000 AXNT20 KNHC 111055 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...SPECIAL FEATURES... Central Atlantic Gale Warning: A stationary front extends from 31N35W to 18N55W. A new low-pressure center has formed well behind the front near 37N44W. This has reinforced the pressure gradient to its south, with earlier scatterometer data confirming westerly winds have reached near gale to gale force north of 27.5N, between 49W and 55W. These winds will shift eastward tonight before lifting north of the area late Sat morning. Seas are currently peaking near 18 ft. Associated seas of 12 ft and higher are currently observed between 26W and 66W, reaching as far south as 22N. The swell from this event will gradually abate through the weekend, with seas subsiding be 12 ft Sun morning. SW Atlantic Gale Warning: A cold front has entered the SE US coastal waters tonight, and extends SW across northern Florida. This front will move eastward over the next few days. Gale force winds have developed to the N of 30N ahead of the frontal boundary early this morning, and will shift eastward ahead of the front through Sun, and will be confined mainly north of 27N. Seas will quickly build to 12-14 ft today ahead of the front. Westerly gales will develop behind the front Sat night, mainly N of 30N, and generate seas to near 23 ft by late Sun. Seas greater than 12 ft will remain north of 27N with this event. Winds and seas will abate early next week as the frontal system racing quickly eastward of the area. 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 24W then continues to coastal Brazil near 03S43W. Scattered moderate to strong convection is noted from 01S to 06N between 10W and 21W. Scattered moderate isolated strong convection is observed from 05S to 02N between 21W and 33W. GULF OF MEXICO... A weak frontal boundary extends from the Florida Big Bend to the mouth of the Mississippi River then runs along the coast of Louisiana to SE Texas, where it has become stationary. Scattered convection observed earlier tonight near the front in the far NE Gulf has shifted eastward into the Atlantic. Otherwise, high pressure ridging from the Bahamas to the north central Gulf dominates the pattern. Gentle to moderate winds and slight seas prevail across the basin. For the forecast, the cold front will weaken quickly today as the eastern portion moves southward across Florida and the adjacent Gulf. Another cold front is forecast to approach the northern Gulf late Sat night and 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, then is expected to weaken across the SE Gulf Wed as it exits the basin. In response, fresh to strong NE winds are expected N of the front Mon through Tue night. CARIBBEAN SEA... A weak shearline has become ill defined across the southeast Caribbean overnight, where scattered showers are noted south of 13N and east of 63W. from 16N61W to 15N70W. Elsewhere fair weather and small areas of low clouds and weak showers are noted across the basin. NE winds are fresh in the Windward Passage, Mona Passage, in the lee of the Dominican Republic. NE winds are strong offshore Colombia. Otherwise winds are gentle to moderate across the basin, as weak high pressure resides N of Puerto Rico along 26N. N-NE Atlantic swell to 8 ft is propagating through the Mona and Anegada Passages. Seas are 4-6 ft offshore Colombia. Otherwise, seas are in the 3-5 ft range across the basin. For the forecast, the weak high pressure N of Puerto Rico will shift quickly E through Sun night as a frontal system moves ESE across the western Atlantic. Large northerly swell impacting the regional Atlantic waters, including passages of the NE Caribbean, will gradually subside through Mon. Trade winds off the coast of Colombia will pulse to strong at night through Sun night. Fresh to strong ESE winds are expected across the the Gulf of Honduras late tonight through Tue morning. Moderate to fresh trade winds will return to much of the basin Mon night. Looking ahead, a cold front is forecast to enter the northwestern basin early Wed, which will bring fresh to strong NE winds and rising seas. ATLANTIC OCEAN... Please read the Special Features section for details on two separate gale force wind warnings and associated high seas across the Atlantic forecast waters this week. Scattered moderate isolated strong convection is noted across the NW waters along and ahead of the cold front, covering the area from 27.5N to 31N between 71W and 79W. This active weather is expected to shift eastward with the front today. A stationary front extends from 31N35W to 18N54W. Scattered moderate convection is observed ahead of the frontal boundary, north of 27.5N and west of 32W. S-SW winds are fresh to strong in this area. A large area of fresh and stronger winds are also noted behind the front from 40W to 60W, north of 24N. A combination of wind driven waves and a northerly swell are causing rough seas in excess of 8 ft to cover the majority of the subtropical Atlantic east of the Bahamas and north of 15N. The only exception is in the eastern Atlantic east of a line from 31N19W to 11N49W, where seas are in the 6-8 ft range. For the forecast W of 55W, the weak high pressure centered E of the Bahamas will slide eastward today through Sun as the cold front across the far NW waters and N Florida moves quickly E-SE. The front will reach from near Bermuda through the NW Bahamas to near Miami this evening, then from 28N55W to central Cuba Sun evening before dissipating. Strong to gale-force SW to W winds are expected N of 25N and ahead of the front through Sun night, while strong to gale-force NW winds prevail W of the front. Moderate to large N to NE swell currently dominating the regional waters will gradually subside through 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. Another frontal system 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. $$ Stripling