Rain creeps into Southern California with surprise late July showers: ‘This is unusual’

A storm system moved into Southern California on Monday, bringing record-setting rainfall to some parts of the drought-stricken region.

Downtown Los Angeles recorded 0.12 inch of rain, three times the previous daily record set in 2013 and enough to make it the area’s third-wettest July on record. The wettest July ever in the city was in 2015, when 0.38 inch of rain fell. The second-wettest was in 1886, with 0.24 inch.

Mt. Baldy, which recorded 0.37 inch by 5 a.m., was the “rainfall winner,” said David Sweet, a meteorologist with the National Weather Service in Oxnard.

Monday’s rainfall was unusual, given that Los Angeles often records “just a couple-hundredths of an inch, if at all, in July,” Mark Jackson, the meteorologist in charge of the National Weather Service’s Los Angeles office, told Weather Nation. July is typically the driest month of the year in Los Angeles, Jackson said.

The threat of monsoonal showers — including brief heavy downpours and gusty winds — lingered through the afternoon. The weather service had issued a flash flood warning for the Antelope Valley and some mountainous areas of Los Angeles and Ventura counties but called them off about 7 p.m. Monday.

The weather service warned that thunderstorms could develop Tuesday afternoon, bringing a chance of heavy downpours and strong winds.

A flash flood watch was issued Monday morning across the Inland Empire, and portions of San Bernardino and Inyo counties. The NWS lifted the warnings about 6 p.m. Monday but warned motorists to heed road closures and watch for poor road conditions.

In the Coachella Valley, the showers caused power outages that left some 900 households in Palm Desert and 240 in Desert Hot Springs without power as of 8 p.m. Monday, according to Southern California Edison’s outage map.

Lighter showers also moved through Orange County.

Weather experts said a low-pressure system embedded inside the typical summer monsoon pattern was behind the spate of moisture.

“It is related to monsoon season, which runs July through September, but this is particularly strong,” said Matt Moreland, a meteorologist with the National Weather Service in San Diego. “Normally you don’t see the rain in the cities in the lower elevations in the summertime.”

The rain diminished Monday evening, but a few lingering showers will be possible Tuesday over the Los Angeles and Ventura county mountains, as well as portions of the Antelope Valley, Santa Barbara and San Luis Obispo County.

Although the rain will bring a welcome bit of relief for the drought-stricken West, it won’t do much to permanently reduce the state’s shriveling reservoirs or overall dryness.

“Any area that receives more than a quarter of an inch will receive maybe 12 to 24 hours of enhanced moisture before things dry out again,” said Sweet, the NWS meteorologist, noting that some hillside vegetation is so dormant that it won’t even receive the rainfall.

“Let me just say,” he said, “this will do almost nothing for the drought.”

Still, Southern Californians who awakened to wet grounds and gray skies rejoiced in the moisture.

“It’s not much but it’s soooo welcomed. We need every drop we can get out here,” one person said on Twitter.

“More rain, please!” said another.