Strong Santa Ana winds are occurring across Southern California causing windblown dust in many areas, as well as windblown ash from brush fires that occurred this past summer. The local National Weather Service has predicted strong and potentially damaging northeasterly winds through Saturday. The strongest winds are expected in the mountains and through and below passes and canyons, but windblown dust and ash can also be transported across the Basin. Windblown ash will occur downwind of the burn areas from the summer brush fires, especially the Sand Fire in Santa Clarita, the Blue Cut Fire in the Cajon Pass, and the Reservoir and Fish Fires near Azusa and Duarte.

Areas of elevated PM10 particulate matter, due to windblown dust and ash, are likely to occur at times throughout the South Coast Air Basin and the Coachella Valley, with many areas potentially reaching the Unhealthy for Sensitive Groups level at times, or higher.

In areas where windblown dust and ash are occurring: Everyone should avoid any vigorous outdoor or indoor exertion; people with respiratory or heart disease, older adults, and children should remain indoors. Keep windows and doors closed or seek alternate shelter. Run your air conditioning system (cooling or heating) if you have one and keep the fresh air intake closed and the filter clean to prevent bringing additional particulates inside. Avoid using a swamp cooler or whole-house fan to prevent bringing additional smoke inside. To avoid worsening the health effects of particulates, don’t use indoor or outdoor wood-burning appliances, including fireplaces.