After years of drought, California faces devastating floods

Hundreds have been evacuated, and schools and roads have been closed. And climate change is a partial culprit.

Road crew member Jeremy Brown helps clean up state route 140 near the Merced River in a closed off Yosemite National Park, Calif., Sunday, Jan. 7, 2016. CREDIT: Gary Kazanjian/AP Photos
Road crew member Jeremy Brown helps clean up state route 140 near the Merced River in a closed off Yosemite National Park, Calif., Sunday, Jan. 7, 2016. CREDIT: Gary Kazanjian/AP Photos

California and parts of Nevada were hit with a massive winter storm over the weekend, in which at least three people died. Roads, schools, and even ski resorts were closed.

The National Weather Service is predicting more precipitation for the region in the coming week, with storms expected Tuesday and Thursday.

“A series of Pacific storm systems will continue to impact the western U.S. through midweek, bringing periods of rain and snow, some of which could be heavy, to many areas,” the organization said. “At the lower elevations along the West Coast, rain will continue for many areas, some of which could be heavy and lead to areas of flooding or flash flooding.”

Three people in California have died due to the flooding, the Weather Channel reported. Hundreds of homes were evacuated, and flooding triggered mudslides in some areas.

“This is a serious flood situation,” the National Weather Service said in a statement to multiple news outlets.

The storm also took down a massive, iconic sequoia tree. The Pioneer Cabin tree, which had been hollowed out a century ago to boost tourism, is no more, according to The Calaveras Big Trees Association.

CREDIT: Tom Purcell/Flickr
CREDIT: Tom Purcell/Flickr

“This iconic and still-living tree — the tunnel tree — enchanted many visitors. The storm was just too much for it,” the group wrote on Facebook.

Despite the rainfall — which was nearly 9 inches over 48 hours in some places — it will not be nearly enough to reverse the more than half a decade of drought in California.

According to a 2014 report, California consumes about six million acre-feet more water per year than it replenishes. That means it has been steadily eroding its supply of groundwater for years. It would take 50 years for the Central Valley’s groundwater to replenish to pre-Depression Era levels.

Much of Northern California and parts of Nevada have been issued a flood advisory (light green), with flash flooding advisories (dark green) and winter weather watches (dark blue) in effect in other places. CREDIT: NOAA
Much of Northern California and parts of Nevada have been issued a flood advisory (light green), with flash flooding advisories (dark green) and winter weather watches (dark blue) in effect in other places. CREDIT: NOAA

Climate change is largely blamed for drying out California, which provides more than a third of the country’s vegetables and two-thirds of the country’s fruits and nuts. Hotter, drier conditions (spurred by a global uptick in temperatures) cause drought.

But climate change is likely also on the hook for some of the flooding. Warmer air can fuel stronger, faster-moving storms that form over the ocean. Warmer air can also hold more condensation, which means there can be more water in a single storm. That phenomenon has been blamed for a series of large-scale hurricanes in the Pacific, as well as record storms on the East Coast.

The rainfall hitting Northern California and Nevada is coming from what is known as an atmospheric river — a current of moisture-laden air stretching from Hawaii to the Sierra Nevada mountain range. Also known as the “Pineapple Express” because of its point of origin, atmospheric rivers are actually a relatively common weather phenomenon in California, and account for some 80 percent of the state’s precipitation. However, as with so many weather events, climate change is expected to affect how atmospheric rivers work.

“Climate models and basic physics suggest that atmospheric rivers will become moister and more intense in the future, as a warmer atmosphere can hold more water vapor (about 4 percent more for every degree 1°F of warming),” Andrea Thompson wrote for Climate Central last year.