A storm system that reached the Inland Empire Thursday will stagnate over the region into Friday, bringing heavy precipitation and the possibility of localized flooding, according to the National Weather Service.
“The forecast is showing a broad area of rainfall totals Wednesday night into Thursday,” according to the NWS. “Amounts for Wednesday through Friday morning are 1 to 2 inches in the coastal areas and valleys (and) 2 to 5 inches on the mountain slopes below 5,000 feet.”
Desert areas will receive up to a half-inch, while snow levels will remain above 5,000 feet, with the greatest accumulations — as much as three feet — above 7,000 feet, forecasters said.
“Snowfall amounts will be highest in the San Bernardino Mountains, with lesser amounts in the Riverside County mountains,” the Weather Service stated.
A flash flood watch will be in effect until 4 p.m. Thursday, with the NWS cautioning that “excessive runoff may result in flooding of rivers, creeks, streams and other low-lying, flood-prone locations.”
Motorists were urged to be on alert when trying to navigate roads with standing or moving water. The NWS uses the “Turn Around, Don’t Drown” exhortation with flood warnings.
According to the agency, in Riverside County, Monday night’s storm produced the greatest recorded rainfall in south Riverside — 0.59 inches. Beaumont received the next highest total at 0.49 inches, while Temecula received about 0.28 inches. East of the San Gorgonio Pass, little to no precipitation fell.
There were minor snow accumulations in the mountain communities south of Interstate 10, but mostly trace amounts, including in Pine Cove, according to the NWS.
Two road closures remain in effect following the Christmas Eve storm, according to the Riverside County Department of Transportation.
Leon Road, between Domenigoni Parkway and Olive Avenue, remains closed in Winchester, and a segment of Bridge Street between Fernandez and Gilman Springs roads remains shut down just north of San Jacinto. According to the California Highway Patrol, a big rig nearly became stuck on the corridor Tuesday morning when the driver ignored the closure signs and tried to cross it.
The trough of low pressure that’s enveloped the area originated from the Gulf of Alaska and will drag in copious moisture, according to the NWS.
The agency published prognostication charts showing the rain arriving in some areas just to the north of the inland region late Tuesday night, with heavier precipitation sprawling across the area Wednesday afternoon, and the worst of the inclement weather continuing through Thursday before gradually moving eastward Friday morning, though showery activity could linger into Friday night.
Temperatures will continue to be well below average during the day and night.
In the Riverside metropolitan area, the highs will remain in the low to mid 50s until Saturday, with lows around 40 degrees. In the Coachella Valley, the mercury will top out close to 60 degrees over the four-day period, with lows in the mid 40s, and in the Temecula Valley, highs will be in the mid 50s, with lows around 40, forecasters said.