909 AXNT20 KNHC 191015 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun Nov 19 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... Western Atlantic Gale Warning: A 1003 mb low pressure system is located north of the central Bahamas near 29N73W. Tight gradient between this system and a large 1034 mb North Atlantic High is producing near-gale to gale-force southerly winds north of 27N between 60W and 65W. Seas in this area range from 12 to 15 ft. These conditions are expected to persist today. As the low moves northeastward into the north Atlantic this afternoon and evening, both winds and seas should gradually subside. Please read the latest High Seas Forecast issued by the National Hurricane Center at the website - www.nhc.noaa.gov/text/MIAHSFAT2.shtml and latest Offshore Water Forecast west of 55W at www.nhc.noaa.gov/marine/offshores.php for more details. Significant North Swell in the Central Atlantic: Residual large northerly swell generated by an earlier storm over the north Atlantic will maintain 11 to 12 ft seas north of 23N between 39W and 51W. Fresh mainly E winds are also found in this area. This swell will decay today, which should allow seas to drop below 11 ft. Please read the latest High Seas Forecast issued by the National Hurricane Center at the website - www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic from Senegal and extends southwest to 08N19W. An ITCZ then continues from 08N19W across 06N30W to 04N43W. Scattered moderate convection is seen south of the monsoon trough from 03N to 08N between the Sierra Leone- Liberia coast and along the ITCZ from 03N to 10N between 22W and 38W. The eastern end of the East Pacific monsoon trough is producing scattered moderate convection over the southwestern Caribbean Sea, south of 12N near Panama and northwestern Colombia. ...GULF OF MEXICO... A weak cold front extends from near Clearwater, Florida, to near 25N91W, where it becomes stationary and continues to the mouth of the Rio Grande. A weak surface trough is sinking southward through the northern Bay of Campeche. Convection associated with both features has dissipated overnight. Mainly light winds encompass the central and western Gulf, with gentle NE winds in the east. Seas are generally 1 to 3 ft, except some 4 ft seas are present in and near the Yucatan Channel. For the forecast, the cold front and trough will dissipate today. High pressure will build in its wake, with mainly gentle N winds over the basin today becoming E by tonight. Southerly winds will form Mon and increase to fresh in the western Gulf. The next cold front will move off the Texas coast Mon night, with gales expected to develop over the west-central and SW Gulf Tue through Wed. Seas are forecast to build to 14 to 16 ft over the SW Gulf by Tue night into Wed morning. ...CARIBBEAN SEA... A surface trough from the SW Caribbean Sea to the eastern tip of Cuba is helping to focus numerous moderate to isolated strong convection within about 120 nm E and W of its axis. Locally heavy rainfall is impacting portions of Hispaniola in association with this trough. Elsewhere, a 1009 mb low pressure is centered near 17N91W, with a surface trough extending W from it to the Yucatan coast. Convection associated with these weakening features has diminished overnight. Moderate to fresh SE winds prevail in the eastern Caribbean, with light to gentle winds impacting much of the central and western basin. However, a zone of fresh to locally strong NW winds are present near the coast of eastern Honduras and NE Nicaragua and fresh to locally strong SW winds are occurring offshore Colombia. Seas are 5 to 7 ft where winds are moderate or greater, with 3 to 5 ft seas elsewhere. For the forecast, the pressure gradient between a ridge across the Yucatan Peninsula and northern Central America and a low pressure over the NW Caribbean supports and area of fresh to locally strong NW winds offshore eastern Honduras and NE Nicaragua that will diminish this morning. A surface trough will remain over the central Caribbean into Tue night. A weak low could develop along the trough axis. Ahead of this trough, fresh to locally strong SW winds are expected today offshore Colombia. ...ATLANTIC OCEAN... Please refer to the SPECIAL FEATURES section for details about gales in the western Atlantic and large north swell in the central Atlantic. A broad surface trough extends from Bermuda to the Turks and Caicos Islands to the eastern tip of Cuba. Numerous moderate to isolated strong convection in association with this trough extends from Bermuda to the Antilles between 60W and 70W. Strong to gale force SW winds are occurring E of this trough axis N of 25N, extending E to 60W. To the west, another surface trough extends from a 1003 mb low pressure center near 29N73W to central Cuba. Fresh NE winds are ongoing to the NW of this trough and low, with scattered moderate convection NE of the center of this low, N of 28N between 69W and 73W. Farther E, a cold front extends from 32N26W to 25N34W, where it becomes stationary and continues to 25N48W. Fresh E wind dominate areas N of this boundary, with a corridor of scattered moderate convection within 90 nm SE of the cold frontal portion of the boundary. For the remainder of the waters of the central Atlantic, moderate to fresh trades prevail, with eastern Atlantic waters dominated by mainly gentle NE winds. E of 70W, a very expansive area of northerly swell translates to seas of 8 to 11 ft, with 4 to 7 ft seas over open waters to the W of 70W. For the forecast W of 55W, the low NE of the Bahamas will move N of area today, with the trough evolving into a cold front. As the low moves N of the area, S winds ahead of the front will gradually diminish, but fresh NW to N winds will develop NW of the cold front. $$ Konarik