SAN FRANCISCO – It was a dry first half of December for much of California, but we're switching gears for the second half with a week of showers and thunderstorms in the forecast, threatening areas of flooding and travel challenges as a one-two punch of storm systems settles in off the Pacific coast.
Rainfall is increasing across California on Monday, spreading south into the Los Angeles area and east into the Sierra Nevada for the first round of rain and snow. It'll be the first measurable rain for Los Angeles since mid-November, while snow totals could reach 6-12 inches in the higher elevations of the Sierra.
In addition, some of the showers will likely intensify into thunderstorms, especially from Central California and the Bay Area to Northern California, bringing small hail and heavy downpours, triggering localized areas of flash flooding.
Showery weather continues on Tuesday while the storm system drifts north and pulls the bulk of its rain into the Pacific Northwest, only to have a second storm system develop off California in its place, renewing the rainy forecast for the second half of the week.
This second system is forecast to concentrate its rain on the southern half of the state, with a rainier forecast for Los Angeles and Southern California from Thursday into Friday, eventually spreading into the Desert Southwest over Christmas weekend.
"It’s this second storm that dives in behind that low-pressure system by midweek on Wednesday that finally does move in – takes that more southerly track down the coastline and keeps that rain in the forecast and unsettled weather into the end of the week," FOX Weather Meteorologist Jane Minar said.
By the time the one-two punch of storms has exited the region, overall rainfall totals are expected to reach at least 2-3 inches, with several coastal areas receiving as much as 5 inches.