000 AXNT20 KNHC 210552 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Tue Dec 21 2021 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...SPECIAL FEATURES... ...GULF OF MEXICO GALE-FORCE WIND WARNING... A cold front extends from a 1009 mb low pressure center that is near 25N89W, to 21N90W. Expect N gale-force winds, and sea heights ranging from 9 feet to 11 feet, from 19N to 27N between 88W and 96W. The gale-force winds are forecast to last for the next 18 hours or so. Please, refer to the latest High Seas Forecast, issued by the National Hurricane Center, at the following website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, for more details. ...ATLANTIC OCEAN GALE-FORCE WIND WARNING... The forecast, in 24 hours, consists of: a cold front will be along 31N76W 25N81W. Expect gale-force W winds, and sea heights ranging from 10 feet to 12 feet, from 29N to 31N between 76W and 78W. Please, refer to the latest High Seas Forecast, issued by the National Hurricane Center, at the following website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the Prime Meridian at 02N, to 02N02W. The ITCZ continues from 02N02W, to 01N05W, 05N09W, 04N20W, 02N24W, to 01N47W. Precipitation: from 03N to 14N between 13W and 27W, and within 270 nm to the north of the ITCZ between 35W and 41W. ...GULF OF MEXICO... Please, read the SPECIAL FEATURES section, for information about the current frontal boundaries and the associated gale-force winds. A 1009 mb low pressure center is near 25N89W. A warm front extends from the 1009 mb low pressure center, to south Florida, to just to the south of Lake Okeechobee, beyond the NW Bahamas. A cold front extends from the 1009 mb low pressure center, to the western sections of the Yucatan Peninsula and NW Guatemala. Precipitation: scattered moderate to widely scattered strong is within 60 nm on either side of the line that stretches from the northern parts of Belize, to the Yucatan Channel, to 26N84W, to 27N86W. Broken to overcast multilayered clouds, and other rainshowers, cover the Gulf of Mexico from 88W eastward. A 1009 mb extratropical low in the central Gulf is accompanied by gales. This low will strengthen as it moves NE and into Florida on Tue, with gales continuing along its path, mainly within about 120 nm from the center in the NW semicircle. Showers and thunderstorms will also accompany the low pressure as well as the trailing cold front that will cross out of the basin by Tue night. Strong to near gale force NW winds will occur behind the front, but diminish Wed as high pressure builds in. On Fri and Sat, S return flow in the W Gulf will reach fresh to locally strong. ...CARIBBEAN SEA... Isolated moderate rainshowers are in the SW corner of the Caribbean Sea, from 14N southward from 72W westward. The precipitation is within 240 nm to the north of the eastern Pacific Ocean monsoon trough, that is reaching northern sections of Colombia. Isolated to scattered passing rainshowers are in patches of low level moisture, that are embedded in the trade wind flow, throughout the remainder of the Caribbean Sea. The trade winds have diminished, as the Atlantic Ocean high pressure moves eastward. Gentle to moderate wind speeds cover most of the basin, with mainly light winds in the lee of Cuba. Moderate to fresh trades will prevail over the central and eastern basin into midweek, with light to gentle winds in the northwest. Locally strong winds will pulse offshore Colombia tonight. A cold front will cross the Yucatan Channel Tue, then gradually stall from eastern Cuba to the coast of Nicaragua for the latter half of the week. Fresh N winds can be expected behind the front. For tropical Atlantic waters E of the Lesser Antilles, fresh to strong trades and large N to NE swell will prevail through Tue. ...ATLANTIC OCEAN... Please, read the SPECIAL FEATURES section, for information about the situation for forecast gale-force winds. The current Gulf of Mexico 1009 mb low pressure center is forecast to move northeastward, across Florida, and into the Atlantic Ocean off the coast of Florida. A cold front passes through 31N60W, to 28N70W, and to 27N74W. The front continues as a warm front, westward, beyond south Florida just to the south of Lake Okeechobee, and into the Gulf of Mexico, to the 25N89W 1009 mb low pressure center. Precipitation: broken to overcast multilayered clouds, and isolated moderate rainshowers, are from 27N northward between 40W and 80W. A 1020 mb high pressure center is near 25N52W. A surface ridge is along 24N/25N between 40W and the 1020 mb high pressure center, and along 23N/25N between the 1020 mb high pressure center and 70W. Precipitation: broken to overcast multilayered clouds, and isolated moderate rainshowers, are from 26N northward from 30W eastward. The clouds and precipitation are related to two frontal boundaries that are from 31N northward from 24W eastward. Fresh NE winds are to the N of 27N and to the W of the front. Fresh SW winds are N of 30N and SE of the front between 55W and 70W. The sea heights range from 8 feet to 12 feet almost everywhere from 50W eastward. The sea heights range from 8 feet to 9 feet from the frontal boundary northward from 70W westward. The sea heights range from 3 feet to 5 feet in the remainder of the Atlantic Ocean. A cold front extends from east of Bermuda to 27N73W. The front becomes warm, and it continues to South Florida. The cold front will stall and the warm front will continue northward as low pressure cross the NE Gulf and Florida into Tue. This low will then move NE to the north of the area Tue night into Wed, with gale force winds developing on both sides of it for areas N of 27N and W of 70W. A trailing cold front will cross the region Wed through Thu. Building high pressure behind the low should lead toward tranquil conditions Thu night and Fri. $$ mt/sk