What does an avalanche watch, warning and special advisory mean?

The U.S. Forest Service Northwest Avalanche Center (NWAC) produces daily avalanche forecasts for 10 mountain forecast zones across Washington and north Oregon during the winter season. The forecasts are created by analyzing snow observations from across the area combined with computer weather prediction guidance.

Daily avalanche forecasts are issued at 6 pm.

Special forecast products are issued when very dangerous avalanche conditions are expected to help alert the public.

An avalanche warning is issued when high or extreme avalanche danger in all three elevation bands (below treeline, near treeline, above treeline) of a forecast zone is expected to occur within 24 hours of the forecast issuance. A warning may be issued more than 24 hours in advance if forecast confidence is very high.

Due to very dangerous avalanche conditions during a warning, backcountry travel is not recommended and all avalanche terrain should be avoided.

During an avalanche watch, warning conditions are expected to develop within 24-48 hours of the forecast issuance to provide additional lead time but forecast confidence is lower. In the majority of instances, when a watch is issued, the avalanche watch will be upgraded to a warning closer to the anticipated event.

Use this advance notice of potentially dangerous avalanche conditions to adjust your backcountry travel plans.

A special avalanche advisory is issued when unusual and dangerous avalanche conditions are forecast and merit extra attention. A special avalanche advisory does not meet watch or warning criteria and is generally issued outside of the daily forecast season, usually in the fall or spring.

Find out more about the North American Public Avalanche Danger Scale here. For more Washington and north Oregon Cascade and Olympic Mountain weather forecasts, observations and avalanche conditions, visit the NWAC website.