Atlantic Discussion

  • NHC Atlantic Tropical Weather Discussion
    by nhcwebmaster@noaa.gov (nhcwebmaster) on September 20, 2020 at 5:43 AM

    000 AXNT20 KNHC 200543 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sun Sep 20 2020 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Tropical Storm Beta is centered in the Gulf of Mexico near 26.8N 92.2W at 20/0300 UTC, or 205 nm SE of Galveston TX moving NNE at 2 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Peak seas are currently 23 ft. Isolated moderate to strong convection is within 120 nm of the center in the northern semicircle. A slow WNW motion is expected today, followed by a slow NW to N motion late Mon and Tue. On the forecast track, the center of Beta will move toward the coast of Texas and potentially move inland late Mon or early Tue. Little change in strength is forecast during the next couple of days before Beta reaches the Texas coast. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and the Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml for more details. Major Hurricane Teddy is centered near 27.3N 61.2W at 20/0300 UTC or 350 nm SSE of Bermuda moving NW at 11 kt. Estimated minimum central pressure is 956 mb. Maximum sustained wind speed is 100 kt with gusts to 120 kt. Peak seas are currently 54 ft. Scattered to numerous moderate and isolated strong convection is within 180 nm of the center, except 120 nm in the NW quad. Teddy is expected to turn toward the north tonight followed by a faster northward motion later on Monday. On the forecast track, the center of Teddy will pass just east of Bermuda Monday morning. A weakening trend is expected to begin tonight. Teddy has a very large wind field. Large swells generated by Teddy are affecting the Lesser Antilles, the Greater Antilles, the Bahamas, Bermuda, and the east coast of the United States. These swells are likely to cause life-threatening surf and rip current conditions. Please read the latest NHC Public Advisory at: https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and the Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more details. Tropical Storm Wilfred is centered near 14.5N 40.5W at 20/0300 UTC or 960 nm W of the Cabo Verde Islands moving WNW at 14 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas are currently 14 ft. Scattered moderate isolated strong convection is within 270 nm of the center, but there is no convection in the SW quadrant. Wilfred will continue moving toward the WNW or W for the next couple of days until it dissipates on Tuesday. Please read the latest NHC Public Advisory at: https://www.nhc.noaa.gov/text/MIATCPAT3.shtml and the Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details. Post-Tropical Cyclone Paulette is centered southwest of the Azores near 35N29N with a central pressure of 1012 mb. The low is drifting southward. The cyclone is forecast to continue southward for the next day or so and then begin moving eastward in a couple of days. There is a medium chance the cyclone could reacquire tropical or subtropical characteristics early this week. For more information about marine hazards associated with this system, see High Seas Forecasts issued by Meteo France. ...WEST ATLANTIC GALE WARNING... A cold front extends from 32N72W to a 1012 mb low near 29N79W to Melbourne Florida to Tampa Bay. A recent ASCAT pass shows NE winds of 30 to 35 kt north of the low and north of the front, between 76W and the coast of NE Florida. Gales in this area should persist through late tonight or early Mon morning. Seas are currently 12-16 ft in this area and are forecast to build to 15-20 ft by tonight. Please see the latest High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...TROPICAL WAVES... An eastern Atlantic Ocean tropical wave has its axis along 20/21W from 18N southward, moving W around 15 kt. Scattered moderate isolated strong convection is seen from 16N-20N between 16W-22W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends off the coast of Mauritania near 18N16W to 13N28W. Scattered moderate to strong convection is seen well south of the monsoon trough along the west coast of Africa from 06N-11N between 12W-17W. GULF OF MEXICO... Please see the Special Features section above for details on Tropical Storm Beta in the NW Gulf of Mexico. As of 20/0300 UTC, a cold front extends from Tampa Bay to 28N84W and continues as a stationary front to 28N89W. Scattered moderate isolated strong convection is near the west part of the stationary front from 27N-29N between 87W-89W. A recent ASCAT pass shows near gale E winds to the north of the front over the NE Gulf. Gale force winds are west of 87.5W north of the front, and can be attributed to Beta and the front. Surface troughing over the Bay of Campeche is leading to scattered moderate showers. In addition to Tropical Storm Beta over the NW Gulf, the aforementioned front will move through the northeast Gulf into Mon, bringing strong NE winds through early week. CARIBBEAN SEA... A weak surface trough extends across the eastern Caribbean from NW Venezuela to the Leeward Islands. A few showers are noted near the eastern portion of this trough over the Leeward Islands. Fairly dry conditions are noted elsewhere except for some showers seen near the south coast of Cuba. Large, long period northerly swell originating from Hurricane Teddy in the Atlantic is penetrating into the Atlantic passages from the Mona Passage through the Leeward Islands, but is also active just outside of the Windward Island passages. The subtropical ridge that is normally north of the region has been displaced by the tropical cyclone activity, leaving gentle E to SE winds and slight seas elsewhere across the basin. For the forecast, the Atlantic swell from Hurricane Teddy will continue to impact the passages from the Leeward Islands to the Mona Passage through Mon, but should gradually ease in the Windward Island Passages. This may be short lived as a new round of large, long-period northerly swell is expected by mid week. This northerly swell will impact much of the eastern Caribbean by mid week. Mariners are advised to check local marine forecasts for more information. ATLANTIC OCEAN... Please see the Special Features section above for details on the gales east of northern Florida, Hurricane Teddy, Tropical Storm Wilfred, and Post-Tropical Cyclone Paulette. Scattered moderate isolated strong convection is noted along the front mentioned above in the Special Features section, mainly north of 28N and west of 77W. To the SE of that front, a dissipating cold front extends from 32N70W to 29N75W. A surface trough continues from 29N75W to 26N78W. Isolated showers and gentle winds are near this boundary. Gentle winds generally prevail south of the front mentioned in the Special Features section and west of 70W. Farther east outside of tropical cyclones, generally moderate to fresh trade winds persist. 8 to 10 ft seas primarily in mixed swell cover much of the open northern Atlantic south of 32N due to the continuous tropical cyclone activity over the past several days, but mostly from Hurricane Teddy. Teddy will move north of the area, and Wilfred will gradually dissipate west of 50W through the early part of the week. Swell generated by Teddy will continue to impact all area waters into Mon. The cold front mentioned in the Special Features section above will move SE across the Florida Peninsula and the west Atlantic while weakening, then stall Tue from near Bermuda to the Florida Straits. Behind the front, near gale force NE winds are anticipated across a broad area of Atlantic waters N of 25N into Mon night, with an area of gale force winds through late tonight or early Mon. This will bring a new round of large, long-period northerly swell to the waters west of 50W through mid week. $$ Hagen

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