Thunderstorm, Winds Forecast Tonight In Coachella Valley

COACHELLA VALLEY, CA — 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 NWS's forecast for Thursday night in the Coachella Valley reads, "A chance of showers between 11 p.m. and 2 a.m., then a chance of showers and thunderstorms after 2 a.m. Areas of blowing dust before 8 p.m. Partly cloudy, with a low around 59. Breezy, with a southwest wind 15 to 25 mph becoming west 5 to 10 mph after midnight. Winds could gust as high as 40 mph. Chance of precipitation is 30 percent."

The likelihood of high winds stirring up dust that could impact the health of Coachella Valley residents prompted the South Coast Air Quality Management District Thursday to issue a Windblown Dust Advisory.

The agency said that the advisory will be in effect until 3 p.m. Friday "due to high winds and dry conditions" affecting the area between Whitewater and Desert Center, producing particulate matter that will lower air quality.

The SCAQMD alert follows a Wind Advisory posted by the National Weather Service Thursday, warning of 25-35 mph winds throughout the area as the storm front approaches.

"In areas directly impacted by high levels of windblown dust, limit your exposure by remaining indoors with windows and doors closed and avoiding vigorous physical activity," the SCAQMD said. "Run your air conditioner or an air purifier. If temperatures allow, avoid using whole-house fans or swamp coolers that bring in outside air."

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 percent 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.

— City News Service contributed to this report.