The weather lately has been so boring in this part of the country. I keep seeing memories of old photos from past years in which we already had snow storms in the high elevations of the Wasatch by this time. In fact, this is the latest I've gone without having a hike in the snow for at least 4 years. Looks like at least another week before we even have any chance for snowfall here in Utah. Last night, a cold front moved through. It was mostly a dry front, but there was enough instability combined with daytime heating for a few showers and storms to develop. It rained just enough to wet the ground at my place, and of course, timed perfectly for when I was outside grilling. The main effect from this front is that temps will be 10-15 degrees cooler today and tomorrow than they were over the weekend. Then a gradual warming trend back above normal heading into the upcoming weekend.

Wish I could say there was something interesting happening in the short-term, but aside from temps bouncing around a bit, it should be relatively boring end to September.

In the extended forecast, things could be a bit more interesting.  Both the EC and GFS have been flirting with ideas of more active weather returning to the region.  The EC is currently showing high pressure retrograding off the west coast, which would allow systems to track from the northwest into our area next week.  Starting around next Tuesday (October 2), we would see cool, autumn-like storms bring showers to the region.  This is the current full 10-day precip output from the Euro: 

Notice that the precip in the image above is mostly to our north and as you go south in the state, it generally tapers off.  Because of the cool northwest flow, we would also have a chance for snowfall as seen when we look at the same image, but using just a snowfall parameter: 

Now the GFS has a completely different scenario.  The GFS allows a cut-off low to park itself somewhere off the west coast.  This becomes a forcing mechanism to pull up tons of moisture from the remnants of a tropical system.  I tried to find the best way to illustrate this to you.  I converted the GFS loop to an animated GIF to try to show what happens -- notice the massive amount of moisture at the end of the run that pushes up into southern California, Arizona and southern Nevada.  This eventually is pulled into Utah.  

This scenario would be far warmer and wetter than the Euro.  It's unusual for the GFS to be this bullish on an idea that isn't in the Euro at all.  We are 7-10 days out from any such event so differences are to be expected, but this is a vast chasm between the two models.  In such a situation, I typically like to look at the ensembles to see if there is a favored outcome.  I checked the ensemble means of both the GFS and Euro today and it seems that both model suites do have certain ensembles that show each solution, so maybe the both are possible.

You should never get too hung up on one run of one model (especially the GFS), but the idea of subtropical moisture feed has been in several runs, so it's worth noting.  I think it's more likely that the Euro has a better handle on the situation, but we'll just have to wait and see. Either way, we'll hopefully have something to watch and talk about in he coming week.  

Evan | OpenSnow