A Little Something for Park City?

How about that.  It snowed.  Alta-Collins came in with about 7" through this morning, including 4" yesterday morning and afternoon and 3" overnight.  By historical standards, it ain't much, but we can't be choosy anymore.  

The next trough swings through tonight and tomorrow.  It's a deep and complicated system as it swings across Utah.  Below is the GFS surface forecast valid at 0900 UTC 23 February (2 AM MST Wednesday).  The surface low is in southwest Utah with a fairly strong warm front extending across southern Utah and a trailing cold front across Nevada.  The flow in northeast Utah is predominantly easterly.   

This general pattern extends to 700 mb (10,000 feet).

Model soundings show a very sharp transition to southerly flow above 700 mb.  Below is the sounding from Salt Lake City.  Easterlies extend right to 700 mb, above which the flow veers (turns clockwise with height) to southwesterly.

These conditions are consistent with the presence of a warm-frontal zone aloft, to the north of the surface-based warm front over southern Utah.  Additionally, temperatures through a deep layer, extending from 800 to 600 mb, are between about -10 and -20˚C, which is good for dendritic snow growth (translation: low-density snow).  

These are conditions in which the Wasatch Back sometimes does quite well.  Basically, Park City and Deer Valley will be on the windward side of the Wasatch tonight and tomorrow morning, with large-scale forcing from the warm front and good conditions low-density snow.  

Curiously, some of the models are not being very generous for precipitation totals.  Focusing on the period from 5 PM this afternoon through 11 AM tomorrow, the 6Z GFS only puts out 0.17" of water and 3.6" of snow for Alta-Collins (I don't have a product from the GFS for Park City, so we'll improvise here).  Similarly, the NAM is only putting out 0.12" and 3.5" of snow for Alta-Collins during that period.  These numbers are fairly close to the SREF mean of about 0.2" of water and 3" of snow.  The 12Z HRRR on the other hand was more excited and generating more than an inch of water for most of the central Wasatch.  

My synoptic gut tells me that the Wasatch Back is going to do better than those numbers suggest through 11 AM tomorrow morning.  I want to go for 6-12" for Deer Valley and PCMR through 11 AM tomorrow (perhaps a bit less for the Canyons Village area), but I'd be a real outlier if I did so.  The NWS has 2-4" tonight and 1-2" tomorrow for their forecast grid-point near Empire Peak.  

Thus, I'm going to remind you that this is a blog, that my gut is often wrong, and that you should monitor official forecasts, such as this one for Empire Peak.  Additionally, low expectations are the key to a happy life, plan on dust on crust and hope for the best.