Why is the diurnal temperature range on the Cascade volcanoes so small?

Question

Ski-mountaineering in the Pacific Northwest I am frustrated that the snow pack isn't refreezing at night. There is about a 20F difference between the day and night temperatures in Seattle. Looking at forecasts for Mt. Rainier and Mt. Baker, the night temperature looks to be the same or sometimes even warmer. I think I have seen these kinds of forecasts even when the sky is clear, when I would expect the snow pack to release a lot of longwave radiation. What is going on here?

Answer 1

Hi Asked,

The weather forecast may be for "clear" in Seattle (really??), but high-elevations may have orographic-effect clouds. I know Mt. Washington (~ 6000') in New Hampshire is frequently cloudy from that, so I would assume Mt. Baker and surround in the Cascades would be even more affected (hence the "rain forest" on the west, and the arid climate on the east).

-- Cheers, -- Mr. d.