767 AXNT20 KNHC 071203 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun Jan 7 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 0600 UTC surface analysis and satellite imagery through 1140 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: A cold front extends from Ft. Myers, FL to 25N85W, where it becomes a stationary front to the SW Bay of Campeche. The front will move northward across the basin as a warm front tonight through early Mon, accompanied by scattered showers and thunderstorms, as southeasterly winds increase to strong to near gale force across much of the basin. A very strong cold front will enter the western Gulf of Mexico early Mon evening, reach from Pensacola, FL to Veracruz, Mexico early Tue and from near Ft. Myers, FL to Cancun, Mexico Tue evening. Gale force winds are expected to begin by late Mon morning over the north-central Gulf, with gusts reaching strong gale force speeds. Near-gale force winds are expected for most of the Gulf of Mexico on both sides of the front Mon through Tue, with several areas experiencing sustained gale force winds. Aided by favorable upper- level jet stream dynamics, a squall line containing severe thunderstorms with very strong gusts is expected to occur over the northern Gulf of Mexico just prior to the frontal passage. Seas of 12 to 18 ft are expected with these winds over the northern half of the Gulf of Mexico Mon through Tue night. Winds will diminish by early Wed morning. Caribbean Sea Gale Warning: Broad ridging will build in to the north of the Caribbean today. The gradient between the ridge and lower pressures over Colombia will lead to gale-force NE to E winds tonight within 90 nm of the coast of Colombia. Seas will peak around 12 ft with the strongest winds. Winds Mon night will peak at near-gale force in the same area. Atlantic Ocean Significant Swell Event: NW to N swell of 12 to 18 ft is occurring north of 27N between 37W and 58W. A 07/0900 UTC altimeter pass shows sea heights of 15 to 18 ft north of 29N between 42W and 45W. Another 07/1000 UTC altimeter pass shows seas of 10 to 13 ft north of 27N between 55W and 58W. This large swell will spread toward the east through today. Seas will decrease below 12 ft south of 30N tonight. The next large and powerful storm system moving from west to east across the mid-latitudes currently extends a cold front from 31N76W to 28N80W. The front will extend from 31N48W to 25N60W to 23N72W by Mon evening, and from near 31N35W to 21N50W to 21N58W Tue evening. Extremely large NW to N swell will traverse the area behind the front Mon afternoon through late this week. From Mon night through Tue night, seas of 18 to 25 ft are forecast north of 24N between 35W and 60W. Seas of 12 to 18 ft can be expected during that time elsewhere north of 20N between 30W and 68W. Please read the latest High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details on the three Special Features discussed above. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Sierra Leone near 08N13W to 06N18W. The ITCZ extends from 06N18W to 06N35W to 00N50W. Scattered moderate convection is observed within 210 nm on both sides of the monsoon trough and ITCZ. ...GULF OF MEXICO... Please refer to the Special Features section above for details on the Gale Warning for the Gulf of Mexico. A cold front extends from Ft. Myers, Florida to 23N89W, then transitions to a stationary front to near Veracruz, Mexico. Scattered moderate convection is noted near and just SE of the front from 22.5N to 26N between 82.5W and 88W. Fresh to locally strong N winds are likely occurring within 120 nm NW of the front, with seas 5 to 6 ft. Similar conditions are in the NE Gulf. A 1020 mb surface high pressure is analyzed near 27.5N95W. Gentle winds and 2 to 3 ft seas are in the NW Gulf, due to the high pressure. Cloudiness with possible showers are occurring over portions of the west-central and NW Gulf. For the forecast, the front will become stationary early this evening from the Straits of Florida to 20N95W. The front will then move northward across the basin as a warm front tonight through early Mon, accompanied by scattered showers and thunderstorms, as southeasterly winds increase to strong to near gale force across much of the basin. A very strong cold front will enter the western