572 AXNT20 KNHC 281750 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Sat Dec 28 2024 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 1800 UTC. ...SPECIAL FEATURES... Central Atlantic Gale Warning and Significant Swell Event: A 1002 mb low centered near 29N53W will deepen and move eastward through Sun, supporting gale force winds and very rough seas on the western side of the low today. A recent scatterometer pass indicated gale-force winds extending up to 250 nm W of the low center. Strong to near gale-force winds with rough seas and large swell of 12 to 16 ft will cover the waters north of 21N and between 35W and 65W through Mon. Expect fresh to strong winds and rough seas with large swell of 8 to 12 ft north of 15N between 25W and 55W Tue into Wed as the low lifts to the northeast of the area. For more details, please refer to the latest NWS High Seas Forecast issued by the National Hurricane Center at the website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic from the coastal plains of Liberia near 05N10W and continues westward to 05N15W. The ITCZ continues from 05N15W to 02N32W to 01N50W. Scattered showers and thunderstorms are active within 150 nm north of the ITCZ between 26W and 50W. ...GULF OF MEXICO... Scattered moderate convection is developing in the north-central Gulf north of 28N between 85W and 90W. Upper-level divergence is also causing scattered showers and isolated thunderstorms to form in the SE Gulf and the Florida Straits. Outside of convection, surface ridging prevails across the Gulf, driving moderate to fresh SE winds and seas of 2 to 5 ft across much of the basin. For the forecast, relatively weak high pressure over the NE Gulf will shift eastward through Sun as a weak cold front moves into the western Gulf tonight. In advance of this front, moderate southeast to south winds over the eastern Gulf will increase to fresh speeds today and into tonight. Moderate southerly winds over the western Gulf will become fresh south to southwest winds during this morning. The front will reach from near Mobile, Alabama to the SW Gulf early Sun, from the Florida Big Bend region to near the northwest part of the Yucatan Peninsula Sun evening, from southwest Florida to near the northeast part of the Yucatan Peninsula early Mon before becoming stationary and dissipating during Mon. Winds behind the front will be at moderate to fresh speeds tonight and Sun. Scattered showers and thunderstorms are expected ahead of the front into Sun. A second and stronger cold front is expected to move into the northwest Gulf Tue morning, reach from northeast Gulf to the north-central Gulf, to near deep South Texas Tue night and from the Straits of Florida to the far south-central gulf by Wed night. It is expected to be followed by moderate to fresh north to northeast winds, except for fresh to strong north to northeast winds in the western Gulf. Seas with the strong winds are forecast to reach around 8 or 9 ft in the far west-central Gulf Wed night. ...CARIBBEAN SEA... Fresh to locally strong NE winds and 4 to 7 ft seas persist across the Windward Passage and also off the northern coast of Colombia, south of high pressure over the northwest Atlantic. Moderate to occasionally fresh winds and 3 to 5 ft seas are noted elsewhere. Scattered moderate convection is ongoing in the vicinity of the Eastern Pacific monsoon trough which extends across the far SW Caribbean. For the forecast, the pressure gradient between high pressure that is building over the western and broad deepening low pressure in the central Atlantic will continue to induce fresh to strong northeast winds through the Windward Passage, and also over the waters south of Hispaniola through Sun night. These winds will then be at moderate to fresh speeds Mon through Wed night. Otherwise, the pressure gradient between the western Atlantic high pressure and relatively lower pressure in the southwestern Caribbean and northern South America will for generally moderate to fresh trades to exist over the central and eastern sections of the basin. Light to gentle trades will continue over the western half of the basin through Tue night before increasing to moderate speeds Wed and Wed night. Scattered showers and thunderstorms are quite active over some sections of the southwestern and western Caribbean. Little change in this activity is expected through at least Sun. ...ATLANTIC OCEAN... Please see the Special Features section for details about an ongoing gale and significant swell event in the central Atlantic. A cold front extends from the low pressure to near 20N67W. Aside from the conditions mentioned in the Special Features section, moderate to fresh NE winds and 5 to 7 ft seas follow the front across the waters north of 20N and west of 60W. East of the front, the remains of a stationary front are indicated by a large area of scattered showers and isolated thunderstorms north of 24N between 37W and 45W. A recent scatterometer pass indicated fresh to strong SE winds within the strongest convection. Gentle to moderate breezes and 4 to 6 ft seas are evident elsewhere west of 40W. East of 40W, moderate to fresh NE to E winds and 4 to 6 ft are noted. For the forecast west of 55W, an intensifying low pressure system of 1002 mb is east of the forecast waters near 29N53W, with a trailing cold front to near 20N67W. The low will continue to intensify as it moves east-southeastward through Sun. Its expanding wind field consisting of strong to gale-force winds will continue to impact the eastern half of the offshore zones through Sun. As a result of these winds, rough to very rough seas will impact the waters east of about 71W through tonight, then shift to east of 65W Sun and to east of 60W Mon. The low pressure will track to the northeast Sun through Mon night, with its associated wind and sea conditions shifting E of 55W. The cold front will weaken as it shifts southeast of the offshore zones Sun. Southerly winds will increase offshore the southeastern United States and northern Florida beginning Tue ahead of an approaching strong cold front. The front is expected to move off the southeastern United States coast late Tue night, and reach from near 31N70W to 28N73W and to near the central Bahamas by Wed night. Fresh west to northwest winds will follow the front north of about 28N. $$ Adams