000 AXNT20 KNHC 172259 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Tue Jul 18 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 2230 UTC. ...SPECIAL FEATURES... Tropical Depression Don is centered near 38.1N 41.6W at 17/2100 UTC or 690 nm W of the Azores moving SE at 12 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate convection is noted along and east of the center from 37N to 42N between 33W and 42W. The 12 ft seas extend 120 nm in the SE quadrant and 30 nm in the SW quadrant with peak seas to 12 ft. Don should turn southward on Tuesday, westward on Wednesday and west-northwestward on Thursday over the open waters of the central Atlantic. Don could become a tropical storm by midweek with additional strengthening possible by late week. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 39W from 17N southward, moving W at 20 kt. Scattered showers are noted along the wave from 08N to 09N between 38W and 41W. Seas near this wave are up to 8 ft. A Caribbean Sea tropical wave is along 69W from 19N southward, moving W at 15-20 kt. Scattered moderate convection is noted across the Dominican Republic, the Mona Passage and portions of western Puerto Rico from 16N to 19N between 66W and 70W. A Caribbean Sea tropical Wave is along 83W from 18N southward to Costa Rica, moving W at 15-20 kt. Scattered moderate to isolated strong convection is noted off the coast of Costa Rica and Nicaragua, S of 16N and W of 79W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends off the coast of Senegal near 14N17W to 10N37W. Scattered moderate to isolated strong convection is along the monsoon trough from 09N to 15N and E of 27W. The ITCZ extends from 10N41W to 10N58W. Scattered moderate convection is noted from 08N to 12N between 43W and 53W. GULF OF MEXICO... Broad surface ridging extends across the Gulf of Mexico. Scattered moderate convection is noted over the eastern and central Gulf from 25N to 28N and E of 90W. Light to gentle winds are noted over most of the basin with moderate winds off the Yucatan. Seas are up to 2 ft. For the forecast, high pressure will prevail through the forecast period supporting mainly gentle to moderate winds. A trough will develop over the Yucatan Peninsula each evening and move offshore. This pattern will maintain pulsing of moderate to fresh winds north and west of the Yucatan peninsula during the late afternoon and evening hours. CARIBBEAN SEA... Please read the TROPICAL WAVES section for details on two tropical waves in the Caribbean Sea. Scattered thunderstorms are noted across the northwest Caribbean especially along the Greater Antilles in addition to the Gulf of Honduras. Otherwise, the most active convection is associated with the tropical waves. Fresh to strong winds are noted across the south-central Caribbean, especially north of Colombia and in the Gulf of Venezuela. Fresh to strong winds are likely occurring off the coast of Nicaragua due to the tropical wave. Moderate to locally fresh trade winds are noted in the eastern Caribbean. Gentle to moderate trade winds prevail in the NW Caribbean. Seas range 8-10 ft in the west-central Caribbean due to the strong winds in the south-central basin. Otherwise, 4-6 ft seas are in the eastern basin and 4-5 ft in the NW basin. For the forecast, the pressure gradient between high pressure over the Atlantic and the Colombian low will maintain fresh to strong winds across the central Caribbean through Fri night. High pressure N of the area will build further westward, producing an increase in areal coverage of the fresh to strong winds from the middle to end of the week. Moderate to fresh winds are forecast for the Gulf of Honduras through Fri. ATLANTIC OCEAN... Please read the SPECIAL FEATURES section for information about Tropical Depression Don in the central Atlantic Ocean. Scattered moderate to isolated strong convection is noted off the coast of Florida, northern Bahamas and the SW N Atlantic from 23N to 31N and W of 65W. Gentle to moderate winds are noted over these waters with seas to 4 ft. Over the central Atlantic, surface ridging extends across the area anchored by a 1026 mb high pressure located near 32N56W. Light to gentle NE winds prevail N of 26N under the influence of the high pressure. S of 26N to the ITCZ from the coast of Africa to the Bahamas, easterly moderate to locally fresh winds prevail with seas 5-8 ft. S of the ITCZ, light to gentle winds with 4-5 ft seas are noted. For the forecast W of 55W, surface high pressure will prevail across the forecast waters this week. This will support mainly moderate to fresh E to SE winds, except for fresh to strong winds and rough seas N of Hispaniola at night. $$ AReinhart