Full List of Weather Warnings as Atmospheric River Hits US

An atmospheric river battering the Pacific Northwest has prompted the National Weather Service (NWS) to issue a slew of weather warnings.

An atmospheric river hit the Pacific Northwest over the weekend, with a second round of heavy rain and snow arriving earlier this week. Poor weather conditions are expected across three states in the Northwest through Thursday.

Atmospheric rivers are a “long, narrow region in the atmosphere—like rivers in the sky—that transport most of the water vapor outside of the tropics,” according to the National Oceanic and Atmospheric Administration. The storms contributed to alleviating much of California’s drought last winter, but they also contributed to devastating floods and mudslides.

As of Wednesday afternoon, multiple weather warnings related to the storms were in place across Washington, Oregon and northern California.

Flood-Related Warnings

Weather alerts related to flood risk were the most widespread warnings from the atmospheric river.

In Washington, meteorologists issued a coastal flood warning and a flood warning.

“Motorists should not attempt to drive around barricades or drive cars through flooded areas,” the warning said. “Turn around, don’t drown when encountering flooded roads. Most flood deaths occur in vehicles.”

The flood warning was for the Skokomish River in Mason County and will remain in place through Friday morning. The river is expected to cause moderate flooding, with “deep and quick flood waters inundating some residential areas,” the warning said.

Most of northwest Oregon was under a flood advisory. As of Wednesday morning, the heaviest rain had ended, but flood threats remained.

Winter Storm Warnings

A winter storm warning was in place in northern Washington, southern Oregon, and northern California, and winter weather advisories extended further into the Golden State.

The NWS office in Medford, Oregon, warned of additional heavy wet snow of up to 6 inches in Pondosa, Etna, Tennant, Somes Bar, Happy Camp, Callahan, Bray, Fort Jones, Scott Bar and Greenview.

“Travel could be very difficult,” the warning said. “Very strong winds could cause extensive damage to trees and power lines.”

High Winds Cause Dangerous Travel Conditions

Strong winds related to the storm also prompted a slew of weather alerts. Wind-related alerts were placed in Oregon, Washington, California, and Nevada.

Wind gusts up to 65 miles per hour were possible.

“Strong winds will be capable of blowing down trees and power lines. Power outages are possible. Travel will be difficult, especially for high profile vehicles. Gusty winds will blow around unsecured objects.”

Other Warnings

In addition to impacting the northern part of California, the atmospheric rivers also contributed to dangerous waves in San Francisco. An offshore swell related to the atmospheric river generated waves as high as 18 feet, NWS meteorologist Dylan Flynn told Newsweek.

The waves traveled for a day before reaching the San Francisco coast earlier this week. On Wednesday morning, another high surf advisory was issued for waves related to the second atmospheric river.

Earlier in the fall, AccuWeather meteorologists predicted that atmospheric rivers would impact northern California and the Pacific Northwest at the start of the winter season, then shift to impact central and southern California in January and then return north to finish out the winter season.

AccuWeather long-range expert Paul Pastelok previously told Newsweek he expects this incoming winter season to resemble 2022-23 in terms of atmospheric rivers. The forecast could change if the water temperatures in the Pacific undergo a drastic change. If the warmest waters shift east, Pastelok warned, California could experience a dry, warm winter similar to the 2013-14 season.