A record-breaking warm winter in San Francisco does not bode well for drought conditions this spring, which begins today.
There has been just one day of measurable rainfall so far this month (three one-hundredths of an inch on March 11) and nothing but a few sprinkles are anticipated in The City in the coming week. And longer-term drought conditions for California, Oregon and Nevada released Thursday by the National Oceanic and Atmospheric Administration as part of its national Spring Outlook show no signs of relief.
“The weather this winter has in part set the stage for what we expect this spring: above-average temperatures from the Rockies to the West Coast,” said Jon Gottschalck, a branch chief at NOAA’s Climate Prediction Center.
Nearly 40 percent of California remains in the most severe federal drought classification, according to the U.S. Drought Monitor. At this time last year, 22 percent of the state was in D-4 status, which means exceptional drought.
In January, San Francisco was lowered from D-4 to D-3, or extreme drought, but that month also marked the driest January on record in The City, with zero measurable rainfall.
A soggy first three weeks of December brought 11.7 inches of rain to The City and larger amounts to other Bay Area counties. But after the winter season officially began Dec. 21, no significant rainfall was recorded in San Francisco, save for three days in February that brought less than 1.5 inches, said Warren Blier, science officer for the National Weather Service forecast office.
Even more concerning is that San Francisco’s December rain was primarily from warm storm systems and did not contribute significantly to the Sierra Nevada snowpack, which is California’s No. 1 source of water. It is currently at a near-record low.
“We’re past the point of a little bit of rain making a significant difference,” Blier said.
The total system storage for the San Francisco Public Utilities Commission, including the Hetch Hetchy Reservoir, was at just 57 percent of maximum storage capacity as of March 8, compared to 69.2 percent on March 16, 2014.
“The water situation is serious,” said Charles Sheehan, a spokesman for the SFPUC. “We’re now in [the] fourth year of a very serious drought, and we’re simply not getting enough rain and snow to replenish our reservoirs.”
In addition to the lack of rainfall, San Francisco experienced its warmest winter at least since 1875, with three days tying or breaking record highs since Dec. 21, the first day of winter. The average of the high temperatures each day was 64 degrees, a full degree more than the 63-degree average of record-breaking warm weather in The City last winter.
“Beating it by a full degree is pretty impressive,” Blier said. “It reflects the prevailing large-scale weather pattern that we’ve had for virtually all of the winter season.”
But San Francisco is also one of the lowest water consumers in California. In response to a voluntary call to reduce water use by 10 percent last year, consumers actually cut back by 14 percent. That voluntary call is still in effect.
San Francisco gardeners are among those conserving water. Dave Stoner, president of Sloat Garden Center that operates nine stores in the Bay Area, said customers for years have been shifting toward more drought-tolerant plants.
“Drought tolerance is a major concern, but [customers] also don’t want to let their gardens go,” Stoner said. A more effective irrigation system can help combat water reduction, he noted.
“The secret is deep irrigation, less frequently,” Stoner said.
Meanwhile, city officials are continuing to enforce water conservation requirements that went into effect in The City and statewide last year. As of Thursday, there have been 815 reports of potential water waste in San Francisco.