As you may have figured out from some of my previous posts, I am spending this week "spring skiing" up at Timberline. The conditions have been different than I expected, but I haven't done a lot of spring skiing before.

I didn't get a chance to ski on Monday because of a dentist appointment Monday morning that took longer than I had expected. Tuesday, was nice; Partly sunny, not too warm and not too slushy. Today (Wednesday) I went out just after 9:00. The temperature was 52 degrees and it was cloudy all day. I was fully prepared for slop and what did I find? Corral reef. Yup, the entire top 1/3 of the mountain was corral. I can't really explain it because I'm pretty sure wind chill doesn't affect inanimate objects; must be a GW thing. It softened up below that but the corral stayed hard until I went in at 11. When I came back out around 1:00 it was softer, but not "soft". Timberline has not groomed since Sunday. I think this is smart (although tough on the legs). Because of this, a "shell" has formed over the trails and I think it is conserving the cold - but what do I know?

One thing I know is that the trails look and feel great. I don't think that T-Line will have any problem making it through to the end of March. I will have a better feel if the predicted rains come tomorrow, but I'm not concerned at this point. All trails are open and the only thin spots are on the "natural" areas - glades, Thunderdraft and Silver Streak. Everything else seems to have 3'+ of base.

For what it's worth, here is a picture of some of the snow evaporating this morning.....


Clay

Thanks for the report Clay!

Basically, it comes down to a balance between external heating and the huge (cold) thermal mass of the snowpack. This determines what the trail surfaces are like. With a deep base, it takes more heat to soften up the surface.

The other night at Wintergreen, the day's slush (resulting from temps around 50F) began firming up as the sun set, even though temps remained well above freezing while we were still there. That's the massive cooling effect of the base kicking in without the sun to battle it. The base does give up some energy/depth to keep the surface chilled, which is why the base gradually shrinks.

So I imagine that's what you noticed at TL -- the base on the upper part of the mountain must have been chilling the surface pretty well. Starting Thurs night, temps will drop below freezing and that will retard melting even further. The lower temps drop below freezing, the more the base will get charged up with cold, allowing it to resist the next heat wave.

Craig