RIVERSIDE (CNS) – Spring will arrive with more rainfall and considerable snowfall throughout the Inland Empire, the National Weather Service said Friday.

The agency said that back-to-back troughs of low pressure will push into the region from the Pacific Northwest beginning Sunday night, casting precipitation across Riverside County over two days.

“(Forecast models) are in agreement with the timing … of rainfall associated with the atmospheric river moisture,” the NWS said in a statement.

Meteorologists said that the early stage of the “significant storm system” will be in the predawn hours Monday, followed by deeper cells and heavier precipitation going into Monday night and continuing all of Tuesday, fragmenting by Wednesday morning.

“Snow levels Monday night through Tuesday morning will be quite high, as the warm atmospheric river moisture moves through,” the Weather Service stated. “Snow levels will start out around 6,500 to 7,000 feet Monday night, lowering to 5,000 feet by Tuesday afternoon, then further dropping to 4,000- 4,500 feet by Wednesday morning.”

Although the mountain areas within Riverside County, including along Highway 243 through Idyllwild-Pine Cove, are passable despite the heavy snowfall of the past month, hamlets and enclaves in and around the San Bernardino National Forest north of the San Gorgonio Pass remain buried, and residents there were bracing for the next round of winter weather.

“Preliminary forecast snow totals are, three to six inches from 4,000- 5,000 feet, six to 10 inches from 5,000 to 6,000 feet, 10-18 inches from 6,000-7,000 feet,” the NWS said. “Above 7,000 feet, two to three feet is possible. There will also be strong west winds with this storm over the mountains and deserts, with peak gusts 40 to 50 mph.”

The first official day of spring is Monday.

The most recent storm activity, which whipped the inland region Monday and Tuesday, unloaded heavy downpours and forced multiple road closures due to flooding in unincorporated communities.

No flash flood watches or winter weather advisories have been issued yet by the Weather Service.

Forecasters said that this weekend, the region will catch a brief respite, with a slight warm-up and mostly sunny conditions.

Daytime temperatures in the Riverside metropolitan area on Saturday will be in the low 70s, while on Sunday, the mercury will top out in the upper 60s, with lows in the low 50s both nights.

In the Coachella Valley, temperatures will peak in the mid to upper 70s Saturday and Sunday, with lows in the mid 50s, while in the Temecula Valley, temps will peak in the upper 60s this weekend, with lows in the mid to upper 40s, according to the NWS.

Spring Will Start with Downpours Across Inland Region