Air quality hits hazardous levels in Coachella Valley as storms bring dust and rain
Air pollution in the Coachella Valley reached hazardous levels Monday, while some areas were also drenched as thunderstorms moved through the area.
Because of particulate matter, the air quality index in the valley hit 681, according to the U.S. Environmental Protection Agency. Anything over 300 is considered hazardous.
At levels that high, pollution can pose a risk to anyone, and people are advised to stay indoors and limit activity, the EPA said. As of 3 p.m., air quality readings in most of the valley were still above 300.
National Weather Service meteorologist Brian Adams said the poor air quality was the result of storm activity coming west from Arizona that was producing thunderstorms, heat and humidity observed throughout the Coachella Valley early Monday.
Those storms collapsed and pushed a gust of strong winds that lifted a significant amount of dust into the air, overwhelming the valley, said Scott Epstein, the program supervisor of air quality assessment for the South Coast Air Quality Management District, the environmental regulator for Southern California. That dust front moved through the valley to the San Gorgonio Pass and on to the Inland Empire.
The rain was expected to be less of a tenth of an inch in most areas, although some isolated spots could see more.
The biggest impact from the storm was the winds, which gusted to as high as 46 mph in Desert Hot Springs and 41 mph in Cathedral City early Monday morning. The air quality readings in the Coachella Valley were some of the worst in Southern California, a situation Epstein attributed to the path the storm moved through the region.
The dust front moved through the Coachella Valley first, but stayed low to the ground and was unable go over the surrounding mountains, leaving it to instead to move out through the comparatively narrow San Gorgonio Pass. He compared the way the dust moved through the valley to the way smog and other human-made pollution often settles in valleys throughout Southern California.
Weather service meteorologist Adam Roser said that while the storm brought intense winds that blew up plenty of wind and dust, it was not large or tall enough to be categorized as a "haboob" by the agency.
Roser said some of the weather service's models showed the dust would likely clear Monday night, although it is possible storms to the east could push more wind into the area and create a similar effect again Tuesday morning. However, Roser said it's unlikely the dust Tuesday will be as bad as on Monday.
Any precipitation that reaches the ground could also clear the air sooner, but Epstein said the most of the rain that had fallen in the valley so far Tuesday had evaporated before hitting the ground.
Adams added that the thunderstorm activity made it feel more humid at a time when valley residents might be looking for relief from recent sweltering temperatures. Adams said that while Monday’s high of 104 is significantly cooler than those of recent days, residents should keep in mind the humidity will make it feel warmer.
The stormy weather will continue Tuesday, with a high near 102, gusty winds and a 40% chance of precipitation in Palm Springs. It is then expected to gradually dry out and start to warm back up, with a high of 105 predicted for Friday and one of 108 on Sunday.
Paul Albani-Burgio covers breaking news and the city of Palm Springs. Follow him on Twitter at @albaniburgiop and via email at paul.albani-burgio@desertsun.com.
This article originally appeared on Palm Springs Desert Sun: Air quality hits hazardous levels as storms hit Coachella Valley
