Rare 'High Risk' Flood Threat for Southern California as Atmospheric Rivers Target the State Through Friday

After flooding rain the past few days, a more dangerous flood threat looms for California through Friday. Rainfall is becoming more widespread, and several inches of rain have already fallen as of Wednesday morning. A dramatic increase in rainfall rates and wind gusts is expected by Wednesday morning, along with an increase in snowfall rates in the Sierra.

Some computer models show an organized squall line moving from west-to-east through the Los Angeles basin and Traverse Ranges of Southern California from Wednesday morning to early Wednesday afternoon. This is the most likely time period for extreme flash flooding, although flooding could persist through Christmas.

Strong winds with the next two Pacific storms will down trees and knock out power, particularly in areas where the ground is soaked. Some gusts could reach 60-80 mph in the highest terrain of Southern California. Wind gusts up to 55 mph are possible in the L.A. Basin.

A very limited tornado threat exists along the California coast or in the Central Valley on Christmas Eve. Locally heavy rain will also spread into parts of the Desert Southwest Wednesday, including Las Vegas and possibly as far east as Phoenix Wednesday night.

Christmas Day - Friday: A second strong Pacific storm is forecast to surge into California Christmas Day, with a second round of heavy rain, strong winds and heavy Sierra snow. A few strong thunderstorms are possible right along the coast from San Francisco to Los Angeles on Christmas, including a brief tornado or two. Rain showers and mountain snow will linger into Friday. Some locally heavy showers are also possible in parts of the Desert Southwest both days.

Weekend: While a few showers may linger in the Four Corners Saturday, California and the rest of the Desert Southwest will dry out once again.

We recognize the severe impact that current conditions are having on our customers, and we are committed to restoring service levels as quickly as possible. As a result of these weather issues, the ALG Client Service Team will send daily updates as we monitor the progress and track job level.