Moonlight Skiing Anyone?

Photo: Wikipedia Commons

Last night I enjoyed great food and conversation at Alta's Shallow Shaft Restaurant with a group of meteorologists and snow-safety pros from Alta and the eastern United States.  There's nothing I like more than talking Wasatch weather and climate with locals and visitors who are passionate about snow and want to know more about the secrets of the Greatest Snow on Earth.

After the weather and snow geek talk, our attention turned to the incredible moonlit slopes of upper Little Cottonwood Canyon.  Leaving the restaurant at 10 PM, one could easily have gone for a quick lap sans headlamp.  How I wish I had my gear!  I ended up slithering down the canyon to return home to Salt Lake, but wonder if my dinner companions ultimately opted for a lap or two.

The full moon comes today, so what are the chances of moonlit laps tonight?  The clouds have moved in this morning and much (but not all) of the Intermountain West is currently overcast.

There are, however, some gaps upstream over Nevada and this airmass will be moving in for the evening.  In particular, note how the 600-400 mb relative humidity decreases later this afternoon in the NAM model time-height section for Alta.

On the other hand, cirrus clouds are tricky to forecast and the NAM and other computer modeling systems don't do a great job representing them.  Further, we're not dealing with "severe clear" upstream, but the hope that an area of clear skies moves over us in the large-scale southwesterly flow ahead of the upper-level trough.  Thus, I have to waffle this forecast.  The best option is to enjoy a drink or two at the bar this evening and the seize the moment should the opportunity present itself.