According to the National Weather Service, an avalanche is a rapid flow of snow down a hill or mountainside.
"While avalanches are sudden, there are typically a number of warning signs you can look for or feel before one occurs," according to the NWS. "In 90 percent of avalanche incidents, the snow slides are triggered by the victim or someone in the victim's party."
More than 150 people are killed worldwide each year by avalanches, according to the NWS.
In order to avoid becoming the victim of an avalanche, the National Avalanche Center offers the followings warnings signs to look out for when hitting the slopes:
You see an avalanche happen or see evidence of previous slides
If there are new or recent avalanches in a particular area, that means more are possible.
Signs of unstable snow
According to the Avalanche Center, cracking or collapsing snow around one's feet or skies is a warning sign that an area is unstable. Hearing a "whumping" sound as one walks indicates that the snow is settling and a slab might release.
Heavy snowfall or rain in the past 24 hours
If there are significant amounts of snow or rain, the snowpack on hillsides can be made unstable.
"Avalanches are often triggered the first clear day after a storm," according to the Avalanche Center. "Because it is sunny does not mean it is safe."
On gusty days, snow that's blown on mountainsides can accumulate in a dangerous way.
According to the Avalanche Center, windblown snow loads tend to pile up on leeward slopes, even when it's not snowing out. Those loads can then get deposited in dangerous drifts that could release further down a mountain.
Significant warming or rapidly increasing temperatures
When temperatures quickly rise, gravity can cause snow packed on hillsides to creep downhill and become less stable, eventually triggering an avalanche.