Winter Weather Warnings Issued for Six States as Atmospheric River Hits

A stock photo shows a road in the middle of a blizzard. California is under a blizzard warning and other western states are under winter storm watch.

Weather warnings have been issued in six western states as an atmospheric river hits the region.

The National Weather Service (NWS) has issued a rare blizzard warning in California and winter storm warnings in other western states including parts of Nevada, Oregon, Washington, Idaho, and the western part of Wyoming.

The precipitation is caused by a corridor of concentrated, tropical moisture known as an atmospheric river.

When atmospheric rivers make landfall, they result in heavy rain and snowfall. California has seen a series of them, which have caused flooding and landslides in recent weeks.

While the weather event is also affecting surrounding states, California will be the most affected.

The rare blizzard warning is concentrated in the north-central part of the state. The mountainous areas will be the worst affected, with forecasters predicting “very high probabilities” of snowfall exceeding 48 inches for certain portions of the Sierra Nevada mountain range. There is a potential of snow reaching above 80 inches.

The winter storms are set to impact the western United States from Thursday through the end of the weekend.

“On the west coast, another significant winter storm is expected to begin late Wednesday and last through the weekend. Impacts include heavy mountain snow, heavy rain and gusty winds,” a statement from the NWS read.

The weather service also reported that snow and coastal rain will fall over the Pacific Northwest through Saturday.

“In addition, the widespread damaging wind will develop over the Western U.S. Wind gusts of 55+ mph are forecasted across much of the West, particularly across higher elevations and the Intermountain West, where 75+ mph gusts are possible. These winds would likely down trees and power lines, resulting in power outages across affected areas,” the NWS said.

Although the incoming winter weather conditions will be disruptive, this amount of snow could increase snowpack levels in the western mountains. Snowpack buildup is essential to the water supply for the region, as when the weather warms, it turns into meltwater that feeds into the rivers and reservoirs.

In recent years, parts of the Western U.S. have been in a severe megadrought, causing many reservoirs and rivers in the region to experience extremely low water levels. In 2023, however, intense winter storms built up the surrounding snowpack to record levels.

Before this most recent storm, snowpack levels in California have been below average. It remains to be seen how high they will be following these intense winter storms.

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