Frigid moist air is bound for the Inland Empire, bringing with it what’s expected to be the first precipitation of the winter season, arriving this weekend, according to the National Weather Service.
Forecasters said that after another Santa Ana wind event blows through Wednesday afternoon and night, regional climatic patterns will briefly stabilize, followed by a storm system on Saturday and Sunday.
“Guidance has a very cold upper level low (pressure) digging west as it drives south from Canada for the weekend,” the NWS said in a statement. “The dynamics and instability given this track could bring widespread showers, and even locally heavy showers … in the mountains and foothills.”
Prognostication charts showed the trough diving out of Canada, sweeping across virtually all of California, beginning Friday night. The first signs of precipitation will likely appear Saturday morning in the extremely dry inland region.
There will be more than one low pressure system trundling over the area, slowly exiting to the east Monday morning, according to meteorologists.
No predictions on rainfall amounts were available yet.
“It looks to be wetting rainfall and low elevation snows, down to 3,500 feet, with the main system overhead on Sunday,” the weather agency stated.
The offshore wind event on Wednesday, triggered by a disturbance over the Rockies, will likely generate northeast winds of 10 to 15 mph, gusting to 40 mph in wind-prone locations, forecasters said.
A Red Flag Warning remains in effect across the region until 8 p.m. Thursday, due largely to relative humidity levels in the single digits.
Daytime temperatures in the Riverside metropolitan area from Wednesday to Friday will peak in the mid 70s, dropping into the mid 40s during the night. This weekend, the mercury will peak in the mid to upper 50s, with nighttime lows in the upper 30s.
In the Coachella Valley, temps will also make it into the mid 70s from Wednesday to Friday, followed by lows in the mid 40s. Saturday and Sunday, however, the highs will top out in the low to mid 60s, and back down to the mid 40s at night.
In the Temecula Valley, the Wednesday-to-Friday temperature band is almost identical to Riverside metro, but through the weekend, the overnight lows in Riverside County’s southwest pocket may drop to freezing, according to the NWS.