Just out from a week at Selkirk Lodge (halfway
between Rogers Pass and Revelstoke), where conditions
went from full spring corn/powder to a midwinter snowpack over the space of
three days.
Currently an impressive spring storm has
deposited between 40-60 cm. of snow in the last 48hrs. at Treeline elevations
and likely closer to a meter in the high alpine – we observed snowfall
rates yesterday afternoon in excess of 3 cm/hour that continued well into the
night – moderate to strong winds from the SW accompanied this snowfall
until they switched to moderate to strong from the North last night. This was
followed by a dramatic cooling overnight (Friday April 14th) with
morning temps of -10 Celsius Saturday morning which seemed to help with the
bonding of the storm snow to the crust below it.
We ski cut several steep rolls to test
them with no results and other test results were likewise favorable – however
when the skies cleared this afternoon while we waited for the helicopter to
arrive we observed that the entire head of the valley (an exposed alpine
cirque) had released sometime late in the storm propagating over a distance
of 2 kilometers and involving the release of terrain that was in the 25 degree
incline – though much of it was steeper than that – aspect ranged
from NE through NW – visibility was still foggy but it seemed to be
several large slabs that I am highly suspect released simultaneously but that
had small pieces of terrain still intact between them – anyway quite an
event for sure and quite contradictory to our evidence a few kilometers away
(and also several hours of time different).
All that to say that conditions have
changed significantly in the mountains and special attention should be paid to
the affects of daytime heating and the still lurking presence of the late March
buried surface hoar layer in the high north facing alpine.
Cheers,
Scott Davis
Mountain Guide