A storm will enter the region Sunday night into Monday with significant snowfall possible. All Utah mountains will likely see good accumulations with the highest totals in the Cottonwood Canyons. Very cold temperatures and snow levels down to valley floors will accompany this system.
A few very light snow showers in Northern Utah this morning. These should clear up quickly. Our cold front from Thursday evening dropped south to Southern Utah where it stalled yesterday. Good snowfall totals are being reported down at Brian Head where they’ve seen 14″ in the last 24 hours. They have been having a good start to their season. Trips to Southern Utah are definitely in the cards this winter!
The last two days, I mentioned that I would wait until Saturday before getting invested/excited for the upcoming storm. We’ve had some poor luck with the way storms have evolved so far this season and it was prudent to wait until we were within closer range and therefore had more confidence. I’m happy to report that models have stuck with the idea of this storm being a good one for Utah mountains. If anything, they’ve trended a bit stronger in the last 24 hours.
It looks like the cold front will enter the area late Sunday night. Snow should start in the Wasatch during the wee hours of the morning on Monday. Widespread snow should continue through Monday morning. I’d expect several inches at most resorts by the time the lifts start spinning with the snow getting deeper throughout the day. By Monday afternoon, the snow should taper to showers. This storm looks to have a good prolonged period of a northwest flow that will hopefully keep snow showers going thru Monday night and possibly into Tuesday.
As for snowfall totals, I think most Wasatch resorts will be in the 6-12″ range by the end of the day on Monday. The trough will then linger over the area through Tuesday and likely bring an additional 3-6″ for most area. The Cottonwoods, which are more favored in the northwest flow, could see an additional 6-12″ Monday evening thru Tuesday. So… in total I’d say 8-16″ for most Wasatch mountains with 1-2 feet for the Cottonwoods. Southern Utah mountains should see 6-12″ of snow as well.
In support of these numbers, let’s look at the QPF from the NAM:
This is for the Upper Cottonwoods. You can see the precip starting around midnight on Sunday night and falling heavily through noon before changing to more gradual accumulations through Tuesday morning with over an inch of liquid total. At an average of 18:1 ratios, that would yield close to 20″ of snow.
The NAEFS ensembles are in good agreement with this storm:
Similar timing of the onset of precip for most models. These models give a QPF range of 1.5″ to 3.0″. I’ve said before, I think this is generally over-done. But still, it demonstrates that almost all ensembles are in agreement in at least a decent snowfall event with a good chance for it to venture into “significant” territory. Significant of course is a subjective term, but I’d say most of us would agree that if we have a chance for a couple feet of snow in the Cottonwoods, with a foot or more elsewhere, that counts as significant.
As for temperatures, they will be cold. Single digits and teens in the mountains behind the front on Monday, with the cold air likely lingering through mid-week. This cold air also means that snow levels will quickly drop to valley floors. I don’t do much forecasting for the valleys, but I’d expect that commuting, perhaps even getting to resorts on Monday morning could be a bit tricky with heavy snow falling at all elevations.
Overall, I’m feeling confident that we’ll have a good storm. Just glanced at the latest 12z NAM and it still looks good.
Models are not in good agreement later next week. I don’t see any additional major storms, but at the same time, there is no sign of persistent ridging so the pattern should remain active right up through Christmas.
P.S. As always, please consult the Utah Avalanche Center if you plan to venture in the the backcountry during or after the upcoming storm. The storms in November have turned into a weak, rotted base. Good chance the snowpack will be unstable for awhile after this storm.