The National Weather Service (NWS) has advised residents in southern and southeastern California to keep their windows and doors closed due to poor air quality. The Environmental Protection Agency's (EPA) AirNow map indicates that fine particle pollution has reached 'unhealthy' and 'very unhealthy' levels in several areas. Strong westerly winds, ranging from 25 mph to 35 mph with gusts up to 60 mph, are causing windblown dust, particularly affecting the Coachella Valley and Imperial Valley.