SR 20, North Cascades Highway - pass status


SR 20, North Cascades Highway - Washington Pass on Dec. 1, 2008
Originally uploaded by wsdot.

Wondering about the status of North Cascades Pass? It's still open.

Before Thanksgiving, the tall (6 to 8,000 foot starting zone) avalanche chutes were about halfway to where they'd need to be to cause a threat and we haven't gotten much more snow (6 to 10,000 feet) over the last week. The forecast doesn't call for much more for the rest of the week, so until we get some "winter" it's going to continue as it has - crews plowing, etc. as needed. Our forecaster says Washington Pass ought to get another 2-3 inches between now and Thursday, which isn't real "threatening”.

Remember that the traditional closure dates are between Thanksgiving week and the 2nd week of December. One substantial storm is really all that is needed to fill those chutes and cause the avalanches that will close it for the season - and it's very likely to happen over the next two or three weeks, but who knows? We have around 14" to 16" of snow on the ground at the summit. A General rule for avalanche danger that closes the highway is 24” to 36” of snow coupled with some additional trigger, i.e. rain or more snow or a big temperature change.

When the season closure comes, it usually happens fast, so if you’re planning a trip, check the pass report and the web page (www.wsdot.wa.gov/traffic/passes/northcascades/) before you leave or call 5-1-1. Washington and Rainy are a thousand feet higher than Stevens and two thousand higher than Snoqualmie, so they often get snow when the others are getting rain.