State drought report shows dry areas expanding
Following another week without rain — and none forecast through the end of this month across Northern California — the federal government on Thursday announced that unusually dry conditions are expanding across a wider swath of California’s landscape, increasing concerns about
summer fire risk and the possible return of at least a modest drought this year.
Overall, 59.9% of the state’s land area is now classified as “abnormally dry,” up from 46.1% last week, according to the U.S. Drought Monitor, a weekly report issued by the National Oceanic and Atmospheric Administration, the U.S. Department of Agriculture and the University of Nebraska-Lincoln.
All nine Bay Area counties are now classified as abnormally dry. So are places that have suffered devastating fires in recent years: Sonoma, Napa, Lake and Mendocino counties. Without significant rain in March or April, fire danger in those areas and other parts of the state will be higher than normal again this summer.
“Given what we’ve seen so far this year and the forecast for the next few weeks, I do think it’s pretty likely we’ll end up in some degree of drought by this summer,” said Daniel Swain, a climate scientist at UCLA, on Thursday.
Swain noted, however, that the state is equipped to handle one-year droughts pretty well without major water shortages because of water stored in reservoirs, groundwater wells and conservation.
It’s when dry conditions persist for several years, as they did during the state’s historic drought from 2012 to 2017 that problems arise.
“Assuming this year ends dry, which is pretty likely,” Swain said, “the question is what happens next year?”
Of note in Thursday’s federal report: The area of California where abnormally dry conditions are now present is 14 million acres larger than it was last week, a landscape 44 times the size of Los Angeles.
“The plants and the forests don’t benefit from the water storage reservoirs,” Swain said. “If conditions remain very dry heading into summer, the landscape and vegetation is definitely going to feel it this year. From a wildfire perspective, the dry years do tend to be the bad fire years, especially in Northern California.”
Last year, following a wet February and March, the state experienced a mild fire year, with high moisture levels in grasses, shrubs and trees — a welcome departure from prior years when major fires devastated Napa and Sonoma County, along with the town of Paradise in Butte County.
Altogether, Thursday’s report noted, 58% of California’s population, or 21.7 million people, are currently living in areas that are in moderate drought or are abnormally dry.
The amount of the state in “moderate drought,” a more serious category, remained the same this week as last week, at 9.5%. But that’s expected to increase if the National Weather Service’s dry forecast for the next two weeks bears out.
The reason for the dry conditions is a persistent weather pattern that is sending California’s rain toward Seattle.
“High pressure off the California coast kept much of California, Nevada, Arizona, and Utah precipitation-free this week, with above-normal temperatures in California,” wrote David Miskus, a NOAA meteorologist and author of Thursday’s drought report.
“Instead, Pacific storm systems were deflected northward or southward, allowing the Pacific Northwest to receive welcome moisture.”
The area in moderate drought Thursday, the driest in California, was in the Central Valley, covering roughly 10 million acres from Tuolumne County to Kern County.
The new report does not mean, however, that California is heading back into the kind of severe drought that the state experienced from 2012 to 2017.
There is still another month in the state’s rainy season. And California has had very wet “Miracle March” conditions in years past.
By comparison, five years ago, on the week of Feb. 17, 2015, an overwhelming 98% of the state was in at least a moderate drought, and 41% was in exceptional drought, the most severe of the five categories used in the report. That drought was broken by a series of massive atmospheric river, or “Pineapple Express,” storms that roared in off the Pacific in early 2017 and caused flooding in downtown San Jose and the collapse of the spillway at Oroville Dam in Butte County.
This winter season, although California experienced some decent rainfall around Thanksgiving and into December, the storms all but shut down after the New Year, and January and February have been unusually warm and dry.
Just one day in 2020 so far, Jan. 16, has had enough rain to bring at least 1 inch to San Francisco, Oakland and San Jose.