Donate to the 2024 Spring Campaign to help rebuild the UAC website.

Forecast for the Salt Lake Area Mountains

Mark Staples
Issued by Mark Staples for
Tuesday, April 27, 2021
During the spring there are typically three different avalanche problems:
1. Wet snow: Wet loose avalanches, wet slab avalanches, and lastly glide avalanches.
2. New snow: New storm snow instability as soft slab avalanches as well as loose dry avalanches.
3. Wind Drifted Snow: Wind slabs - soft or hard drifts of wind blown snow.
Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Special Announcements
Regular avalanche forecasts have ended, and we will no longer be updating this page. We will continue to post all observations, so please keep submitting them as you get out in the mountains.
Weather and Snow
Monday, April 26 had 11.5 inches of snow (1.57 inches of water) in the upper Cottonwoods. Snow totals were much less at lower elevations. Sunshine and dry weather are expected for the rest of April.
A full list of mountain weather stations can be found HERE.
Recent Avalanches
There were seven human-triggered slides reported on Monday, April 26. There will be more avalanches when (1) the sun comes out after a storm, when (2) the wind blows, or when (3) it snows again.
  • A list of all observations and avalanches can be found HERE.
Ad
Avalanche Problem #1
Wet Snow
Type
Location
Likelihood
Size
Description
When cold, dry snow becomes wet for the first time, it almost always means wet sluffs (loose snow that fans outward as it descends).
Larger wet slab avalanches can happen when melt water percolates through a layered, winter snowpack for the first time especially after 3 days of strong melting combined with no refreeze at night.
Luckily, wet avalanches usually don't last forever because over time, days or weeks, of percolating melt water, all the layers in the snow disappear and the snow becomes homogenous and dense, turning into a stable summer-like snowpack. Typically, this cycle of instability maturing into stability occurs first on the south facing slopes in early spring, then progresses to the east and west facing slopes in mid spring and finally by late spring, the upper elevation north facing slopes go through a wet avalanche cycle.
Finally, glide avalanches occur regularly in spring as the entire snowpack slides slowly on the ground like a glacier until they suddenly release into a full-depth avalanche. These occur regularly on steep rock slabs and occasionally on steep grassy slopes. Notorious glide avalanche locations include places Stairs Gulch or the rock slabs in Broads Fork, which you should always avoid in spring. Avoid crossing under any slopes with telltale glide cracks in the snowpack. Remember they come down randomly, even at night.
The bottom line for wet avalanches:
Get out early and get home early. Get off of--and out from underneath--any slope approaching 35 degrees or steeper when the snow becomes wet enough to not support your weight. Warning signs may include:
  • Roller balls (pinwheels) in new snow that is getting wet for the first time
  • Natural or human triggered wet sluffs
  • Small sluffs fanning out into larger slides, or running long distances
  • Cornices breaking off
  • Several days of strong melting combined with no refreeze at night
Any of these signs mean it's time to head home, or at least change to an aspect with cooler snow. Remember, even "smaller" slides can be dangerous in high-consequence terrain, such as above a terrain trap, trees, rocks, cliffs or a long, large avalanche path. Plan your trip to have a safe exit back to the car.
Avalanche Problem #2
New Snow
Type
Location
Likelihood
Size
Description
We almost always get several winter-like snow storms in April and May. Treat each storm just like you would in winter. Avalanches can occur within the new snow typically from 1) low density layers deposited during the storm, 2) high precipitation intensity during a storm and 3) from wind slabs created during the storm.
It's easy to test the new snow as you travel by jumping on small test slopes to see if they avalanche or just dig down with your hand to see how well the new snow is bonding. Snow can change dramatically in both space and time so never let your guard down. Especially avoid any steep slope with recent wind deposits, which are almost always dangerous.
Practice usual backcountry protocol, go one at a time, never travel above other people and practice all the usual risk reduction measures and low-risk travel ritual you learn in avalanche classes.
Avalanche Problem #3
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
For each storm it will be worth looking at the winds to find out which direction that have blown from and what direction they will be blowing for the day. Wind can rapidly load snow onto steep slopes making those slopes more prone to avalanching. Wind drifted snow looks rounded and pillowy, in some cases it can sound hollow like a drum. If you see shooting cracks it's a sign you may of hit a wind slab. Be sure to click on the this link HERE and check upper elevation winds for speed and direction.
Additional Information
Regular avalanche forecasts with avalanche danger ratings have ended. We will continue to post all observations so please keep submitting them.
Learn what to watch for during spring avalanche conditions when the snow becomes wet with this video from the UAC.
Thanks to all of you who have sent observations this season. Crowd-sourcing is the most valuable information we get. Other avalanche centers all over the world are modeling our program. And special thanks to all the Utah avalanche professionals: ski areas, Utah Department of Transportation, guides, and educators, Powderbirds and Park City Powder Cats.
Thanks to Rusty Billingsley and the National Weather Service who provide office space, weather forecasting, tech support and great company.
A special thanks to all of you who donate directly to the Utah Avalanche Center. We couldn't do this without your support.
Ski areas are closed and each has a different uphill travel policy. Remember that areas open to uphill travel are no longer doing any avalanche mitigation work and must be treated as backcountry terrain.
Be sure to mark your calendars - join us for the 27th Annual Fall Party at Black Diamond on Thursday, September 10th and the 13th Annual Utah Snow and Avalanche Workshop at Mountain America Expo Center Saturday, November 6-7.
The Utah Avalanche Center is a partnership between the Forest Service and the non-profit Utah Avalanche Center. On the Forest Service side, thanks to unwavering support from our boss Renee Flanagan, Forest Supervisor Dave Whittekiend, the rest of the Uinta-Wasatch-Cache National Forest, Brian Murdock of the Manti-La Sal National Forest and the financial support from Chris Hartman of the Forest Service Intermountain Region. Two-thirds of the Utah Avalanche Center funding along with the awareness and education programs comes from the non-profit Utah Avalanche Center. Our forecast staff includes Director Mark Staples, Drew Hardesty, Toby Weed, Craig Gordon, Brett Kobernik, Eric Trenbeath, Trent Meisenheimer, and Nikki Champion. Our nonprofit staff includes Executive Director Chad Brackelsberg, Greg Gagne, Paige Pagnucco, Andy Nassetta, Hannah Whitney, and Trent Meisenheimer. Board of Directors Kate Bowman, Ted Roxbury, Mike Brehm, Michael Brill, Al Richards, Tyler Hansen, Nicole Sumner, Caitlin Hansen, Jacob Splan, Rich Mrazik, Eric Quilter, Kim Reid, and Michael Shea.
Direct funding comes from longtime partners, Utah Division of Parks and Recreation, Utah Division of Emergency Management, Utah Department of Transportaiton and Salt Lake County.
Generous support in the form of donated lift tickets and daily observations comes from Ski Utah, Alta, Brighton, Beaver Mountain, Deer Valley, Powder Mountain, Snowbasin, Snowbird, Solitude, Sundance, and Vail Resorts.

Business sponsors who donate to the Utah Avalanche Center are too numerous to list here but you can find them on our Sponsors Page
General Announcements
This information does not apply to developed ski areas or highways where avalanche control is normally done. This forecast is from the U.S.D.A. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.