According to Bradley Whitaker, spokesman for the South Coast AQMD,  air quality levels are showing moderate in portions of the basin where smoke and ash can be seen. In these areas, although the skies may look smoky, the smoke can stay up very high without reaching the lower, breathing levels. Although ash may be seen in those areas, this can be because ash is heavier and falls quicker.
However, conditions can change quickly based on the weather. We encourage those who smell smoke or see ash to stay indoors with the windows and doors close, and to avoid physical activity.

Valid: Thursday, Sept. 10 through Friday, Sept. 11, 2020
This advisory is in effect through Friday afternoon. South Coast AQMD will issue an update if additional information becomes available.
Two major local wildfires as well as wildfires in Northern and Central California are affecting air quality in the region. A wildfire named the Bobcat Fire is burning north of Azusa and Monrovia in the Angeles National Forest. As of 11 a.m. on Thursday, the burn area was approximately 23,890 acres with 0% containment. Current information on the Bobcat Fire can be found on the Incident Information System (InciWeb) at https://inciweb.nwcg.gov/incident/7152.
A wildfire named the El Dorado Fire is burning in the San Bernardino Mountains near Yucaipa in San Bernardino County. As of 7 a.m. on Thursday, the burn area was reported at 12,610 acres with 23% containment. Current information on the El Dorado Fire can be found on the Incident Information System at: https://inciweb.nwcg.gov/incident/7148/.
Smoke from fires in Northern and Central California is also being transported south and may impact the South Coast Air Basin and Coachella Valley.
Past and Current Smoke and Ash Impacts. The Bobcat Fire is producing substantial amounts of smoke on Thursday morning based on satellite and webcam imagery. The El Dorado Fire is still producing smoke visible on satellite and webcam imagery, but the plume is much smaller than that of the Bobcat Fire. Falling ash has been reported downwind of the Bobcat Fire throughout the South Coast Air Basin. Smoke aloft from fires in Northern and Central California moved into the South Coast Air Basin and Coachella Valley overnight and is present this morning.
While there is heavy smoke aloft over the South Coast Air Basin, surface fine particulate matter (PM2.5) levels have been in the Good and Moderate Air Quality Index (AQI) categories in much of the Basin except in areas adjacent to the fires. Temporary monitors deployed in Azusa near the Bobcat fire and Redlands near the El Dorado Fire, as well as South Coast AQMD’s monitor in Glendora, have measured hourly values in the Unhealthy AQI category. Low-cost sensors in the San Gabriel Valley, the Santa Monica Mountains, and portions of the Inland Empire have been in the Unhealthy AQI category. Visit https://www.aqmd.gov/aqdata to view current air quality conditions.
In any area impacted by smoke. If you smell smoke or see ash due to a wildfire, limit your exposure by remaining indoors with windows and doors closed or seeking alternate shelter, and avoiding vigorous physical activity. For more tips on protecting yourself during a wildfire, see South Coast AQMD’s Wildfire Smoke & Ash Health & Safety Tips page: http://www.aqmd.gov/wildfire-health-info-smoke-tips.
Forecasted Smoke and Ash Impacts. Most of the South Coast AQMD jurisdiction will experience smoke impacts with the highest AQI values occurring in direct proximity to the Bobcat and El Dorado Fires. Smoke transported from fires in Central and Northern California may also contribute to widespread elevated PM2.5 concentrations. Smoke impacts will be highly variable in both timing and location through Friday.
• Thursday afternoon through Thursday evening: Smoke from the Bobcat and El Dorado fires will impact areas to the east and northeast of the fires, within the San Gabriel Mountains, San Bernardino Mountains, San Bernardino Valley, and San Gorgonio Pass. Smoke impacts from the El Dorado Fire will likely be largely confined to the area between Yucaipa to Banning.
• Overnight Thursday through Friday morning: Areas south of the Bobcat fire along the I-210 corridor from Pasadena to Rancho Cucamonga will likely see the highest PM2.5 levels as smoke is likely to remain closer to the ground overnight. Smoke impacts from the El Dorado Fire are predicted to be largely confined to the area between Yucaipa to Banning, with some smoke moving into western Riverside County and the Coachella Valley. Portions of Los Angeles County could see moderate smoke impacts on Friday morning.
• Friday afternoon: Onshore winds will start around noon and move smoke to the east and northeast towards the San Gabriel Mountains, San Bernardino Mountains, and San Bernardino Valley.
Overall, meteorological conditions will bring smoke and ash into portions of Los Angeles, San Bernardino, and Riverside Counties. Unhealthy or higher AQI levels due to PM2.5 concentrations are possible in areas of direct smoke impacts. Impacts will be highly variable throughout the day, impacting different parts of the region at different times.
Areas of direct impacts and poor air quality may include portions of:
• Los Angeles County: Central Los Angeles (Area 1), Southeast LA County (Area 5), West San Fernando Valley (Area 6), East San Fernando Valley (Area 7), West San Gabriel Valley (Area 8), East San Gabriel Valley (Area 9), Pomona-Walnut Valley (Area 10), South San Gabriel Valley (Area 11), South Central Los Angeles County (Area 12), San Gabriel Mountains (Area 15)
• Riverside County: Corona-Norco (Area 22), Metropolitan Riverside County (Area 23), Perris Valley (Area 24), Lake Elsinore (Area 25), Temecula Valley (Area 26), Anza Valley (Area 27), Hemet-San Jacinto Valley (Area 28), San Gorgonio Pass (Area 29), Coachella Valley (Area 30), East Riverside County (Area 31)
• San Bernardino County: Northwest San Bernardino Valley (Area 32), Southwest San Bernardino Valley (Area 33), Central San Bernardino Valley (Area 34), East San Bernardino Valley (Area 35), West San Bernardino Mountains (Area 36), Central San Bernardino Mountains (Area 37), East San Bernardino Mountains (Area 38)