000 AXNT20 KNHC 271728 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Fri Dec 27 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 1715 UTC. ...SPECIAL FEATURES... Central Atlantic Gale Warning and Significant Swell Event: A cold front is analyzed from near 31N55W to 26N65W, where it becomes a dissipating cold front to 26N70W. The front will quickly move eastward and catch up with a 1015 mb low pressure that is near 28N52W. The cold front will then extend from this low to 25N50W and to near 20N65W. The low pressure will be invigorated resulting in it deepening resulting in an expanding northerly near gale to gale-force winds roughly north of 26N and between 53W and 57W, with seas of 10 to 15 ft. Elsewhere, north of 23N west of the front to near 65W fresh to strong northerly winds can be expected at that time along with seas of 8 to 12 ft. The low pressure is forecast to transition to an occluded system and lift northeastward into the north-central Atlantic Sun through Tue. Fresh to strong winds along with large swell generated from the event and producing seas of 12 or 13 ft will continue over the waters north of 20N between 25W and 55W into the middle part of next week. 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 axis extends from the coastal plains border of Ghana and Ivory Coast to 04N15W, where it transitions to the ITCZ and continues to 05N20W and to near 05N45W. Scattered moderate convection is seen within 60 nm north of the ITCZ between 24W and 25W, within 60 nm of the ITCZ between 26W and 28W and within 30 nm north of the ITCZ between 30W and 35W. The eastern Pacific monsoon trough extends across the far southwest Caribbean from the Panama/Costa Rica border to the central coast of Colombia. Scattered moderate to isolated strong convection is active along the monsoon trough. ...GULF OF MEXICO... A relatively weak pressure is over the basin as a weak and broad ridge stretches southwestward from the eastern United States to the eastern Gulf. Meanwhile, a cold front has recently become stationary in the western Gulf within about 40 to 60 nm offshore the Texas coast. Weakening scattered showers and thunderstorms are near the southwestern coast of Louisiana. Latest buoy observations and latest altimeter satellite data passes indicate seas of 4 to 6 ft north of about 27N, except for higher seas of 5 to 7 ft north of 28N between 86W and 88W. Lower seas of 3 to 4 ft are south of 27N, except for seas of 2 to 3 ft south of 22N. Moderate to fresh southeast winds are over the NE Gulf while gentle to moderate southeast to south winds are over the rest of the Gulf, except for gentle south to southwest that over the NW Gulf. Satellite imagery shows scattered showers and isolated thunderstorms confined to the Straits of Florida, also over far western Cuba and over the Yucatan Channel east of 86W. For the forecast, the 5 to 7 ft seas will subside to 4 to 5 ft by early this evening. Fresh east to southeast winds will develop over the Straits of Florida this evening, with moderate to locally fresh southeast winds expanding over the eastern Gulf by early Sat as the aforementioned high moves eastward. Elsewhere, moderate to locally fresh southeast winds will develop across the western Gulf Sat morning ahead of a weakening cold front moving through the south-central United States. The front will enter the northwest Gulf Sat night and weaken as it moves southeastward this weekend before dissipating over the central Gulf early next week. Looking ahead, another cold front will enter the basin next Tue and move into the central Gulf through Tue night. ...CARIBBEAN SEA... The pressure gradient between high pressure over the western Atlantic and relatively lower pressure to its south is allowing for generally fresh trades to exist between 70W and 81W, including the Windward Passage and over waters off Colombia. Latest ASCAT satellite data passes depict gentle to moderate trades elsewhere. Seas are in the range of 4 to 6 ft in the central Caribbean, and 2 to 4 ft elsewhere. Scattered showers and thunderstorms are confined to south of the western tip of Cuba to near 20N and between 83W and 86W. This activity is part of an extensive plume of deep tropical moisture that is streaming north-northeastward from the eastern Pacific to over the western Caribbean. The eastern Pacific monsoon trough extends across the far southwestern Caribbean from the Panama/Costa Rica border to the central coast of Colombia. Latest satellite imagery shows scattered moderate to isolated strong convection along and near the trough. For the forecast, moderate to locally fresh trade winds will prevail across central and eastern portions of the basin this weekend. The strengthening pressure gradient between a building ridge in the western Atlantic, strengthening low pressure in the central Atlantic and low pressure in the south-central Caribbean will promote locally strong northeast winds through the Windward Passage and south of Hispaniola tonight through Sun morning. These winds will diminish early next week. Looking ahead, building high pressure north of the area will support increasing winds and seas across the basin by the middle of next week. ...ATLANTIC OCEAN... Please see the Special Features section for details about an upcoming gale event that is forecast to begin on Sat afternoon. A central Atlantic cold front stretches into the forecast area near 31N54W, and continues southwestward to 28N59W and to 27N64W and weakening to 26N70W. Fresh to strong north winds are northwest of the front between 60W and 67W, except for near gale north winds north of 28N between 61W and 62W. Seas with these winds are 8 to 10 ft. Mostly moderate northeast winds with seas of 4 to 6 ft are south of the front west of 66W. Gentle northeast to east winds are elsewhere south of the front, with seas of 4 to 6 ft in northeast to east swell. Patches of moderate rain with embedded scattered showers and isolated thunderstorms are noted north of 28N between 53W and 58W. Scattered showers and isolated thunderstorms are along and just south of 31N between 50W and 52W. To the east of the front, a recent ASCAT satellite data pass revealed low pressure near 28N52W. The low was analyzed with a pressure of 1015 mb. A trough extends north from the low to 32N52W and south-southeast from the low to near 25N49W. To the east of this feature, a stationary front is analyzed from near 31N38W to 26N44W and to 23N47W, where it begins to weaken to near 19N56W. A trough is analyzed along 50W from 10N to 19N. No significant weather is occurring with this feature. Broad high pressure riding stretches from a strong 1032 mb that is west of Portugal south-southwestward into the eastern part of the area. The related pressure gradient is supporting gentle to moderate winds west of 35W. Seas of 4 to 6 ft in north to northeast swell are over these waters. To the east of 35W, weak low pressure of 1018 mb is located near the Canary Islands. Gentle to moderate east to southeast winds are northeast and east of the low pressure as indicated in the latest ASCAT satellite data pass over that part of the area. Seas east of 35W are 4 to 6 ft, except for a pocket of 5 to 7 ft from 07N to 10N between 29N and 32W. For the forecast west of 55W, a 1015 mb low pressure centered near 28N53W will strengthen and move eastward through this weekend. A wide swath of fresh to strong northwest to north winds will occur surrounding the low, with these winds occurring north of 25N between 55W and 68W by this evening, and north of 21N between 55W and 65W by Sat morning. Gale-force winds are expected Sat afternoon into very early on Sun north of about 27N and near 55W. Rough seas will accompany this system, and seas in excess of 12 ft will occur near the strong winds. These winds and seas will shift east of 55W through late Mon as the low pressure drifts eastward. Elsewhere, moderate to locally fresh northeast to east winds will continue to the north of the Greater Antilles and west of the low pressure system this weekend, along the periphery of high pressure moving off the coast of the United States. Looking ahead, expect increasing southeast to south winds and building seas off northeast Florida on Sun ahead of cold front approaching the region over the southeast United States. $$ Aguirre