Due to the Marek wildfire in the Angeles National Forest, concentrations of fine particulate may reach the Unhealthy for Sensitive Groups category or higher in areas of Los Angeles County.

The San Fernando Valley and portions of the San Gabriel Mountains near the fire and directly impacted by smoke may reach the Unhealthy category.

In addition, strong Santa Ana winds will likely cause fine particulate concentrations to reach the Unhealthy for Sensitive Groups level in any area where windblown dust is visible, especially through and below passes and canyons.

Wind- and dust-prone areas are likely to include: the San Bernardino Valley, southwest Riverside County, Orange County, the South Bay-Long Beach area and the Santa Monica-Malibu area.

All individuals are urged to exercise caution and avoid unnecessary outdoor activities in any area directly impacted by smoke or windblown dust. This includes areas where residents can smell smoke or see smoke or dust.

In areas directly impacted by smoke or windblown dust: Everyone should avoid any vigorous outdoor or indoor exertion; people with respiratory or heart disease, the elderly, and children should remain indoors. Keep your windows and doors closed unless it is extremely hot inside. In these cases, seek alternate shelter. Run your air conditioner if you have one. Keep the fresh air intake closed and the filter clean to prevent bringing additional smoke inside.