RIVERSIDE (CNS) – Another round of cold storms are bearing down on California and will spread into the Inland Empire beginning Tuesday night, bringing more rain and snow, according to the National Weather Service.

The agency said that back-to-back troughs of low pressure will push into the region from the Pacific Northwest, overlaying Riverside and San Bernardino counties until at least Thursday morning.

“Rainfall is expected to range from around one-half inch near the coast to one to 1.5 inches in the mountains, with locally greater amounts,” the NWS said in a statement. “Rainfall of one-quarter inch or less is likely for the high deserts, and one-tenth of an inch or less for the lower deserts.”

No flood or winter weather advisories had yet been posted. The Weather Service said that snow levels will initially remain high before the second and last trough of low pressure begins exiting on Thursday, when freezing levels will drop to as low as 3,500 feet.

“Snowfall is expected to range from three to six inches from 5,000 to 6,500 feet, with snowfall of six to 10 inches from 6,500 to 7,500 feet, and local amounts of 10 to 14 inches on the higher peaks,” the agency stated.

Snow packs throughout California have reached levels unseen in 40 years, and in some locations, have set record highs, according to the California Department of Water Resources and other agencies.

Meteorologists said that because of a low slung jet stream and consequent “atmospheric river” rolling over the Golden State, storms have fallen into a consistent pattern, plowing through most areas on a near weekly basis going back several months.

Roads throughout the San Bernardino National Forest remain obstructed by thick snow, mud and other hazards. Last week, the U.S. Forest Service announced that more than 50 mainly dirt passages leading to hiking, camping, hunting and other recreational spots could remain closed until June.

A ridge of high pressure was anchored over the region Monday, but it will give way to the incoming lows Tuesday, lowering temperatures for the rest of the week, forecasters said.

Daytime temperatures in the Riverside metropolitan area on Tuesday will be near 70, while on Wednesday and Thursday, the mercury will stall in the mid 50s, with lows in the low 40s.

In the Coachella Valley, temperatures will peak in the mid to upper 70s Tuesday, followed on Wednesday and Thursday with highs in the mid 60s, with lows in the mid 40s.

In the Temecula Valley, temps will top out in the upper 60s Tuesday, but on Wednesday and Thursday, the thermometer will read 10 to 15 degrees lower during the day, with lows around 40 for the remainder of the week, according to the NWS.

Sunny and slightly warmer daytime conditions are forecast throughout the region going into the weekend.

More Heavy Weather to Wallop Inland Region