000 AXNT20 KNHC 152320 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Thu Feb 16 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... Caribbean Sea Gale Warning: The induced pressure gradient due to the combination of a 1028 mb high center that is north of the area, with comparatively lower pressure in the south-central Caribbean Sea and in Colombia is expected to support fresh to strong NE to E trade winds along with seas of 8-11 ft. The pressure gradient will tighten just enough at night through the weekend allowing for these winds to pulse to gale-force. As this happens, seas with these winds are expected to build slightly higher to about 10-13 ft. Please read the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. Gulf of Mexico Gale Warning: A strong cold front will emerge off Texas coast Thu morning. Strong to near gale force N winds can be expected behind the front in the western and central Gulf Thu into early Sat. Gales will develop offshore Tampico, Mexico, Thu evening, spreading S to off the coast of Veracruz, Mexico, overnight Thu. The gales in the western Bay of Campeche will persist into Fri night. Seas in this area will build to near 16 ft by Fri afternoon. Conditions will improve Sat into Sun. Please read the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coastal plains of Sierra Leone near 08N13W southwestward to 05N17W. The ITCZ continues to below the Equator near 25W. Scattered moderate convection is from the equator to 03N between 13W-22W. ...GULF OF MEXICO... A Gale Warning is in effect for portions of the offshore waters of Mexico. Please, see the Special Features section above for details. A ridge dominates the Gulf waters anchored by a 1028 mb high located W of Bermuda near 32N67W. The pressure gradient between the ridge and low pressure across the Southern Plains is maintaining moderate to fresh southeast winds over the basin. Seas are generally in the range of 4-6 ft, except for slightly higher seas of 5-7 ft in most areas of the western Gulf. Seas are 3-5 ft in the southeastern Gulf. Scattered small-type low clouds, moving northward with to the moderate to fresh southerly wind flow, are noted over parts of the Gulf. For the forecast, the Atlantic subtropical ridge will gradually shift eastward over the next few days. Fresh to strong winds will continue in the Gulf of Mexico in advance of the next cold front, which will emerge off Texas Thu morning. Gales will develop offshore Tampico, Mexico, spreading S to off the coast of Veracruz, Mexico. Please, see the Special Features section for more details. ...CARIBBEAN SEA... Please read the Special Features section above for details on a Gale Warning that is in effect for the coastal waters offshore Colombia. Ample subsidence aloft throughout the basin and associated dry sinking air is inhibiting convection from forming. Only isolated showers moving westward in the trade wind flow are noted across the basin. The weather pattern is dominated by the Atlantic subtropical ridge. The associated gradient is resulting in generally fresh to strong NE to E trade winds throughout the basin, except in the south-central Caribbean where mainly strong trades prevail and within about 60 nm S of Hispaniola. A recent ASCAT pass revealed strong to near gale-force NE to E trade winds within 75 nm of the coast of northwestern Colombia. Fresh SE winds are in the far western Caribbean Sea, with fresh to strong SE winds in the Gulf of Honduras. Seas are 8-10 ft near the coast of Colombia, and 6-8 ft over the remainder of the central Caribbean. Seas are generally 4-6 ft elsewhere. For the forecast, a persistent subtropical ridge north of the area will sustain fresh to strong easterly trades through the forecast period. Winds will pulse nightly to gale force off the coast of Colombia into early next week. Elsewhere, large NE to E swell with seas to 10 ft is over the tropical N Atlantic. Winds and seas in this region will slowly diminish through tonight. However, a new area of northerly swell will enter the tropical Atlantic Thu, persisting into the weekend. Winds will increase to strong speeds east of the Leeward Islands Thu night into Sat. ...ATLANTIC OCEAN... A cold front stretches from near 31N48W to 23N58W, where satellite imagery indicates that it is dissipating and continues to near 21N73W. Scattered showers with embedded thunderstorms are noted on satellite imagery within about 150 nm SE of the front N of 25N. Isolated showers are possible along the weakening part of the front. Fresh N winds follow the cold front to about 60W based on the most recent scatterometer data. Moderate to fresh NE to E winds are N of the weakening part of the front, while gentle to moderate NE winds are to its S. Seas of 8-12 ft in long period NW swell are in the wake of the front, mainly N of 25N and E 64W. Seas of 6-7 ft are noted elsewhere behind the front. the remainder of the Atlantic forecast area is under the influence of 1033 mb high pressure located over the southern Azores. The pressure gradient between this system and lower pressures in the vicinity of the ITCZ is resulting in a large area of fresh to strong trade winds S of 25N E of 50W. Fresh to strong northerly winds are also observed between the above mentioned high pressure and a 1015 mb low pressure located E of the Madeira Islands near 33N13W. Seas are 8 to 11 ft E of 35W due to mixed NE and NW swell. In the tropical Atlantic S of 20N between 50W and the Lesser Antilles, moderate to fresh trades prevail along with seas of 6-8 ft. Satellite imagery reveals the presence of an extensive plume of Sahara Air Layer (SAL) dust in the far eastern Atlantic east of about 26W. Recent surface observations from along the coast of W Africa are reporting blowing dust and sand. This observation of the SAL is quite early for this time of year. For the forecast W of 55W, the aforementioned frontal boundary will continue moving eastward, exiting the basin tonight. A building ridge north of the area will strengthen the trades south of 25N tonight into Sat, with seas in this zone increasing to 11 ft. A cold front is forecast to enter the Gulf on Thu and will reach the waters off NE Florida late Fri. This will support strong winds ahead and behind the frontal boundary Fri night into Sat as the frontal boundary moves eastward, mainly N of 28N. Also, a low pressure will develop this weekend along the weakening cold front in the eastern waters and the gradient between the low and the ridge will sustain strong NE winds N of 24N and E of 50W. Seas will build to 12 ft by Sat. $$ GR