April 11, 2010

Sun Crust and Powder of South Fork

Scritchy sun crust under grey skies... If you don't know the area and if the skies are cloudy, it can be difficult to find the shady slopes with the soft snow this time of year. There are still a quite a few places that still preserve the sweet soft snow, but my group unfortunately did not find a lot of it because we did not choose the best aspect.

Aspect is the slope orientation with respect to the sun in this context. The combination of inclination and azimuth, or direction, of the incline are the elements of slope aspect. As the sun's path across the Alaskan sky lengthens, the aspect becomes more important to finding soft snow. Sunshine melts the steeper south-facing slopes first, and then progressively affects the east, west and finally north-facing slopes. North-facing slopes are crucial this time of year for powder preservation, and the best powder bowls are north-facing cirques with steep walls that provide shade from the morning and afternoon sun.

Temperature and wind, of course, are key elements for powder preservation any time of year. And the aspect with respect to wind can be really important for powder preservation, too.

Eventually, regardless of aspect, powder will disappear from most slopes, except the really high ones, as the days grow warmer (or windier). And, then we'll be left with skiing slushy snow or riding bikes through verdant forests.

No comments: