Warming in Solitude Canyon

Toured to the top of Solitude Canyon to the top of Solitude Peak. Given that warming was going to be fairly obvious on southerly aspects, wanted to track warming on E-N-W aspects and by elevation.

4 sets of field weather observations to quanifty the warming.

Site 1 at 8500' on a W aspect taken at 935am: Sky=Clear, Wind=Calm, HS=70cm, Ski pen=10cm, Boot pen=30cm, Surface snow=Dry MFcr, Tair=8 deg C!, Tsurf=-1 deg C, T-20= -1 deg C.

Site 2 at 9131' on an E aspect taken at 1020am: Sky=Clear, Wind=Calm, HS=120cm, Ski pen=5cm, Boot pen=35cm, Surface snow=Moistening NSF on top of MFcr, Tair=7 deg C, Tsurf=0 deg C already, T-20= -2 deg C.

-Saw small rollerballs from yesterday on N and NE aspects below rock bands at 1050am at 9300'.

Site 3 at 9650' on a W aspect taken at 1110am: Sky=Few clouds, Wind=Light from the N, HS=75cm, Ski pen=5cm, Boot pen=15cm, Surface snow=Moistening NSF on top of MFcr, Tair=8 deg C, Tsurf=0 deg C, T-20= -2 deg C.

-Saw several natural small loose wet slides and medium sized rollerballs release from below rocks and vegetation on the N and E aspects of a little bowl at 1120am at 9670' (see photo).

-Toured up a sheltered NW facing aspect where the snow surface was faceted and probed around for the deep weak layers. Still felt very soft 4F-F hard layer (probably depth hoar) just above the ground in many areas. The HS going up this slope ranged from 185cm to 250cm and there was thick layers of ~1F or even P and K hard snow over top of the soft layers. It seems like it would be really hard for a skier, rider, or group to trigger the softer deep layer with that hard snow over top.

Site 4 at 10600' on a W aspect taken at 1215pm: Sky=Few clouds, Wind=Calm, gusting Light from the N, HS=270cm, Ski pen=3cm, Boot pen=40cm, Surface snow=Dry surface hoar on top of MFcr, Tair=7 deg C, Tsurf=0 deg C, T-20= -6.5 deg C.

-N aspects between 10400' and 9200' were dry surface facets, some very small loose dry sloughing on the way down Solitude. NW aspects below 9200' had warmed through with ankle deep ski pen and many rollerballs by 1pm.

-Traversed across the Tele Bowls on the way out, across N and NE aspects holding at about 8400' at 130pm: ankle deep ski pen through very moist snow, medium sized rollerballs, a few hockey stops triggered very very small loose wet slides. Loose wet here seemed less than touchy, more just reactive. Everthing below 8500' by this point, all aspects, was wet glop.

General Impression: The warming is working it's way around the compass and starting to affect lower elevations northerly slopes and warming E-S-W facing slopes appreciably up to above 10,500' by mid day. Things aren't really scary wet yet, but thaw instabilities are begining to show, especially near rocks and vegetation and in bowls and cirques on all but true N aspects.