000 AXNT20 KNHC 142322 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Jul 15 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... Subtropical Storm Don is centered near 34.1N 48.0W at 14/2100 UTC or 1040 nm W of the Azores moving NW at 7 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Tropical storm-force winds extend within 150 nm NE and 80 nm SE quadrants of center. Seas in excess of 12 ft seas extend within 240 nm NE, 210 nm SE, 70 nm SW and 180 nm NW quadrants of center. A band of showers with embedded thunderstorms is to E of the center of Don. On the forecast track, a turn toward the north at a similar forward speed is expected by Saturday night, followed by a turn toward the east by Sunday night. Some slight weakening is forecast during the next couple of days, and Don could possibly become a post-tropical cyclone or remnant low at any time. Please read the latest HIGH SEAS FORECAST issued by Ocean Prediction Center at web-site https://www.opc.noaa.gov/text/MIAHSFAT1.shtml and the latest Subtropical Storm Don Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Gale Warning E of 35W: A gale warning is in effect between the Canary Islands until 15/0000 UTC. The forecast calls for NE winds force 8 on the Beaufort Wind Scale with severe gusts. For more details, refer to the Meteo-France High Seas Forecast, listed on the website, https://wwmiws.wmo.int. ...TROPICAL WAVES... A tropical wave extends along 40W, south of 19N, moving westward at 15 to 20 kt. Convection is limited near the wave axis. A tropical wave extends along 55W, south of 19N, moving westward at 15 to 20 kt. Scattered moderate convection is on both side of the wave axis, mainly from 10N to 14N between 55W and 61W. Moisture associated with this wave will spread across the Windward Islands to night and Sat increasing the chance of showers and isolated thunderstorms. A tropical wave is moving across the Caribbean Sea. Its axis extends along 80W from central Cuba to western Panama. This system is moving westward at 10 to 15 kt. The wave is likely supporting scattered moderate convection over central Cuba and over the SW Caribbean and western Panama. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Senegal near 12.5N16.5W and continues westward to 10N37W. The ITCZ extends from 08N41W to 08N55W. Aside from the convection described in the TROPICAL WAVES section, scattered moderate to isolated strong convection is evident from 07N to 10N between 17W and 25W likely associated with a tropical wave. GULF OF MEXICO... A ridge dominates the Gulf of Mexico. Numerous showers and thunderstorms are noted over Florida, the Florida Keys and over the NE Gulf. A diffluent pattern aloft is helping to induce this convective activity. The most recent scatterometer data indicate gentle to moderate SE to S winds over the western Gulf with seas of 3 to 4 ft, and mainly light to gentle anticyclonic flow over the eastern Gulf with seas of 1 to 3 ft. For the forecast, a ridge will continue to dominate the Gulf waters through the next several days, while a trough will develop over the Yucatan Peninsula each evening and move offshore. This pattern will maintain moderate to fresh winds pulsing north and west of the Yucatan peninsula during the late afternoon and evening hours. Elsewhere, gentle to moderate winds and slight seas will prevail. CARIBBEAN SEA... Numerous showers and thunderstorms are observed over Cuba, from Pinar del Rio to Camaguey, over most of Nicaragua, and also over the SW Caribbean. Similar convective activity is noted near Cabo Gracias a Dios, Nicaragua and region waters, particularly from 13N to 16N between 80W and 83W. A tropical wave, combined with an upper-level low located S of Jamaica, is helping to induce this convective activity. The pressure gradient between the ridge to the north and lower pressures across NW South America support fresh to near gale-force easterly trade winds in the central Caribbean, with the strongest winds occurring off NW Colombia where seas are in the 8 to 10 ft range. Elsewhere across the central Caribbean, seas are 6 to 8 ft. Moderate to fresh easterly winds and seas of 4 to 6 ft are noted in the eastern Caribbean. Moderate or weaker winds and slight to moderate seas prevail elsewhere. For the forecast, a tropical wave along 80W will move across the remainder of the Caribbean through late Sat. Another tropical wave will move across the Windward Islands and through the southeastern Caribbean Sat, then weaken as it moves across the central Caribbean through late Sun and across the western Caribbean Mon and Mon night. The passage of the tropical waves will modulate fresh to strong winds across mainly the central Caribbean through the period. ATLANTIC OCEAN... Please refer to the SPECIAL FEATURES section for information regarding Subtropical Storm Don in the central Atlantic and a GALE WARNING in the eastern Atlantic. A weak ridge dominates the western Atlantic, including the Bahamas due to the presence of Subtropical Storm Don over the central Atlantic. A 1029 mb high pressure near the Azores extends a ridge over the eastern Atlantic, including the Canary Islands. The pressure gradient between this system and lower pressure over W Africa supports gale force winds between the Canary islands. Numerous showers and thunderstorms are seen over the Bahamas and regional waters are associated with the western extent of an upper-level trough that crosses the NW Bahamas. Moderate to locally fresh SE winds are noted per scatterometer data over the central Bahamas with light to gentle winds over the NW Bahamas. Moderate E winds are N of Puerto Rico to about 21N. Light and variable winds are elsewhere W of 60W with seas of 3 to 5 ft E of the Bahamas. Moderate to locally fresh easterly winds are present south of 20N and between 50W and the Lesser Antilles, along with seas of 4 to 6 ft. In the remainder of the basin, moderate or weaker winds and moderate seas prevail. For the forecast west of 55W, high pressure will persist northeast of the Bahamas through Sun, supporting pulses of fresh to strong NE to E winds and rough seas off Hispaniola. Looking ahead, the ridge will shift northward early next week ahead of a tropical wave that will be approaching the area from the east. $$ GR