000 AXPZ20 KNHC 202138 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1947 UTC Thu Aug 20 2020 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 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 2020 UTC. ...SPECIAL FEATURES... Tropical Storm Genevieve is centered near 23.9N 112.4W at 20/2100 UTC moving NW at 10 kt. Estimated minimum central pressure is 985 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Seas 12 ft or greater are within 120 nm of center with peak seas to 26 ft. Scattered moderate and isolated strong convection is within 180 nm in the N semicircle and 90 nm S semicircle. Genevieve will continue weakening as it passes offshore of Baja California, then weaken to a tropical depression by early Sat while moving away from Baja California. 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 axis is analyzed near 79W from the NE coast of Ecuador N across the Gulf of Panama into the SW Caribbean Sea, moving W at 15 kt. Scattered moderate and isolated strong convection is noted from 05N to 12N between 78W and 88W. Heavy rainfall could lead to flash flooding over portions of Central America through the weekend. A tropical wave axis is analyzed near 104/105W from 05N to 18N, moving W at 10-15 kt. Scattered moderate and isolated strong convection is noted from 07N to 16N between 99W and 106W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 11N76W to 09N81W to 11N88W to low pressure near 11N95W to 13N101W, then resumes from 18N108W to 14N115W to low pressure near 15N124W to low pressure near 15N125W to 11N135W to 12N140W. Besides the convection described above, scattered moderate and isolated strong convection is noted from 06N to 13N between 90W and 98W, and from 12N to 17N between 108W and 121W. Scattered moderate convection is noted from 07N to 11N between 125W to 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details about Hurricane Genevieve. Peak seas are currently around 26 ft west of southern Baja California Sur near 24N112.5W. Swell associated with Genevieve is likely producing 8-11 ft seas in the southern Gulf of California. Genevieve will continue producing dangerous, life-threatening marine conditions over the next few days as it crosses the Baja California offshore waters. Elsewhere, expect fresh to strong S to SE winds in the northern Gulf of California today and Fri with seas around 5-7 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Recent scatterometer data showed moderate to locally fresh SW winds south of the monsoon trough, which extends along 10N this afternoon. Associated seas are 6-9 ft per earlier altimeter data well offshore of Costa Rica. The monsoon trough will gradually lift northward over the next several days. This will result in freshening winds and building seas off the coast of Central America through the upcoming weekend and into early next week. Seas will build to 8-10 ft offshore of Central America by this weekend in association with the strongest winds, then continue building to 9-12 ft early next week as monsoonal flow continues strengthening. REMAINDER OF THE AREA... A modest pressure gradient between high pressure north of the area and the monsoon trough is supporting gentle to moderate trades N of 20N and W of 125W, as shown in earlier scatterometer data. Moderate to locally fresh SW winds persist south of the monsoon trough, with the strongest winds noted between 90W-100W and 110W-130W. Seas peak around 8 ft within these fresh trades. This monsoonal flow is expected to strengthen E of 115W this weekend into early next week, with seas building to 8-12 ft. Elsewhere, northerly wind waves combined with SE swell from Genevieve will produce combined seas of 8-10 ft over the northern waters between 120W and 130W later today and into the weekend. An area of low pressure is expected to form this weekend several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system, and a tropical depression could form by the middle of next week while it moves little. This system has a medium chance of tropical cyclone formation during the next five days. $$ Hagen