UDOT PLANNED AVALANCHE CLOSURES!!

Forecast for the Salt Lake Area Mountains

Trent Meisenheimer
Issued by Trent Meisenheimer for
Tuesday, April 30, 2019
Regular avalanche forecasts with avalanche danger ratings have ended. We will continue to post all observations so please keep submitting them as you get out in the mountains.
During the spring we typically deal with three different avalanche problems:
1. Wet snow: 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.
2. New snow: 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) when cold, dry snow becomes wet for the first time, it almost always means wet sluffs (loose snow that fans outward as it descends). This can happen within minutes of direct sun on cold snow.
3. Wind Drifted Snow: 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. Be sure to check upper elevation wind sites in the links below to get an idea of what the winds have been up to.
Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Weather and Snow
This does not mean the end of avalanches. Spring storms and warm temperatures may make avalanche danger rise. If you scroll down, we provide some general avalanche advice to follow for typical spring weather patterns and we provide a series of other links you can use for current conditions and mountain weather.
  • A full list of mountain weather stations can be found HERE.
  • The most recent observations can be found HERE.
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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
  • Punchy or collapsing crusts
  • 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. Below are a few of my favorite wind stations for the SLC area:
Top of Collins 10,400'
Cardiff Peak 10,000'
Top of Great Western Lift 10,500'
Reynold Peak BCC 9,400'
Jupiter Peak Park City Ridge 10,000'
Deer Valley Mount Baldy 9,350'
Additional Information
  • 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.
  • Ski areas are closing 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 26th Annual Fall Fundraiser Party at Black Diamond on Thursday, September 12th and the Utah Snow and Avalanche Workshop at Snowbird Saturday, November 2.
  • 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, Ted Scroggin and Rich Schuler at the Evanston Ranger District, Brian Murdock and Michael Diem 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 (Executive Director Chad Brackelsberg, employees Bo Torrey, Greg Gagne, Paige Pagnucco, Paul Diegel, and Trent Meisenheimer, interns Tomasz Stefankowski and Lewis Taylor, and Board of Directors Reid Persing, Kate Bowman, Ted Roxbury, Steve Achelis, Mike Brehm, Michael Brill, Al Richards, Liz Pedersen, Tyler Hansen, Nicole Sumner, Caitlin Hansen, and Jacob Splan.
  • Direct funding comes from longtime partners, Utah Division of Parks and Recreation, Utah Division of Emergency Management, Salt Lake County and a grant from the Utah Recreational Trails Programs.
  • Business sponsors who donate to the Utah Avalanche Center are too numerous to list here but you can find them on our Sponsors Page.
  • And a special thanks to all of you who donate directly to the Utah Avalanche Center. We couldn't do this without your support.
  • Learn what to watch for during spring avalanche conditions when the snow becomes wet with this video from the UAC.
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.