Overrunning moisture will bring the threat of light snow to the Northern Wasatch late in the day on Wednesday. A stronger storm moves in Thursday night with high elevation snow likely on Friday into Friday night.
Winds and clouds will pick up today as moisture and a jet stream increase over the region. By Wednesday afternoon, the threat for snowfall will be present roughly from the Cottonwoods north to the Idaho border thanks to overrunning moisture. This is relatively weak and won’t do much, but mountains could pick up a few inches late Wednesday. By Thursday, this moisture will buckle and push north into the Tetons.
Thursday will be very warm ahead of the incoming storm with a strong flow out of the southwest. This is going to push snow levels way up as the next storm pushes in.
Our main storm will move in late Thursday night and last through Friday into Friday night. This storm has some good news about it, but it also has some bad. The good news is that this storm is very moisture-laden with another sub-tropical, atmospheric river components to it. Currently, the GEFS ensembles are portraying impressive QPF:
If this were to be believed, the GFS is going for 3-5″ of liquid over the next 5 days. I have to think this is overdone by quite a bit. Probably at least 30%. I could be wrong, but I think 2-3″ is a more likely scenario. This is still quite a bit of liquid, and could translate to hefty snowfall totals.
The bad news about this storm is that it has a lot of warm air that it’s pulling up into the area ahead of the cold front. This also appears to be the time with the best precipitation rates. Snow levels could be very high for this portion of the storm. Perhaps jumping over 8000 feet at times. Yikes! It should also be very windy on Friday. Wet and wild day, especially early on.
The cold front will finally push through the region during the day on Friday. Models differ on the timing. After this front pushes through, snow levels will rapidly drop all the way down to valley floors. The problem is that this storm has most of its moisture and dynamics before the cold front, so we may not see huge amounts after the temps cool later on Friday.
Overall, the highest elevations (above 9000 feet) could do quite well with this storm. The lower elevations of resorts, especially in PC, Snowbasin, Sundance, etc, could see rain for a good portion of the storm before changing to snow late. That could severely limit their snowfall totals on the lower mountain.
Despite all of this, I do think late in the day Friday and especially Saturday morning could feature good skiing and riding. The snow on top should be quite fluffy as the airmass behind this storm is cold. It’s just going to be an adventure getting to that point.
Looks like we’ll have a break for the rest of the weekend after clearing out on Saturday. Break should continue into early next week. Next chance for a storm looks to be around December 21. Hard to get any sort of details this far out, but it looks to be a colder storm with more arctic origins as a ridge amplifies in the Pacific. At this point it looks like generally troughiness will stick around for the days leading up to Christmas, which could mean chances for additional storms. It’s been a full month already of consistent storms, and that should continue for the foreseeable future without any major breaks. The one thing long range ensembles seem to agree on is that a strong ridge will remain parked around 165W in the Pacific. That is usually a good spot for troughing to continue downstream over the Western U.S.