The Weather Channel has gotten into the habit of naming winter storms and is calling this one Winter Storm Europa. I give them credit for coming up with catchy names, but I think they should call this one Santa's Storm as the big guy is delivering one that should make for great skiing.
Snow conditions in the Wasatch yesterday were best described as "tired." We have a decent early season base, but desperately need a freshening up. From late yesterday through 7 AM this morning, Alta-Collins picked up 4" of snow with .34" of water. I don't have an up-to-date new snow total for Snowbasin Middle Bowl, but their water is up to 0.5" and that all fell as snow. It's not a lot, but it's creamy and should help greatly improve ski conditions. Plus, it's just the start.
Between now and Christmas, a strong upper-level trough will swing through the southwest States. By 0900 UTC (2 AM MST) Christmas Morning, when Santa will be delivering presents to all the good girls and boys across the region (you know who you are and aren't), the trough axis is expected to be over Arizona with northern Utah in the so called "TRough of Warm-air ALoft" or TROWAL to the north.
As a result, I expect a slow frontal progression and decline in temperatures through northern Utah tonight. Although the mountains will see periods of snow today, the Salt Lake Valley will see rain at times, which is good for those of you desperate to finish your last second shopping. Snow levels should lower to bench levels this evening and the valley floor tonight.
There is a remarkably tight clustering of forecasts produced by the NCAR ensemble for Alta Collins from 5 PM MST yesterday (i.e., "Festivus" afternoon) through 5 PM Christmas, with a range from about 2.2 to 3.2 inches of water. Note, however, that the forecast through this morning is somewhat overdone as we've had only .34" through 1400 UTC (14Z) this morning.
Weighing over this and other forecasts, I'm going for 1-2 inches of additional water and 12-24 inches of snow at Alta-Collins from 8 AM this morning through 5 PM Christmas afternoon. This will be a right-side-up storm producing splendid turning conditions. This year, Santa is delivering the goods.
For the lower elevations, things are looking good for a white Christmas on the benches, despite the loss of snow today, as it will snow tonight. Most of the valley floor should also get some snow. Enjoy the White Christmas!