000 AXPZ20 KNHC 101551 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Sep 10 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Newly downgraded Tropical Storm Olaf is centered near 24.1N 111.3W at 10/1500 UTC moving NW at 9 kt. Estimated minimum central pressure is 990 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Scattered moderate convection is noted within 150 nm in the northeast and southern quadrants of Olaf. Seas in excess of 8 ft cover the waters off Baja California Sur south of Cabo San Lazaro, and over the southern Gulf of California south of Loreto. Olaf will move to the northwest along the coast of Baja California Sur to just off Cabo San Lazaro by late today, then start to move farther offshore as it continues to weaken. Olaf is expected to produce total rainfall amounts of 5 to 10 inches with maximum amounts of 15 inches across portions of southern Baja California Sur through today. This rainfall may trigger significant and life- threatening flash flooding and mudslides. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPEP5.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMEP5.shtml for more details. ...TROPICAL WAVES... The axis of a tropical wave is 90W north of 02N, moving west at 10 to 15 kt. Scattered moderate and isolated strong convection is evident from 10N to 15N between 91W and 97W. This tropical wave will be monitored over the next several days for the potential for tropical cyclogenesis. The axis of a tropical wave is near 102W north of 03N to 16N, moving westward at 10 to 15 kt. Scattered moderate convection is noted from 08N to 12N between 100W to 105W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 11N86W to 11N90W to 13N115W to 08N125W to 08N130W. Aside from the convection mentioned in the Tropical Wave section, scattered moderate to isolated strong convection is evident from 04N to 07N between 78W and 83W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on Hurricane Olaf. Aside from Olaf, fresh to strong winds and seas of 5-7 ft are noted over the Gulf of Tehuantepec. Otherwise, a weak pressure pattern prevails producing gentle to moderate winds west of Baja California and light to gentle winds elsewhere. Seas are in the 4-6 ft range over the open waters off Mexico, and 3 ft or less over the Gulf of California. For the forecast, a tropical wave is in the far eastern Pacific waters off central America and southern Mexico. A broad area of low pressure is expected to form along this wave off southern Mexico during the next day or two, and the low could then develop further into a tropical depression late this weekend or early next week while it moves west- northwestward or northwestward near the southern and southwestern coasts of Mexico. Regardless of development, seas will build off southern Mexico Sat into Tue due to southwest swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate south to southwesterly monsoon flow prevails south of the monsoon trough with light winds north of the monsoon trough. Seas are in the 4-6 ft range across the Central American offshore waters, with 6-8 ft seas over the waters between Ecuador and the Galapagos Islands in southwest swell. For the forecast, fresh to strong south to southwest winds are expected over the offshore waters of Guatemala and El Salvador late Sat through late Sun as low pressure develops south of the southern coast of Mexico. Seas offshore Guatemala, Honduras and El Salvador are expected to build this weekend due to strong south to southwest winds combining with southwest swell that will be propagating through those same offshore waters. These seas will begin to slowly subside early next week. REMAINDER OF THE AREA... Low pressure of 1011 mb is centered near 15N135W. Moderate to fresh winds are north of the low, with gentle to moderate winds south of the low. Another area of low pressure is centered near 24N130W. This is a weaker low with a pressure of 1014 mb, supporting gentle winds around the low. Light to gentle winds prevail elsewhere north of 10N. Gentle to moderate winds prevail south of 10N. Seas are in the 5-6 ft range in the vicinity of the low, and 4-5 ft elsewhere north of 10N. South of 10N, seas are in the 6-8 ft range east of 115W, and 5-6 ft west of 115W. Southwest swell will propagate through the waters E of 130W through the upcoming weekend, with seas ranging between 8-11 ft through early next week. $$ Christensen