041 AXNT20 KNHC 292338 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Mon Dec 30 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 1800 UTC surface analysis and satellite imagery through 2330 UTC. ...SPECIAL FEATURES... Central Atlantic Significant Swell Event: A 999 mb low centered near 29N47W will move eastward through tonight, supporting near- gale force winds and rough to very rough seas of 12 to 18 ft covering the waters north of 17N and between 35W and 65W through Mon, primarily in N swell. In addition, expect fresh to strong winds and rough seas with large swell of 8 to 12 ft north of 15N between 20W and 55W Tue into Wed as the low lifts to the northeast of the area. The large swell may create hazardous rip current conditions for Puerto Rico and other areas in the northern Leeward Islands. Refer to local weather advisories for more information. For more details on the marine conditions, 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 remains inland over Africa. The ITCZ begins near 06N11W and runs west-southwestward to near 00N47W. Scattered moderate to isolated strong convection is occurring from the Equator to 06N between 29W and 44W. ...GULF OF MEXICO... Scattered showers and thunderstorms are occurring off the coast of Tampa Bay as the remnants of a squall line weaken. Scattered showers and thunderstorms are also noted through the Florida Straits, resulting from upper-level dynamic forcing. At 1800 UTC, a cold front spanned from 30N85W in the panhandle of Florida to 22N95W in the southwestern Gulf. Behind this front, high pressure is building over the south-central United States. Gentle to moderate N to NW winds and slight seas prevail over much of the basin. For the forecast, the aforementioned cold front will move E into the SE Gulf of Mexico tonight, then weaken and dissipate Mon, with thunderstorms ending. Another cold front will move into the NW Gulf Mon night, then move slowly SE and exit the basin Wed night. Fresh N to NW winds and building seas will follow the front, with locally strong winds possible in the far southwest Gulf along the coast of Mexico. ...CARIBBEAN SEA... Scattered strong convection continues over the northwestern Caribbean, from 17N to 21N between 81W and 85W, resulting from upper-level divergence and convergent surface winds. Scattered moderate convection is also occurring in the far SW Caribbean, near the eastern extension of the East Pacific monsoon trough. Outside of convection, fresh NE winds are occurring in the central Caribbean downwind of Hispaniola and through the Windward Passage as a strong pressure gradient between high pressure in the western Atlantic and low pressure in the south-central Caribbean prevails. Seas are 6 to 8 ft in this region. Elsewhere, moderate to fresh E to SE winds and 3 to 6 ft seas are noted through the rest of the basin. For the forecast, high pressure centered north of the area will continue to support fresh to locally strong NE winds across the Windward Passage and south of Hispaniola, and moderate to fresh trade winds across the central Caribbean into early Mon before diminishing. Winds may increase across the central Caribbean by midweek as high pressure builds again north of the area. ...ATLANTIC OCEAN... Please see the Special Features section for details about the significant swell event in the central Atlantic. The two main features over the northwest Atlantic are the 999 mb low pressure near 29N47W, and 1025 mb high pressure centered to the northwest of the low pressure near 36N67W. The pressure gradient between these features is supporting the strong to near- gale force winds and rough to very rough seas described in the Special Features section, encompassing the area north of 20N between 30W and 65W. Fresh to strong SE winds and seas of 6 to 8 ft are evident off the coast of Florida, driven by the pressure gradient between the aforementioned 1025 mb high and a cold front moving through the southeastern United States. Moderate NE to E winds and seas of 6 to 8 ft are noted elsewhere west of 70W within the ridge axis. Gentle to moderate breezes and 4 to 6 ft seas in N swell are noted over the tropical Atlantic south of 20N and west of 35W. Moderate to fresh NE winds and 4 to 6 ft seas are noted east of 35W. Forecast for west of 55W, strong N winds and very rough seas will continue for NE waters, N of 21N and E of 65W, through tonight, as a low pressure E of the area slowly moves NE. Elsewhere E of 70W, associated large swell will prevail through Mon. Strong S winds will prevail offshore FL and N of The Bahamas until a cold front moves off the Florida coast Mon morning. Ahead of this front, some thunderstorms are possible offshore NE Florida. Strong S winds will redevelop Tue, ahead of another cold front that will move offshore Tue night. This front will reach a line from E of Bermuda to central Cuba by Thu morning. $$ ADAMS