Solar heating has already exerted significant impacts on the snowpack this week. A bigger punch is forecast to arrive Saturday which may have the biggest effect yet.
While the dry snow on higher, north slopes will draw travelers this weekend, be warned that this is also where the risk of triggering the persistent slab is the greatest.
Below the recent snow, a 90-150 cm slab sits on the weak Jan 30 facet layer. On all but high north aspects, recent sun crusts and the March 27 rain crust cap this slab, providing some security. Continue to use caution in thinner, high areas or when these superficial crusts are weak or are breaking down.
While there are crusts almost everywhere on solar aspects, solar inputs will still affect steep and / or rocky areas. As heating develops, higher and partially shaded slopes will be affected as well. Sluffing off of steep rocky faces should be expected and cornice failures are more likely
No new activity was reported today in this subregion.
Surface crusts on all aspects to ~2800 m except north, where up to 30 cm of dry snow is found at higher elevations. On southerly aspects, this 30cm contains several crusts.
Below this, a prominent rain crust (Mar 27) is found everywhere up to at least 2300m and ridge top on solar slopes.
This sits on approx 80 cm of firm snow that overlies the Jan 30 facets. These are stronger in Little Yoho than further east but still show potential for propagation with sudden planar test results.
Solar heating is the most important input right now.
A ridge brings light to moderate west winds under clear skies through Sunday night.
Overnight lows Friday night near treeline will be near -10C with the freezing level climbing to near 2400m Saturday afternoon.
While the winds may be enough to discourage the effects of solar inputs in higher, open areas, expect moist snow on sheltered steep slopes
