Twitter user @UtahWxMan took this great photo of the shelf cloud accompanying the front as it moved through Bountiful.
Shelf cloud associated with the cold front moving through Bountiful right now. @ChaseThomason @AllisonCroghan @NWSSaltLakeCity @JimCantore @StormHour @WasatchSnow @ProfessorPowder @ABC4Devon @kvandykewx @Ginger_Zee @ReedTimmerAccu @weathercaster @spann #UTwx pic.twitter.com/W5UimC2nbq— Darin Brooks (@UtahWxMan) November 24, 2018
For the most part, the past three days have produced as expected. Through 8 AM, the Snowbasin Middle Bowl site (7400 ft) has recorded a total since Thanksgiving of nearly 2.6 inches of water.
The forecast for today is a bit tricky, which reflects the usual post-frontal crap shoot. It appears the frontal precipitation may linger for a couple of more hours in the Cottonwoods. Then we'll have to see on the instability snowshowers. For many days, the models called for a quick shutdown, but they've been a bit more bullish recently. The HRRR, for example, is generating post-frontal bands that I would describe as somewhat unrealistic in their intensity and spacing, but perhaps indicative that we will have some shallow instability to play with this afternoon.
So, perhaps another 2-5 inches at Alta Collins from 8 to 11 AM and then we'll see what the post-frontal crapshoot can produce.
Two aspects of the storm cycle that we're not as well forecast were the break yesterday, which produced a nicer day than expected, and the persistence of the overnight warmth, which led to temperatures as high as 33.5˚F at the base of Alta at 4 AM this morning. Temperatures also reached 33.7˚F at the Snowbasin Middle Bowl site (7400 ft). While I wasn't surprised to see warm temperatures ahead of the front, I thought we would have seen peak temperatures earlier during the storm, perhaps Friday afternoon or early Friday night. This reflects a stronger trough, which led to flow with a more southerly component in the pre-frontal environment, and may have limited overnight snowfall in the mid elevations.
By and large, however, this is a game changer, although sympathies to the Park City side of the mountain where accumulations have lagged (although that's not unusual). Although there will be a break Sunday and Monday, forecasts show an active pattern later next week. We'll have to see how it comes together.