A weather disturbance forecast to sweep across the Inland Empire Saturday could trigger thunderstorms, especially in and around mountainous areas, according to the National Weather Service.
The agency announced a cold low-pressure system moving toward Southern California from the Pacific will drag inclement conditions into the region during the predawn hours Saturday, ratcheting up the chances of rain by late morning.
“The highest chances of precipitation (are) in Orange County, the Inland Empire and the San Bernardino Mountains,” the NWS said in a statement. “Areas of drizzle or light rain are possible ahead of the main organized band of precipitation. Rainfall rates will be mostly light to moderate … The cold air, combined with some weak instability, will lead to a … chance of thunderstorms along and west of the mountains.”
No flood, wind or other hazard advisories had been posted Friday by the Weather Service.
Meteorologists said the drop in temperatures associated with the trough may lower snow levels to 5,000 feet, but the only appreciable amounts of frozen precipitation would likely occur above 6,000 feet Saturday.
The heavy clouds and periodic rain were expected to continue through Sunday regionwide as the trailing edge of the system moved eastward into Arizona. By Monday, a high-pressure ridge was forecast to build over the West Coast, ushering in clear and warmer conditions, according to meteorologists.
Highs in the Riverside metropolitan area Saturday were expected to top out at or just below 60 degrees, with overnight lows in the upper 40s. Sunday’s highs would likely reach the mid-60s, with lows again in the upper 40s.
In the Coachella Valley, the mercury was forecast to crest in the lower 70s Saturday, with lows in the low 50s, followed by highs in the mid-70s Sunday and overnight temps in the mid-50s.
In the Temecula Valley, daytime temperatures will hover around 60 Saturday, followed by lows around 40, with a similar Fahrenheit band Sunday.