At first glance, Boise, Idaho should be a place of brutal winters with howling winds and huge piles of snow. A closer look reveals a much different reality. Boise is nestled in the Treasure Valley underneath the Boise foothills, which divert the worst of the arctic winds and precipitation to the east of Boise. The result is frequently cold weather, but not much snow or rain and little, if any wind chill.
The downside of being on the lee side of the foothills is that a stagnant layer of air can settle in for days at a time before a change in the weather pattern stirs up enough wind to clear the air. That's been the case for the last week as Boise residents have been hit with fog in the morning and highs below freezing in the afternoon.
Worst of all, the current inversion has trapped a solid cloud cover over the entire Treasure Valley. Boise residents desperate for a dose of sunshine have been heading for the hills...literally. One of the most popular destinations for sun seekers is the Bogus Basin ski resort, less than 20 miles via a winding mountain road from the center of downtown Boise.
A look at the photo accompanying this article shows the phenomenon quite clearly: The cloud layer stops at about 5 thousand feet and everything over it is bathed in brilliant sunshine. The cloud layer itself is about three thousand feet thick, leading to near-white out conditions on Bogus Basin road. Underneath Boise residents are still grumbling about the unusually gloomy weather and anxiously watching the local weather forecasts in hopes that a predicted wind shift will materialize sometime during the week and bring back the sunshine.
The video accompanying this article also gives another illustration of the inversion phenomenon and is worth a look and listen.