Temperatures in the Inland Empire and Riverside County valleys are expected to drop below freezing levels prompting a frost advisory from National Weather Service Friday.
The frost advisory will be in effect until 9 a.m. Friday and from midnight to 9 a.m. Saturday. Temperatures are expected to drop to 32 degrees.
A winter weather warning issued Thursday has expired in the mountain communities.
The winter weather warning was in effect until 10 a.m. Friday with heavy snow between 2 and 4 inches expected at elevations above 5,000 feet, and 4 to 8 inches above 6,000 feet. Wind gusts are expected to be as high as 60 mph in mountain areas.
Forecasters said Interstate 15 through the Cajon Pass might be impacted by the wintry weather Thursday night into Friday.
“There is also some indication that an isolated thunderstorm or two could develop as cold air aloft moves into the area and vorticity moves through the main flow … both Wednesday evening and Thursday,” the NWS stated.
Thunderstorm cells developed in the Riverside metropolitan area Sunday night as the past weekend’s storm activity subsided.
After the upcoming storm system exits Friday, a dome of high pressure will deliver clear and warmer conditions for the weekend, but the Weather Service said more precipitation may arrive at the start of next week.