Snow is expected to fall in the mountains as part of a winter storm expected to move into the area Tuesday, Dec. 14. Valley News/Diane Sieker photo

RIVERSIDE (CNS) – A cold, slow-moving storm will bring heavy rain throughout Riverside County, as well as a chance of snow in the mountains, forecasters said.

Heavy showers are expected throughout the day  in the Riverside metropolitan area, the San Gorgonio Pass near Banning and the Riverside County mountains, according to the National Weather Service. The Coachella Valley is also expected to get wet today but with much lighter showers.

The storm system moving southeast is expected to drop rain showers through Thursday afternoon, NWS meteorologist Miguel Miller said. There is also a slight chance of thunderstorms throughout the region until Thursday afternoon.

Rainfall amounts through Thursday could reach 3 inches in the Riverside metropolitan area, 4 inches in the San Gorgonio Pass near Banning, 5 inches in the Riverside County mountains and 1.5 inches in the Coachella Valley, Miller said.

Low-lying areas in the Inland Empire could see some flooding today, but the rain showers will be much lighter the rest of the week, he said.

A winter storm warning is in effect until 5 a.m. Thursday in the mountain communities above 5,500 feet in Riverside and San Bernardino counties.

Snow levels will be around 6,000 feet this morning, then rise to 6,500 feet today before dropping to 5,500 feet on Tuesday, Miller said. Idyllwild could get trace amounts of snow, while up to a foot of snow is expected to fall near the peak of Mount San Jacinto.

Big Bear Lake is expected to get between 2-4 feet of snowfall by Thursday, but some of that snow will melt because of warm ground temperatures, Miller said.

NWS officials warned that roads could be slippery and visibility will be limited by falling snow, making travel difficult on routes above 5,500 feet.

High temperatures today could reach 57 degrees in Riverside, 67 in the San Gorgonio Pass, 75 in the Coachella Valley, 40 in Idyllwild, 53 in Temecula and 57 in Hemet.

The storm is expected to move east out of the region through Friday, then dry weather will return through at least the weekend, Miller said.