000 AXNT20 KNHC 081805 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Thu Jul 8 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 1700 UTC. ...SPECIAL FEATURES... Tropical Storm Elsa is centered near 35.0N 79.7W at 08/1500 UTC or 70 nm SW of Raleigh North Carolina moving NE at 17 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. On the forecast track, Elsa will move over South Carolina and North Carolina today, pass near the eastern mid-Atlantic states by tonight, and move near or over the northeastern United States on Friday and Friday night. The system should move over Atlantic Canada by Friday night and Saturday. Elsa is forecast to become a post-tropical cyclone by Friday night. As Elsa moves across North Carolina and Virginia today, heavy rainfall may result in limited flash and urban flooding. Heavy rainfall from the Mid-Atlantic into New England through Friday could lead to considerable flash and urban flooding. 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: An ASCAT pass from this morning revealed gale force winds over the south- central Caribbean near the coast of Colombia due to the combination of high pressure north of the area and lower pressures over northern Colombia. Gales will pulse tonight through tomorrow 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 E of 35W: The pressure gradient between high pressure of 1029 mb located about 400 nm east-northeast of the Azores and lower pressures over Africa is resulting in strong to gale-force north to northeast winds north of 20N and east of 25W, including the Canary Islands. Meteo-France has issued a Gale Warning for Agadir from 08/12 UTC to 09/00 UTC. The forecast calls for north 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... A far eastern Atlantic tropical wave has its axis along 24W south of 10N southward, moving westward at 10-15 kt. This wave is surrounded by a moist atmospheric environment. Scattered moderate convection is within 340 nm W of the wave axis from 03N-08N. A central Atlantic tropical wave, with a larger amplitude, has its axis extending from 23N35W to 14N36W and to 04N36W. It is moving westward 10-15 kt. A small area of scattered moderate convective is within 200 nm of the wave south of 07N. A tropical wave has its axis along 58W extending south of 12N to inland over South America, moving westward at 10-15 kt. Scattered moderate convection is within 300 nm of the wave from 07N-10N. A tropical wave over the south-central Caribbean has its axis along 76W south of 14N. It is quickly moving westward due to the strong trade winds near 20 kt. Isolated showers are possible near this wave over the extreme southwestern Caribbean. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast of Guinea near 11N15W to 07N21W to 08N34W. A segment of the ITCZ is analyzed from 07N38W to 07N48W. Scattered moderate convection is well south of the monsoon trough from 02N to 07N between 10W to 18W. 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 1007 mb low is analyzed over southern Texas. A trough is just inland over the Texas coast extending south along the northeastern coast of Mexico. The combination of divergence east of the upper- level trough along with the aforementioned surface features is leading to large clusters of scattered moderate to strong convection over the NW Gulf from 21N to 30N and W of 91W. A recent ASCAT pass revealed gusty winds associated with this convection. This activity will continue into the evening. Elsewhere in the Gulf, moderate to fresh SE winds continue except in the northeast section of the basin where gentle southwest to west winds remain in the wake of Tropical Storm Elsa. Seas are generally 3-6 ft throughout the Gulf. For the forecast: High pressure from the Atlantic will build westward across the area through the next few days, with relatively quiet conditions expected. A trough over the Yucatan Peninsula will shift westward to the SW Gulf during the mornings through the weekend followed by fresh to strong southeast winds. Scattered to numerous showers and thunderstorms over the NW Gulf are expected to continue through this evening. CARIBBEAN SEA... Please see Special Features above for details on the Gale Warning in effect for the south-central Caribbean near the coast of Colombia. Strong trades continue in the central Caribbean, with resulting wave heights of 8-12 ft. Fresh strong trades are also occurring in the Gulf of Honduras with wave heights of 4-6 ft. Moderate to fresh trades prevail over the remainder of the Caribbean. Wave heights range from 5-8 ft in the eastern Caribbean, 6-9 ft in the north central Caribbean, and 4-6 ft in the NW Caribbean and Windward Passage. For the forecast: A ridge of high pressure north of the area combined with the Colombian low will continue to enhance near gale force winds pulsing to gale force in the south-central Caribbean and strong winds in the central Gulf. 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... As of 1700 UTC, scattered moderate convection is over waters north of the Bahamas, west of 76W. A cluster of showers and thunderstorms is moving northeastward off the coast of Florida, north of 27.5 north. Seas in this region are 3 to 5 ft. The Bermuda-Azores high dominates the Atlantic forecast waters. The 1030 mb high is centered near 37N37W. Circulation around the high results in gentle to moderate easterly winds and seas of 5 to 7 ft across the basin north of 23N and mainly west of 25W. Fresh to strong NE are located east of 25W from the Canary Islands to 20N due to the pressure gradient caused by the Azores high and lower pressures over Africa. Seas in this region are 6 to 9 ft. For the forecast W of 65W: Fresh to strong south to southwest winds over the far northwest part of the area will lift north of the area this morning as Tropical Storm Elsa, currently over South 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. $$ Mora