000 AXNT20 KNHC 152326 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Jul 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... Subtropical Storm Don is centered near 37.3N 48.6W at 15/2100 UTC or 1030 nm W of the Azores moving N at 8 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Only a weak band of moderate convection is noted on the southeastern side of the circulation, mostly removed from the center. Tropical storm-force winds extend within 120 nm NE and 80 nm SE quadrants of center. Seas in excess of 12 ft seas extend within 210 nm NE, 180 nm SE, and 180 nm NW quadrants of the center of Don. On the forecast track, Don should turn toward the east on Sunday, southeast on Monday and toward the south by Tuesday. Little change in strength is forecast for the next several days, and Don could become a remnant low pressure area in a few days. Please, read the latest HIGH SEAS FORECAST issued by the Ocean Prediction Center, at the web-site https://www.opc.noaa.gov/text/MIAHSFAT1.shtml, and the latest Subtropical Storm Don Forecast/Advisory and the Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 21W/22W, south of 18N, moving westward at 10 to 15 kt. A few showers are near the wave axis. A tropical wave is along 49W/50W, south of 19N, moving westward at 15 to 20 kt. A dry Saharan airmass has enveloped the wave and no deep convection is associated with this feature. A tropical wave is over the eastern Caribbean along 63W/64W, south of 19N, moving westward at 15 to 20 kt. Scattered showers and thunderstorms are near the wave axis. moderate convection is ahead of the tropical wave over the Windward Islands. A second tropical wave is over the western Caribbean. Its axis is along 84W/85W south of 20N, and stretches from western Cuba across Central America into the eastern Pacific region. It is moving at 10 to 15 kt. The wave is helping to induce showers and thunderstorms over Pinar del Rio and the Isle of Youth in Cuba as well as over most of Nicaragua and parts of Honduras. Similar convective activity is also noted over the SW Caribbean. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean through the coast of Mauritania near 19N16W and continues SW to 10N27W, and then to the W to near 08N48W. The ITCZ extends from 09N51W to 09N59W. Aside from the convection described in the TROPICAL WAVES section, scattered moderate to isolated strong convection is observed from 08N to 11.5N between 28W and 33W. GULF OF MEXICO... A weak ridge remains in control of the weather pattern across the Gulf region. Gentle to moderate SE winds and seas of 2 to 4 ft are noted over the western Gulf while mainly light and variable winds and seas of 1 to 2 ft dominates the remainder of the basin. A few showers and thunderstorms are noted over the eastern Gulf. Numerous showers and thunderstorms are occurring over Florida and the Yucatan Peninsula. For the forecast, a ridge will persist from southwest Florida to the central Texas coast through mid-week, 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... Aside from the convection described in the TROPICAL WAVES section, multilayer clouds, with possible showers, are noted over most of the eastern Caribbean and across the south-central Caribbean. Scattered showers and isolated thunderstorms are seen over the Virgin Islands, Puerto Rico and the Mona Passage based on the San Juan Doppler radar. Similar convection is noted over Hispaniola. An earlier scatterometer satellite pass captured strong to near gale-force easterly trade winds in the south-central Caribbean Sea, with the strongest winds occurring within about 90 nm of NW Colombia. Seas in these waters are 8 to 11 ft. Fresh to strong easterly winds and seas of 5 to 8 ft are noted in the north- central Caribbean waters. Moderate to fresh easterly winds and seas of 4 to 7 ft are evident in the eastern Caribbean. Moderate or weaker winds and seas of 3 to 5 ft prevail elsewhere in the basin, except in the lee of Cuba and near the Yucatan Channel where seas of 1 to 3 ft are noted. For the forecast, the tropical wave over the western Caribbean near 85W will move across the remainder of the Caribbean tonight into early Sun. Another tropical wave currently over the eastern Caribbean will weaken as it moves across the central Caribbean through late Sun and across the western Caribbean late Mon. A third tropical wave will move into the eastern Caribbean from late Sun into Mon, then move across the central Caribbean during Mon and Mon night, and the western Caribbean Tue. The passage of the tropical waves will modulate fresh to strong winds across mainly the central Caribbean through the period. Winds may reach near gale force along the coast of Colombia tonight with seas building to 11 or 12 ft. ATLANTIC OCEAN... Please refer to the SPECIAL FEATURES section for information regarding Subtropical Storm Don. The western Atlantic is dominated by a 1022 mb high pressure system located W of Bermuda near 32N67W. This pattern is supporting fresh to locally strong E winds off Hispaniola, confirmed by scatterometer data. Seas are 4 to 6 ft in this area, reaching 7 ft near the Windward Passage. Elsewhere west of 55W, moderate or weaker winds and slight to moderate seas prevail. In the eastern Atlantic, a 1029 mb high pressure system centered south of the Azores supports fresh to strong NE to E winds north of 20N and east of 35W. The strongest winds are occurring between the Canary Islands. Seas in the region are 8 to 11 ft based on altimeter data. Moderate or weaker winds and moderate seas are prevalent in the remainder of the tropical Atlantic. For the forecast west of 55W, high pressure will persist east of the Bahamas along 25N through Sun, supporting pulses of fresh to strong NE to E winds and rough seas off Hispaniola. The ridge will shift northward into Mon ahead of a tropical wave that will be approaching the area from the east. Looking ahead, the northern portion of the tropical wave will move westward south of 22N into mid week. Scattered to numerous showers and thunderstorms over the waters east of Florida to near 72W are expected to remain quite active into Mon. $$ GR