000 AXPZ20 KNHC 082157 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Sep 8 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 2250 UTC. ...SPECIAL FEATURES... Tropical Storm Olaf is centered near 19.4N 107.7W at 08/2100 UTC moving NW at 5 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Satellite imagery indicates scattered moderate to isolated strong convection is concentrated within 150 nm of the center in the NE quadrant and within 120 nm of the center in the SE quadrant. Olaf will continue to move towards the NW along with an increase in forward speed through Friday. A turn toward the west-northwest is forecast by Friday night, followed by a turn toward the west on Saturday. On the forecast track, the center of Olaf will move just to the southwest of southern Baja California Sur on Thursday and Friday. Olaf could be near hurricane strength by late Thursday. The storm is expected to begin weakening on Friday. Olaf is expected to produce total rainfall amounts of 3 to 6 inches with maximum amounts of 10 inches across portions of far southern Baja California Sur Thursday through Friday. The rainfall may trigger flash flooding and mudslides. Olaf is expected to generate swells that will affect portions of the coasts of Baja California Sur and Sinaloa by Thu, spreading northward along the west coast of Baja California Sur through Fri. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and 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... A tropical wave has its axis along 92W north of 04N to inland the western part of Guatemala. It is moving westward at 10 kt. Scattered moderate convection is from 07N-14N near the coast of Guatemala and eastern Mexico between 87W to 95W. A tropical wave has its axis along 102W from 05N to 18N. It is moving westward at about 10 kt. Isolated showers and thunderstorms are near the wave axis from 05N to 07N between 99W to 103W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from just inland northwestern Colombia to across Panama and southern Costa Rica to 10N85W to 09N100W. It resumes at 12N113W to 12N130W to 15N140W. Aside from the convection associated with Tropical Storm Olaf and the tropical waves, scattered moderate isolated strong convection is within the trough between 94W-99W, and from 05N to 13N between 109W-116W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on Tropical Storm Olaf. A weak 1013 mb low is centered near 25N126W. A trough extends from it to 25N133W. No convection is occurring with this low as it is surrounded by a very dry and stable environment. Latest ASCAT data depicts gentle to moderate northwest winds off the Baja California peninsula with seas to 4 ft in long-period south to southwest swell. ASCAT data revealed light to gentle variable winds across the Gulf of California. Seas are less than 3 ft, except 3-4 ft just south of the entrance to the Gulf. Scattered moderate convection is just inland Mexico from northern Jalisco to southern Nayarit due to the northeast fringe of Tropical Storm Olaf. ASCAT data showed fresh to strong east-southeast winds on the outer periphery of Tropical Storm Olaf along and offshore the coast from Jalisco to Guerrero. Earlier altimeter data showed seas of 8-9 ft in that area. Otherwise, light to gentle variable winds are across the Nayarit offshores in addition to Oaxaca and Chiapas. Seas are 5-7 ft in long-period southwest swell. Tropical Storm Olaf will move just to the southwest of southern Baja California Sur on Thursday and Friday. Some strengthening is forecast during the next day or so, and Olaf could be near hurricane strength by late Thursday. The storm is expected to begin weakening on Friday. The strengthening cyclone is expected to generate swells that will affect portions of the coasts of Baja California Sur and Sinaloa by Thu, spreading northward along the west coast of Baja California Sur through Fri. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. In the Gulf of California, light and variable winds will continue through Thu night, then become moderate southeast winds. Light to gentle winds will continue across southern Mexico. Fresh to strong gaps winds could develop across the Gulf of Tehuantepec beginning Thu night and continuing into the upcoming weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate south to southwesterly winds is noted south of the monsoon trough with light and variable winds north of the monsoon trough. Seas are 3-6 ft in the Central American offshore waters and 6-7 ft seas off of Ecuador and the Galapagos Islands. Satellite imagery shows scattered showers and thunderstorms along and just offshore the coast of Costa Rica and Panama. Seas are 3-6 ft in the Central American offshore waters, except for higher seas of 5-7 ft over the waters between Ecuador and the Galapagos Islands due to a southwest swell. These seas will build to 6-8 ft due to a southwest swell beginning Wed. Winds in Papagayo region will become moderate southerly in direction beginning Fri and increase to fresh speeds Sat. Moderate to fresh southwest winds are expected along the offshore waters of Costa Rica, Panama, Colombia, Ecuador and Galapagos Islands through the weekend. 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 in these waters will remain in the 6-7 ft range, except near 8 ft seas in the region west of Ecuador. Seas offshore Guatemala, Honduras and El Salvador are expected to build to possibly 9 ft during Sat and Sat night due to the expected strong south to southwest winds combining with southwest swell that will be propagating through those same offshore waters. REMAINDER OF THE AREA... Broad high pressure dominates the waters north of the monsoon trough. The gradient between the high and the lower pressure to the south in the monsoon trough region is allowing moderate to fresh north-northeast winds and seas 7 ft south of 21N and west of 134W. Moderate southerly winds remain south of the monsoon trough, with seas to 7 ft. Seas to 8 ft due to a southwest swell continue south of the Equator and west of the Galapagos Islands through this evening before another set of southwest swell begins to propagate through the waters west of the Galapagos Islands from Thu through the upcoming weekend. Seas will range between 8 to 9 ft through early next week. $$ Torres