293 AXPZ20 KNHC 102151 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Tropical Storm Olaf is centered near 24.6N 112.7W at 10/2100 UTC moving WNW at 9 kt. Estimated minimum central pressure is 1001 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Olaf will be diminishing over the next day or two as it moves to the west or west-southwest off Cabo San Lazaro. There is no significant convection near the center of Olaf. However, it remains a fairly well developed, if rather small, circulation. It will lose the characteristics of a tropical cyclone as moves farther west offshore and into cooler waters. If this happens before the winds can diminish below gale force, a gale warning may be required for a short period off Baja California Sur. 12 to 16 ft seas off Baja California Sur will diminish below 12 ft through Sat. 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 91W north of 05N, moving west at 10 to 15 kt. Scattered moderate is evident from 10N to 12N between 91W and 94W. 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 103W north of 05N to 16N, moving westward at 10 to 15 kt. No significant convection is noted with this tropical wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 11N86W to 13N90W to 13N115W. The intertropical convergence zone reaches from 08N120W to 07N130W. Aside from the convection mentioned in the Tropical Wave section, scattered moderate to isolated strong convection is evident from 05N to 09N between 78W and 82W, and from 10N to 15N between 95W and 97W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on Hurricane Olaf. Fresh N gap winds may be starting to pulse across the Gulf of Tehuantepec currently, responding to a tightening pressure gradient ahead of an approaching tropical wave currently over Guatemala. Long- period SW swell is also starting to impact the waters off Chiapas and eastern Oaxaca, reaching 5 to 7 ft, along with clusters of showers and thunderstorms. SW swell is also impact most of the remaining open waters off southern Mexico, with mostly 5 to 6 ft seas. Farther north, strong to near-gale strength southerly winds are starting to diminish over the southern Gulf of California, although seas to 8 ft persist between La Paz and Loreto. Moderate SE winds and slight seas are noted elsewhere across the Gulf of California. Outside of the immediate area of Olaf, gentle to moderate NW winds persist off Baja California, with moderate seas. For the forecast, a broad area of low pressure is expected to form along tropical wave off southern Mexico during the next day or two, and there is a medium chance this low could 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. Coastal areas in southern Mexico from Chiapas to Guerrero may see hazard surf and heavy rainfall Sat through early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... A recent scatterometer satellite pass indicated at least fresh SW winds over the offshore waters of Guatemala and El Salvador. It also showed strong SW winds, but in heavy rainfall and therefore may have been a little exaggerated. While no recent altimeter satellite data has been available from this area, seas may be already reaching 6 to 9 ft off Guatemala and El Salvador due to SW swell. A recent altimeter pass id show 6 to 7 ft seas off Costa Rica, likely in SW swell.The monsoon trough extends from central Panama to the Pacific coast of northwest Costa Rica and Nicaragua. Convergent SW flow into the monsoon trough is supporting areas of showers and thunderstorms along these coastal areas, to include in the Gulf of Panama. Clusters of showers and thunderstorms are active off the Azuero Peninsula of Panama as well. Farther south, gentle southerly winds persist off Colombia and Ecuador, with seas estimated to be 6 to 8 ft in SW swell. For the forecast, large SW swell will impact region into early next week, along with moderate winds. REMAINDER OF THE AREA... A recent scatterometer satellite pass showed a large area of fresh S to SW winds south of 10N and east of 110W. This is part of a larger surge of southwesterly winds starting over this region. Concurrent altimeter data showed seas to 8 ft over the tropical waters east of 120W, partly due the local wind flow, but also due in part to a larger area of cross-equatorial SW swell. Mainly gentle to moderate winds persist west of 120W, with seas to 8 ft in southerly swell reaching as far west as 130W south of 08N and 5 to 7 ft seas elsewhere. Southwest swell will continue to propagate through the waters east of 130W through the upcoming weekend, with seas ranging between 8-11 ft through early next week. $$ Christensen