000 AXNT20 KNHC 170536 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Fri Dec 17 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 0500 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic from the coast of Guinea near 12N34W then transitions to the ITCZ and continues from 12N34W to 04N26W to 04N40W. Scattered moderate convection is from 03N to 08N between the coast of Africa and 18W. Isolated showers are noted from 01N to 05N between 27W to 36W. GULF OF MEXICO... A broad surface trough extends from the NE Gulf of Mexico near 29N86W to the Yucatan Peninsula. Isolated showers are within 30 nm of the trough axis north of 25N. Moderate E winds dominate the Gulf basin, except locally fresh winds within the Florida Straits and off the southern Texas coast. Seas are 3 to 5 ft across the basin. For the forecast, high pressure will prevail across the northern forecast waters through Sat, supporting moderate to locally fresh winds. A cold front is forecast to enter the basin Sat night into early Sun. Fresh to strong winds and building seas will prevail west of the front. CARIBBEAN SEA... An area of scattered moderate and isolated strong convection is observed on satellite imagery from 09N to around 17N between 79W and 85W, including over portions of eastern Honduras and Nicaragua where heavy rainfall is likely falling. The pressure gradient between high pressure centered over the western Atlantic and lower pressure over Colombia is supporting fresh to strong trade winds over the central Caribbean, including the Windward Passage. Moderate to fresh winds prevail elsewhere. Seas are in the 6 to 9 ft over the central Caribbean, 6 to 8 ft over the eastern Caribbean, and 4 to 6 ft over the western Caribbean. For the forecast, strong high pressure will prevail over the western Atlantic through the forecast period. This will support fresh to strong trade winds over the central Caribbean into nearly next week. Moderate to fresh trades are expected elsewhere. ATLANTIC OCEAN... A surface trough is analyzed from 31N31W to 23N38W, which lies to the east of a cold front that extends from 31N32W to 25N40W to 23N53W, then continues as a stationary front to 23N61W. High pressure of 1031 mb is building in the wake of the aforementioned front, creating a strong pressure gradient between lower pressure over Colombia. A satellite scatterometer pass reveals the pressure gradient is supporting strong winds from 20N to 25N between 55W and 65W. Fresh to strong winds are elsewhere south of 31N between 40W and 70W, except in the western Atlantic west of 70W where winds are gentle to moderate. Gentle to moderate winds are also noted in the far eastern Atlantic, east of the surface trough. Gales north of the area have generated a large northerly swell which has propagated into the northern waters. The swell is producing seas of 12 ft or greater north of 24N and behind the front to around 70W, and are currently peaking near 19 ft over the discussion waters along 31N between 40W and 46W. West of 70W, seas range from 5 to 8 ft For the forecast, high pressure north of the area is supporting moderate to fresh winds over the forecast waters. The area of high pressure will build southward, bringing an increase in winds and seas. $$ Mora