Wednesday Evening Update:
Third update of the day! Something must be happening! Yep, things are happening indeed. Good news/bad news situation…. Bad news is that the threat for freezing rain is still there for tomorrow morning in the lower valleys. This has the potential to create major issues for the morning commute should it come to pass. The good news is that all 18z guidance kept moving in a favorable direction for all Wasatch ski areas. It looks like the boundary just may stall directly over the central Wasatch (Cottonwoods/PC). If it were to happen, accumulations in the mountains of upwards of a foot are not out of the question.
Because the models have been wobbling a bit, I’m still not 100% confident in this scenario. If the boundary stalls too far north or south, these same areas could see the skunk with only a couple inches. Remember, that is a distinct possibility — but we deserve to get lucky. Tomorrow should be a powder day — just watch out for shallowly buried rocks, logs, etc!
By the way, the first warm advection rain drops are currently falling at my house. Temp outside is 29F. AKA freezing rain conditions. :-\
Wednesday Afternoon Update:
Conditions are looking more favorable for a freezing rain event tomorrow morning along the Wasatch Front. Cold air trapped in the valleys with a warmer mid-layer is expected, thus allowing precip to fall as rain and freeze on contact with the surface. You may remember a similar event during last January’s inversion. Please check with the National Weather Service for the latest on the potential for freezing precip. Precip will likely change to all snow eventually, but that will fall on top of a frozen layer — very dicey! This will likely effect the morning commute, stay home if possible.
The good news is that the new 18z NAM is even more vigorous with the boundary and places it directly over the Cottonwoods and PC tomorrow. If this plays out as the models suggest, we could see more significant snowfall totals than earlier forecasted. Stay tuned . . . WSF
A series a small to moderate systems will move into Utah starting tonight bringing snow to the mountains and hopefully scouring out the valley inversions.
Very complicated pattern taking shape over the next couple days. Splitting system will be dropping into the area tonight. Initial wave will bring a period of light snow to the area overnight. Tomorrow, a cold front boundary is expected to stall somewhere between about Nephi and SLC. This boundary will form a deformation zone that will have a band of locally heavy precip. Snowfall amounts in the Wasatch are very dependent on exactly where this band sets up. If it’s south of the area, we will likely just see storm totals of 2-4″. If we get lucky and it stalls right overhead, the Cottonwoods and PC resorts could get 6-12″. Unfortunately, it looks at this point like Snowbasin and PowMow might be too far north to get in on the best action.
Due to all the uncertainty regarding where this snow band sets up, the best forecast is probably a conservative one. Best guess: 2-4″ north of I-80 late Thursday evening with 4-8″ south of I-80. I fully expect snowfall amounts to be highly variable.
The next system will be right on the first one’s heels. It’s not a particularly strong system by any means. But another 4-8″ is not out of the question if everything goes according to plan. Snow should start with this system late Friday night or early Saturday morning and continue through the day on Saturday. Right now, I think Saturday would be the day I’d choose for resort skiing, and Sunday might be money in the backcountry.
Overall, accumulations from tonight through late Saturday should be in the 5-15″ range, with the highest amounts falling in the South and Central Wasatch. Remember, on Sunday it was looking like we’d be lucky to get anything before Christmas, so be thankful we are getting any snow at all. Models still hint at a chance for another weak system for Christmas eve, but we’ll give them a chance to iron out the details before we call it a forecast.
The broad picture is still pretty ugly. A strongly positive AO seems to be the culprit and with all other teleconnections in a weak phase, there seems to be nothing to overcome the AO, which is forcing strong, persistent ridging on the west coast. For us to get consistently strong storms, we need this AO to start heading back toward neutral (and hopefully negative) territory. It’ll happen eventually, but I think we can all agree: the sooner, the better.