000 AXNT20 KNHC 182106 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Mar 19 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2050 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: High pressure building southward behind a cold front making its way across the Gulf of Mexico is supporting minimal gale-force winds along the coast of Mexico with NW winds at 30-35 kt. Winds are forecast to diminish below gale force this evening, then remain NW-N at 20-30 kt until around midnight. Seas around currently peaking around 9-11 ft. Please read the latest NWS High Seas Forecast from the National Hurricane Center at the website: www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Sierra Leone near 09N13W to 02N33W. The ITCZ continues from 02N33W to 00N40W to the coast of Brazil near 02S46W. Scattered moderate and isolated strong convection is noted offshore of Sierra Leone and Liberia to the equator between 07W-14W. Scattered moderate convection is noted from 00N-02N between 30W-36W, and from 01N-03N between 44W-50W. GULF OF MEXICO... Please see the Special Features above for more details on the Gulf of Mexico Gale Warning. A cold front extends from the eastern Florida Panhandle across Apalachee Bay to across the central Gulf of Mexico to the central Bay of Campeche. A line of scattered thunderstorms, some severe with frequent lightning, is along and ahead of the front, mainly north of 26N. Scattered showers are noted elsewhere near the front. Fresh to strong NW winds follow elsewhere behind the front along with seas of 6-9 ft. Southerly flow of moderate to fresh are ahead of the front north of 25N, with gentle to moderate southerly winds south of 25N. A weak surface trough is analyzed along the western Yucatan Peninsula from 23N88W to 18N91W. The cold front will continue moving southeast and reach from southern Florida to the Yucatan peninsula Fri morning, then move southeast of the basin by Fri evening. Fresh to strong N-NE winds and building seas are expected in the northeast Gulf of Mexico Sat night through Sun night as the pressure gradient tightens there. Southerly return flow will then dominate across the basin early next week, fresh to locally strong in the central and western portions of the basin. CARIBBEAN SEA... A dissipating cold front is analyzed across the northeast Caribbean Sea extending from near Montserrat to south of Puerto Rico and the Dominican Republic terminating near 15N69W. Scattered showers are are noted along the dissipating front and within 45-90 nm south of the front. Earlier scatterometer data indicated a surface trough in the southwestern part of the Caribbean Sea. The trough extends from near the Panama Canal to the southeast coast of Nicaragua to across inland portions to eastern Honduras near 15N85W. This trough is enhancing scattered moderate and isolated strong convection within 60-120 nm on either side of the feature. Fresh to strong trades are noted in the south-central Caribbean where the pressure gradient is tight between low pressure over northern Colombia and Atlantic high pressure northeast of the area. Seas are 7-11 ft across the south-central Caribbean. Mainly moderate to fresh easterly winds prevail elsewhere, along with 4-7 ft seas, locally to 8 ft. The front in the northeast Caribbean will drift southward and continue to weaken through tonight. Large northerly swell will subside across Tropical N Atlantic waters and Caribbean Passages through Fri. Fresh to strong trade winds will prevail in the central Caribbean through Fri morning, with near gale-force winds expected near the coast of Colombia tonight. A cold front from the northeast Gulf of Mexico to the Bay of Campeche will reach the Yucatan Channel Fri afternoon, western Cuba to Belize Sat, then meander across the NW Caribbean through Sun. Fairly tranquil marine conditions are forecast early next week as the front dissipates while weakening the pressure gradient across the basin. ATLANTIC OCEAN... A stationary front is analyzed from 31N35W to near Montserrat and continuing into the northeast Caribbean Sea. Broken to overcast multi-layered clouds, and isolated to scattered showers are within 60-120 nm on either side of the frontal boundary. Broad surface anticyclonic wind flow, associated with high pressure north of 32N, covers the Atlantic Ocean north and northwest of the cold front. Remnant northerly swell of 7-11 dominates the waters east of 65W. A 1017 mb low pressure center is just east of Bermuda near 32N63W. A stationary front trails from the low center to 31N70W, then continues northwest as a warm front to the North Carolina Outer Banks. Isolated to scattered showers are possible north of 28N between 55W-75W. Moderate to fresh southerly winds are noted within 60-90 nm south of the boundary and south of 31N. Scattered showers and thunderstorms ahead of a cold front moving through the southeast United States are moving into the waters east of northern Florida. Fresh to strong southerly flow is noted ahead of the front north of 27N and west of 75W. Seas are building in this area of increasing winds, currently 5-8 ft, with 4-7 ft seas elsewhere west of 65W to the Bahamas. The stationary front across the central Atlantic will meander and weaken through Fri. The remnant northerly swell east of 65W will subside through Fri. A cold front will move east of northern Florida tonight, extend from near 31N70W to the Straits of Florida Fri evening, then become stationary on Sat. An area of low pressure forming along the stationary front will intensify northerly winds east of northern Florida Sat through Mon, with gale conditions possible. Conditions should then gradually improve Mon night through Tue night as the low pulls away from the area to the north-northeast. $$ Lewitsky