Thursday, February 26, 2009
Day 57 Feb 26
Last night it snowed and blew really hard. This afternoon a friend came into the preschool classroom and told me that I had to go check out the lake. During the windstorm thousands of snowballs formed in one certain area of the lake. Almost like snow crop circles! It's like God decided to have a snowball fight and got a whole bunch ready!
Update...I received this information from a friend...
Listed below is an excerpt from a website that explains how they form. If you want to know more about this phenomenon, go to the website listed below.
Here is how they form. First, the ground surface must have an icy, crusty snow, on which new falling snow cannot stick. On top of this, a couple centimeters (about an inch) of loose, wet snow — that sticky kind that makes good snowballs — must have accumulated. The optimum air temperature appears to be around the freezing mark, from -2 to 2 oC (28 to 34 oF). Finally, a strong and gusty wind, usually blowing at 40 km/h (25 mph) or higher, is needed to build the snowroller.
Snowroller formation begins when the wind scoops chunks of snow out of the snowfield or pushes giant snowflakes downwind. These "seeds" roll, bounce and tumble, like snowy tumbleweeds, over the surface under the herding of wind. Additional snow then adheres to the seed, and the snowroller grows until it finally becomes too heavy for the wind to push. Snowrollers leave behind a characteristic track linking the snowroller's origin to its final resting spot.
The snowroller's path can be straight ahead or erratic depending on how the gusty wind pushes the roller along. Sloped terrain may also assist in the formation and movement of the snowroller seed as the force of gravity assists the wind force pushing on the rolling snow body.
Once the snowroller becomes stationary, it enters its next stage of existence. Further snowfall may bury or surround the roller and hide its track, thus making it indistinguishable from snow covering rocks, vegetation or bumps in the surface. If the snowroller remains exposed for any length of time, various processes will work on the snow transforming the snowroller into a rather unspectacular lump of snow. Eventually, the snow melts, thus ending the life of the snowroller.
For additional information and other images check out the link below!