298 AXNT20 KNHC 291743 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Sun Dec 29 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 Significant Swell Event: A 1000 mb low centered near 27N48W 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 18N and between 40W and 65W through Mon, primarily in northerly swell. In addition, 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. 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 06N10W and runs west-southwestward to near 00N48W. Scattered moderate and isolated strong convection is occurring from the Equator to 08N between 30W and 47W. ...GULF OF MEXICO... A squall line is occurring from the Big Bend Region of Florida to about 28N85W out ahead of a cold front that runs from near Pensacola, Florida to about 23N95W. Numerous moderate convection is occurring along and within 20 nm of this line as it moves eastward. Numerous moderate to strong convection is also occurring due to convergent surface winds in the far SE Gulf near the Florida Keys and northern Florida Straits. Outside of convection, moderate N to NE winds are occurring in the northern and western Gulf behind the cold front, while gentle to moderate SW winds prevail elsewhere. Slight seas also prevail across the basin. For the forecast, scattered thunderstorms, some strong with locally higher winds and seas, are ongoing within about 120 nm of the Florida coast, ahead of a cold front that extends through the central Gulf of Mexico. This 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 Tue, then move slowly SE and exit the basin Wed night. Fresh winds and building seas will follow the front, with locally strong winds likely in the far southwest Gulf along the coast of Mexico. ...CARIBBEAN SEA... A combination of upper-level divergence and convergent surface winds over the NW Caribbean is leading to scattered strong convection from 18N to the south coast of Cuba between 81W and 85W. Scattered moderate convection is also occurring in the far SW Caribbean, along and near the eastern extension of the East Pacific monsoon trough. Outside of convection, fresh to strong NE winds are occurring in the central Caribbean downwind of Hispaniola as a strong pressure gradient between high pressure in the western Atlantic and low pressure of 1011 mb off the Colombian coast 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 over the western Atlantic is supporting fresh to strong NE winds across the Windward Passage and south of Hispaniola, and moderate to fresh trade winds across the central Caribbean. These winds and seas will diminish early this week. Looking ahead, winds and seas may increase across the central Caribbean by mid week as high pressure builds again north of the area. ...ATLANTIC OCEAN... Please see the Special Features section for details about a significant swell event in the central Atlantic. The two main weather features over the northwest Atlantic are the 1000 mb low pressure near 27N48W, and 1028 mb high pressure centered to the northwest of the low pressure near 37N66W. The 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 35W and 70W. Fresh to strong SE winds and seas of 6-8 ft are evident north of Cuba between 75W and the Florida coast, driven by the pressure gradient between the aforementioned 1028 mb high and low pressure over the Mississippi Valley. 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, into tonight, as a low pressure E of the area slowly moves NE. Elsewhere E of 70W, associated large swell will prevail into Mon. Strong S winds will prevail offshore FL and N of The Bahamas until a cold front moves off the Florida coast on Mon. Ahead of this front, some thunderstorms are possible offshore NE Florida today and tonight. Strong southerly 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 western Cuba by Thu morning. $$ Adams