000 AXNT20 KNHC 211038 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Fri Jul 21 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 1030 UTC. ...SPECIAL FEATURES... Tropical Storm Don is centered near 35.4N 45.6W at 21/0900 UTC or about 910 nm west of the Azores. It is moving WNW at 8 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained winds are 45 kt with gusts to 55 kt. Seas are peaking to 20 ft near the center with 12-15 ft seas up to 120 nm in the northern semicircle, and 60 nm in the southern semicircle from the center. Scattered moderate convection is noted up to 50 nm in a southern semicircle from the center. Satellite imagery shows a rather wide convective band consisting of numerous moderate convection that just about wraps entirely around the center starting from the W quadrant and ending in the NE quadrant. The center is about 15 nm in diameter. Don is forecast to maintain its current motion over the next day or so. A turn to the northwest and then north is forecast over the weekend. Little change in strength is forecast during the next couple of days. Weakening is forecast to begin later this weekend. 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. Eastern Atlantic Gale Winds: Meteo-France forecast gale winds developing in the Agadir Marine Zone, starting 21/1500Z. Please read the High Sea Forecast and Warning at https://wwmiws.wmo.int/index.php/metareas/affiche/2 for more information. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis extending from 19N32W to 06N33W. It is moving westward at 10-15 kt. Only isolated showers and thunderstorms are noted from 06N to 10N between 30W-35W. A central Caribbean tropical wave has its axis along 77W south of eastern Jamaica to inland northwestern Colombia. It is moving westward around 15 kt. No significant convection is seen near this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic along the Mauritania coast just north of Nouakchott and continues southwestward to 15N22W to 12N27W to low pressure near 12N39W 1014 mb and to 08N46W. Aside from convection noted in the TROPICAL WAVES section above, scattered moderate convection is present from 05N to 09N between the Guinea-Sierra Leone coast and 30W, and within 30 nm north of the 1014 mb low. Similar convection is near the end of trough from 05N to 08N between 44W-48W. ...GULF OF MEXICO... A surface trough is over the central Gulf from 28N86W to 23N89W. Isolated small showers ad thunderstorms are from 23N to 26N and between 86W-90W. The northern tip of a East Pacific tropical wave is causing scattered showers and isolated thunderstorms over the western part of the Gulf of Campeche. Otherwise, broad and weak high pressure covers is present over the region. The associated gradient is allowing for generally light to gentle winds and seas of 1-2 ft over the eastern and north-central Gulf. Gentle to moderate east-southeast winds and seas of 2-4 ft are the remainder of the Gulf. For the forecast, weak high pressure will remain in place across the Gulf waters through early next week. This will support mainly gentle to moderate winds, except over the Bay of Campeche where winds will be enhanced slightly by a thermal trough coming off the Yucatan Peninsula during the night hours. ...CARIBBEAN SEA... Convergent easterly trade winds are coupling with mid-level troughing leading to scattered to numerous showers and thunderstorms over the northwest section of the basin north of 16N and west of 80W. A tight gradient between the Bermuda High and Colombian Low is maintaining strong to near-gale easterly winds along with seas of 8-11 ft over the south-central part of the basin north of Colombia. Overnight ASCAT data passes captured some of these winds. Fresh to strong east winds and seas of 6-9 ft are over the north- central part of the basin. Gentle northeast to east winds with seas of 3-5 ft due to an easterly swell are near Costa Rica and Panama, and also between Cuba and Jamaica. Moderate to fresh easterly trades and seas of 4-6 ft seas are elsewhere in the basin. For the forecast, the aforementioned pressure gradient will maintain fresh to near-gale trades across the central Caribbean through Sat. Winds should diminish to between fresh and strong Sun through Tue. Fresh to locally strong trades will develop over the Gulf of Honduras Sat night through Mon. ...ATLANTIC OCEAN... Please see the SPECIAL FEATURES section for more information on Tropical Storm Don in the north-central Atlantic, and for developing gale winds in the eastern Atlantic. The gradient associated to the Bermuda High near 27N69W is supporting light to gentle winds and seas of 3 to 5 ft north of 24N between 43W and the Georgia-Florida coast. To the south, moderate with locally fresh northeast to east to east-southeast winds and seas at 4-6 ft are noted from 20N to 24N and between 43W and the Bahamas. Farther east, the Azores High is channeling gentle to moderate northeast to east to southeast winds with 4-6 ft seas north of 20N between 25W-20W. Near the Canary Islands, moderate to fresh with locally strong north to northeast trade winds and seas of 6-8 ft are present north of 19N between the Africa coast and 25W. For the tropical Atlantic, gentle to moderate northeast to east trades and seas of 4-6 ft are present from 04N to 20N between 45W and the Lesser Antilles, and from 13N to 20N between the Cabo Verde Islands and 45W. Gentle to moderate southerly and monsoonal westerly winds along with seas of 4-6 ft prevail for the remainder of the Atlantic Basin. An area of scattered moderate convection moving southward is seen from 23N to 30N and between 59W-65W. Isolated showers and thunderstorms are from 23N to 30N between 55W-59W. For the forecast west of 55W, the Bermuda High will weaken and shift east-southeastward through the weekend. Fresh to strong trades just north of Hispaniola and over the Windward Passage will diminish Fri. Elsewhere across forecast waters, winds will be moderate or weaker through Tue. $$ Aguirre