West Slopes South - South of I-90 to Columbia River
Winter 2017-18 Forecast Schedule
Mountain Weather Forecasts, issued once a day in the afternoon, began Monday, November 13th.
Avalanche and Weather Summaries will be issued:
Wednesday, November 15th
Friday, November 17th
Monday, November 20th
The first* Avalanche Forecast will be issued Tuesday, November 21st @ 6 PM, valid for Wednesday November 22nd. The full winter forecast schedule will follow through mid-April.
*This date may change depending on how conditions develop this week.
NWAC avalanche forecasts apply to backcountry avalanche terrain in the Olympics, Washington Cascades and Mt Hood area. These forecasts do not apply to developed ski areas, avalanche terrain affecting highways and higher terrain on the volcanic peaks above the Cascade crest level.
Avalanche and Weather Summary
Valid Tuesday, November 14th - Wednesday, November 15th
The next Avalanche and Weather Summary will be issued Wednesday, November 15th.
Strong, moist SW flow is streaming across the Olympics and NW Washington Cascades with a strong gradient in recent precipitation amounts from north to south. The water amounts have been impressive over the past 48 hours in places like Mt Baker and Hurricane Ridge under the strongest flow with over 5 and 3 inches of water equivalent respectively. Latest update below.
Total snowdepth now ranges, in general, from less than a foot in the passes and lower elevations below 3-4000' to 2-3 feet or more on the volcanoes and above 5-6000'. Snow levels lowered over the past 24 hours with some healthy new snowfall totals, mostly ranging from 1-2 feet in the areas with heavier precipitation and 6-12" or less in the passes and less favored areas.
Warmer temperatures late last week helped consolidate the older snowfall and along with rain Sunday, has left a strong rain crust below the most recent snow in many areas.
Periods of strong easterly winds, specifically in the Crystal area, last week stripped much of the previous snow along ridgetops above treeline.
Another round of strong winds and snowfall is heading our way Tuesday. This next system should be a repeat performance favoring the Olympics and Mt Baker area, with very little precipitation expected to reach the Mt Hood area.
Early season avalanche awareness is still the travel mindset, with exception of the note below regarding local conditions in the Mt Baker area. See Forest's excellent blog post when thinking about traveling in avalanche terrain earlier in the season. Isolated areas of storm or wind slab may exist above treeline.
We want to continue to call out one area of caution for the Mt. Baker area on Tuesday. Increasing heavy precipitation and relatively low snow levels are forecast for Tuesday midday through Tuesday night, avoid traveling above treeline (generally 5000 feet) as the avalanche danger will likely ramp up quickly with building and increasingly sensitive storm and wind slabs. Don't be lured into the higher terrain by the lower
USE AT YOUR OWN RISK
This Backcountry Avalanche Forecast is provided in conjunction with the US Forest Service, and is intended for personal and recreational purposes only. Safe backcountry travel requires preparation and planning, and this information may be used for planning purposes but does not provide all the information necessary for backcountry travel. Advanced avalanche education is strongly encouraged.
The user acknowledges that it is impossible to accurately predict natural events such as avalanches in every instance, and the accuracy or reliability of the data provided here is not guaranteed in any way. This forecast describes general avalanche conditions and local variations will always occur. This forecast expires 24 hours after the posted time unless noted otherwise.