Hey google, How Do I Get My Car Out of A Snowdrift?

TL;DR: An arctic cold front will impact Northern Utah this evening bringing snowfall and high winds to the region. A shortwave trough aligned with a decaying atmospheric river from the Pacific Northwest will bring warm moist air into Northern Utah Saturday night supplying us with another burst of snowfall. One thing is sure, get ready for a LOT OF SNOW.

Nowcast: It is snowing at Alta and currently 13 F at the base and 3 F at the top of Collins with moderate wind from the WNW. So far, this storm has delivered over two feet of snow for Wasatch resorts, here are the totals thus far: 

Snow Totals 1/10-1/12 (72 Hrs):

Alta: 32”   Brighton: 31”   Deer Valley: 21”

Snowbird (48 hrs): 19”   Solitude: 32"   Park City: 23”

(Alta: https://www.alta.com/weather)

Short-Term: Tonight, a cold front will plunge into Northern Utah around 6-7 pm bringing prefrontal and postfrontal snowfall. A strong upper-level jet will bring high winds at upper elevations from the NW, wind chill values will drop into the negatives. For reference, some statistics are showing 100 mph wind gusts tonight at Mt Baldy, Snowbird. 11,000’ ridgelines will see sustained 60 mph winds and 9,000’ ridgelines will see sustained 25 mph winds. These winds peak around midnight tonight.

(University of Utah: https://weather.utah.edu/. A lot is going on here so bear with me. First off, this plot is read with time increasing from right to left. Imagine everything you see from the right to left is coming into Utah. The red region btwn 06Z and 00Z Sat shows theta_e contours that are packed tightly together, meaning temperature is decreasing rapidly with time. This is our cold front tonight. Next, the yellow highlighted wind barbs show strong NW flow which is associated with the strong jet I was telling you about. For reference, 700 mb is ~ 11000’. These winds increase until about midnight and then steadily decrease after that. The red arrow and “W” indicate warm air advection. I will talk more about this in the Long Term Section

Long-Term: After the cold front passage on Friday night, an atmospheric river will begin penetrating northern CA and Oregon on Saturday. Atmospheric rivers are associated with warmer air and lots of moisture. Additionally, we see winds switch to the SW Saturday afternoon, resulting in warm air advection. On top of all this a shortwave trough barrels through Northern Utah Saturday into Sunday, making a recipe for a good storm. Expect the most intense snowfall periods to be Friday night into Saturday morning and Saturday night into Sunday morning. I would like to mention snowfall will likely persist in the northern mountains with brief breaks between both major events discussed in Short-Term and Long-Term. However, these events will account for an overwhelming amount of snowfall throughout the storm sequence.

(Univ Utah: https://weather.utah.edu/. Here is the shortwave trough axis shown in blue that will bring snowfall to the region Saturday night into Sunday Morning.) 

Snow Forecast: Long story short, it's about to snow, A LOT. I’m sure you’ve seen others attempt to forecast snow for this system. Models are being put to the test and it seems silly for me to put numbers out there. This forecast is better understood through words. So, expect many FEET of snow through Sunday 5pm. The upper end at Alta is looking well above 100” while the lower end is around 60”. Either way, it's more snow than you need to go skiing.

Backcountry comments: With all this new snowfall and high winds, avalanche danger will be at a season-high this weekend. Logan is already showing extreme avalanche hazard. For detailed information visit UAC.