Temperatures near 50F degrees cannot sustain a strong snowpack for very long. The rapid increase in wet instabilities is directly due to sun & warm air temperatures. Look for the more shaded aspects for the best snow, especially in the afternoon when the loose activity is most pronounced. Relatively small in size, a loose wet avalanche can send you into a terrain trap, over a rock band or into the trees unwillingly.
On ridgelines & some vertical terrain features, winds help create larger accumulations of snow on leeward aspects. When this develops a cornice, unsupported overhanging snow, the potential for this drift to fall & create a large avalanche is nearly inevitable. Cracks were easily seen in cornices yesterday, as wet snows have begun to creep along with gravity. Look up & take notice of dangers above you every time you ride.
Weak layers remain within our snowpack where facets & surface hoar exist. As you dig a test pit look for layers that have poor resistance & are likely to just fall out of your snow pit walls. These grains do not support rapid weight changes well. What they do well is collapse & propagate avalanches. It may be hard to get a catastrophic failure but do not exclude this hazard from your decision making repertoire. Yesterdays pit revealed this problem to be 26cm (10") deep.
Observations from treeline yesterday on a North & East aspect showed a pack of 135cm (53"). Surface melting was apparent on solar aspects, & only isolated pockets contained dry snow not effected by sun & wind. Yesterday's observation showed that 26cm (10") deep exists our persistent slab problem which was the interface where failures in test were occurring. Although stubborn to initiate & propagate collapse, this layer still contains facets & some buried surface hoar which are in the process of rounding. The rounding of these problem grains can improve stability. Temperatures are continuously above freezing in the alpine & percolation of water through the snowpack will degrade bonds amongst snow grains decreasing stability. A density change in the uppermost wind effected layer has also shown to be a moderately weak interface
Cornices can have catastrophic failures from rapid melting & loosening of snow grains. Pictures from yesterdays observation clearly show South facing cornices are primed to break away from the ridgeline. Cornices can be a dramatic avalanche problem, especially when then they fall in an already loaded starting zone creating wet slab & loose wet avalanches. Pinwheels & rollerballs are putting a fine texture to our rapidly melting slopes & are a great indicator of wet instabilities. Creeks, rocks, asphalt & vegetation are melting out creating harsh riding conditions especially below 8500' elevation.
|0600 temperature:||38 deg. F.|
|Max. temperature in the last 24 hours:||50 deg. F.|
|Average wind direction during the last 24 hours:||West|
|Average wind speed during the last 24 hours:||mph|
|Maximum wind gust in the last 24 hours:||mph|
|New snowfall in the last 24 hours:||0 inches|
|Total snow depth:||20 inches|
Hot, dry & devoid of snow. At the rate of losing almost 2" of snow each day we are struggling to keep a snowpack near 8500'. Blocking High Pressure has consumed our region & any precipitation is going to the Northwest. Mount Baker is the place to be if you want deep pow right now, they are having a record January. Clouds tomorrow will help curtail some sublimation & melting.
This snowpack summary applies only to backcountry areas in the Bridgeport Winter Recreation Area. Click here for a map of the area. This snowpack summary describes general avalanche conditions and local variations always occur. This snowpack summary expires in 48 hours unless otherwise noted. The information in this snowpack summary is provided by the USDA Forest Service who is solely responsible for its content.
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