Avalanche Explainer, Castle Peak, CA

An avalanche impacted several skiers in the Castle Peak region of California in the Sierra Nevada mountains. This mountain is about 24 miles northwest of Truckee, California and is a favorite spot for winter outdoor enthusiasts.

The Avalanche was more than likely caused by the tremendous and rapid buildup of snow in the area. An atmospheric river this week deposited nearly 4 feet of snow across portions of the Sierra Nevada Range which destabilized the snowpack and increased the risk of an avalanche.

For the article on the Skiers trapped by the avalanche, click here.

Weight and gravity play a role in these types of events. The new snow settles on the old snow base, but with the amount of new snow and the weight of the new snow, the area was compromised. If the new snow is not "set" or stable, it is easier for a slide to occur.

Several factors are in play when an avalanche occurs, one of them is rapid snow growth on the mountain. Four feet of snow in three days will qualify as rapid accumulation rate, or snow growth.