833 AXNT20 KNHC 180553 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sat Sep 18 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... Tropical Storm Odette is centered near 36.4N 71.2W at 18/0300 UTC or 230 nm SE of Cape May New Jersey and moving NE at 9 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Seas are peaking at 12 to 13 ft near and up to 90 nm in a semicircle N of the center. Numerous moderate to isolated strong convection is noted well NE of the center from 36N to 40N between 65W and 69W. Odette is expected to continue a NE track with little change in speed through Sunday. This will take Odette S of the Northeast U.S. and Atlantic Canada coasts over the weekend. Odette is forecast to maintain its current intensity while transitioning into an extra- tropical storm through Saturday night. Afterward, gradual strengthening is likely and Odette will become a strong extratropical storm on Sunday. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml for more information. The Atlantic Offshore Waters Forecast issued by OPC can be found at https://www.ocean.weather.gov/offshore/indexphp?basin=atl&type=offshore#close Showers and thunderstorms are gradually becoming better organized in association with an area of low pressure and tropical wave located about 1100 miles ESE of the northern Leeward Islands. Fresh trades and seas of 6 to 8 ft are found from E to NE to NNW of this system from 13N to 21N between 43W and 49W. Environmental conditions are expected to be conducive for further development during the next couple of days, and a tropical depression is likely to form during the next day or two while the system moves toward the WNW at about 15 mph. This system is expected to be near the northern Leeward Islands on Monday and Tuesday, and interests there should monitor the progress of this disturbance. The system has a high chance of formation within the next 48 hours. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...TROPICAL WAVES... An Atlantic tropical wave is along 23W from 19N southward through the Cabo Verde Islands and a broad 1010 mb low pressure near 09N25W, and moving W near 15 kt. Scattered moderate to isolated strong convection is found from 04N to 10N between 21W and 30W. Scattered moderate convection is seen near the Cabo Verde Islands from 11N to 16N between 20W and 28W. The system has a low chance of formation within the next 48 hours. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. Another Atlantic tropical wave is near 50W from 19N southward through a 1011 mb low pressure, and moving W near 15 kt. Scattered moderate to isolated strong convection is present from 13N to 18N between 44W and 52W. See the Special Features section above for potential development of this system. A W Caribbean tropical wave is along 85W from 18N southward across Honduras, Nicaragua and Costa Rica to the E Pacific Ocean, and moving W near 10 kt. Scattered showers and isolated thunderstorms are occurring over these nations and adjacent waters. ...MONSOON TROUGH/ITCZ... A monsoon trough extends across the African coast near the Mauritania-Senegal border at 17N16W through the 1010 mb low mentioned in the Tropical Waves section above to 11N38W. No ITCZ is present based on the latest analysis. Scattered moderate convection is evident near the Mauritania and Senegal coast from 15N to 21N. The E end of the E Pacific monsoon trough is triggering scattered showers and thunderstorms near the Panama-Colombia border. ...GULF OF MEXICO... A surface trough reaches northeastward from the N Bay of Campeche to the N central Gulf. Aided by divergent winds aloft, scattered heavy showers and thunderstorms are present over the central and E Gulf, including the W coast of central Florida. Locally moderate to fresh winds and seas at 4 to 5 ft are possible near these showers and thunderstorms. Otherwise, light to gentle winds and seas at 1 to 3 ft prevail across much of the Gulf. For the forecast, weak high pressure will extend across the E and central Gulf through early next week. This pattern will support continued gentle 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 over SE Cuba and S Hispaniola, and adjacent waters. Refer to the Tropical Waves section above for additional convection in the Caribbean Basin. Tightening gradient between the Atlantic ridge to the north, and E Pacific monsoon trough near Panama and N Colombia is generating fresh to strong NE to ENE trades and seas at 6 to 8 ft over the S central basin. Gentle trades and seas of 2 to 4 ft are present across the E basin. Gentle to moderate trades and seas at 3 to 5 ft prevail across the remainder of the basin, including the Yucatan Channel. For the forecast, the Atlantic ridge will shift westward through Sun, as Tropical Storm Odette, off the middle Atlantic coast, lifts northward. This will support fresh to strong winds over the S central Caribbean and Gulf of Honduras into early Sun. The ridge will weaken starting Sun night as a tropical wave and area of low pressure currently across the central Atlantic move to the northeast of the Leeward Islands early Mon, then begin to move more NW. There is a high chance this low pressure will form into a tropical cyclone over the next several days. Regardless of further development, expect increase winds, seas and thunderstorms N through E of the Leewards early next week. ...ATLANTIC OCEAN... Please see the Special Features section above for potential tropical development in the Atlantic Basin. The combination of a mid to upper-level trough near 29N50W and a surface trough at 23N51W is triggering scattered moderate convection from 21N to 31N between 46W and 53W. Locally fresh winds and seas up to 6 ft are possible near this convection. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection across the basin. An expansive surface ridge extends southwestward from a 1027 mb Azores high across S of Bermuda to Florida. This feature is providing gentle to moderate winds with seas at 3 to 4 ft N of 26N between 36W and the Georgia-N Florida coast. Other than the fresh winds and higher seas mentioned near the 1010 mb low in the Special Features section, gentle to moderate winds and seas of 3 to 4 ft are seen N of between 10N and 26N between 50W and the S Florida Coast and the Lesser Antilles. Moderate to locally fresh NE trades and seas at 6 to 8 ft are evident N of 27N between the African coast and 36W. Gentle to locally moderate winds and seas of 4 to 6 ft prevail across the rest of the basin. For the forecast west of 65W, weak ridging through the N Bahamas will support mostly light breezes and slight seas north of 22N through early next week, and moderate trade winds and moderate seas south of 22N at least through Sun. Meanwhile, an area of low pressure currently well to the SE over the central tropical Atlantic will approach the waters NE of the Leeward Islands Sun and Mon, then begin to move more NW over open Atlantic waters. There is a high chance this low pressure will form into a tropical cyclone over the next several days. Regardless of further development, expect increase winds, seas and thunderstorms N through E of the Leewards Islands and NE of Puerto Rico early next week. $$ Chan