Many small avalanches today. All aspects. Only 2-3" deep. My guess is that they occurred during a high PI event towards the end of the storm which put down approx. 7" of snow. basal 3-4" was very light by south west Idaho standards. Combination of needles and irregular crystals. Upper 2-3" were similar but rimed and denser, creating a density inversion which lead to a slab like behavior. Very sensitive this morning, sensitivity decreased during the day. Overall not a big concern in this area, however, if one were on a bigger slope, it might of been possible for one of these to entrain enough snow to knock you over.
Photo is a typical example, one of many.
All observed slides were < size 1, I did hear e report of one 12" crown on a SE facing side of a ridge in the area but did not see it.
Signs of Unstable Snow
Did you see shooting cracks?
Did you experience collapsing or whumpfing?
Shooting cracks were all shallow and up to 20' or so.
Wind was calm today with occasional flurries, no significant accumulation after 10am.
Other than the upper 2-3" as described above, I did not observe any instabilities or red flags.
I was traveling based on a Moderate type of hazard scenario. that would have likely changed if I was in exposed avalanche terrain.
Toddeo - FPAC Observer Coordinator
Observed Avalanche Problem #1:
Upper 2-3" due to density inversion. minor in this area due to nature of terrain. In the am, I was not able to isolate the upper 2-3", in the afternoon, it was possible on occasion. This settled out some today, but the inversion is something I will be keeping my eye on.
Observed Avalanche Problem #2:
Having spent a few days in this area recently with high winds, I know there are some buried wind slabs. Recently, some of these were not easy to isolate in hand/pole columns and did propagate in ECTs (during the last week). Based on hand/pole columns today, these may have stabilized a bit. 3 quick ECTS isolated with poles near the ridge line did not fail or propagate (see photo below). Still something to be aware of in more exposed terrain.