The sun at this time of year can pack a punch so watch for signs of warming in recent snow on steep south aspects. The most likely place to trigger an avalanche is in wind-loaded terrain features. In the north island around Mt Cain, wind slabs may be especially reactive due to an underlying crust.
Recent snow and wind have formed soft, fresh, reactive wind slabs in leeward terrain features. In the north island around Mt Cain, wind slabs may sit on top of softer snow on a crust, which can act as a slick bed surface. for avalanches
On Tuesday our field team observed several size 1-2 wind slab avalanches at Mt Cain which they estimated to be around 1-2 days old. Some of them failed down to a buried crust.
Explosive control work produced size 1-2 storm/wind slab avalanches on Monday and Tuesday in the Mt Washington area.
If you head into the backcountry please consider sharing your observations on the Mountain Information Network!
Small amounts of new snow continue to accumulate. 30-60 cm of recent snow has been blown into wind slabs at upper elevations.
A thick, widespread crust formed in mid February now sits 40-80 cm deep. Near Mt Cain, the crust is glassy with faceted crystals sitting on top of it, which makes for a poor bond to the overlying slab of snow. For more details, check out this reel from our field team last week. Elsewhere the crust seems to be bonding well. You can check the bond in your local area by performing a simple hand shear test on an isolated block.
The mid and lower snowpack is well consolidated, containing a series of well-bonded crusts.
Wednesday night
Up to 10 cm of new snow. Moderate to strong southeasterly wind. Alpine low -6 ˚C.
Thursday
A mix of sun and cloud. Strong southeast wind easing in the afternoon. Alpine high -1˚C.
Friday
Mostly sunny. Light northwest wind. Alpine high of 0 ˚C.
Saturday
5-20 cm of new snow. Strong southwesterly wind. Alpine high -1 ˚C.
More details can be found in the Mountain Weather Forecast.
