Evaporation

There is snow in a few places across ski country, but most of us are still rollerskiing. I just spent 7 days at West Yellowstone and skied on an excellent surface up on the South Plateau. But when I returned to Bend, Oregon, it was 58 and sunny. Oh well, back to rollerskis. So, this morning at 6:45 I put on my S5E skate skis and headed out into my favorite venue, the Tetherow golf course road system. It had rained a bit last night and the roads were wet. A quick test of easy step turns and a "snow-plow" proved successful and the wet road surface felt ok. I decided, just to be on the safe side, not to do the steep hill sections. On a fairly flat part of the road I encountered a physics lesson. I was skiing and easy V2 out in the right lane when I heard a car behind me. I pulled into the bike lane and began to double pole until the car came past. It was just before sunrise and there was a slight breeze, the humidy going down. What I found in the bike lane was black ice! I now know that you can do a real snow-plow on rollerskis if there is a thin layer of black ice under your skis. The evaporation of the moisture in the decreasing humidity, the breeze and the overnight low temp just before sunrise all combined to create little patches of ice that looked like wet road. As I headed back to the pickup I encountered more of the wet/icy road. Caution prevented any falls, but I did cut the workout a bit short. So, remember those old high school physics classes and the cooling effect of evaporation.

Happy rollerskiing until the snow flies. It looked like there was some new snow above 4500 feet.

Bert