It's Been Raining a Ton in California! Does That Mean the Drought Is Over?

Rain in California
A woman walks down a street as standing water remains following an El Niño–strengthened storm in Ocean Beach, California, on January 6. Mike Blake/Reuters

If you have any friends in Los Angeles, you've probably seen roughly four bazillion photos of the rain in the past week. Because it's been raining in L.A. Yes, that's a big deal for the typically dry city, and for the state, which has endured four years of punishing drought. But does this mean that the drought is over?

Nope. Far from it.

But first the good news. The recent heavy rains were sparked by a ferocious El Niño, a streak of warm ocean that warms the air above it, making it more buoyant and more likely to lift condensation to levels at which clouds can form. This, in turn, drives rains onshore. The rainfall means some reservoirs in the state are filling up again, after spending last year as pathetic shadows of themselves, mere puddles in the mud.

Folsom Lake, a reservoir made famous nationally last year due to pictures of cracked earth where water should have been, has gained 28.5 feet of water height in just one month of wet weather. The state's six largest reservoirs now hold between 22 and 53 percent of their historical averages in late December, which is good news, according to Frank Gehrke, who oversees snow surveys for California's Department of Water Resources.

"There is a good chance that if everything goes right over the next four months we could end up with good reservoir recovery," Gehrke told National Geographic. "We need much better than average snowpack this year for complete reservoir recovery, and so far we are encouraged."

Snowpack is looking good, this month, too. Recent snowy weather in the mountains of California, pushed into being by the El Niño rains combined with a frigid northern jet stream coming down from Canada, has done a few spectacular things for the state: The snowpack in the Sierra Nevada mountains, a critical water resource that was literally nonexistent last year, hitting a five-century low, is now at 109 percent of average.

Still, though, snowstorms at the right elevations must continue rolling in for the next several months if this moment of good news is going to translate into a reliable water supply for the state in the coming summer season.

The heavy snowfall is "a reasonable start, but another three or four months of surveys will indicate whether the snowpack's runoff will be sufficient to replenish California's reservoirs by the summer," Mark Cowin, the director of California's Department of Water Resources, said in a statement.

Meanwhile, data from the National Oceanic and Atmospheric Administration clearly shows that neither California nor the rest of the West is out of the thick of the drought yet. As of the agency's last reading, on December 29, 18.7 percent of the United States is still in the midst of "moderate to severe" drought, with much of that area clustered west of the Rockies.

There's Still a Drought in California and the West
In this map from December 29, 2015, drought conditions are still seen across much of the Western United States. NOAA