543 AXNT20 KNHC 082359 TWDAT Tropical Weather Discussion...UPDATED NWS National Hurricane Center Miami FL 0005 UTC Fri Jul 9 2021 Updated with the 0000 UTC Intermediate Advisory for Tropical Storm Elsa 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 1940 UTC. ...SPECIAL FEATURES... Tropical Storm Elsa is centered near 36.8N 77.4W at 09/0000 UTC or 55 nm W of Norfolk, Virginia moving NE at 18 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Numerous moderate convection is noted within 240 nm in the northeast semicircle of Elsa with a band of scattered moderate convection within 150 nm southeast of a line from 35N77W to 29N84W. Heavy rainfall is forecast across central and eastern North Carolina into southeastern Virginia, and from the Mid-Atlantic into New England through Friday are possible, which could result in limited-to-considerable flash and urban flooding, as well as isolated minor river flooding. Elsa will move to 38.7N 75.1W Fri morning, becoming extratropical near 47.0N 63.0W Sat morning, and will dissipate by Sun afternoon. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml, Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml, and the High Seas Forecast issued by the NWS Ocean Prediction Center at https://ocean.weather.gov/shtml/NFDHSFAT1.php for more details. For marine information within 60 nm of the coast, please see products from your local NWS Weather Forecast Office at www.weather.gov. Caribbean Sea Gale Warning: Gale force winds over the south- central Caribbean near the coast of Colombia are continuing due to the combination of high pressure north of the area and lower pressures over northern Colombia. Gales will pulse tonight through Fri with seas building to 12 to 14 ft. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at the website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml. Gale warning east of 35W: The pressure gradient between high pressure of 1031 mb located across the Azores near 38N28W and lower pressure over Africa is supporting gale force winds in the Agadir area of the Meteo-France High Seas Forecast waters. The Gale Warning for Agadir continues to 09/00 UTC. The forecast calls for N winds Force 8 in the Beaufort Wind scale with gusts. For more details, refer to the Meteo-France High Seas Forecast listed in their website: www.meteofrance.com/previsions-meteo-marine/ bulletin/grandlarge/metarea2. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis near 27W south of 11N, moving quickly W at 20 to 25 kt. This wave is surrounded by a moist atmospheric environment. Scattered moderate convection is noted from 02N to 06N between 27W and 33W. A central Atlantic tropical wave with a large amplitude has its axis near 37W/38W south of 23N, moving quickly W at around 20 kt. Isolated to scattered moderate convection is noted near the southern portion of the wave axis from 03N to 06N between 33W and 41W. A tropical N Atlantic tropical wave has its axis near 60W south of 12N to across northern South America, moving W at around 15 to 20 kt. Scattered moderate and isolated strong convection is noted from 08N to 11N between 54W and 68W with additional convection over portions of northern South America. A Caribbean Sea tropical wave has its axis near 78W/79W south of 14N to across eastern Panama and into the eastern Pacific Ocean, moving quickly W at around 20 kt. Scattered moderate and isolated strong convection is noted south of 10N between 79W and 82W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast of Africa near 12N16W to 08N23W to 10N30W to 08N35W. The ITCZ extends from 07N40W to 10N58W. Convection is described in the tropical waves section above. GULF OF MEXICO... A middle to upper-level low is over southern Texas. A trough extends from the low to over northern Mexico. At the surface, a 1009 mb low is analyzed over southern Texas near 28N98W. A trough is just inland over eastern Mexico from 26N98W to near Tampico, Mexico continuing along the coast of Mexico to 18N95W. The combination of divergence east of the upper-level trough along with the aforementioned surface features is leading to a large complex of scattered moderate and isolated strong convection within 240 nm southeast of a line from 31N93W to 23N99W. Heavy rainfall and flash flooding will be possible along the Texas Gulf coast over the next few days. See products issued by your local National Weather Service Forecast Office for additional information. Isolated thunderstorms are noted over the central Gulf between 85W and 90W. Moderate to fresh SE-S winds are noted in the NW Gulf, with moderate SE-S winds elsewhere west of 90W along with seas in the 4 to 6 ft range, with gentle to moderate SE-S winds east of 90W along with seas in the 2 to 4 ft range. For the forecast, high pressure from the Atlantic will build westward across the area through the next few days, with relatively quiet conditions expected. The Yucatan Peninsula trough will shift westward to the SW Gulf during the mornings through the weekend followed by fresh to strong southeast winds. A broad low pressure remains nearly stationary over South Texas enhancing scattered to numerous strong thunderstorms over the western Gulf. These storms will continue to produce frequent lighting and fresh to strong southeast winds in the northwest Gulf. This activity will continue through tonight. CARIBBEAN SEA... Please see the Special Features above for details on the Gale Warning in effect for the south-central Caribbean near the coast of Colombia. Elsewhere in the central Caribbean, fresh to strong trades prevail. Moderate to fresh trades prevail across the remainder of the Caribbean basin except light to gentle south of 10N in the SW Caribbean. Seas are in the 8 to 12 ft range in the central Caribbean, and 4 to 7 ft elsewhere. Isolated to scattered showers and thunderstorms extend from 10N to 14N west of 82W to across eastern Nicaragua, and from 14N to 18N west of 85W including across eastern and central Honduras. For the forecast, a ridge north of the area combined with the Colombian low will enhance strong to gale force winds north of Colombia through Fri. Widespread fresh to strong trades will continue in the south-central Caribbean and the Gulf of Honduras through Fri night. Fresh to strong winds will pulse at night in the Gulf of Honduras through early next week. ATLANTIC OCEAN... Please see the Special Features above for details on the Gale Warning in effect for the Agadir area of the Meteo-France High Seas Forecast waters. A band of scattered moderate convection is noted from the far NW Bahamas and north of 27N and west of 77W with additional activity across the Florida Peninsula. The Bermuda-Azores high dominates the Atlantic forecast waters. The 1032 mb high is centered near 36N38W. Gentle to moderate anticyclonic winds prevail around the high across the waters north of the ITCZ and west of 30W, except moderate to fresh offshore of northern Florida, fresh to strong south of 22N offshore of northern Hispaniola, and moderate to fresh across the tropical N Atlantic west of 55W. Seas of 4 to 7 ft dominate the waters west of 30W. Fresh to strong N-NE winds are located from 19N to 31N east of 22W to the coast of Africa due to a locally tight pressure gradient, with moderate to fresh N-NE winds elsewhere north of 15N and east of 30W. Seas are in the 7 to 11 ft range in the area of fresh to strong winds. For the forecast west of 65W, outer bands of Tropical Storm Elsa extend southwest into the western Atlantic enhancing showers and thunderstorms over the region. Fresh to strong southwest winds over the far northwest part of the area will lift north as Tropical Storm Elsa, currently over North Carolina, continues to pull away from the region. High pressure will then build westward across the area through Sun night. East winds will pulse to fresh to strong speeds at night between the southeastern Bahamas and Hispaniola through the period. $$ Lewitsky/Mahoney