000 AXNT20 KNHC 202312 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Tue Sep 21 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... Tropical Storm Peter is centered near 20.0N 61.8W at 20/2100 UTC or 130 nm NE of the northern Leeward Islands moving WNW at 12 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. On the forecast track, the center of Peter will pass north of the northern Leeward Islands and Puerto Rico through Tuesday. Rainfall around the southern periphery of Tropical Storm Peter could produce rainfall totals of 1 to 3 inches, with locally higher amounts possible across portions of the Northern Leeward Islands, including the Virgin Islands, as well as Puerto Rico and the northern portions of Hispaniola through Tuesday. This rainfall may lead to areas of urban and small stream flooding. Swells generated by Peter are expected to affect the northern Leeward Islands early this week, and then reach the Bahamas by midweek. These swells could cause life-threatening surf and rip current conditions. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT1.shtml and Forecast Advisory at https://www.nhc.noaa.gov/text/MIATCMAT1.shtml for more details. Marine interests in the area can read the latest NHC Offshore Waters Forecasts at https://www.nhc.noaa.gov/marine/offshores.php Tropical Storm Rose is centered near 18.4N 34.4W at 20/2100 UTC or 610 nm WNW of the Southernmost Cabo Verde Islands moving NW at 14 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Rose is moving toward the northwest, and this general motion with a decrease in forward speed is expected during the next couple of days. Rose will likely turn north-northwestward on Thursday. No significant change in strength is anticipated today, with weakening likely beginning on Tuesday and continuing through midweek. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and Forecast Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml 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 Ocean tropical wave is along 22W/23W, from 19N southward, moving westward 10 to 15 knots. A 1009 mb low pressure center is along the wave axis near 09.2N 22.8W or about several hundred miles south of the Cabo Verde Islands. Showers and thunderstorms associated with this system are still showing some signs of organization, although there does not appear to be a surface circulation at this time. Upper-level winds, however, are expected to become conducive for further development by midweek, and a tropical depression is likely to form by Thursday or Friday while the system moves westward at 10 to 15 kt across the eastern and central tropical Atlantic Ocean. The latest Tropical Weather Outlook states that this system has a low change of tropical cyclone formation through 48 hours, and a high chance through 5 days. Please, refer to the latest Tropical Weather Outlook, at www.hurricanes.gov for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic ocean through the coast of Guinea near 10N14W, then continues westward to the above mentioned 1009 mb low pressure center located near 09.2N 22.8W to 07N37W. The ITCZ extends from 07N37W to 08N42W to the coastal plains of Suriname. No significant convection is evident along the monsoon trough or ITCZ. GULF OF MEXICO... A weak ridge dominates the Gulf waters producing gentle to moderate winds and mostly slight seas across the region. Scattered showers with embedded thunderstorms are noted over the NE Gulf and the State of Florida. A diffluent pattern aloft supports this convective activity. For the forecast, weak high pressure will extend across the eastern and central Gulf of Mexico through Tue. This pattern will continue to support gentle to moderate winds and mostly slight seas across the Gulf waters. An early season cold front is expected to enter the NW Gulf early Wed and reach from the NE Gulf to central Bay of Campeche by late Thu before stalling. Fresh to locally strong northerly winds and building seas are expected in the wake of the front. CARIBBEAN SEA... Please read the Special Features section above for details on Tropical Storm Peter which is forecast to track well north of the NE Caribbean. An upper-level trough that crosses the Windward passage and Jamaica is helping to induce scattered showers and thunderstorms over Hispaniola and Puerto Rico. On the W side of this trough, strong N-NE winds support scattered showers and thunderstorms over most of Cuba, including the Isle of Youth. Convection has also flared- up over most of Central America due to a diffluent pattern aloft and the E extent of the eastern Pacific monsoon trough. Gentle to moderate trades are seen across most of the basin, with 2 to 4 ft seas, except for light breezes and 1 to 3 ft seas over the northwest Caribbean. For the forecast, Tropical Storm Peter is forecast to move northward toward Bermuda through the rest of the week. As this occurs, trade winds over the south-central Caribbean will diminish through Thu night. Look for associated showers and thunderstorms to affect the NE Caribbean and adjacent waters through Tue morning. ATLANTIC OCEAN... Please read the Special Features section above for details on Tropical Storm Peter located NE of the northern Leeward Islands and Tropical Storm Rose situated WNW of the southernmost Cabo Verde Islands. In addition, refer to the Tropical Wave section for details on a low pressure system, with potential of tropical cyclone formation along a tropical wave located near 22W/23W. The Cumbre Vieja volcano on the island of La Palma in the Canary Islands has been erupting since 19/1410 UTC. The ash plume is expected to remain below 8,000 ft in the vicinity of the volcano while drifting SE, causing a reduction in visibility. Marine and aviation interests should monitor this on-going situation by reading Volcanic Ash Advisory issued by Meteo-France at http://vaac.meteo.fr/volcanoes/la-palma/ A cold front enters the forecast area near 31N55W then continues WSW to near 28N70W where it becomes stationary to the coast of the State of Georgia. A concentrated area of showers and thunderstorms is observed along the frontal boundary between 65W-70W. An upper level low centered near 24N64W is supporting scattered showers and thunderstorms just N of Hispaniola. A ridge dominates the Atlantic waters E of 40W, including the Azores, Madeiras and Canary Islands. The pressure gradient between this ridge and T.S. Rose is producing a belt of moderate to fresh NE-E winds roughly from 19N-28N E of 35N. Seas are in the 5-7 ft range within this area of winds. For the forecast west of 65W, the frontal boundary will remain across the waters N of 27N through Tue while gradually weaken. Strong high pressure in the wake of the front is forecast to bring moderate to fresh NE-E winds across the forecast region N of 27N W of 65W. Seas of 8 ft generated by Peter will reach 65W by tonight, and approach the Turks and Caicos Island late on Tue or Tue evening. $$ GR