Atlantic Discussion

  • NHC Atlantic Tropical Weather Discussion
    by nhcwebmaster@noaa.gov (nhcwebmaster) on June 20, 2021 at 6:00 PM

    324 AXNT20 KNHC 201800 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sun Jun 20 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 1200 UTC surface analysis and satellite imagery through 1750 UTC. ...SPECIAL FEATURES... Tropical Depression Claudette is centered near 33.8N 84.2W at 20/1500 UTC or 10 nm ENE of Atlanta Georgia moving ENE at 15 kt. Estimated minimum central pressure is 1009 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. On the forecast track, the system should continue to move across portions of the southeastern U.S. through tonight, move over the coast of North Carolina into the western Atlantic Ocean on Monday, and pass near or just south of Nova Scotia on Tuesday. Some re-strengthening is expected tonight, and Claudette is forecast to become a tropical storm again late tonight or early Monday over eastern North Carolina. Further strengthening is possible over the western Atlantic Ocean through early Tuesday. Claudette is expected to become a post-tropical cyclone by late Tuesday. See the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml and Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details. ...TROPICAL WAVES... A tropical wave extends from 04N to 14N with axis near 42W, moving W at 5-10 kt. Scattered moderate convection is noted from 09N to 11N between 40W-44W. A tropical wave extends from 07N to 19N with axis near 67W, moving W at 10-15 kt. Isolated showers are occuring across Puerto Rico, Hispaniola, central and eastern Caribbean. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of West Africa near 10N15W to 06N20W to 05N31W. The ITCZ continues from 05N31W to 08N40W then continues west of a tropical wave near 08N44W to 08N59W. Aside from the convection associated with the tropical wave, scattered moderate convection is from 02N to 10N E of 25W, from 05N to 10N between 27W and 33W. GULF OF MEXICO... Tropical Depression Claudette is moving ENE across the state of Georgia. However, an outter rainband associated with the cyclone continues to support heavy showers and tstms across the northern Gulf waters. The heaviest showers are over Louisiana adjacent waters just below an area of diffluent flow aloft. Recent scatterometer data show gust to gale force winds over this area of strong convection and oil platforms as well as ships over this area are reporting dense fog and hazy skies. So visibility is another concern in this region at the moment. Moderate to locally fresh return flow is elsewhere across the basin with seas with seas ranging between 3 to 5 ft. Fresh to locally strong return flow is forecast from this afternoon through Mon, when winds are expected to diminish to moderate to locally fresh. CARIBBEAN SEA... A tropical wave along 67W is generating isolated showers and tstms over Puerto Rico, Hispaniola, the central and the eastern Caribbean. The pressure gradient between the Azores high and lower pressure associated with the tropical wave is supporting moderate to fresh winds across the eastern half of the basin, with fresh to strong winds occuring over the south-central waters. Seas range between 5 and 7 ft. Otherwise, gentle to moderate E to SE winds are over the NW Caribbean, except in the Gulf of Honduras where winds pulse to fresh to strong. Atlantic high pressure will combine with the Colombian low to support fresh to strong trades over the south-central Caribbean through Tue. Pulsing fresh to strong E to SE winds are expected in the Gulf of Honduras at night through Wed night. A tropical over the eastern Caribbean along 67W will move across the central Caribbean on Mon. ATLANTIC OCEAN... Scattered showers and isolated tstms are N of Cape Canaveral W of 79W associated with an outer band of Tropical Depression Claudette, which is moving across the state of Georgia. The Azores high extends a ridge axis into the area W of 65W and supports mainly moderate to fresh return flow. Light to gentle variable winds are across the central Atlantic while a stronger pressure gradient due to lower pressure over northern Africa supports moderate to fresh NE winds over the E Atlantic E of 35W. For the forecast west of 65W, surface ridging will dominate the area during the next several days. Fresh to locally strong winds are expected to pulse at night over Hispaniola adjacent waters, including approaches to the Windward Passage, through Thu night. Fresh to strong S to SW winds are expected to develop over waters N of 30N W of 70W tonight and Mon due to the pressure gradient between the Atlantic high pressure and Tropical Depression Claudette, which is forecast to move into the western Atlantic Ocean on Monday. $$ Ramos

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