Powder Rains on 3 Counties : Dust Storm Closes Inland Highway 138

Winds whipped up choking dust clouds in the Southern California deserts Wednesday, causing closure of a major Antelope Valley highway and scattering a mysterious white powder that came down with the rain over a wide area in Riverside, San Bernardino and San Diego counties.

No one was certain just what the sticky substance was, but South Coast Air Quality Management Control District spokeswoman Kate Wallace said, “We think it’s a natural dust cloud blown up in the desert and coming down with the rain. There is no reason to think this is anything dangerous at this time.”

Nevertheless, the district had inspectors out gathering samples and said a report would be issued this morning.

Police and fire departments in Colton, Riverside, San Bernardino and other communities began getting calls from worried residents about 4 p.m. as small white spots appeared on automobiles and almost any dark object.

The spotting was reported from Adelanto in the Mojave Desert to Fallbrook in San Diego County and from Ontario to Palm Desert.

Northwesterly winds up to 40 m.p.h. were blowing from the Mojave Desert through the Palm Springs area Wednesday night. There was some light snow in the San Bernardino Mountains and light rain showers at lower elevations.

Some brown snow was reported as the desert dust was carried up to 6,000 feet by the strong winds.

California Highway Patrol officers closed California 138 through the Antelope Valley between the Lancaster and Gorman areas about mid-morning, when visibility dropped to less than three feet and they needed goggles and breathing equipment to aid motorists involved in several accidents.

Even after the highway was reopened early in the afternoon, there were wind warnings for motorists with campers and trailers from Mojave to Newhall and Acton to Gorman. Permit loads were still being prohibited. There were also alerts for travelers in the mountains because of fog and snow flurries.

The National Weather Service said an upper-level low-pressure area over Nevada and California “helped to squeeze” drizzles and light showers out of a deep marine layer along the coast, but rainfall amounts were all less than a tenth of an inch.

Downtown Los Angeles registered no more than .01 of an inch, bringing the season total to 11.30 inches. Normal to date is 10.31 inches.

Winds gusting to 30 m.p.h. are expected below the passes today. It should be clear and a little warmer. Winds should decrease on Friday. Wednesday’s high in downtown Los Angeles was 66 after a low of 53. The relative humidity ranged from 53% to 74%.