Another Bout of Atmospheric River, Pair of Storms, Flooding Expected for California for the Weekend

Following a significant power outage resulting from the bomb cyclone that affected about 200,000 homes, California is once again at risk of an atmospheric river, two storms, and flooding, among other weather disturbances this weekend.

Atmospheric River and the Rising Death Toll

After several rounds of storms caused widespread flooding, significant damage, and at least 19 fatalities, forecasters warn that more intense storms in northern California could cause excessive flooding and landslides this weekend. This is because another heavy band of rain known as an "atmospheric river" is expected to strike the state.

An atmospheric river and a sudden drop in air pressure known as a "bomb cyclone" brought heavy rain to California late last month. On New Year's Eve, San Francisco received 5.46 inches of rain, making it the second wettest day on record, as reported by NWS.

A second atmospheric river in northern California earlier this month resulted in the deaths of two people, the collapse of two piers, and the loss of electricity for more than 180,000 homes and businesses.

Then a storm in California dumped up to 16 inches of rain in some places, resulting in widespread flooding as well as sinkholes and forcing authorities to issue evacuation orders, including one for the affluent coastal city of Montecito.

According to poweroutage.us, as a new band of rain moves through the state on Friday morning, more than 15,000 homes and businesses in California are without power. Last week, an earlier atmospheric river caused nearly 200,000 people to lose power.

Another Bout of Atmospheric River

New Atmospheric River. Although some areas in northern California & southern Oregon could experience rainfall rates as much as half an inch per hour, forecasters with the National Weather Service anticipate that overall rainfall from a new atmospheric river will be less in most of California than it was during the previous two weeks.

Excessive Rainfall. While meteorologists from AccuWeather warn that it could renew the risks of landslides and flooding the NWS also cautions that excessive rainfall could likely result in more flooding.

More Flooding. According to forecasters, the active pattern in the western US will persist, and the region is expected to experience at least another pair of storms in the coming week. These additional moisture waves will tap into a sizable atmospheric river, increasing the risk of flooding.

The National Weather Service has issued high surf advisories for coastal communities located in northern California between the cities of Point Arena, and Eureka, and has issued flood watches for inland areas, including San Francisco, Santa Cruz, and Fresno, Forbes reports.

Moving West

According to the Weather Prediction Center, as Saturday's ridging begins to dissipate, moisture will also start to move further inland over the West. It is predicted that little to no accumulations will occur in the Great Basin and the Central and Northern Rockies due to the wintry mix of sleet and snow that will begin as snow over most lower-elevation valley locations on Saturday.

Up to 8 inches of snow may fall locally in higher elevation mountain locations, especially from central Idaho southward into Nevada as well as the Four Corners region, through Sunday morning.

Overall temperatures will stay mild due to ridging that will be present before the storm system is expected on Saturday. For the Pacific Northwest, Rockies, Great Basin, and northern and central California, highs on Friday and Saturday will fall between the 40s and 50s, while southern California as well as the Desert Southwest will experience highs between the 60s and 70s.