Friday, February 28, 2025

Spring-like this weekend, winter-like next week

TL;DR:

A relatively warm and dry, but somewhat windy and cloudy couple of days are ahead; next week, we'll see the return of winter with upwards of a foot of snow likely by Friday.

Nowcast:

It's a (relatively) warm and sunny morning in the mountains; even Snowbird's Hidden Peak at 11,000' is above freezing (although it's worth noting that there is a bit of wind chill, bringing the feel-like temperature into the mid-20s °F):


Weather data from Snowbird's Hidden Peak, courtesy of the National Weather Service

For today, expect mountain highs in the mid to high 30s °F, sunny skies, and mostly light winds. It's not quite spring skiing yet, but it is a good teaser!

Short-term:

The weekend weather will be similar to the weather of the past couple of days in that it'll be mild and dry; however, winds and cloud cover will increase ahead of next week's snow. Keep reading for more on that...

Long-term:

It's pretty clear from the models that winter is returning to the Wasatch next week:


Utah snow ensemble plumes for Canyons-Daybreak, courtesy of the U of U's Department of Atmospheric Sciences

However, they're struggling on the strength and timing of the storm. Even the snow ensemble plume above has two main possibilities: the GEFS (blue line) shows two distinct waves with a storm total of 30", while the ENS (pink line) favors a more gradual/continuous accumulation topping out at just over 15". A couple of other models I looked at seemed to like the "two distinct waves" solution better and favored 12-20" by next Friday.

Either way, I'd mark March 4th and 6th-7th on your calendars as potentially deep days...


If you will be traveling in the backcountry, make sure you have the proper gear and training and know before you go. For the avalanche forecast and other avy-related resources, go to utahavalanchecenter.org.

Monday, February 24, 2025

Warm, dry week ahead


 TL;DR:


Not much happening over the next week, just warmer than normal and dry conditions. Next possible moisture perhaps over the weekend towards next Tuesday (March 4).


Nowcast:


Clear conditions over SLC and the Wasatch mountains. Highs anywhere from 30-50 degrees depending on the mountain you're on and the elevation. Make sure to bring sunblock, as it'll be nice and sunny.

Mount Superior current conditions, courtesy of Alta


Short term:


Tomorrow, a small cold front will come through the Salt Lake area and Northern Utah. This cold front will generally be dry, but might possibly cause some orographic lifting and precipitation in the mountains. Temperatures will be cooler tomorrow and Wednesday as a result of the cold front.


Long term:


Following cold front passage, a high-pressure ridge will build over the area. Temperatures will rise and sunny conditions will prevail. Once we reach the weekend, a trough system should move through possibly bringing precipitation. As we get closer to the weekend, models will become more accurate regarding this trough system and what precipitation it will bring.

Snow forecast for Alta, courtesy of U of U's Department of Atmospheric Sciences


The snow forecast for Alta, provided by the University of Utah's Department of Atmospheric Sciences, shows a rise in precipitation in the evening of March 2nd and rising through the next several days. As we get closer to the weekend, the models will get more accurate in regards to total precipitation and how long it'll precip for.


Backcountry comments:


If you will be traveling in the backcountry make sure you have the proper training and equipment and know before you go. For the avalanche forecast and other avy-related resources, visit utahavalanchecenter.org.


Thursday, February 6, 2025

Friday snow day

TL;DR:

Snow starts tonight and continues through early Saturday morning, with totals around 10". More snow possible next week.

Nowcast:

Mountain temps this morning have returned to relatively more seasonal numbers (between 25 and 35°F) and we're seeing a mix of sun and clouds. Park City and BCC are more on the sunny side of that equation, while LCC seems to be more on the cloudy side:


The view from Snowbird's Hidden Peak, courtesy of Snowbird

For today, expect mountain highs in the low 30s °F, a continued mix of sun and clouds, and increasing winds.

Short-term:

Our next round of snowfall moves in tonight and sticks around for 24-30 hours, granting the Central Wasatch around 10" of snow. Temps will be colder (finishing around ~15°F) with this storm, so expect better snow quality than we've seen recently! Friday should be the best storm skiing day while Saturday should be a first-chair best chair kind of day.

After Saturday morning, we clear out for a bit.

Long-term:

We'll stay dry for a couple of days, then snowfall looks to return to the area; you can see that from the upward trend on the snow ensemble plumes:


Snow ensemble plumes for Alta, courtesy of the U's Department of Atmospheric Sciences

We'll keep an eye on it and see how this develops...


If you will be traveling in the backcountry, make sure you have the proper gear and training and know before you go. For the avalanche forecast and other avy-related resources, go to utahavalanchecenter.org.


Forecaster's Corner bonus feature

As a fun little side note for those of you who read this far, here's a little discussion on forecast uncertainty...

One of the websites I use for forecasting snowfall is the National Weather Service's probabilistic snowfall page, which is exactly what it sounds like: it shows the chance a particular location has of exceeding a certain amount of snowfall as well as predicted snowfall totals based on the high-end, low-end, and expected scenarios. Usually, the low-end, high-end, and expected snowfall totals are in a somewhat close range (within 5-10"), but that was *not* the case this morning. Here are a few of my favorites:

- Snowbird: low-end 3", expected 8", high-end 40"

- Canyons base: low-end 2", expected 4", high-end 16"

- Garden City: low-end <1", expected 1", high-end 10"

- Park City Mountain: low-end 4", expected 7", high-end 24"

- Provo Canyon: low-end <1", expected 3", high-end 46"

From 3" to 46" in Provo Canyon!

I'm 99% sure these numbers are determined by running a large number of computer models, each with slightly different atmospheric conditions, and then forecasting totals from the most likely scenario that all those models are showing. With regard to our situation here, this means that enough computer models forecasted those crazy high totals that the high-end amounts shown here are reasonable. For the record, those high-end totals are unlikely (there is a 90% chance that less snow will fall and only a 10% chance that more snow will fall), but they aren't completely outlandish...

Thanks for reading and have an awesome day :)