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We have quit issuing avalanche advisories for the season. But I will still try to post your observations each day until about the end of May, so if you're getting out, you can let everyone in our community know what you find.
This does not mean the end of avalanches. It just means that we have reached the end of our funding for the season and all of our forecasters are headed to their summer employment. If you scroll down, I provided some general avalanche advice to follow for typical spring weather patterns and I provide a series of other links you can use for current conditions and mountain weather.
First, I have a long list of people to thank:
Visit the Snow Page to see all the automated weather stations and web cams in the mountainous areas of Utah. Also, I will continue to post Observations each day, so please share what you find with everyone else in our mountain community. You can submit an observation by clicking HERE or fill out the form from our home page.
Here is some general avalanche advice for spring. As my 96-year-old mother-in-law from the Czech Republic says, "Spring is a fight between winter and summer." In the mountains, this means that spring weather alternates between spring snow storms and wet avalanches when it heats up between storms. So first for wet avalanche advice:
Snow does not like rapid change, and when cold, dry snow becomes wet for the first time, it almost always means wet sluffs (loose snow that fans outward as it descends) and occasional wet slabs. Also, slabs can involve old snow 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 after a few day 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 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:
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 and inescapable in steep terrain - they can take you off a cliff or for a long ride. Plan your trip to have a safe exit back to the car.
We almost always get several winter-like snow storms in May and sometimes into June. 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.
Finally, remember, most of the ski resorts are closed for the season with no avalanche control, so treat it just like backcountry terrain. Each spring several close calls and occasional fatalities occur at ski resorts closed for the season. Steep slopes at ski resorts are safe all winter ONLY because of regular avalanche control with explosives so after the resort closes it instantly becomes backcountry. It's hard to get your head wrapped around the fact that a slope that has moguls all winter can be dangerous avalanche terrain when the resorts are closed. 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. We've had 4 tragic fatalities this season. We don't need more.
Here are my favorite links for mountain weather:
The good-old National Weather Service forecast is always, hands-down, the best forecast you can find. For instance, HERE is one for Alta and you can go to the map and click on any region of Utah to create a customized forecast for that 1-mile square area. While you're there, you can click on the satellite loop, the radar loop or--my favorite-- the graphic display of hourly weather for that area.
A couple other more geeky links I like include:
The University of Utah Department of Meteorology products such as the Time-Height plots. (Time is on the horizontal axis and runs from right to left and the height of the atmosphere is on the vertical axis.) Yep, it's pretty geeky, but it is a very powerful weather display.
For maps, I like the Penn State display of various maps.
If you trigger an avalanche in the backcountry - especially if you are adjacent to a ski area – please call to report the slide even if everyone is OK. Rescue teams can be exposed to significant hazard when responding to avalanches, and do not want to do so when unneeded. In the Salt Lake mountains please call. Alta Central Dispatch (801-742-2033).
Remember your information can save lives. If you see anything others should know about, submit a snow and avalanche observation from the link on the home page.
For a print version of this advisory click HERE.
This advisory is produced by the U.S. Forest Service, which is solely responsible for its content. It describes only general avalanche conditions and local variations always exist. Specific terrain and route finding decisions should always be based on skills learned in a field-based avalanche class.