Signs point to prolonged dry spell for most of state
Lack of rain means drought danger for 81% of California
California’s droughtprone hills and valleys are on the verge of another troubling dry spell.
The U.S. government’s Drought Monitor on Thursday classified more than 80% of California as abnormally dry because rain has eluded the state for most of the fall. Forecasting models, meanwhile, suggest little change in the near future — maybe some drizzle late next week, maybe not.
San Francisco hasn’t seen real rain since September, when it got only a sprinkle, making it among the driest starts to the wet season that the city has seen in 170 years of record keeping.
But weather watchers aren’t ready to panic. While the lack of precipitation remains worrisome for firefighters, who continue to sweat the tinderdry landscape, waiting for rain in autumn is simply an annual ritual for Californians. And with a changing climate, scientists think the wait just might be getting a little longer.
“The falls have been pretty dry,” said Mike Anderson, state climatologist at the California Department of Water Resources. “The narrative of climate change speaks to a compression of the (wet) winter season. You see it starting later and ending earlier.”
But the later start of rain, Anderson noted, doesn’t necessarily mean less of it.
Take last year. California saw almost no rain in October and only a handful of wet days in
November and December before January came with a shelling of Pacific storms. The 201819 rainy season turned into one of the wettest of the decade.
“It’s been a slow start to this water year, to be sure,” Anderson said. But “we know things here can turn pretty quickly.”
For much of the fall, a ridge of high pressure over the Pacific has blocked eastmoving storms from hitting California. It’s a pattern that’s common during dry periods, and was often present during the state’s fiveyear drought earlier this decade.
Over the past week, the pattern has been particularly strong. The jet stream has not only steered cool, wet weather away from California but pushed it into the eastern half of the country.
In recent days, the Midwest has wrestled with singledigit temperatures and earlyseason snowstorms. The Gulf states have experienced rare freezes. Even Nashville saw a half inch of snow, the most it has had in decades. New York City plunged into the 20s, also setting records.
“When we have a ridge on the West Coast, that often means they have a trough on the East Coast,” said Jan Null, meteorologist with Golden Gate Weather Services. “You have this whole pattern, and when things get into equilibrium, they don’t move much.”
With dry weather locked in over California, San Francisco has seen just 0.13 of an inch of rain since July 1, about 5% of average for the period. Null said that if the rainless streak continues through the month, the city will have experienced its seconddriest start to the wet season since 1849. In 1929, the city saw 0.01 of an inch of rain through November.
Sacramento, meanwhile, has seen 0.06 of an inch of rain since July 1, about 3% of average for the period. Fresno hasn’t even gotten enough rain to measure. It usually has an inch of rain by midNovember.
The U.S. Drought Monitor, which assesses the nation’s water picture based not only on precipitation but other factors, such as soil moisture and river levels, reported that 81% of California is “abnormally dry.” It’s the category just shy of drought.
Last week, only 18% of the state fit the classification, a stark change that reflects how much an ongoing delay of the rains can dry out California.
A sliver of desert down south, which represents just under 4% of the state, has already slipped into drought, according to the Drought Monitor. On the other hand, California’s northernmost counties remain entirely free of abnormal dryness.
The biggest concern about the dry conditions, at least for the time being, remains wildfire.
“It’s a bit stressful for everyone here,” said Steve Leach, fire meteorologist at the Northern California Geographic Area Coordination Center, a joint federal and state firefighting operation in Redding. “The more days we go without rain, the more days that fuels are staying dry — in fact, extremely dry.”
The strong offshore winds that can quickly turn a small wildland fire into a catastrophic inferno have, fortunately, not been present lately, Leach said. However, he worries that the menacing gusts could return before the rains arrive.
The state’s water managers are a little more at ease.
Because last winter was wet, California’s big reservoirs are in good shape. Lake Shasta was 71% full on Wednesday, holding 20% more water than it usually does this time of year. Trinity Lake was 80% full, with 23% more water than average for the date.
“This enables us to sustain a dry year,” said Anderson, the state climatologist, noting that most water supplies are designed to hold two years or more worth of water. “We’ll probably have people soon looking to the year after (to make sure supplies are sufficient).”
Forecasters at the National Weather Service say the highpressure air off the coast is slowly breaking down, which explains why clouds have been moving in over parts of California in recent days — San Francisco even got a sprinkling on Thursday. However, they still don’t foresee significant rain ahead.
“There might be something mid to late next week, but it doesn’t look very impressive,” said weather service meteorologist Anna Schneider.
Schneider, though, remained optimistic that the situation will change — if not soon, eventually: “Even though we’ve had a dry start, we’ll have a few systems as we get deeper into the season.”