Quick report
- Red Flags
- Recent Avalanches, Wind Loading, Rapid Warming, Poor Snowpack Structure
- Red Flags Comment
- <p>Poor snowpack structure can be found within the latest event, and it's interface to the old snow/new snow layer appears to be inverted and exhibiting very easy shears. The last half of the storm came in much denser and this combined with the wind and warming has set up a structure of concern. On slopes that had developed a m/f crust prior to the event this bed surface appears to be helping in the avalanches observed on Tuesday and Wednesday. Shady aspects with slope angles greater than 35 degrees that did not have the new snow stripped off by the wind are suspect. And in other steep areas where the loading built hard slab potential it may be worth digging quickly to see if there is loose snow at the old snow/new snow interface. </p>
Snowpack
- Instability Comment
- <p>Extreme/rapid warming forecasts for Thursday may be enough to help trigger many of the overhanging Cornices that were not only increasing in size during Tuesdays event, but along with this many of these Cornices have significant overhanging lower lips. </p> <p>Wet Slabs at mid to lower elevations appear to be a possibility with the sustained periods of lack of overnight refreezes that we have been experiencing. Overnight from Tuesday to Wednesday was the only night it actually got below 32 and it barely did this. Wednesday night and Thursdays chance of hitting 50 degrees at 9000 feet appear to be substantial, and possibly enough to bring on this problem on Thursday. In the isolated mid elevation areas that were still housing Persistent Weak Layers these warm temperatures may reactivate these layers. Additionally, the possibility of any sustained periods of rain may worsen this situation. Perk tubes and drainage channels are already in place in many areas in the mid to lower elevations.</p> <p>Along with this continual Loose Snow Wet Avalanches will be possible on shady aspects that received new snow on Tuesday. </p> <p>Wednesday appeared to see the avalanche conditions settle out significantly from Tuesday and in most areas it was Moderate. All the possibilities cited above appear to indicate a rising Danger for Thursday and Considerable appears likely. </p>
Variable conditions exist with widespread wind damage above 8500 feet on almost all aspects. Intense wind speeds, a period of high density snow fall, and warming temperatures on Tuesday created a mixed bag of surface conditions that were noticeably different than with the initial snowfall that began this latest event. Supportable smooth wind board was the predominant snow surface found in the upper elevations. Unfortunately there were also areas where the wind board was not quite supportable. There were isolated patches of 1 to 2 inch carvable graupel that were probably the best riding in the exposed upper elevations. In the limited protected terrain there was 4 to 5 inches of settled very dense loose snow. Daytime warming dampened everything on the lower half of the compass at elevations above 9000 feet; and at 8000 feet the snowpack is still saturated.