Snoqualmie Pass

text size: T T T

Snoqualmie Pass Closure and Snowfall Records

Snowfall depth update - as of May 4, 2008
The current snowfall for the 2007-2008 winter season is 588 inches, 172 percent of the five-year average.

How does this snowfall compare to the highest totals ever? We put together a chart to show the amount of snow we have now compared to the highest amount of snow ever fallen. View the historical snow fall graph (pdf 13kb)
 
Snoqualmie Pass
Interstate 90 Snoqualmie Pass is a crucial transportation artery carrying passengers and freight across Washington. More than 10 million travelers, including significant commercial traffic, cross Snoqualmie Pass each year. In 2005, the Washington State Legislature funded five miles of improvements for I-90 east of Hyak.

Why was the Pass Closed?
Highway maintenance crews are ready 24 hours a day, seven days a week to treat the roadway and remove snow and ice. There are times when short-term roadway closures are necessary to safely clear incidents and remove snow and ice. As you can see below, avalanche impacts and traffic collisions contribute to most pass closures. Avalanche closures include avalanche control work, natural avalanches, and avalanche danger. Collision closures include traffic collisions, spin outs, blocking vehicles, and more.


Graph of snowfall measurements and closures on Snoqualmie Pass.


Snowfall and avalanche control

When the snow piles up and conditions are right, avalanches result. While Snoqualmie Pass has began to accumulate snowfall, WSDOT’s focus on avalanche control (intentionally triggering an avalanche) minimizes natural avalanches.

Drivers are at risk without a comprehensive program to monitor and bring down the unstable snow pack. The work is usually necessary during times of heavy snowfall. It is critical that avalanche control be done before unstable snow naturally slides. When possible, WSDOT performs avalanche control during periods of light traffic since traffic must be stopped for safety.

Over the past five-year period, Snoqualmie Pass received an average annual snowfall of 342 inches per year. View historical snowfall data (pdf 21kb).