000 AXNT20 KNHC 111742 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Mar 11 2023 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 1700 UTC. ...SPECIAL FEATURES... Central Atlantic Gale Warning: A stationary front extends from 31N33W to 20N45W. A frontal trough continues from 20N45W to the Windward Islands crossing near Barbados and St. Vincent where some showers have been reported. A recent scatterometer pass indicates minimal gale force winds west of the front near 31N45W while fresh to strong winds are noted on either side of the front N of 27N between 30W and 50W. Seas are currently peaking near 16 ft based on altimeter data. Associated seas of 12 ft and higher are currently observed N of 22N and E of 50W. The swell from this event will gradually abate through the weekend, with seas subsiding below 12 ft Sun morning. Winds will be below gale force early this afternoon. SW Atlantic Gale Warning: A cold front enters the forecast waters near 31N73W and continues westward across north-central Florida into the NE Gulf of Mexico. Strong to gale force winds are ahead of the front N of 28N to about 68W based on scatterometer data. Fresh to strong SW winds extend S to about 25N. Numerous showers and thunderstorms are ahead of the front affecting mainly the waters N of 27N between the front and 70W. This active weather is expected to shift eastward with the front the rest of today. The front will move quickly E-SE and reach from Bermuda to near Miami, Florida, this evening, then from 28N55W to just offshore Cuba Sun evening before dissipating. Strong to gale-force SW to W winds are expected N of 26N and ahead of the front into Sun night, while strong to gale-force NW winds prevail W of the front and N of 26N. Moderate to large N to NE swell currently dominating the regional waters will gradually subside into Mon to the S of 25N, while seas remain 10 ft and higher to the N of 25N as the frontal system sweeps across the area. Altimeter data and buoys observations indicate seas of 8 to 12 ft SE of the front and E of the Bahamas, with seas of 9 to 13 ft reaching the Atlantic regional waters of Puerto Rico. Please read the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details on the gale and swell events. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coastal border of Sierra Leone and Liberia near 07N11W to 05N14W. The ITCZ continues from 05N14W to the equator at 30W then continues to coastal Brazil near 00N51W. Scattered moderate to isolated strong convection is noted from 00N to 06N between 15W and 22W. Similar convective activity is noted where the ITCZ meets the coast of Brazil, mainly from 00N to 03N between 48W and 51W. GULF OF MEXICO... A cold front extends from near Tampa Bay, FL to the coast of SE Louisiana near 29N90W where it becomes stationary. A weak 1016 mb high pressure is analyzed S of the front near 25N87W and dominates the remainder of the Gulf waters. A narrow line of clouds with isolated showers is associated with the front. Under this weather pattern, a light to gentle anticyclonic flow prevail, with the exception of gentle N winds behind the front. Seas are generally in the 1 to 3 ft range. For the forecast, the cold front will dissipate this afternoon as it moves southward across Florida and the adjacent Gulf. Another cold front is forecast to approach the northern Gulf Sun, inducing moderate to locally fresh southerly flow across the entire Gulf. This front will enter the northern Gulf Sun evening, then sink gradually southward through Tue night, and exit the basin Wed. In response, fresh to strong NE winds are expected N of the front Mon through Tue night. CARIBBEAN SEA... As previously mentioned, a frontal trough from the Atlantic is crossing near Barbados and St. Vincent where some showers have been reported. Elsewhere, patches of low level moisture embedded in the trade wind flow are noted producing isolated to scattered passing showers, more concentrated over Haiti and just W of Jamaica. Recent satellite derived wind data show fresh to locally strong NE winds offshore Colombia with mainly gentle to moderate trades elsewhere. N-NE Atlantic swell, with seas of 6 to 8 ft, is propagating through the Mona and Anegada Passages. Seas are 4-6 ft offshore Colombia, and in the 3-5 ft range across the remainder of the central and eastern Caribbean. Seas of 1 to 3 ft dominates the NW part of the basin. For the forecast, a series of high pressures will pass N of the area, maintaining a tradewind dominated regime into next week. Large northerly swell impacting the regional Atlantic waters, including passages of the NE Caribbean, will gradually subside into Mon. Winds off the coast of Colombia will likely pulse to strong at night into Sun night. Fresh to strong ESE winds are expected across the the Gulf of Honduras Sun through Mon night. Looking ahead, a cold front is forecast to enter the northwestern basin early Wed, which will bring fresh to locally strong NE winds and rising seas. ATLANTIC OCEAN... A cold front enters the forecast waters near 31N73W and continues westward across north-central Florida into the NE Gulf of Mexico. Gale force winds are ahead of the front over the Atlantic waters. A stationary front extends from 31N33W to 20N45W. Gale force winds are on the W side of the front. Please read the Special Features section for details on these two separate gale force wind warnings and associated high seas across the Atlantic forecast waters. A weak 1017 mb high pressure is NE of the Leeward Islands near 22N55W while a ridge, anchored on a 1027 mb high pressure located NE of the Madeira Islands, dominates the remainder of the Atlantic forecast region. Moderate to fresh N to NE winds are over the Cabo Verde Islands with fresh to locally strong winds between islands. For the forecast W of 55W, a cold front over the far NW waters and N Florida will move quickly E-SE and reach from Bermuda to near Miami, Florida, this evening. Please, see the Special Features section for more details. Another cold front will move across the far NW waters Mon and drag a cold front SE across the area, reaching from 31N58W to eastern Cuba by Wed evening. $$ GR