Windslabs in alpine terrain should be expected near cols and crests of features. The thin snowpack also is a concern in terms of triggering the deep persistent slab problem. Temperatures have stayed warm overnight and as a result, refreezes have been very limited. Conservative terrain choices is a good way to manage the uncertainty within the snowpack right now. Hopefully we get a good overnight freeze soon!
Watch for windslabs on all aspects in alpine areas. These slabs will be more reactive where they are overlying a temperature crust.
Facets near the base of the snowpack may be triggered from thin areas and this season there are lots of thin areas. Dont try to outsmart the snowpack and stick to conservative terrain until we get into a good spring diurnal cycle.
A few loose dry avalanches from steep terrain up to sz 1.5.
20-40cm of recent snow (40cm on the eastern side of the range) is overlying a temperature crust that developed early in the week. This crust is being found up to 2300m and while supportive to skiing, its sitting on top of a generally moist snowpack. Crusts are common on the solar aspects but less so on the more polar sides. There are some isolated windslabs in alpine areas along ridgelines but this problem does not appear to be widespread. Thin weak areas are getting harder to determine and during a tour on Friday forecasters were getting moderate results in the basal facets from thin <1m areas at treeline. Recent snow combined with cloudy weather hasnt allowed the snowpack to get a significant refreeze that is common for spring time. Conservative terrain was the place to be for us on Friday.
An important thing to consider at this time of year is the Quality of the freeze overnight. Over the past 2 days, freezes have been generally poor with overnight lows only around -5C. Avalanche danger can change from low in the cool mornings to high in the hot afternoons. The timing of this change is important to monitor so plan you trips with these factors in mind.
Not much of a change for Saturday. Cloudy skies will continue which will limit our re-freeze and only a trace of new snow is forecast on Saturday. Freezing levels will rise from the valley floor to 2000m throughout the day. Winds are generally forecast to be light. If the sun comes out, expect avalanche danger to quickly increase.
More details can be found in the Mountain Weather Forecast.
