The theme right now is weak, moisture-starved systems dropping down the backside of our retrograding ridge.  We had a weak system move through yesterday.  I said in yesterday's forecast that we could expect clouds and some light breezes, but probably not much in the way of precip.  I'm happy to say the system surprised and most locations saw at least some light snow.  A dusting here, a dusting there.  While it's not enough to really help, we are a bit colder this morning under clear skies.  Resorts are making snow wherever possible this morning.  Snowbird is looking particularly attractive, here is Mineral Basin looking SW toward Powder Paradise, Bookends/Mary Ellen, and Utah Valley in the distance (shrouded in fog).  

We still have an inversion, but perhaps slightly weakened from yesterday.  

We will be clear today into Friday before another weak system drops down into the region Friday night into Saturday.  This system is still lacking moisture but will be a bit better organized and more of a direct hit.  We should see snow showers moving from north to south from Friday night thru Saturday evening.  Should soften up turns on Saturday.  Right now it looks like 2-4" of snow could fall in the high mountains.  Again, a reinforcing shot of cold air.  

Then, we clear out again on Sunday into early next week with warming temps. Both the EC and GFS have another system dropping down into the intermountain west sometime around Wednesday/Thursday of next week.  This system is may have a little more potential but models have gone back to a cut-off low type of system (which makes sense to me).  These are notoriously hard to predict.  If it drops to our west, we could miss out.  If it drops to our east... same.  So it's far from a guarantee but it's another solid chance for snow prior to Christmas weekend.  

Here is the GFS forecast currently now thru Christmas Eve: 

...and the Euro...

Too early to take any of this as gospel, but the idea is that both major mid-range models are showing a couple separate chances for snow over the next 10-days.  Definitely an improvement in the forecast.  

As nice as it is to see the weak storms in the short-range, what we really need is a major pattern change to bring in some big storms.  For that we've got to look far out and take a look at the synoptic pattern to see what's going on.  For the next ten days the ridge will be retrograding west and allowing the storms to drop down the backside of the ridge, that's discussed above.  After Christmas, the ridge continues to amplify up into Alaska while retrograding.  That is going to allow a deeper trough over the intermountain west.  It may also open the potential for some undercutting of the ridge which would allow systems to tap into Pacific moisture.  If you look at the EPS ensemble heights for December 29th, you can see this pattern clearly: 

This pattern is more typical of a -PNA and La Nina, so it has a lot of support.  This is also quite good agreement for this far out.  These same ensemble means had similar agreement a couple weeks ago for the mega ridge that's been plaguing us lately.  I think that we'll continue to see cool, weaker storms now through the end of the December.  Right around New Years, I think the door will open for stronger storms.  Time will tell...

Evan | OpenSnow