Utah Daily Snow
By Evan Thayer, Forecaster Posted 3 months ago November 30, 2023
Snow begins on Friday and continues off and on through the weekend into early Monday. Significant snowfall totals in the mountains of northern Utah are likely, but it's a complicated forecast. High pressure returns for next week.
Short Term Forecast
It has been a nervous past 24 hours of model-watching. The nature of this type of moisture hose means that slight variations in its track and orientation can drastically impact our totals. Yesterday, we saw a "mini trend" of sending moisture farther north. Subsequently, our totals in a few models dropped significantly. The good news is that largely we are close to where we were yesterday morning, but I have a lot of nerves heading into this storm. Let's dive in.
The first wave is going to arrive on Friday with snow developing in northern Utah mountains, this will continue into Friday evening, but we may see a break Friday night. This first wave is cold, and snow should pile up quickly. Although, liquid amounts aren't all that impressive. Here is the NBM total liquid through early Saturday morning:
You can see a region of 0.5-1" of liquid along the spine of the Wasatch. This would mean easily 6-12" possible by Saturday morning. This snow should be quite fluffy as well with cold air in place.
The next wave arrives on Saturday and continues through Saturday night. We should see a bit denser snow with this, but not bad. This wave is fairly strong and likely more than doubles the total liquid. Here is the cumulative total by early Sunday morning:
Easily another 6-12+" for Sunday morning, that puts totals generally in the 1-2 FEET range by Sunday.
The final wave is the one that we have seen trend farther north. It was always going to be the warmest wave and so perhaps this is good news that the warmest wave is the one that now looks likely to head to our north. Still, additional accumulation is likely above 6000 ft. By the time all is said and done on Monday, there are the overall total liquid amounts in the NBM:
That's a broad area of 1.5 to 2.5" of liquid in the Wasatch mountains. When converted to snow, and zoomed in, we see plenty of accumulation:
Some of my trepidation revolves around the fact that models still aren't 100% zeroed in on this all happening. There's still quite a bit of spread in the ensembles, notice how different each tiny grey line (individual ensemble) is in the below graph:
I know it's hard to see, but essentially they show anywhere from 1" of liquid to 3" of liquid, with a mean just above two. That's a lot of spread this close to an event.
Our OpenSnow algorithm, also has just about 2" of liquid still for Alta:
You can see though that the tail end of precip late Sunday into Monday is now less than yesterday. Here is a similar graphic, but showing snow level during the times of highest precip:
Low snow levels through Sunday morning, but then they spike up to 6 or 7k feet by late Sunday and Monday. This is why I say perhaps it's good news the last wave is trending north. Upside down snow does weird things, so I do worry that the ski conditions could start to get funky on Sunday and Monday. We shall see.
All of that said, here I my expected totals for this storm:
- Park City mountains: 10-25"
- Cottonwoods: 20-35"
- Snowbasin/PowMow/Beaver: 15-25"
- Sundance: 10-20"
- Eagle Point / Brian Head: <10"
I adjusted the low end down a bit on a few of these because I can't shake the feeling that this storm has a higher bust potential than most. No matter what, this is valuable snow that will go a long way to helping our early season snowpack -- but it might not be the best ski storm with limited terrain and upside down snow.
High pressure takes control for most of the upcoming work week. Yesterday, I mentioned the Euro showed a trough for late in the week. That's still in the cards. The GFS has sorta picked up on it, but doesn't bring it as deep as the Euro. Still, we should have a chance for precip late Friday and/or Saturday of next week (December 8-9). Doesn't look significant, but it should help us clear out the inversions that are sure to re-develop.
Evan | OpenSnow