Avalanche Forecast

Fair - Due to variable snopack conditions

A weakening cold front associated with the big weekend storm slides across the region Monday night persisting into Tuesday. The South Columbia will receive light precipitation out of the system; I'm not expecting more than 10 cm by the end of the day Tuesday. A ridge of high pressure builds in Tuesday afternoon bringing dry conditions and lowering freezing levels down to valley bottom by Tuesday evening. Moderate to strong winds will be blowing out of the NW Tuesday in exposed locations. Expect a daytime high of -6 with an overnight low of -9 @ 1500m. Wednesday looks to be cool and dry with no precipitation expected.

Widespread sluffing of the new snow to size 1 was reported Sunday. In most of the region only 10 - 15 cm of snow was involved which makes this a manageable avalanche problem. Two large natural avalanches were reported in the North of the region, but details are sparse at this time. Wind slab activity has really slowed down over the weekend.

The region has received 30 - 70 cm of snow out of the latest storms. This new snow has been redistributed into wind slabs at both treeline & alpine elevations. Slopes facing N, NE & E are immediately lee to the recent SW winds, so the most pronounced wind slabs are found on those slopes. Slopes facing NW & SE are likely crossloaded. There are currently three different surface hoar layers in play. Moving from top to bottom, the first one is the January 3rd SH which is being reported from many different locations, down 30 - 70 cm below the snow surface. The next one is the December 24 SH buried 60 -90 cm below the surface. The last one is the December 11th SH buried 100 - 150 cm below the surface. Test results continue to show sudden planer results on this layer with hard triggers. It's been the most sensitive on south through east facing slopes around the treeline vegetation band, but it is present on all aspects. The last significant layer in our snowpack is a rain/temperature crust that can be found from valley bottom up to about 1600m. As much as 40 cm sit over this crust in the western portion of the region.