Bringing Light to the Darkness

In these difficult times, it's important to bring light to the darkness, and Mother Nature is doing that for many parts of the Wasatch Range that are in the shade for much of the winter.

One of the more striking changes that occurs from February through April is how the early morning sun begins to lightup the Coalpit Headwall.  The Coalpit Headwall is a north-northeast facing slope to the north of North Thunder Mountain.  This morning, as shown in the picture below (inside circle), it was illuminated well by the sun.

The sun angle is pretty low early in the morning, so in part this reflects altitude, aspect, and the fact that the sun rises north of west east, which allows it to kiss the north-northeast slope early in the morning.

Below is a comparison of the sun exposure in the Coalpit Headwall area (inside circle) at about noon in January (left) versus 7 AM in April.  In January, the Coalpit Headwall is a shady place (indicated by purple).  Even at noon, it's in the shade and in fact, there is no time of day in January when the Coalpit Headwall is directly illuminated by the sun.  That's great for powder preservation, but also growing facets if the snowpack is thin.

Sun exposed (yellow) and shady (purple) areas based on analysis by caltopo.com

In April, however, the Coalpit Headwall sees the sun.  In fact, it gets the first rays of sun in the morning (right image above) and the sun is high enough in April that it gets sun during the day as well, although shadows begin to creep across its face after mid afternoon, as illustrated by the photo below, which I believe was taken a bit earlier in late March.

These changes in sun exposure are important to recognize if you travel in the backcountry or even ski at a resort. At a resort, however, it's pretty easy to move to a different aspect.  If you are ski touring, however, the timing of sun exposure or shadowing can make or break your adventure depending on the snow (powder or corn) and avalanche conditions.