Flood Watch Issued In RivCo, Mountains Under Winter Storm Watch

RIVERSIDE COUNTY, CA — Storms rolling through Southern California will produce heavy rain at times over the coming days, prompting the National Weather Service to issue a flood watch across western Riverside County from 10 p.m. Tuesday through Friday afternoon.

The Coachella Valley is under a flood watch starting at 4 a.m. Dec. 21 through 4 p.m. Dec. 22.

"For San Diego and western Riverside Counties, rainfall is expected to range from 2 to 3 inches for the coast and valleys, with 2 to 4 inches in the mountains," the NWS reported.

A winter storm watch is also in effect for the San Bernardino County mountains beginning at 6 p.m. Thursday through 10 a.m. Saturday. Snow is forecast to drop to the 7,000-foot level, possibly 6,000 feet by Saturday night, according to the NWS.

Forecasters said two troughs of low pressure will slide through the region, with the current one exiting to the east Wednesday, and the next one reaching the coast as an occluded front soon afterward, moving slowly across the region, gradually pushing into Arizona Saturday.

The NWS predicted isolated thunderstorms, with the highest probability on Thursday, Dec. 21, the official start of winter.

Temperatures will remain at a seasonal average throughout the storm series, with no influence from the Polar jet stream, according to meteorologists.

In the Riverside metropolitan area, highs Tuesday to Friday will hold in the mid-60s, with overnight temperatures in the low 50s.

In the Coachella Valley, the daytime mercury will hover around 70 and fall into the mid-50s overnight this week, while in the Temecula Valley, the temperature band will be virtually identical to Riverside metro Tuesday to Thursday, though the daytime high will peak in the upper 50s on Friday.