000 AXNT20 KNHC 220555 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sat Jul 22 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 0000 UTC surface analysis and satellite imagery through 0555 UTC. ...SPECIAL FEATURES... Tropical Storm Don is centered near 37.4N 48.6W at 22/0300 UTC or 590 nm SSE of Cape Race, Newfoundland moving NW at 12 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Scattered moderate to isolated strong convection is mostly confined over the eastern semicircle, mainly within 120 nm from the center. Seas are up to 21 ft near the center. Don is forecast to turn to the north on Saturday followed by a northeastward motion on Sunday. Some slight strengthening is possible over the next several hours, however, weakening is forecast to begin by Saturday night, Don is expected to become a post-tropical cyclone on Sunday. Please read the latest HIGH SEAS FORECAST issued by National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest T.S. Don Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Central Tropical Atlantic (AL95): A 1012 mb low pressure is centered near 12N40W in the central Atlantic. Easterly wind shear is displacing the deep convection to the western quadrant, mainly within 150 nm from the center. Although environmental conditions are only marginally conducive, slow development is expected and this system will likely become a tropical depression by early next week while it moves westward across the tropical Atlantic. Interests in the Lesser Antilles should monitor the progress of this system. The disturbance has a medium chance of development over the next 48 hours. Refer to the latest Tropical Weather Outlook at www.hurricanes.gov for more details. Gale Warning E of 35W: Meteo-France is forecasting frequent gusts to gale force and rough to very rough seas in the Agadir and Canarias Marine Zone. Please read the High Sea Forecast and Warning at https://wwmiws.wmo.int for more details. high pressure of 1018 mb centered near 25N73W will change little through the weekend. Fresh trades just north of Hispaniola and over the Windward Passage will diminish tonight. Elsewhere across forecast waters, winds will be moderate or weaker into next week ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis along 31W, south of 19N, moving westward at 10-15 kt. A few showers are noted near the trough axis south of 12N. A central Caribbean tropical wave has its axis along 80W, south of 19N, moving westward at 10-15 kt. The interaction between the trough axis and the eastern Pacific monsoon trough is generating deep convection over the SW Caribbean, especially south of 11N. ...MONSOON TROUGH/ITCZ... The monsoon trough reaches the Atlantic through the coast of Mauritania near 19N16W and continues to 11N25W, 13N37W and 10N44W. Scattered moderate convection are observed south of 10N and east of 25W. ...GULF OF MEXICO... Scattered showers and isolated thunderstorms are found in the Bay of Campeche associated with a large area of storms that formed over the Yucatan peninsula earlier in the day. However, the storm activity is quickly losing strength. Farther north, a few showers are seen near a weak surface trough along 90W. Weak high pressure dominates the Gulf waters, resulting in moderate or weaker winds and 1-3 ft seas. For the forecast, weak high pressure centered near the eastern Gulf will remain remain dominate into early next week. This will support mainly gentle to moderate winds, except over the eastern Bay of Campeche where winds will be enhanced by a thermal trough coming off the Yucatan Peninsula during the overnight hours. ...CARIBBEAN SEA... Divergence aloft in the western Caribbean Sea and plenty of tropical moisture support scattered moderate to isolated strong convection, mainly west of west of 84W and south of 21N. The remainder of the Caribbean Sea is under the influence of a subtropical ridge positioned near the Azores. Dry Saharan dust covers most of the eastern and central Caribbean, resulting in drier conditions, above normal daily temperatures and reduced visibility. The pressure gradient between the ridge and lower pressures in NW South America continue to sustain fresh to strong easterly trade winds in the central Caribbean. In the latest satellite- derived wind data, the strongest winds are occurring in the south- central Caribbean. In the remainder of the basin, moderate or weaker winds prevail. The wave heights are 6-10 ft in the central Caribbean and 2-6 ft elsewhere. For the forecast, the aforementioned pressure gradient will maintain strong trades across the central Caribbean through Sat night. Winds should diminish slight to fresh to strong Sun through Tue night. Fresh to locally strong trades will develop over the Gulf of Honduras Sun through Mon. Low pressure, AL95, well east of the region is forecast to move into Atlantic waters E of the Lesser Antilles early next week, possibly as a tropical cyclone. Expect increasing wind and seas over these waters in association with this low pressure system. ...ATLANTIC OCEAN... Please see the SPECIAL FEATURES section for information on Tropical Storm Don in the north-central Atlantic, gale winds in the eastern Atlantic, and INVEST 95L in the central Atlantic. An upper level trough between Bermuda and Puerto Rico is producing scattered moderate convection, mainly north of 22N and between 63W and 67W. The rest of the tropical Atlantic is under the dominance of a 1030 mb subtropical ridge centered near the Azores. A large outbreak of Saharan dust continues to propagate across the central and eastern Atlantic, suppressing the formation of showers and thunderstorms. The pressure gradient between the aforementioned ridge that extends into the SW Atlantic and lower pressures over the eastern United States result in moderate to fresh W-SW winds north of 27N and west of 66W. Seas in these waters are 4-7 ft. Moderate easterly winds and 2-4 ft seas are noted between the SE Bahamas, northern Hispaniola and NE Cuba. Elsewhere west of 55W, light to gentle anticyclonic winds and slight seas prevail. In the remainder of the tropical Atlantic, moderate or weaker winds and slight to moderate seas are prevalent. For the forecast west of 55W, weak high pressure of 1018 mb centered near 25N73W will change little through the weekend. Fresh trades just north of Hispaniola and over the Windward Passage will diminish tonight. Elsewhere across forecast waters, winds will be moderate or weaker into next week. $$ DELGADO