Gulf of Mexico early Mon evening, reach from Pensacola, FL to Veracruz, Mexico early Tue, from near Ft. Myers, FL to Cancun, Mexico Tue evening, and move southeast of the basin late Tue night. Gale force winds are expected to begin by late Mon morning over the north-central Gulf, with gusts reaching strong gale force speeds. Near-gale force winds are expected for most of the Gulf of Mexico on both sides of the front, Mon through Tue, with several areas experiencing sustained gale force winds. A squall line containing severe thunderstorms is likely to occur over the northern Gulf of Mexico just prior to the frontal passage. Conditions quiet down Wed through Thu as high pressure shifts E across the central Gulf in the wake of the front. ...CARIBBEAN SEA... Please refer to the Special Features section above for details on the Gale Warning offshore Colombia. Strong mid-level anticyclonic flow over the Caribbean Sea is leading to subsidence and dry air. Strong ENE to E trades cover the south-central Caribbean Sea south of 15N between 71W and 78W, where seas are 8-10 ft. Moderate to fresh trades are elsewhere south of 18N and east of 81W, with 4 to 7 ft seas. In the Gulf of Honduras, fresh SE winds and seas to 5 ft are occurring. Elsewhere north of 18N and west of 81W, winds are moderate or weaker with 3 to 4 ft seas. For the forecast, the pressure gradient between high pressure centered north of the basin and lower pressure over South America will support strong winds in the south-central Caribbean through Tue night, pulsing to near-gale force at night offshore Colombia. Winds near the coast of Colombia will reach gale force tonight. SE to S winds in the northwestern Caribbean are expected to increase to fresh to strong late Mon through Tue as a strong cold front traverses the Gulf of Mexico. The front will weaken significantly as it reaches the Yucatan Channel Tue night, and winds in the NW Caribbean will diminish Wed and Wed night as high pressure shifts eastward across the central Gulf of Mexico. In the central Caribbean, winds will diminish to mainly fresh speeds by mid week. ...ATLANTIC OCEAN... Please refer to the Special Features section for details about the significant swell in the Atlantic. A cold front extends from 31N76W to Melbourne, FL. The pressure gradient between 1024 mb high pressure positioned near 30N58W and the cold front support fresh to strong winds north of 28N and west of 63W. Seas in these waters are 7-10 ft. Farther east, a cold front extends from 31N30W to 24N43W, where it becomes a stationary front that continues west-southwestward to 22N65W. Scattered moderate convection is found ahead of the front, mainly north of 24N between the front and 21W. Moderate to fresh winds are within 150 nm NW of the front. North of that, high pressure ridging extends eastward from the aforementioned 1024 mb high pressure. A narrow surface ridge is also south of the front, extending from 1019 mb high pressure near 24N31W west- southwestward to near 20.5N60W. Large swell occurring over this portion of the Atlantic is discussed above in the Special Features section. Farther south in the deep tropics, fresh NE to ENE trades and 6 to 8 ft seas prevail from 06N to 18N between 35W and 60W. For the forecast W of 55W, the cold front extending from 31N76W to Melbourne, Florida will continue to produce fresh to strong winds on both sides of it north of 27N as it moves eastward. The front will reach from near 31N68W to the Straits of Florida this evening, from near 27N55W to 23N72W and stationary to 24N80W Mon evening, and weakening as a stationary front Tue evening from near 21N55W to 23N71W. SE winds will increase to strong to near gale force west of 70W Mon night, then increase to gale force Tue through Tue night north of 28N and west of 70W as a cold front approaches from the west. The cold front will move off NE Florida early Tue evening. By Wed evening, the front will be weakening as it reaches from near 31N68W to Eleuthera Island, Bahamas, but very rough seas will continue Wed night east of Florida and northeast of the Bahamas. A squall line containing strong to severe thunderstorms may occur just prior to the frontal passage late Tue into early Wed. Seas will subside Thu and Thu night as high pressure builds over the western Atlantic. $$ Hagen