000 AXPZ20 KNHC 200846 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0845 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURES... Hurricane Genevieve is centered near 22.5N 110.4W at 20/0900 UTC moving NNW at 6 kt. The estimated minimum central pressure is 976 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Seas 12 ft or greater are within 150 nm of center with peak seas to 31 ft. Scattered strong convection is noted within 60 nm of center except 30 nm SW quadrant. Elsewhere, scattered moderate convection is occurring from 21N to 25N between 106W and 112W. Genevieve is expected to turn toward the northwest later this morning, with that motion continuing through Sat. The center of Genevieve is expected to pass just to the southwest and west of the southern portion of the Baja California peninsula as a hurricane today, and move away from the peninsula on Fri. Further gradual weakening is expected today and through the weekend. 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 102W south of 18N, moving W at 10-15 kt. Scattered moderate isolated strong convection is noted from 14N to 18N between 98W and 102W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N76W to 09N82W to 11N87W to 1010 mb low pressure near 09N94W to 11N98W, then resumes south of Hurricane Genevieve from 19N109W to 1009 mb low pressure near 15N124W to 12N129W to 13N140W. Besides the convection described above, scattered moderate isolated strong convection is noted within 150 nm S of the monsoon trough between 82W and 87W, and within 180 nm N of the monsoon trough between 87W and 91W. Scattered moderate convection is occurring from 06N to 10N between 92W and 97W, and from 13N to 18N between 108W and 114W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details about Hurricane Genevieve. Peak seas are currently around 31 ft south of the southern tip of Baja California Sur near 22.5N110.5W. Swell associated with Genevieve is producing 8-12 ft seas in the southern Gulf of California, per recent altimeter data. Genevieve will continue producing dangerous, life-threatening marine conditions over the next few days as it crosses the Baja California offshore waters. Elsewhere, expect strengthening S to SE winds in the northern Gulf of California today and Fri with seas building to around 5-7 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Overnight scatterometer data shows moderate to locally fresh SW winds south of the monsoon trough, which extends along 09N-10N this morning. Associated seas are 6-8 ft per recent altimeter data offshore of Nicaragua and 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 recent scatterometer data. Moderate to locally fresh SW winds persist south of the monsoon trough, with the strongest winds noted between 90W-100W and 110W-120W. 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 later this week and over the 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 mid next week while it moves little. This system has a medium chance of tropical cyclone formation during the next five days. $$ B Reinhart