Atmospheric River Storm Approaches: ‘We Think This Will be A Big One’

A storm brought on by an atmospheric river – a ribbon of water vapor extending thousands of miles from the tropics to the West Coast – will bring drenching rains to Northern California after a record dry January in the region.

Parts of northwest California and southwest Oregon could see up to 10 inches of rain over the weekend and into next week, according to the Weather Channel. San Francisco and the Bay Area will receive between one and three inches of rain. Meanwhile, snow will fall in the Sierra Nevada mountains and in the Cascades in Washington and Oregon.

“We think this will be a big one,” National Oceanic and Atmospheric Administration spokeswoman Monica Allen told USA Today.

The rain is a welcome relief for San Francisco, which recorded zero rainfall in January for the first time since record-keeping began in 1850.

Yet perhaps the biggest beneficiaries of this weekend’s storm will be the CalWater field campaign, an inter-agency effort involving scientists from the NOAA, NASA, the U.S. Geological Survey, the Department of Energy and Howard University.

CalWater will pilot aircraft through and on top of the storm while some will sail into the storms aboard the Ronald H. Brown. Ground-based measurements will be taken off of the California coast. Researchers will study the storms’ intensity, speed and temperature, among other data, to help them understand the role atmospheric rivers play in precipitation, drought, and water storage.

“Improving our understanding of atmospheric rivers will help us produce better forecasts of where they will hit and when, and how much rain and snow they will deliver,” NOAA researcher Allen White said in a statement, according to USA Today. “Better forecasts will give communities the environmental intelligence needed to respond to droughts and floods.”

The dangerous effects of the soaking rain are already apparent in some areas; a mudslide had already been reported on Highway 101 south of Crescent City, California on Friday morning, as well as a rock slide in another Northern California city, reports the Weather Channel.

Atmospheric rivers “provide us water, but they are also a major source of our calamity,” USGS project manager Dale Cox told the Los Angeles Times. “Everybody’s hoping for them, but we don’t want too many.”