| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | No |
Observation: Summit
Location: Fresno East Face
Toured up the East face of Fresno to 2050′ in order to get some snow and weather data for the Summit Lake area and also drove the hwy and observed several recent avalanches from this last storm cycle.
Recent Natural avalanche on Tri-Tip, W aspect with debris running almost its full path, stopping just short of Summit Lake.
Obvious signs of instability
Observer Comments
Recent avalanches off of the West face of Butch mountain and the South West shoulder of Lonestar. Significant wind loading ongoing at ridge lines with winds increasing from below treeline up.
Weather
Skies partly cloudy with the sun poking through. Winds light to moderate at treeline. Winds very strong with significant snow transport in the alpine. Winds started out of the south and shifted to blowing out of the north. Temps in the 20s F but cooled noticeably as winds shifted to blowing from the north.
Snow surface
1-2" of loose snow sitting on semi-supportable melt/freeze crust at lower elevations. The surface was ,ore wind affected as we moved toward treeline where the surface had been scoured down to a rain crust in some spots and drifted 4-5" of fresh snow in other spots. At 2050' this crust was only 3-4mm thick.
*This rain crust was formed over Feb.13-15th during a warm wet storm cycle that brought about 1 inch of water (SWE) to this area. This was a mix of rain and snow to mid elevations.
Snowpack
We dug our pit at 2050' on a 24 degree East facing slope. Height of snow was 80cm. Buried surface hoar 15 cm below the surface. The buried surface hoar is within a ~2' 1F hard slab that is sitting on fist hard depth hoar. We had a CT16 on the buried surface hoar layer and a CT19 at the ground on the depth hoar. ECT's yielded an ECTN14 on the buried surface hoar and an ECTP24 and ECTP28 on the depth hoar at the ground.
A rain crust is present below the snow from the recent few storms. The crust was thinning but present at our high point of 2050' but we were told it was gone by 2200'.
The snowpack structure throughout the Summit Lake area continues to be very poor. We found buried surface hoar at several elevation bands though it was fairly nonreactive and was only ~6" below the surface. A 1-2' thick cohesive slab sitting on 6" layer of fist hard depth hoar near the ground remained our primary concern. It was this poor structure that caused us to not continue higher. We did not make it into the alpine where slab depths are more variable and stiffer due to wind loading.
High winds and active wind transport on ridgelines. Recent avalanche off the West face of Butch Mountain. Very deep crown.
Recent avalanche off the South West shoulder of Lonestar. Significant wind loading and scouring of the faces.
Gap in the weather bordered by two large fronts. High winds aloft.
Ravens Ridge and Butch Mountain flagging snow due to high winds. Active wind loading.
Old roller balls formed by wind blowing balls of wet snow.
2-3 cm thick rain crust at lower elevations.
Hand hardness profile. Note the thick 1F slab sitting above fist hard depth hoar.
CT failure on the rotten depth hoar.
~1 cm buried surface hoar within the snowpack.
Large cupped depth hoar from the bottom of the snowpack
Recent natural avalanche on W aspect of Tri-tip that ran just above Summit Lake