TRUCKEE (CBS SF) — A pair of Spring storm fronts swept through the Sierra over the weekend and on Monday morning, forcing travelers to use chains on mountain passes on I-80 and Highway 50 and blanketing the region with as much as 3 feet of new snow at the higher elevations.

What would have been a late season boost to the Tahoe area ski industry has been transformed into a “what if” moment as resorts from Squaw Valley to Heavenly Valley have been shuttered for the season since late March because of the current coronavirus outbreak and social distancing requirements.

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A winter weather advisory expires at noon Monday for Tahoe where 13 inches of snow fell at Incline Village. Mammoth Mountain ski resort reported 35 inches.

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The Sierra Avalanche Center issued a warning for unstable slopes after the strong storm.

“The storm has left unstable slabs of wind drifted snow and softer slabs of storm snow on steep slopes in both exposed and sheltered terrain,” the center warned in a statement. “Recreating on slopes where these problems exist could trigger avalanches.”

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Caltrans closed Highway 89 around Emerald Bay because of unstable hillsides. There was no eta for reopening since more snow was in the forecast Monday and Tuesday before clearing the rest of the week