Central Sierra snowpack water content is below average at 65 percent, based on instrument readings at multiple locations up in the mountains, state Department of Water Resources staff said Tuesday.
Statewide, the snowpack was holding 7.2 inches of water equivalent, which is 70 percent of the Jan. 3 average.
But there’s a lot of snow on north-facing slopes in the mountains above the Mother Lode, with forecasters saying more significant snowfall is on the way. Avalanche warnings were in effect Tuesday north of U.S. Route 50 in the Tahoe National Forest.
At Bear Valley off Highway 4, resort staff reported 6 inches of new snow overnight into Tuesday. National Weather Service staff in Sacramento say Bear Valley could get 3 feet or more of additional snow by early Thursday.
At Dodge Ridge off Highway 108, ski area staff said they measured 4 to 6 inches of snow overnight into Tuesday. Strawberry and Dodge Ridge could get 24 to 30 inches of additional snow by early Thursday.
In their snow report Tuesday, staff at Dodge Ridge advised people to “ski + ride with care, and always ski + ride with a buddy.”
Human-triggered wind slab avalanches occurred Monday on Elephant's Hump in the Carson Pass area near Highway 88 and on Castle Peak in the Donner Summit area south of Interstate 80, staff with Sierra Avalanche Center said.
The state Department of Water Resources focused Tuesday on a manual snow survey at Phillips Station off Route 50, about 90 miles northeast of Sonora. The snow water equivalent there was 6 inches. That’s 5.3 inches less than the early-January average of 11.3 inches at that some location since 1964.
Scientists say snow water equivalence is the depth of water that would result if the entire snowpack melted all at once. Snow water content is more important than depth when evaluating snowpack for water yield.
“We had pretty much bare ground here about a week ago, with a few patches of snow,” Frank Gehrke, chief of the state’s Cooperative Snow Surveys Program, told reporters at Phillips Station. “Most of the snow we measured today came down in the last couple days and is continuing to come down.”
Forecasters in Sacramento said they have growing confidence in chances for more rain and snow in the form of an atmospheric river system, this weekend and into Monday. Forecaster Mike Kochasic said the Sonora area could receive as much as 10 inches of rain between Tuesday this week and Tuesday next week.
At elevations where precipitation falls as rain, extra water added to already wet and nearly saturated ground may cause flooding concerns this weekend. At higher elevations where the wet stuff comes as snow, it’s going to bolster existing snowpack.
“I can see us being potentially at average once that series of storms moves through,” Gehrke said at Phillips Station. “I think it’s a very encouraging start to the winter, and certainly we’ve had other winters when this has been basically a bare field.”
Brandon Schwartz, an avalanche forecaster with Tahoe National Forest based in Truckee, concurred this winter is “a little bit below normal.”
His duties include snowmobiling between Highway 88 and Highway 4 from time to time, a journey of 12 miles on groomed road and 17 miles ungroomed, which he and co-workers can cover in about 60 minutes depending on conditions.
Schwartz cited high-elevation rains in December that hurt snowpack accumulation, while above the rain-snow line, 8,500 to 9,000 feet, “ it's been a more typical winter so far.”
Statewide, 82.5 percent of California remained in stages of drought as of Dec. 27, according to scientists with the U.S. Drought Monitor. That’s an improvement of 17.5 percent since three months ago, when the entire Golden State was classified in one of four drought categories.
All of Calaveras County and all of Tuolumne County remain in severe or extreme drought.