What Does the Polar Vortex "Split" Mean for Utah Weather?

Sudden stratospheric warmings (SSWs), often accompanied by weakening, displacement, or "splitting" of the polar vortex that features strong westerly flow circumscribing the arctic, occur a few times per decade.  One is developing now and getting some attention in the media (see The polar vortex is splitting in two, which may lead to weeks of wild winter weather).  

I've been asked by a few people what this means for Utah weather?  Really, I don't know.  

Below is a loop of the GFS analyzed and forecast 50 mb (roughly 20 km above sea level) geopotential height from 1200 UTC 27 December through 0000 UTC 11 January.  At this stratospheric level, the flow roughly parallels the yellow height contours with lower heights on the left.

At the beginning of the loop, the lowest heights are centered over northern Scandanavia.  There is a single vortex with westerly flow encircling the this upper level trough.  Over time, however, the vortex "splits" and low centers develop.  This is accompanied by dramatic warming of the stratosphere (not shown), which is why the phrase "sudden stratospheric warming" is sometimes used. 

Splitting of the polar vortex is a very dynamic phrase, but what it means for weather in our part of the world, especially snow, is unclear.  This could reflect the fact that it simply hasn't been carefully investigated, or that there aren't clear linkages.  Each SSW/polar vortex split is different and there haven't been a lot of them to build up a solid sample size.  On average, there are 6 a decade.  Each is different and weather is affected by many other factors.  

What I do know is that weather prediction models include the stratosphere and are capable of producing SSWs/polar vortex splits, as is the case in the loop above.  They are also capable of including many other things that affect the weather, such as ocean temperatures, ice cover, etc.  

Those models are imperfect, but through the use of physical laws and integration of the effects of many Earth-systems processes, they provide better forecasts than simple relationships for forecasts of less than two weeks.  Farther out than that, it's unclear if anything provides a forecast with sufficient reliability for useful skill in northern Utah.  

Thus, I don't think much about the SSW/polar vortex split specifically.  What I see in the forecast models is a pattern that continues to favor below average precipitation.  For example, the downscaled NAEFS  plume for Alta includes forecasts from 52 members.  For the next week, snowfall produced by those members ranges from zero to 20 inches, the former if we just miss the storms, the latter the direct hit.  20" in a week is about average for this time of year at Alta, so these forecasts suggest the dice are loaded for us to have yet another below average snowfall week.  

Whether or not that's because of the SSW is unclear, but it is a continuation of a pattern that we've seen for sometime, even before the SSW.  

Let's hope we end up on the high side of these forecasts.