexico, anchored by a 1029 mb high in North Carolina. Winds are generally moderate from the S- SE across the basin with 2-4 ft seas. Fresh southerly winds are noted in the NW Gulf with fresh easterlies in the Florida Straits. Scattered weak convection is observed in the NE Gulf from 25N to 30N, between 84W and 89W. For the forecast, weak high pressure over the area will slide eastward and dissipate by tonight. This will allow for fresh to strong southerly winds to set up in the western Gulf, beginning this afternoon. Winds will diminish by Fri as a weak cold front approaches the NW Gulf coast. Elsewhere, moderate east to southeast winds over the eastern Gulf will become mostly fresh Thu and fresh to strong southeast on Fri. The weak cold front should stall over the northern and western Gulf Fri, then dissipate into Sat night. Gentle to moderate southerly flow will become established over most of the Gulf Sat night and Sun. CARIBBEAN SEA... Abundant mid-level moisture is supporting scattered moderate convection in the NW Caribbean. The gradient between subtropical high pressure and lower pressure in the SW Caribbean is supporting fresh easterly winds across the majority of the basin. Locally strong winds are noted offshore Colombia, Haiti and the Yucatan Peninsula. Seas are generally 5-7 ft, with 8 ft easterly swell possible in the Anegada Passage and other Atlantic Passages between the Leeward Islands. Rough seas to 12 ft are found east of these Islands in the tropical Atlantic. For the forecast, weak surface ridging N of the region will maintain moderate to fresh winds across the eastern, central, and southwestern Caribbean through Thu. Locally strong winds will pulse at times S of Hispaniola and N of Colombia. A cold front north of the basin will weaken, allowing the ridge north of the region to strengthen. As a result, trade winds across the central Caribbean will increase to fresh to strong Thu night through Fri. Trade winds will diminish again to moderate to fresh across the basin for the weekend. East swell will continue to affect the tropical Atlantic and the eastern Caribbean waters through Thu night. ATLANTIC OCEAN... In the western Atlantic, a cold front extends from 31N65W to the SE Bahamas. Scattered moderate convection is observed ahead of the front, north of 22N and west of 63W. Behind the front, winds are moderate to fresh from the NE with 6-8 ft seas. Ahead of the front, winds are moderate from the SW with 7-9 ft seas. The central Atlantic is dominated by a relatively tight gradient between a 1033 mb high pressure centered near 33N40W and lower pressure along the ITCZ. This pattern is supporting fresh to strong easterlies from 10N to 25N, between 30W and 55W. Seas are 10-13 ft in this area. In the eastern Atlantic, the gradient between subtropical high pressure and a 1012 mb low near 21N20W is supporting strong NE winds extending roughly 420 nm north of the low. Sea heights reach 14 ft in this area. A few thunderstorms are noted near the low-pressure center. For the forecast W of 55W, the northern half of the cold front will continue east into the end of the week, while the southern half will devolve into a surface trough tonight that moves northward on Thu before dissipating Fri. Fresh NE winds will prevail behind the front through Thu. Another cold front is forecast to move off the Georgia coast Sun and Sun night. Large E swell east of 65W and south of 25N will slowly subside through Fri. $$ Flynn