000 AXNT20 KNHC 201750 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Thu Jul 20 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Tropical Storm Don is centered near 34.3N 42.2W at 20/1200 UTC. or about 739 nm WSW of the Azores. It is moving west-northwest at 6 kt. The estimated minimum central pressure is 1002 mb. Maximum sustained winds are 45 kt with gusts to 55 kt. Numerous moderate convection is present within 150 nm northeast to east of the center of Don, and within 30 nm southwest of Don. Don is forecast to continue its current motion, with an increase in forward speeds during the next couple of days. Don is later expected to turn northward over the weekend. Slight strengthening is expected during the next day or so, followed by little change in strength through Saturday. 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. ...TROPICAL WAVES... A far eastern Atlantic tropical wave is west of the Cabo Verde Islands with its axis stretching from near 19N28W to 05N31W. It is moving westward around 10 kt. Scattered moderate convection is within 60 nm east of the wave from 07N to 10N. An eastern Caribbean Sea tropical wave has its axis near 71W south of 18N, just south of Dominican Republic to inland Venezuela. It is moving westward at about 15 kt. No significant convection is seen near this wave based on the latest analysis. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic near Bissau west Africa, and continues southwestward to 12N30W and to 07N48W. Aside from convection associated to the far eastern Atlantic tropical wave, scattered moderate to isolated strong convection is moving off the coast of Africa from 06N to 17N. This convection may be associated with the next tropical wave. Scattered moderate convection is within the trough and south of the trough between 33W-41W. In addition, recent scatterometer data revealed localized fresh southeasterly winds whithin this area. ...GULF OF MEXICO... A surface trough along the Florida west coast is producing scattered showers and isolated thunderstorms over the southwestern near shore and off shore Florida waters. Elsewhere, a weak surface high pressure is dominating the sensible weather. Moderate E to SE winds and seas of 3-5 ft are occurring at the central and eastern Bay of Campeche. Light to gentle winds and seas of 1-2 ft are present across the north- central and northeastern Gulf. Gentle to moderate E to SE winds with 2-4 ft seas prevail for the rest of the Gulf, including the Straits of Florida. Winds and seas may be higher in areas of convection. For the forecast, a weak ridge of high pressure will remain in control of the weather pattern across the Gulf waters through the forecast period. This will support mainly gentle to moderate winds, except over the Bay of Campeche where winds will be enhanced by a thermal trough coming off the Yucatan Peninsula during the night hours. ...CARIBBEAN SEA... The GOES-16 Saharan Air Layer Tracking product is showing an area of Saharan dust moving west across the Atlantic Ocean and into the eastern Carribbean. This dust is already moving across the Lesser Antilles, Puerto Rico, and the Hispaniola. Therefore, expect adry and hazy conditions with patches of lower visibility. Convergent ESE trade winds in combination with an mid to upper level disturbance are producing scattered showers and isolated thunderstorms near Jamaica and south of Cuba. Refer to the Tropical Waves section above for more details about additional convection in the basin. A recent scatterometer pass confirmed that the tight pressure gradient between the Bermuda High and lower pressure at northwestern Colombia is producing strong with locally near- gale E to NE winds and seas of 7-11 ft, between Haiti and Colombia. Fresh to strong E winds and 4-7 ft seas are present for the eastern basin. Gentle to moderate NE winds and seas of 6-10 ft are present in the southwestern basin. North of Panama and near western Cuba moderate mainly E winds, with seas 2-5 ft. For the forecast, the aforementioned pressure gradient between the Bermuda High and lower pressure over Central America/N South America will maintain fresh to near gale trades across the central Caribbean through Sat. Winds should diminish down to fresh to strong Sun and Mon. 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 the latest information on Tropical Storm Don. Low level convergence is producing scattered showers and isolated thunderstorms south of Bermuda, north of 28N between 62W-68W. The GOES-16 Saharan Air Layer Tracking product is showing an area of Saharan dust moving west across the Atlantic Ocean. Hence, the lack of convection is the central and western Atlantic. Therefore, expect dry and hazy conditions with patches of lower visibility within this area. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections above for additional cnvection in the tropical Atlantic. The Bermuda High is supporting light to gentle winds with seas at 3-5 ft across the western Atlantic, except for the area north of 20N between 63W and east coast of Florida where seas are 4-6 ft. Over the central and eastern Atlantic, surface high pressure ridging related to a 1023 mb Azores High is maintaining light to gentle winds and 3-6 ft seas north of 20N between 27W-50W. Near the Canary Islands, moderate to fresh NNE trades and seas of 4 to 6 ft dominate north of 21N between the Africa coast and 28W. Across the tropical Atlantic, outside of convection, light to gentle ENE trades with 4-6 ft seas are seen from 07N to 20N between 48W and the Lesser Antilles, and from 12N to 20N between 27W-48W. Near the Cabo Verde Islands, gentle to moderate NE to N winds and seas of 3-5 ft are found from 14N-20N between 20W-27W. Gentle to moderate with locally fresh southerly and monsoonal westerly winds and 4-6 ft in southerly swell prevail for the remainder of the Atlantic Basin. For the forecast west of 55W, the Bermuda High centered near 31N59W this morning will weaken and shift east-southeastward through the weekend. Fresh to strong trades just north of Hispaniola and over the Windward Passage will diminish by Fri. Elsewhere across forecast waters, winds will be moderate or weaker through Mon. $$ KRV