The word ‘Avalanche’ comes from the French verb ‘avaler‘ — to swallow. After observing dozens of avalanches, I understand the naming well. Falling snow not only swallows, but chews up and spits out everything in its path.”
Northern Utah’s avalanche season runs approximately from October to October. The dozens of factors that can lead to avalanche are so complex that forecasting is a fuzzy science at best. Even so, understanding these factors can significantly lower your chances of being bruised, crushed, buried and suffocated in an avalanche.
For up-to-date back country snow conditions in the Northern Utah area, call the U.S. Forest Service Avalanche Forecast Center at (801) 378-4333. Forecasts are updated by 7:30 a.m. daily.Â Listen in regularly to get a better picture of what you’ll find hidden beneath the latest snowfall.
Sign up to recieve this daily report by email and find TONS of extremely valueable and interesting avalanche information and training opportunities at www.avalanche.org/~uac/
95% of slides occur on slopes between 30% and 40%. You’d be surprised to realize how mild such slopes appear. Some avalanche deaths occur in city parks with sledding children. Steeper slopes tend to slough off sooner and not build up to serious avalanche potential–but use good judgment. Cornices and other features often break free with many tons of force. When avalanche conditions are dangerous, stick to safer slopes – less than 30% and not located below steeper danger areas.
If the temperature of the snow near the ground (which stays near 32Â° F / 0Â° C) differs significantly from temperatures higher in the snow pack, then as some of the snow naturally turns to vapor and refreezes, the distribution grows uneven. The snow near the ground can turn to Depth Hoar–tiny, highly unstable balls of ice commonly known as Sugar Snow (we call it avalanche candy). Inuit, with their eleven names for different types of snow, call this Pukak.Â Depth hoar has so little cohesion that it acts as ball bearings below anything that happens to break loose above it.
You can purchase a thermometer to measure snow temperatures and also guage recent weather patterns to get a rough idea of what you might expect below the surface. a difference of 10 degrees within 10 centimeters is enough to cause concern.
The current air temperature at the time the snow fell also impacts snow pack stability. Colder temperatures and dry conditions make for marvelous powder, but when it slides, this freshy fresh doesn’t always touch the ground. Riding on a cushion of air, it can reach speeds between 200 and 300 mph. You thought wind burn hurt your skin? Wind from dry avalanches flattens trees hundreds of feet from where the snow stops.
Warm temperatures and rain can make the snow heavy. If heavy snow rests atop an unstable layer or if its sheer weight overcomes the snow’s cohesion, a wet snow slide may occur. This type of slide is the most destructive. It can follow ravines, even if moving slowly, and stack fifty-foot high piles of snow miles from its beginning point. Use a protractor and measure the angle from you to the potential slide point. If it’s steeper than 20Â°, you run the risk of being in the slide path.Â Look for likely point-release points near rock bands where the sun warms the snow and starts the ball rolling.Â Roller balls (the cute, almost two-dimensional snowballs you sometimes find) indicate a risk of wet slide potential.
Cliff bands, trees, bumps, outcroppings of any kind and even a single bush can provide anchor points to hold the snow pack in place. Later in the year, these anchors are buried and new snow has a smoother surface to ride on if it fails to adhere to previous snowfall. If you must traverse a dangerous slope, be aware that slab fractures often occur right over such features, or just above.
Other Safety Tips:
Dig a snow pit to examine snow layers. Run your fingers up through the snow to feel cohesiveness. Chop out a microwave oven-size block and push against it to determine where the pack breaks and how easily. Measure flake sizes from different spots if you have a card.
If you must traverse a questionable slope, send one person at a time. If it slides, one person (the lookout) should watch the slide to maintain a guess as to where the person ended up beneath the snow. This person should not move until others reach the area (if prudent) so that perspective is not lost. Watch for hats, gloves, or any other clues as to the person’s whereabouts. Always wear a beacon in the backcountry and test it before stepping onto the snow. Bring a shovel and probe. Your chances of survival decrease significantly if you’re not found in the first 15 minutes. Train properly with your equipment. An emergency is not the time to experiment or discover that your batteries have gone dead.
If you don’t have a beacon and don’t have a good guess as to where an avalanche victim has been buried, check first around tree trunks and other obstructions or in the snout (terminus) pile where the avalanche stopped. By the way, what were you doing in avalanche territory without a beacon????
If you get caught in a slide, try to stay near the surface by kicking off your skis and swimming as much as possible.Â Your mouth is likely to fill with snow as you try to breathe. Just before the snowmass grinds to a halt, use one arm to try to create an air space around your face and stick the other hand up.Â Many people are alive today only because someone saw their hand protruding from the snow.
Once the snow stops, it sets up like cement. Â Friction and energy generated in the slide melts the snow and it instantly refreezes.Â Unless you have an arm out of the snow, it’s unlikely you’ll be able to dig yourself out or move at all. Try to slow your breathing and conserve oxygen and wait, and pray harder than you ever have before.
Snow actually contains a large amount of air. The problem is that a buried victim’s breath melts the snow and creates an ice mask that doesn’t allow the oxygen to penetrate.Â Black Diamond makes an instrument called the Avalung that, if positioned properly before burial, allows victims to breathe for over an hour in some tests.Â Don’t take this as a ticket to play safely in avalanche territory, however. A good slide can still squish you like a bug!
Beacon (pieps) Use:
Unless you have a DTS Tracker, Ortovox M2 or S.O.S. beacon that provides arrows to point you in the right direction (or rather, along the oval flux line – shaped like an apple with the beacon at the apple’s core), cross the search area until the signal begins getting weaker. Then turn and walk back to the strongest signal point. Now turn 90Â° and go again to find the strongest signal in the new direction. Fine tune your beacon as necessary until the signal almost disappears. This grid triangulation pattern brings you to the nearest possible area.
Avalanche Probe Use:
Form a line, fingertip to fingertip with other searchers (unless you have enough searchers to conduct a tighter search).Â Reach out right and probe straight down (a.k.a. straight down! Don’t probe at an angle!), then center and left. Everyone should advance at the same time to avoid gaps in the search line. If you hit something that might not be rock or tree, shout out “Hit!” Leave your probe in place. Someone should then start digging to check and see what you hit. This method boasts a 70% find rate on the first pass. If you pass beyond the search area, swing the group around and make another pass. Leave articles to mark where you have searched, but don’t be afraid to re-search and area.
Wanna see something amazing? Watch a rescue dog run across an avalanche path and find people buried many feet down. Without even training this, if they find your feet first, they immediately move to dig out your head first. Dogs are great!