A final storm system dumped rain and snow Monday in the Inland Empire, where frozen precipitation could make for treacherous driving conditions at higher elevations Tuesday.
The National Weather Service issued a winter storm warning until 4 a.m. Wednesday for the Riverside County Mountains and San Bernardino Mountains.
Snow levels were expected to be around 5,500 feet Monday, then drop much lower by Tuesday night, NWS meteorologist Miguel Miller said.
“Very heavy snow is expected to fall near the top of Mt. San Jacinto,” Miller said. “Snowfall totals through Tuesday night are expected to be between six inches and a foot above 6,000 feet, and between one and three feet above 7,500 feet.”
The snow, along with 40 mph winds in the mountain passes, could create hazardous conditions on the roads, the meteorologist said.
According to the NWS, as temperatures plunge Tuesday night, frozen precipitation could materialize down to 2,500 feet, impacting the Anza Valley and other gateway locations to the San Bernardino Mountains, including Banning-Beaumont.
In Riverside County, motorists were advised to be prepared for travel restrictions or mandatory snow chains in multiple locations.
Corridors most likely to experience winter weather are:
— Interstate 10 between Banning and Yucaipa;
— state Route 79 between Beaumont and San Jacinto;
— state Route 60, in the Badlands, between Beaumont and Moreno Valley; and
— all mountain routes between Hemet and Palm Desert, through the San Bernardino National Forest.
Areas affected by the storm in the San Bernardino Mountains will have chain installers available during chain control periods, according to Caltrans.
The Riverside metropolitan area and Lake Elsinore were expected to get up to six-tenths of an inch of rainfall Monday, while the San Gorgonio Pass near Banning could see up to 1.2 inches, meteorologists said. Up to 1.6 inches of precipitation was forecast for Idyllwild and less than one-tenth of an inch was expected in the Coachella Valley.
Multiple neighborhoods fell under mandatory evacuation orders at intervals between Jan. 14 and Jan. 17, when the last storm series produced intense downpours, resulting in a number of street closures. Mud and debris flows, however, did not cause any serious damage to residential properties.
The Riverside County Emergency Management Department issued mandatory evacuation orders Saturday morning for numerous communities in the Holy Fire burn areas, but all mandatory and voluntary evacuation orders were lifted by Sunday morning.
A wide area skirting the eastern side of the national forest, bordering Lake Elsinore and the Temescal Valley, was left exposed to potential flood damage because of the 23,000-acre Holy Fire in August. The blaze, allegedly the work of an arsonist, denuded steep terrain below Santiago Peak, permitting water to flow unchecked onto lower slopes where subdivisions are situated.
Scattered rain and snow showers will linger into Wednesday morning, when the storm system will roll eastward.