This is from Matt Weiser of the Sacramento Bee:
Collecting Snow california
“The latest survey of California’s mountain snowpack on Thursday brought the bad news slamming home: This month will rank as the driest January in state history at many locations, virtually assuring a fourth straight year of drought.
On Thursday, the statewide snowpack was 25 percent of normal for the date. The northern Sierra Nevada – a region crucial to statewide freshwater supplies – holds the lowest January snowpack ever recorded.
Mike Anderson, a climatologist employed by the California Department of Water Resources, did not waffle when asked what this means for the state.
“It will be continuing with drought conditions,” Anderson said. “We haven’t historically seen a change in February, March and April – after a dry January – that would give sufficient conditions to erase the drought.”
Sacramento, with weather records dating to the 1870s, also recorded its driest January in history. Other locations with that dubious distinction include Blue Canyon, at 4,700 feet in the Sierra Nevada along Interstate 80, the town of Paradise in Butte County, as well as Stockton, Modesto, Sonora and Redding.
Average January rainfall for Sacramento is 3.97 inches. The only measurable rain Sacramento received in January came on the 19th, and that measured just 0.01 inches. Aside from that, the weather tap essentially turned off on Christmas Eve.
The month lasts through Saturday, but no storms are forecast that would change the local outlook. The weekend ahead is predicted to be sunny, with temperatures exceeding 65 degrees in Sacramento and other locations.
Winter began with a promising series of wet storms in December. But these storms were warm, so they didn’t deposit a lot of snow in the mountains. They did produce a lot of runoff, and the state’s major reservoirs were able to capture much of it.
As a result, reservoir storage in Northern California, while still well below average, is better than at this time last year. This will not prevent a fourth drought year, but it will help ease the pain. DWR, for example, recently indicated it would be able to provide 15 percent of normal water deliveries to its customers on the State Water Project, including Los Angeles and the Silicon Valley. That’s better than the zero percent offered last year.
Folsom Reservoir in the Sacramento region, operated by the U.S. Bureau of Reclamation, is one of those that benefited. It contains about twice as much water as it did this time last year. This will help the Sacramento region get through 2015. But without more storms this winter, the reservoir will be severely depleted by fall.
Tom Gohring, executive director of the Sacramento Water Forum, a coalition of local water agencies and environmental groups, said water agencies will keep the pressure on for conservation. But he worries public attention will wane.
“At this time last year, we were all looking at Folsom being lower than we’ve seen it in decades and I think it made a huge impact,” said Gohring. “The reservoir isn’t that low now, so people aren’t seeing that signal. I wish we could get a message out to say we’re not out of the woods.”
Although December was wet, the storm track took a detour right after Christmas because of El Niño. El Niño is used to describe conditions when the equatorial Pacific Ocean warms up, causing global shifts in weather patterns. It can cause wet winters in California, so hopes were high when an El Niño was predicted last spring.
But this El Niño proved mild. And a mild El Niño often causes the winter storm track headed toward California to split in two, with storms directed toward Mexico and the Pacific Northwest, bypassing California. That’s exactly what happened this month, said Anderson.
“The split jet stream has kind of left us high and dry,” he said.
Climate change also may have played a role by diverting the polar jet stream, Anderson said. Because the temperature difference between the Arctic and the equator is not as great as it once was, the polar jet stream has a tendency to swing farther south. This causes two things: It contributes to brutal winter storms on the East Coast, and it also helps create a high-pressure ridge on the West Coast that diverts storms from California.
The drought has hurt winter tourism throughout the Sierra Nevada. At least three ski resorts in the Lake Tahoe area closed within the past two weeks. It was the driest January ever at Tahoe City, which saw only 0.03 inches of rain during the month, said Chad Blanchard, the federal watermaster for the Truckee River.
Lake Tahoe itself shrank below its natural rim on Oct. 15, meaning water stopped flowing into the Truckee River, the giant lake’s only outlet. That condition has not reversed, and the lake is now almost 1 foot below its natural rim. Blanchard is hopeful weather conditions will improve during the two months of winter that remain.
“We have been in worse situations than this and still turned it around,” Blanchard said. “There’s still time.”
A long-range forecast issued Thursday provides some reason for hope. The Climate Prediction Center, a branch of the National Weather Service, predicts that Northern California is likely to be wetter than normal over the next two weeks.
January is normally the wettest month of the year in Northern California, Anderson said, and losing it entirely from the water supply picture is a big hit. For drought conditions to end, he said, California needs precipitation that is at least 150 percent of normal by the end of the water year on September 30, or 75 inches as measured in the northern Sierra. As of today, 23.1 inches have been recorded.”