People looking for winter in the Central Sierra can still find ice and snow in some places, but it’s melting away right now in the midst of more than a week of sunny skies and above normal temperatures when it’s supposed to be wet and freezing cold.
It’s obvious off Highway 108 at Dodge Ridge, where managers have decided to close the ski resort just a week after opening for the first time this winter. It’s obvious off Highway 4 at Calaveras Big Trees State Park, where patches of snow are melting in parking lots.
And it’s obvious off Highway 120 at the base of Upper Yosemite Fall, where the ice cone that typically builds up in winter is shrinking again.
People with the state Department of Water Resources say that, despite moderate precipitation in January, manual snow surveying and snowpack sensors this week show snow water equivalents at just 30 percent of average for Feb. 1. December was historically dry.
Since Oct. 1, when the current water year began, precipitation for major Mother Lode watersheds that include the Stanislaus and Tuolumne rivers is just 9.2 inches, less than half the historical average for early February.
Expect more melting
More of the Golden State’s vital snowpack is going to melt in the near future. Unseasonably warm, dry conditions are likely to continue most of the coming week, with daytime highs 10 to 20 degrees above average through Friday, according to National Weather Service forecasters in Sacramento.
In foothill towns like San Andreas, Angels Camp and Sonora, that means sunny skies and highs in the 70s through the end of next week. At Arnold, Pinecrest and Yosemite Valley, people can expect more sunny weather with highs in the 60s and overnight lows up to 15 degrees above freezing.
Winter sports businesses that can make snow are planning to remain open this weekend.
At Bear Valley off Highway 4, staff are making and grooming snow and they’re open with “beautiful sunny weather … through next week,” a ski patrol supervisor said Friday. Bear Valley had about a third of its 75 trails open, seven lifts open, and 30 percent of its 1,680 acres open for skiing and snowboarding.
At Leland High Sierra Snowplay, east of Strawberry off Highway 108, staff say they’ll be open Super Bowl Sunday and perhaps Monday and Tuesday.
But “with drought and rising temperatures in the forecast, we can’t say how long after this next five-day stretch we can reasonably be in operation,” Leland Snowplay staff said Thursday evening.
But at Dodge Ridge, which relies exclusively on natural snowfall, lift operations are on temporary hold beginning today “due to unseasonably warm temperatures and a shortage of snowfall for early February,” the resort’s website states. “We’ll reopen following the next round of significant snowfall.”
Right now, people in the Central Sierra are two months into what are typically California’s wettest three months, with little to show for it other than ample storage from near-record runoff and snowmelt last winter, 2016-17.
A manual snow survey 90 miles northeast of Sonora at Phillips Station on Thursday showed a snow water equivalent of just 2.6 inches, 14 percent of the early February average, people with the state Department of Water Resources said.
Snow water equivalent is supposed to reflect the depth of water that would result if the entire snowpack melted all at once. State authorities are talking about water conservation.
“California experiences the most variable weather in the nation,” Karla Nemeth, the Department of Water Resources director, said Thursday. “It’s vital that water conservation efforts remain consistent regardless of the year’s precipitation.”
Snow survey results show water content far below average for this time of year, said Frank Gehrke, chief of the California Cooperative Snow Surveys Program. Measurements indicate an anemic snowpack to date, but wetter conditions in February and March are still possible.
On average, Sierra Nevada snowpack supplies about 30 percent of the Golden State’s water needs as it melts each spring and early summer.
Near-record precipitation last winter and spring have boosted water storage in more than 150 reservoirs tracked by the state, as well as reservoirs that impound water for 44,000 Tuolumne Utilities District customers and more than 12,000 Calaveras County Water District customers.
Markeya Thomas and Ben Hatchett with Climate Signals say decreasing snowfall and diminishing snowpack are trends driven by climate change.
Hatchett is based on the eastern Sierra at the Desert Research Institute in Reno, Nevada. He studies weather and climate over all time scales, from minutes to millenia.
“The whole Sierra Nevada is hurting,” Hatchett said Friday in a phone interview. “The trees are dying. We don’t have places to ski. And we might not have water for the reservoirs this summer.”
Warming temperatures are reducing snowpack by causing precipitation, when it comes, to fall as rain instead of snow, with snowpack that does form being more likely to melt early, Thomas and Hatchett said. Warming temperatures hit snowpack depths particularly hard at lower elevations. The snow line in the Central Sierra has been retreating to higher elevations in parallel with warming temperatures.
California’s water supply is at risk, Thomas said.
Before sunrise Wednesday, east winds blew 1,430-foot Upper Yosemite Fall sideways and other directions. By 9 a.m. sunlight was striking the cone, highlighting cracks opening on its sides.
The cone, which forms each winter as frozen spray and ice from Yosemite Creek build up, appeared to be 30 feet to 40 feet high, slightly taller than it looked three years ago in February 2015, during one of the warmest, driest recent winters in the Central Sierra.
Last winter, 2016-17, and the one before, 2015-16, the cone under Upper Yosemite Fall built up high and wide enough to block access to the horizontal cave at the cataract’s base. On Wednesday, a slope of melting snow reached up toward the cave entrance. Inside the cave, shifting winds hurled spray sideways through the stony corridor. No ice was evident anywhere in the cave.
Some people who started walking the Upper Yosemite Fall trail early Wednesday dressed for winter, wearing insulated jackets, long pants, warm hats and gloves. Others who started up later in the day dressed in shorts and T-shirts and sunglasses.
It was another warm winter day in the high Central Sierra, and forecasters say there are more warm days on the way.
Contact Guy McCarthy at firstname.lastname@example.org or (209) 588-4585.