What a difference a winter can make.
On Jan. 1, three-quarters of California was in drought. Just eight weeks later, however, a succession of storms have washed drought conditions away from all but a splotch at the far north edge of the state, according to the U.S. Drought Monitor.
Some of Southern California is still considered abnormally dry, which means there are some lingering water deficits.
Considering what the state has been through in recent years, this is good news.
“It’s certainly good as far as the water supply,” said Dan Cayan, a researcher at the Scripps Institution of Oceanography at UC San Diego. He said the snowpack in the mountains this year is “outstanding.”
For the past three years, the drought picture in California has gone through dramatic changes based on the winter weather, according to the Drought Monitor maps, which are put together by academic and federal agencies to assess conditions across the country.
This time-lapse video shows how drought has retreated, spread and retreated once more since summer 2016. (Can’t see the video? Click here.)
By late 2016, drought conditions covered more than 80 percent of California, and about 20 percent of the state was in the worst category: exceptional drought.
An atmospheric river that formed over the Pacific Ocean in early 2017, sending storm after storm after storm toward the West Coast, officially ended the drought.
The winter of 2017-18, however, was unusually dry, and drought conditions spread back over California throughout 2018. They weren’t as severe as they’d been in 2016 — this time, none of the state entered that “exceptional” drought category.
Once again, 2019 has been rainier than average thanks to back-to-back storms throughout January and February. The Drought Monitor shows that as of Feb. 19, less than 4 percent of the state is in drought.
The 29 percent of the state that’s still abnormally dry includes most of Orange, San Diego and Imperial counties and parts of Riverside, San Bernardino and Los Angeles counties.
This graphic shows drought categories throughout California during the same period as the video above. (Can’t see the graphic? Click here.)
The past few years’ experience shows how one good winter doesn’t mean long-term water security for California.
“The climate here is amongst the most volatile in the nation, and our lot in life is to be oftentimes either above average or below average,” said Cayan, the Scripps researcher.
“It’s difficult to make any pronouncements about the next year,” he said, “but this year is looking quite good.”
The storms so far this year have been due to another atmospheric river, and scientists recently announced El Niño conditions have formed and are expected to last through spring. That could mean the above-average rainfall will continue in Southern California.
“We’ve certainly seen El Niños where things have been a bust, so it’s not a guarantee, but it tilts the odds” toward more precipitation, Cayan said.
The current forecast does show more storms lined up to hit California in the final days of February and early March, which Cayan said will continue to replenish the water supply.
“There’s the rest of the winter and through the mid-part of spring that’s still at play, so we’ll see how that works out,” he said. “If it continues at least at a normal pace, California will be doing really well. If for some reason after next week things entirely shut off, we’re probably still in reasonable shape, but not as good as it would be if we got the normal activity.”
What the drought categories mean
- D0 (abnormally dry, not drought): Short-term dryness slowing planting and growth of crops; some lingering water deficits; pastures or crops not fully recovered
- D1 (moderate drought): Some damage to crops, pastures; some water shortages developing; voluntary water-use restrictions requested
- D2 (severe drought): Crop or pasture loss likely; water shortages common; water restrictions imposed
- D3 (extreme drought): Major crop/pasture losses; widespread water shortages or restrictions
- D4 (exceptional drought): Exceptional and widespread crop/pasture losses; shortages of water creating water emergencies
Source: Drought.gov
