Drought conditions returning to state
The federal government classified parts of California as being back in a drought for the first time since last year.
Driven by week after week of unusually dry weather, the federal government on Thursday classified parts of California as being back in a drought for the first time since last year.
Altogether, 9.54% of the state’s land area is now in a moderate drought, with forecasts showing no rain in most of the state for the next 10 days at least. The area classified as in moderate drought Thursday was in the Central Valley, covering roughly 10 million acres from Tuolumne County to Kern County.
That’s the most since Feb. 12, 2019, when 10.55% of California’s land area also was in a moderate drought, according to the U.S. Drought Monitor, a weekly report put out by the National Oceanic and Atmospheric Administration, the U.S. Department of Agriculture and the University of Nebraska-Lincoln.
“Across Nevada and California, dryness and drought intensification prevailed,” wrote Richard Tinker, a meteorologist with NOAA in College Park, Maryland who wrote this week’s report.
“On the 60-day time scale, markedly low precipitation totals (among the driest 5 percent of historical occurrences) covered most of a swath across central sections of California and Nevada, and 30-day amounts were less remarkable but still significantly below normal.”
The last time any part of California was classified as being in a moderate drought was three months ago, when .01% of California’s land area had that classification.
The new report does not mean, however, that California is heading back into the type of harsh conditions that occurred during the state’s historic drought from 2012 to 2017. “Moderate drought” is the mildest of five categories that the federal scientists use to classify drought conditions in the report.
How bad was it back then? By comparison, exactly five years ago, on the week of Feb. 10, 2015, an overwhelming 98.1% of the state was in at least a moderate drought, and 40% was in exceptional drought, the most severe of the five categories.
Nevertheless, after a series of soaking atmospheric river storms that drenched California around Thanksgiving, much of California has seen little rain or snow since then.
The statewide Sierra snowpack, the source of nearly one-third of California’s water, on Wednesday was 58% of its historic average for that date, and down from 92% on New Year’s Day.
Most Bay Area cities have received about half their average rainfall so far this winter season, and only one day in 2020 so far, Jan. 16, brought more than 1 inch to San Francisco, Oakland and San Jose.
Overall, San Francisco has received 8.83 inches of rain since Oct. 1, or 58% of its historical average. San Jose, with only 3.82 inches, is just 42% of average. And Oakland is at 45% of average with 5.8 inches.
Ridges of high pressure have blocked storms coming off the Pacific Ocean, sending them to Washington and Oregon.
There is still another month and a half of winter left, however. And the state has had “Miracle March” conditions before. Last year, after a dry start to the season, a wet late February and March boosted the statewide Sierra Nevada snowpack from 69% on Jan. 1, 2019 to 161% by April 1.
Another positive sign: Many of the California’s biggest reservoirs are holding plenty of water, the result of wet winters over the last two years. On Thursday, Shasta Lake, the state’s largest reservoir, was 78% full — 111% of its historic average for mid-February. Oroville was 65% full, or 94% of its historic average. And San Luis Reservoir near Los Banos was 75% full, or 92% of average for this time of year.
With each passing day, however, as winter conditions begin to wane, the chances of hitting historic seasonal averages fall.
More broadly, while the state is not experiencing severe drought conditions, a growing part of its land area is drying out.
On Thursday, the Drought Monitor classified nearly half the state — 46% — as being “abnormally dry,” up from just 3% month ago. Much of the dry area is also in the Central Valley. But it includes much of the Bay Area including San Mateo, San Francisco, Alameda, Contra Costa, Solano, Napa and northern Santa Clara counties, along with the coastal region from San Luis Obispo to Los Angeles counties.
Meanwhile, the federal government also reported that the Earth’s climate continues to warm. Federal scientists at NOAA announced Thursday that this January was the warmest January ever recorded on Earth back to 1880, when modern temperature records first began.
The January 2020 global land and ocean surface temperature was 2.05 degrees Fahrenheit above the 20th century average of 53.6 degrees Fahrenheit, the researchers said. Russia and parts of Scandinavia and eastern Canada experienced temperatures 9 degrees above average.
While California has had droughts many times in its history, scientists say climate change exacerbates them, making them hotter and drier, and increasing the risk of wildfires in the summer and fall months.
Ridges of high pressure have blocked storms coming off the Pacific Ocean, sending them to Washington and Oregon.