An unseasonably cold and vigorous storm system cut through the southwestern Pacific Coast this weekend, bringing rain, flash flooding and snow to parts of California and other states, forecasters said.
A flood warning was in effect on Sunday in San Diego as the storm continued to move along the coast before it heads inland.
“This storm is going to have an impact all the way across the country, but right now the storm center is off the California coast,” said Bob Smerbeck, a senior meteorologist at AccuWeather. “There’s going to be some flooding issues, mudslides and debris. People should keep their guard up.”
Los Angeles had received two to four inches of rain as of Sunday morning, and parts of Santa Barbara County got up to 6.5 inches of rainfall, the Weather Service said.
The rain was set to continue on Sunday with a chance of thunderstorms, the Los Angeles office of the National Weather Service wrote on Sunday.
Forecasters warned that the storms could produce hail, strong winds and a remote risk of a tornado. The storm was coming off the coast of California and was expected to shift south and eastward, creating the risk of flash flooding in Southern California, said Allison Santorelli, a meteorologist with the Weather Prediction Center in College Park, Md.
The Transverse Ranges and Sierra Nevada could get heavy snowfall, Ms. Santorelli said. Since this was a fairly cold system, significant snowfall was expected above 6,000 feet, with one to three feet of accumulation, and higher amounts possible above 7,500 feet.
Winter storm warnings were in effect for most of the mountains through Sunday evening.
California is expected to dry out by Monday, Mr. Smerbeck said, but the storm will continue to move into Arizona over the weekend.
Scattered to widespread rain showers were expected across Arizona through Sunday and isolated thunderstorms were expected through Monday before dry, warm conditions returned later in the week.
A wind advisory was in effect until 8 p.m. on Sunday in southeastern Arizona and portions of southern New Mexico.
The storm was also expected to bring significant precipitation to parts of Colorado, Nevada, Utah and Wyoming. As of Sunday morning, AccuWeather was forecasting between six to 10 inches of snow in Flagstaff, Ariz.
Amanda Holpuch contributed reporting.