The 1502–2112 UTC (0802–1412 MST) radar loop below shows the highly localized nature of the snow, which has been confined primarily to the Salt Lake Valley and Wasatch Mountains to the east.
Lake effect? Except perhaps near the end of the loop above, I don't think the lake has played much of a role so far. The flow at the top of the Snowbird tram has been westerly, which isn't favorable for carrying lake-effect precipitation into the Cottonwoods.
In addition, usually lake-effect precipitation is characterized by cellular radar echoes and convection. I didn't see much around the Salt Lake Valley for much of the morning and early afternoon to indicate there was any lake-effect convection. Perhaps the lake will eventually kick in, but thusfar, I don't think it's played a significant role.
Instead, there was local precipitation enhancement within a cloud band that extended from southeast Oregon, across
Why? I have ideas, but none of them are very compelling or easy to explain in a few sentences. Maybe you have better ones. I'm just going to say it was the Cottonwoods magic and not spoil a good thing.
The new snow has piqued my interest, but I'm currently laid up with a bad back and unable to ski. Transporting my son from Snowbird this afternoon was serious torture. The only turns I got involved following the red snake back down the canyon!
Get some for me tomorrow.