Track the Latest Atmospheric Rivers to Hit California and the Pacific Northwest

A pair of atmospheric rivers is expected to hit the Western United States and Canada in the coming days.

How Atmospheric Rivers Cause Flooding

In the coming weeks, buckets of rain are likely to batter California. The culprit? Atmospheric rivers. The rains are born far away, deep in the tropical Pacific, where water evaporated from the warm ocean surface is absorbed into the atmosphere.

How California Reservoir Water Levels Changed After Atmospheric Rivers

One reservoir in northern California rose by 5 feet after two atmospheric rivers supplemented the water levels. An atmospheric river began across much of the Pacific Northwest, including Oregon and Northern California, on Friday.

Parade of Cross-Country Storms to Hammer the West Coast Into Mid-January

The weather in the new year will kick off on an active note as a series of storms will travel from coast to coast, bringing heavy rain, snow and thunderstorms over the 10 days. The West will bear the brunt of each storm first, beginning with one arriving early this week, warn AccuWeather meteorologists.

Northwest Drinking Water Concerns Could Get Worse as the Climate Changes

Thunderstorms high in the Cascades recently stirred up a lot of dirt in a central Washington river, causing problems for people on its banks.

All the dirt in the Naches River was too much for the city of Yakima’s water treatment plant to handle. Cities and towns could see situations like this happen more often as the climate continues to change.

Climate change will cause more storm runoff, change when snowpack melts and lead to more severe wildfires and harmful algal blooms, said Amanda Hohner. She studies how post-wildfire runoff affects drinking water treatment plants.

“At least in the Western U.S., the effects of wildfire and also climate change are really starting to challenge drinking water treatment plants, resulting in different water quality than maybe those water treatment plants were designed for,” Hohner said.

Storms to Deliver Rain, Mountain Snow Across Western US Through Christmas

Residents across the western United States who have drought relief on their holiday wish lists this season will be in luck over the next week. A series of storms will take aim at the West Coast and deliver needed rain and mountain snow from Southern California to the Pacific Northwest through Christmas Day.

Series of Wintry Storms Take Aim at Northwest

Another series of storms is set to sweep through the Pacific Northwest and Northern California into next week and not only bring much-needed rain and mountain snow but also flooding concerns.

A dip in the jet stream across the Bering Sea through the northern Pacific Ocean will push waves of energy toward the Canadian Rocky Mountains and Northwest this week, according to AccuWeather Lead Long-Range Senior Meteorologist Paul Pastelok, who added that temperatures will be near to below normal.

San Francisco Could See Its First Rainfall Since January as a Potentially Wetter California Weather Pattern Takes Shape

Much needed rain will finally return to California and will likely end a month-plus dry streak in San Francisco and Sacramento. Dry conditions have prevailed across most of California since late January due to the upper-level pattern.  A strong area of high pressure aloft near California has pushed the jet stream and storm track northward into the Pacific Northwest.

The persistence of this pattern has resulted in drought conditions during the wet season. Nearly 70% of the Golden State is abnormally dry, and about a third of the state is in moderate drought, according to the latest report from the U.S. Drought Monitor.

Water Reservoirs Below Average in Cascades

Coming off a summer of moderate drought with some crop losses, the five Cascade Mountain reservoirs serving irrigators in the Yakima Basin have less water than normal and the winter snowpack outlook is uncertain.

“We are in an El Nino neutral which would mean normal conditions and we would be fairly optimistic. No one has been calling for a dry or mild winter so we have no cause to think it will be,” said Chris Lynch, hydrologist for the U.S. Bureau of Reclamation in Yakima. However, he added, a warm water body off the Gulf of Alaska, reminiscent of one there prior to the drought of 2015, could result in more moderate temperatures and less snow.