Why do “rain shadow” areas of the U.S. get so much snow?

Question

I’m thinking specifically of the eastern Sierra Nevada, eastern Washington & Oregon, and other parts of the Basin & Range.

Why does cold-weather precipitation cross those peaks but not warm?

In: Other

Answer 1

Much of the precipitation for the year for these places comes from powerful winter storms that can add inches of snow every hour to the mountains and still have enough moisture left to snow heavily in the ‘rain shadow’ areas.

Moisture is also far more likely to fall as snow in the interior, as it tends to be colder and hotter on the other side of the mountains from the coastal plains (it’s very rare for snow to fall west of the Cascades or Sierra Nevada’s)