To view current Avalanche advisories, visit the Sierra Avalanche Center page here.

Hazard Description

Earth on Nautilus: How a Snowflake Turns Into an Avalanche

Avalanches are complex natural phenomena involving the interaction of weather, terrain, and mountain snowpack. Slab avalanches are the most destructive type of avalanche. They occur when a weak layer or interface allows cohesive, overlying layers of snow to break loose and slide down a steep slope. As gravity causes the original slab to accelerate, additional snow is entrained below, causing the avalanche to gain mass. The vast majority of avalanches occur during or immediately following winter storms between the months of December and March. The slopes of the Carson Range in Washoe County contain extensive avalanche terrain. The majority of these avalanche areas only affect backcountry travelers. 


Mountain communities in the Lake Tahoe Basin, including Incline Village and Crystal Bay, are vulnerable to the effects of avalanches. When avalanche conditions are present, risks are highest for recreational users and others in backcountry areas who may trigger avalanches or be injured or killed by an avalanche. In addition to injuries and deaths, avalanches can damage or destroy property and utilities and cover roadways in snow. Transportation disruptions caused by avalanches or area closures due to avalanche risks can have economic impacts for ski resorts and other businesses in the Lake Tahoe Basin over a period of days to a week or more.


Sign-up for Alerts

Citizens can register for reverse telephone notification, called Code Red, as well as other notifications concerning alerts. To sign up, click on the “ Regional Notification” link on the menu and follow the instructions.

To learn more about Avalanches, visit the Sierra Avalanche Center here.