East Millcreek: 15 inches
Upper Avenues: 12 inches
Snowbird Base: 11 inches
Alta Base: 8 inches
Alta-Collins: 6 inches
Snowbird Gad-II Snow Cam: 4 inches
You have got to be kidding me. We do get storms from time to time that dump more in the valley than the mountains, but I didn't think this would be it.
Last nights storm featured two phases. The first was the frontal passage, when it is not uncommon for mountain and lowland precipitation to be comparable. The second was the post-frontal period after the front had moved downstream and the flow became northwesterly. This is typically a period when there is strong orographic enhancement and more precipitation in the mountains than the lowlands.
However, this wasn't the case last night. Check out the radar loop below, which covers the late night hours (0815–1300 UTC; 0115–0600 MST) when the front was through and the flow northwesterly. Over the Salt Lake Valley, the strongest and most persistent echoes are located over the eastern half of the valley and over the Wasatch mountains and canyons immediately to the east. There are very few radar echoes in the upper Cottonwoods (although there was light snow falling at times, it wasn't detected by the radar).
This is the type of scenario that one sees often in the European Alps, which are so high and wide that many storms dump their loads over the alpine foothills, with less precipitation falling over the higher interior. In fact, this can be seen quite clearly in the annual precipitation climatology for the central and eastern Alps. Note how bands of higher precipitation surround an area of lower precipitation in southeast Switzerland, northeast Italy, and southwest Austria, which includes the Valais Alps, Otztal Alps, and Dolomites.
|Alpine mean annual precipitation. Source: Christoph Frei, ETH|