ALG Connect: Significant Flood Threat in California Through Early Wednesday Due to Another Atmospheric River Event

Significant Flood Threat in California Through Early Wednesday Due to Another Atmospheric River Event

Another atmospheric river event is hitting the West Coast, just days after California was drenched in heavy rain and high-elevation snow last week. Last week's atmospheric river brought up to a foot of rain in the coastal ranges of central California and the foothills of the Sierra Nevada. In the Sierra, one to two feet of additional snow fell on top of the already impressive snowpack.

Since the rain picked up late Monday night, there have been about two dozen reports of flooding across Northern California from the Mendocino Coast to the Sierra foothills to near Monterey Bay. Numerous roads were closed in Butte County due to flooding. Some mudslides and rockslides were also reported, including one covering both lanes of Skyline Boulevard above Stanford, California.

The strong winds from the storm and soaked ground has also lead to several downed trees, some blocking roads, including in parts of the Bay Area. High wind warnings have been posted by the National Weather Service, along with wind advisories. Wind gusts over 50 mph are possible in areas under high wind warnings. Strong winds may down trees and knock out power.

The National Weather Service has issued flood watches for much of California, including the lower elevations of the Sierra. Flooding is likely due to the combination of recent rainfall, snowmelt and additional heavy rain. S?oils are saturated and rain will run off causing flash flooding, as well as rises in creeks, streams and rivers. Minor to moderate river flooding is possible in some areas.

Winter storm warnings continue in the Sierra Nevada, including the Interstate 80 corridor, where heavy snowfall and strong winds may make travel very difficult to impossible.

As alluded to earlier, rain will taper off for some in central California as drier air pushes in, including the Bay Area. However, soaking rain and high mountain snow will continue in far Northern California and the Sierra into Tuesday night before ending.

In Southern California, rain is expected to continue into early Wednesday morning before winding down.

Areas in red and pink on the map indicate where significant, life-threatening flooding is possible through early Wednesday morning.

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 impact.