000 AXPZ20 KNHC 190855 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0855 UTC Wed Aug 19 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURES... Hurricane Genevieve is centered near 20.2N 109.4W at 19/0900 UTC moving NNW at 9 kt. The estimated minimum central pressure is 960 mb. Maximum sustained wind speed is 100 kt with gusts to 120 kt. Seas 12 ft or greater are within 200 nm N semicircle, 240 nm SE quadrant and 180 nm SW quadrant with seas to 39 ft. Scattered moderate to strong convection is noted within 60 nm of the center of Genevieve. Elsewhere, scattered moderate convection is occurring from 17N to 21N between 106W and 112W. The center of Genevieve is expected to move near but southwest of the southern portion of the Baja California peninsula tonight and Thu, and move away from the peninsula on Fri. Little change in strength is expected today, followed by weakening on Thu and Fri. Large swells produced by Genevieve are affecting portions of the southern coast of Mexico and will spread northward along the southwestern and west-central coast of Mexico to the Baja California peninsula through Thu. These swells are likely to cause life-threatening surf and rip current conditions. 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 along 96.5W south of 18N, moving W at 10-15 kt. Scattered moderate isolated strong convection is noted from 09N to 16N within 180 nm of the wave axis. A tropical wave axis is analyzed along 125W south of 20N, moving W at 10-15 kt. No significant convection is associated with the wave at this time. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 08N77W to 07N82W to 10N95W, resumes SW of Hurricane Genevieve from 16N110W to 11N117W, then continues from 1010 mb low pressure near 16N124W to 11N131W to 14N140W. Besides the convection described above, scattered moderate isolated strong convection is noted within 120 nm S of the monsoon trough E of 80W, 120 nm N of the monsoon trough between 84W and 87W, and within 180 nm S of the monsoon trough between 90W and 94W. Scattered moderate convection is occurring within 120 nm of the monsoon trough between 111W and 117W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details about major Hurricane Genevieve. Genevieve will continue producing dangerous, life-threatening marine conditions over the next few days as it crosses the offshore waters of west-central Mexico and Baja California Sur. As Genevieve passes west of Baja California Sur today into Thu, expect freshening winds over the southern Gulf of California with seas building to 8-12 ft in southerly swell. Otherwise, recent scatterometer data shows light to gentle winds over the Baja California Norte waters and the northern Gulf of California. Gentle to moderate NW winds are noted offshore of southern Mexico. An earlier altimeter pass indicates 8 ft seas in mixed swell extend over 500 nm SE of the center of Genevieve. A cluster of thunderstorms is presently moving westward across the central Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to locally fresh monsoonal flow prevails across the offshore waters south of 08N per overnight scatterometer data. Seas likely peak around 6-8 ft in this region. Elsewhere, light to gentle, variable winds are noted north of the monsoon trough, except for some moderate easterly winds in the Papagayo region. Scattered showers and thunderstorms continue off the coast of Costa Rica and Panama near an active monsoon trough. The monsoon trough will gradually lift northward over the next several days, resulting in freshening winds and building seas off the coast of Central America through the upcoming weekend. REMAINDER OF THE AREA... Please see the Special Features section above for information about major Hurricane Genevieve. Long-period S to SW swell is supporting 7-8 ft seas south of the equator, and these conditions are expected to persist for the next couple days. Elsewhere, the remnant low of post-tropical Fausto has degenerated into a surface trough extending from 24N135W to 18N130W. This weak trough will continue moving SW for the next couple days. The monsoon trough will gradually lift northward over the next several days, resulting in freshening winds and building seas over the waters E of 100W into the upcoming weekend. Looking ahead, an area of low pressure is expected to form later this week several hundred miles southwest of the southwestern coast of Mexico. Conditions appear favorable for some slow development of this system this weekend while it moves little. This system has a medium chance of tropical cyclone formation during the next five days. $$ B Reinhart