"It's still coming down really good," Rochelle Jenkins, a spokesman for Caltrans, said Thursday as crews worked around the clock to keep open Interstate 80, the main highway between Northern California and Nevada. "The valley is clear, but up here it's anything but."
The storm is sticking around longer and delivering more snow than predicted because it got "hung up on the mountains," said Johnnie Powell of the National Weather Service in Sacramento, Calif.
"It's a classic orographic lift," Powell said. "All a storm needs is lift and water. It hits the mountain and goes straight up. This one just stayed there on the mountains."
Powell said the weather service planned to lift the winter storm warning later Thursday, with the expectation that the snowfall would likely end around sunset.
Despite the heavy snowfall, California is far behind in amassing the amount needed to sustain water use in the arid state for the rest of the year. The state uses reservoirs and a system of aqueducts to deliver snowmelt to 28 million Californians who depend on it for all or part of their water.
Measurements on Thursday showed the water content of the snowpack at 34 percent of normal, the fourth-lowest reading since the 1940s, said Dave Rizzardo, chief of snow surveys for the Department of Water Resources. Last year at this time, the snowpack was 124 percent of normal and reached 165 percent by April 1.
"It's a nice change," Rizzardo said of the storm, "but the reality is we need a lot more."
The storm is bringing fresh powder to the ski resorts, but powdery snow lacks the moisture content that Rizzardo wanted to see. Snow in the state currently holds 8 inches of water, compared to 23 inches that would be normal by this date.
"The ski resorts are happy - it will be a nice powder day tomorrow. But we like the wet, cement stuff that really hurts you when you fall down," Rizzardo said. "Nothing personal against skiers."
The lack of water content and the unlikely prospects that enough storms will come to make up the deficit by April's melt has prompted officials to warn Central California farmers that they will receive only half of the water they requested this growing season.
The snowfall, part of a blast from the Gulf of Alaska, fell heaviest in the Northern Sierra, with smaller readings as far south as Yosemite National Park, where chains were required.
"We're running out of time," Rizzardo said. "We have our three wettest months behind us."
Avalanche danger in the Lake Tahoe area was down slightly on Thursday, but warnings still exist due to high winds, new snow and a weak snowpack.
In California, weather forecasters say a sunny weekend should make for ideal skiing conditions.
"Skiers can go have all of the fun they want on the weekend. It worked out perfectly," said weather forecaster Powell. "It should be plowed out and there should be plenty of fresh powder."
As storms moved in from the west, the Colorado Department of Transportation closed the eastbound lanes of Interstate 70 near Glenwood Springs because of accidents as a snowstorm moves into Colorado. Up to six inches of snow had fallen by Thursday afternoon in northwestern Colorado, and up to 18 inches is expected to accumulate in some areas by Friday.
Forecasters were predicting two to four inches of snow throughout Thursday east of the Continental Divide. Farther east, an overnight winter storm dumped nearly a foot of snow in parts of upstate New York, a rare wallop in a season that's been unusually snowless.
More than half a foot of snow also fell across parts of southern Maine by midday, with the National Weather Service calling for accumulations of 5 to 15 inches by the time storm clears out late Thursday.
As in California, the snow in the Northeast was a welcome sign for some students who got a snow day and for snow plow drivers happy to get back to work on Thursday.