With gusts of wind howling around Mount Ashland’s vacant ski lodge this week, Andrew Gast watched from a window as a brief snowfall dusted the landscape. It was not nearly enough.

The ski area’s parking lot remained largely empty. On the slopes, manzanita bushes and blades of grass were poking through patches of what little snow had landed. Even the 7,533-foot summit — the highest point in the Siskiyou Mountains along the Oregon-California border — still had bare spots. These days Mr. Gast has been checking the weather forecast the moment he wakes up, only to learn that warmer and drier days lie ahead.

“I’m trying not to pay attention to it too much right now because it’s just going to cause me heartburn,” said Mr. Gast, who manages the nonprofit community ski area south of Ashland, Ore. He spent much of this week in his office, preparing to issue furloughs or layoffs.

Across much of the West Coast, from the Cascades in the north to the Sierra Nevada in the south, mountain sites are recording less than half of their normal snowpack for this point in winter. The snow that blankets mountain ranges in winters serves as a vital reservoir that is released when temperatures rise each summer. The snowmelt cools rivers enough to sustain salmon runs, propels hydropower systems that provide the region’s electricity and feeds irrigation channels needed to supply the nation’s apples, blueberries and almonds.