A fast-moving storm system that will sweep through the Inland Empire Thursday evening and Friday will generate stiff winds, as well as scattered thunderstorms and light snow at higher elevations, according to the National Weather Service.
The agency said that a cold trough of low pressure spinning out of the Gulf of Alaska will arrive in the overnight hours Thursday and overlay most of the inland region by Friday morning, speeding eastward with a ridge of high pressure in trail that will elevate temperatures and return sunshine for the weekend.
The winter-like weather disturbance will drive temperatures down 2 to 7 degrees below normal and churn up winds.
“The winds will increase Thursday afternoon across the mountains in San Bernardino and Riverside counties, and the deserts,” the NWS said in a statement. “Wind gusts to 70 mph will be possible in the highest wind-prone passes and canyons. Winds will briefly diminish Friday before a second surge develops.”
Rain probability is up to 80% across the region. However, precipitation is generally expected to be light, amounting to a tenth of an inch or less, except where thunderstorms develop, forecasters said.
The greatest chance for thunderstorms will be Friday morning, according to the Weather Service.
“Snow levels will start at 7,000 feet before quickly falling to 5,500 feet Friday morning,” the NWS stated. “Several inches of snow are expected.”
Most of the inclement activity will fade by Friday afternoon, then high pressure systems moving out of the northwest will influence weather patterns going into the weekend and for part of next week, according to forecasters.
“Breezy Santa Ana winds will develop Sunday morning and prevail into early Monday,” the Weather Service said. “Winds will be out of the northeast … through the Inland Empire. These winds look weak to moderate in strength at this time.”
High temperatures in the Riverside metropolitan area are expected to be in mid 60s Friday, with lows in the mid-40s. However, the mercury bounces back, with highs forecast in the upper 70s Saturday and upper 80s Sunday, with lows in the mid-50s.
In the Coachella Valley, the highs will be in the low 70s Friday, with lows in the low 50s, and a Wind Advisory is in effect for the deserts east of Palm Springs, where gusts could top out at 40 mph, according to the NWS. On Saturday and Sunday, temperatures will peak in the upper 80s, with lows in the low 60s.
In the Temecula Valley, the mercury will stall in the low 60s Friday, with lows around 50. Highs for the weekend will hover in the mid 80s, and lows in the low 50s, forecasters said.