Sunday, March 10, 2013

Snow! Perfect snow, powder day

Snow! Light, fluffy, white, and slow moving, real snow. Not wet, not sloshy, nice soft snow. When the snow piles up on the boughs like seen above, we know its quality. As we all have known since we were children, snowflakes have six points on them. This gives them "loft". Loft means the flakes stack up on each other at different points leaving space between flakes. When the air temperature is colder, 32° or below, the snow in Girdwood is drier with lower water content. This is what makes our snow so powdery, fluffy, and lofty. 

Its a beautiful day in Girdwood, all the skiers and riders have got to be loving it! The temperatures in Glacier Valley are just at freezing and they are expected to fall this evening and tomorrow. 

Wind effects on mountain top snow

All day Thursday there were ferocious winds through Glacier Valley, Portage Valley , and the Turnagain Arm. Gusts were as high as 70 miles per hour, the bulk of the wind blowing continuously. When the wind blows for extended periods of time with little precipitation falling, the snow is being blown around. Not only is the snow blowing around, its moving very fast. These high winds, and wind in general, happen frequently in the Chugach and Kenai mountains. After the storm dies down, if there is not further precipitation, we can see crusts that have formed on the mountain tops. 

Above is a photo of Mt. Alpenglow and nearby mountains. There is a light spot visible on the ridge of the mountain coming toward us in the photo. Below is a photo that points out the area I want you to see. This is a snow crust. Although it does not look like it in this representation, when I saw it originally, the snow crust was very bright due to the sunshine. The clouds were moving enough to change the effect of sunlight as I watched. Some clouds were moving east, some west. There is still a big disturbance over the Gulf of Alaska today. 

Basically, the snow has polished itself. I found this to be the case in Moose Meadows today as well. A late afternoon attempt at cross country skiing left me thinking I almost needed ice skates. The surface of the loop was extremely glassy making a good deal of scratchy noise against the skis. Yikes! I wanted toothed grippers on my poles too! The afternoon was lovely never-the-less due to some blue sky in the west past the Glacier Creek valley. I have added a new resource site in the list below. The National Snow and Ice Data Center, very informative for us in snowy climates.