000 AXPZ20 KNHC 192123 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Aug 19 2021 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Linda is barely a tropical cyclone as it crosses into the central Pacific region. At 19/2100 UTC, Tropical Storm Linda is centered near 19.7N 139.5W moving W at 15 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Linda has now lacked organized deep convection and is expected to become a post-tropical cyclone by tonight. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPEP2.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMEP2.shtml for more details. ...TROPICAL WAVES... A tropical wave is along 95W and north of 04N, moving W around 10 kt. Scattered moderate isolated strong convection is noted on either side of the wave axis from 10N to 13N between 90W and 97W. A second tropical wave is along 109W and north of 03N, moving W at 5-10 kt. Scattered moderate convection is from 11N to 13N between 106W and 111W. A third tropical wave is along 122W north of 03N, moving W around 10 kt. Scattered moderate convection is from 11N to 13N between 119W and 121W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across western Panama to 09N90W to 1011 mb low pressure located near 16N103W to 11N115W to 13N130W to 10N140W. Aside from the convection described in the Tropical Waves section, scattered moderate convection is noted from 03N to 07N E of 81W to the coast of Colombia, and from 09N to 12N W of 133W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface trough is analyzed off Baja California Norte supporting mainly gentle to moderate NW winds across the offshore waters of the Baja California peninsula, and moderate to fresh SW winds over the northern Gulf of California. Elsewhere, a surface ridge extends from a 1036 mb high near 44N144W southeastward to near Clarion Island. Seas are generally 5-7 ft in the offshore waters of Baja California primarily due to SW swell. Seas of 3-5 ft are noted in the northern Gulf of California, with slight seas over the remainder of the Gulf. For the forecast, the surface trough just west of Baja California will remain nearly stationary over the next 48-72 hours. Tropical Storm Grace, located over the Yucatan Peninsula, is forecast to move inland over mainland Mexico Friday night and dissipate over Mexico by late Saturday. However, Grace's remnants are expected to continue westward and emerge over the eastern Pacific Ocean off the west-central coast of Mexico early Sunday. Environmental conditions are forecast to be conducive for development, and a tropical depression could form late this weekend or early next week while the system moves westward at 10 to 15 kt away from the coast of Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate winds will persist over the offshore waters of Central American and Equatorial waters through Sun. Seas of 6-8 ft in SW swell are expected across the waters between Ecuador and the Galapagos Islands tonight and Fri. A developing low pressure along the monsoon trough may bring some increase in winds and seas across the offshore waters of Guatemala and El Salvador early next week. Gentle to moderate SW winds are noted per scatterometer data S of the monsoon trough while mainly light winds are observed N of it. Seas are generally in the 5-7 ft range in long period SW swell. Little change in these marine conditions are expected on Fri. Moderate to locally fresh SW winds are forecast S of the monsoon trough during the upcoming weekend. REMAINDER OF THE AREA... Please read the Special Features section for details on T.S. Linda. Elsewhere, a ridge extending from a 1036 mb high near 44N144W dominates most of the northern forecast waters N of 20N and W of 120W. This system is promoting generally moderate or weaker winds north of the monsoon trough. SW winds equatorward of the monsoon trough are moderate to fresh. Seas of 8-9 ft mainly due to SW swell are generally noted from 09N to 12N between 105W and 115W. Northerly swell, with building seas of 8-9 ft, is propagating across the N waters particularly N of 27N between 121W and 135W. For the forecast away from Linda, no significant changes to the winds over the open Pacific are expected for the next several days. Northerly swell will continue to propagate across the north-central waters during the next 48 hours with seas in the 8-9 ft range. $$ GR