000 AXNT20 KNHC 151016 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...SPECIAL FEATURES... Subtropical Storm Don is centered near 35.7N 47.8W at 15/0900 UTC or 1010 nm W of the Azores moving N at 8 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 180 nm N semicircle and 150 nm SE quadrant of center. A band of showers and thunderstorms is found over the northern quadrants, mainly from 90 to 180 nm from the center. On the forecast track, Don will continue northward around 8 kt then toward the east at a similar forward speed Sun, followed by a turn to the southeast by Monday. 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. ...TROPICAL WAVES... A tropical wave is along 21W/22W, south of 18N, moving westward at 15 kt. Scattered moderate to isolated strong convection is observed from 08N and 12N and between 22W and 26W. An earlier scatterometer pass show fresh to strong southerly winds associated with the strongest convection. A central Atlantic tropical wave extends along 43W, south of 19N, moving westward at 15-20 kt. A dry Saharan airmass has enveloped the wave and no deep convection is associated with this feature. Another central Atlantic tropical wave extends along 60W, south of 19N, moving westward at 15-20 kt. Scattered moderate convection is ahead of the tropical wave over the Windward Islands. A western Caribbean Sea tropical wave extends along 82W, south of 20N, moving westward at 10-15 kt. The wave axis stretches from western Cuba to western Panama. The wave is enhancing the scattered showers and thunderstorms off western Cuba and the SW Caribbean. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Senegal near 16N16W and continues to 12N23W and then to 10N42W. The ITCZ extends from 11N48W to 12N58W. Aside from the convection described in the TROPICAL WAVES section, no deep convection is present in the rest of the monsoon trough or ITCZ. GULF OF MEXICO... Fresh SE winds follow a trough over the southwest Gulf, where seas are 3 to 5 ft. A surface ridge extends from southwest Florida to the central Texas coast, maintaining gentle to moderate breezes and slight seas elsewhere. A few showers and thunderstorms are noted over the Straits of Florida, on the northern end of a tropical wave moving into the western Caribbean. Little change is expect through the middle of the week. CARIBBEAN SEA... Aside from the convection described in the TROPICAL WAVES section, only isolated showers and a few thunderstorms are noted off the southern coast of 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 90 nm of NW Colombia and the Gulf of Venezuela. Seas in these waters are 8-11 ft. Fresh to strong easterly winds and seas of 5-8 ft are noted in the north- central Caribbean waters. Moderate to fresh easterly winds and seas of 4-7 ft are evident in the eastern Caribbean. Moderate or weaker winds and seas of 2-5 ft prevail elsewhere in the basin. For the forecast, the tropical wave between central Cuba and western Panama will move across the remainder of the Caribbean through late today. The other tropical wave will move across the Windward Islands and through the southeastern Caribbean today, then 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 by late Sun, then move across the central Caribbean Mon, 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. ATLANTIC OCEAN... Please refer to the SPECIAL FEATURES section for information regarding Subtropical Storm Don in the central Atlantic. The western Atlantic is dominated by a 1019 mb high pressure system located east of the Bahamas near 26N70W. This pattern is supporting fresh to strong E winds off Hispaniola, confirmed by an earlier scatterometer satellite pass. 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 near the Azores supports fresh to near gale-force NE-E winds north of 22N and east of 35W. The strongest winds are occurring off Western Sahara and in the water passages between the Canary Islands. Seas in the region described are 8-12 ft. 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. $$ Christensen