Recap:  

Last week I discussed the chances for snow later in the work week and sure enough, a nice cold front and trough passed thru on Friday and we saw some periods of heavy snowfall. I went on a hike in BCC and there were pockets of 3" or more of snow on the ground.  It was third time I've experienced snowfall in the Wasatch already this September, which seems like a lot so early in the season. 

Forecast: 

Often times these early snow storms can be followed by extended "Indian Summer" periods of high pressure and warmth -- which aptly feels like an extension of summer.  This time, however, we will see some somewhat warmer temps this week with highs in the 70s in the valleys and 60s in the mountain valleys, then we go right back into more winter-like weather.  A trough will be dropping out of the north later this week.  Here you can see the cold air infiltrating the Northern Rockies and intermountain west: 

That will put an end to the more mild air this week.  It will also bring a threat of precipitation to the region late this week into the weekend. 

Timing for this system is tricky.  Yesterday morning, the GFS and Euro models were both relatively in line for this pattern.  But over the past 24 hours, the GFS has began to shift to a more delayed solution that keeps the best cold air and moisture to our north and east, on the other side of the continental divide.  In the Euro's solution, we would see a chance for showers and significantly cooler temps as early as Friday with showers and mountain snow continuing off and on thru the weekend.  The GFS waits until Saturday afternoon before it develops any showers in Utah.  It is also not nearly as cold and moves the cool air out of the state much faster early next week.  

In the Euro, the mountains of Northern Utah would have a good shot at significant snowfall. As seen below:

Both models have the support of their ensembles.  The Euro has been more consistent, but the GFS has been trending toward a less amplified solution over the past few runs.  I'll be curious to see what the 12z model runs depict for each model.  

Either way, what we know for sure is that Northern Utah in particular will get much cooler again by this upcoming weekend.  Snow is possible in the mountains and it could be significant, especially in the Uintas.  

As I touched on above, the GFS would warm us back up next week with a more mild start to October.  The Euro keeps the cold air over the region next week.  Right now I am leaning more toward the Euro as the synoptic patter with ridging in the east seems to favor that.  

If you're wondering if this early season snowfall is any indicator of how our winter will be, I regret to inform you that it's not.  I went back and looked at some seasons with decent September snowfall and some turned out good and others not so much.  We will just have to wait and see.  

I will be putting an update on the top of the this post as soon as we get some clarity between the models -- probably later tonight or tomorrow.  I will also write another post again later this week as we get closer to the storm.  If you want more regular updates, I highly recommend you follow us on Twitter at @WasatchSnow.  I post fairly regular model updates on twitter as it seems to be the best way to communicate real-time weather information these days.  

Evan | OpenSnow