000 AXNT20 KNHC 190601 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sun Sep 19 2021 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 0530 UTC. ...SPECIAL FEATURES... Newly formed Tropical Depression Sixteen is centered near 16.4N 53.1W at 19/0300 UTC or 580 nm E of N Leeward Islands, and moving WNW at 12 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Seas are ranging from 10 to 11 ft near and N of the center. An area of moderate to fresh with locally strong winds with seas at 7 to 9 ft are evident N and NE of the center from 17N to 23N between 49W and 59W. Numerous moderate to isolated strong convection is near and up to 130 nm in a semicircle NE of the center. Sixteen is going to continue a WNW track with little change in speed over the next few days, passing N of the N Leeward Islands Mon and Tue. Steady strengthening is forecast through Sun night, possibly becoming a tropical storm Sun. Heavy rain and large swells are expected to impact the N Leeward Islands, Virgin Islands and Puerto Rico. Interests across these areas should monitor this system closely. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT1.shtml and Offshore Waters Forecasts at https://www.nhc.noaa.gov/marine/offshores.php for more details. Showers and thunderstorms associated with a 1008 mb low pressure centered about 310 nm SW of the Cabo Verde Islands near 10N27W are showing signs of organization. An area of fresh S to SW winds with seas at 6 to 8 ft can be found S and SE of the low from 06N to 10N between 22W and 29W. Environmental conditions appear conducive for further development of this system, and a tropical depression is likely to form during the next day or two while moving toward the NW at 10 to 15 mph to the west of the Cabo Verde Islands. This system has a high chance for tropical cyclone formation in the next 48 hours. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. For sea conditions near this system, please read the Meteo-France High Seas Forecast at: http://weather.gmdss.org/II.html ...TROPICAL WAVES... An Atlantic tropical wave is near 26W from 19N southward through the low mentioned in the Special Features section above, and moving W near 10 kt. Scattered moderate to isolated strong convection is seen near the low from 08N to 12N between 27W and 31W. Scattered moderate convection is present farther N over the Cabo Verde Islands from 15N to 17N between 19W and 27W. ...MONSOON TROUGH/ITCZ... A monsoon trough extends across the Mauritania coast at 17N16W through the 1008 mb low pressure mentioned in the Special Features section, and another low near 07N35W to 06N40W. The ITCZ then continues from 06N40W to 10N47W. Numerous moderate to strong convection is occurring S of the monsoon trough along the coast of Gambia, Guinea-Bissau and Guinea. Scattered moderate convection is present near the second low from 04N to 07N between 34W and 38W, and also near the ITCZ from 03N to 06N between 38W and 43W. The E end of the E Pacific monsoon trough is triggering numerous heavy showers and scattered thunderstorms near the Costa Rica- Panama border, over N Colombia and adjacent waters. ...GULF OF MEXICO... A persistent surface trough meanders east-northeastward from the W central Gulf to N Florida. Scattered showers and thunderstorms are noted across the central and NE Gulf, and N Florida. Another surface trough over the W Bay of Campeche is causing numerous heavy showers and scattered thunderstorms there, and near Jalapa, Mexico. Moderate to locally fresh winds and seas up to 4 ft are possible near these showers and thunderstorms. Otherwise, a broad surface ridge over the SW and E central Gulf is allowing light to gentle ESE to S winds and seas of 1 to 3 ft to prevail across much of the Gulf. For the forecast, Weak high pressure will extend across the E and central Gulf of Mexico through the early part of the week. This pattern will support continued gentle to moderate winds and mostly slight seas across the Gulf through the next several days. Looking ahead, a weak cold front may move into the NW and N central Gulf by mid week. ...CARIBBEAN SEA... Convergent trade winds are producing scattered showers and isolated thunderstorms across the N central basin, including SE Cuba and SW Hispaniola. Refer to the Monsoon Trough/ITCZ section above for additional convection in the Caribbean Basin. Gentle to moderate trades and seas at 4 to 6 ft are evident across the central and W basin. Gentle trades and seas of 2 to 4 ft prevail over the E basin. For the forecast, Tropical Depression (T.D.) Sixteen is near 16.4N 53.1W 1008 mb at 19/0300 UTC and moving WNW at 12 kt. Maximum sustained winds are 30 kt with gusts 40 kt. Sixteen will strengthen to a tropical storm near 17.3N 54.8W Sun morning, move to the NE of the Leeward Islands near 18.5N 57.3W Sun evening. T.D. Sixteen will continue to move northward and away from the Leewards thereafter through mid week. T.D. Sixteen will weaken and displace the Atlantic ridge currently north of the region, allowing trades winds over the S central Caribbean to diminish briefly Sun night, although fresh trade winds will persist Mon through mid week. ...ATLANTIC OCEAN... Please read the Special Features section above for details on newly formed Tropical Depression Sixteen E of the Leeward Islands and a tropical disturbance SW of the Cabo Verde Islands. Convergent trade winds are coupling with divergent flow aloft to generate scattered moderate to isolated strong convection NE of the Leeward Islands from 18N to 23N between 51W and 60W. A modest surface trough is producing scattered moderate convection from 29N to 31N between 47W and 51W. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection across the Atlantic Basin. The Atlantic ridge extends southwestward from a 1028 mb Azores high, passing S of Bermuda to another high N of the Bahamas. These features are providing light to gentle winds with seas at 2 to 4 ft N of 24N between 40W and the Georgia-N Florida coast. Other than the area N and NE of Tropical Depression Sixteen, NE to ENE trades and seas of 5 to 7 ft are seen N of 16N between the NW African coast and 40W, including waters near the Canary and Cabo Verde Islands; and NE of the Leeward Islands N of 17N between 40W and Bahamas. Other than the area near the low mentioned in the Special Features section, light to gentle winds and seas at 4 to 5 ft prevail for the rest of the basin. For the forecast west of 55W, Tropical Depression Sixteen is southeast of the area near 16.4N 53.1W 1008 mb at 19/0300 UTC, and moving WNW at 12 kt. Maximum sustained winds 30 kt gusts 40 kt. Sixteen will strengthen to a tropical storm near 17.3N 54.8W Sun morning, move to 18.5N 57.3W Sun evening, 19.4N 59.8W Mon morning, 20.3N 61.9W Mon evening, 21.3N 64.1W Tue morning, and 22.3N 65.5W Tue evening. Sixteen will change little in intensity as it moves to the southeast of Bermuda by late Wed. Elsewhere west of 70W, gentle to moderate winds and slight to moderate seas will persist over open waters through the early part of the week, with swell to 8 ft associated with the tropical storm reaching the waters east of 75W by Wed. $$ Chan