The first and weaker of two winter storms threatening Riverside County Wednesday may spur light rain in the Inland Empire as early as Wednesday evening, meteorologists said.
A weak trough of low pressure will bring gusty winds and a small chance of light precipitation over and west of the mountains late today into early Thursday, according to the National Weather Service. By early Friday, a second and much stronger storm is expected to bear down on the entire region, including the Coachella Valley.
The U.S. Forest Service warns that snow levels may drop to 6,000 feet over the weekend in the San Jacinto Mountains.
A spokesman for the agency says areas burned by the recent Mountain and Silver fires will be monitored for potential mudslides.
"The Silver and Mountain wildfires impacted state highway 243, south of Banning and south of Idyllwild last year," USFS Spokesman John Miller said. "Caltrans will be closely monitoring conditions during the storm and the highway may be subject to closure if conditions warrant."
"A large strong low pressure system over the Eastern Pacific will move slowly inland through California for Friday through the weekend, bringing periods of heavy precipitation and strong gusty winds," according to the national weather service, which forecast widespread rain and winds Friday morning into Friday afternoon, and intermittent showers and winds from Friday night to Sunday.
Rainfall totals from the second storm are expected to range from a half to one inch in the Coachella Valley to 3 to 5 inches on coastal mountain slopes, though local amounts could exceed 7 inches on south-facing mountain slopes.
"The rainfall could cause flash flooding and mud and debris flows near recent burn areas as well as urban and small stream flooding," an NWS advisory said.
Wind gusts on Friday are expected to be around 65 miles per hour in the mountains and Coachella Valley, and around 40 mph in the Inland Empire.
A winter storm watch for snow that may impact travel is scheduled for the region's higher elevations from Friday morning to Saturday night.
Snow levels are expected to lower to around 6,000 feet by Friday night and down to 5,500 feet Saturday night.
Six to 10 inches of snow accumulation is possible in mountain areas above 6,000 feet with local amounts of 2 to 3 feet on higher peaks, mainly above 7,500 feet, according to the NWS.
The agency advised motorists in the mountains to carry chains, as well as extra food and clothing, with them when venturing out during the storm.
– City News Service contributed to this report.