Wow
January 9, 2010 –
Look at these! A natural phenomenon (and you know you want to sing the muppets song right now, dont you? Oh go on then :)
Anyway, these things were found in Somerset (the snow things not the muppets), in a field. My first thought was. ‘Oh those naughty crop circle boys have got nothing to do again’ But apparently not, these things, they start off with nice thick layer of snow, with the top snow just on the point of melting either because of general temperature or sunshine on the surface.
The top snow layer becomes a bit sticky, and you then need a fairly strong wind. The sticky layer can be peeled off the colder and more powdery snow underneath by the wind forming a roll. In the first picture you can see some of the powdery stuff sticking to the lower outside surface of the roll. I suppose it is a natural version of making a snowman. (You can tell by now that I didnt write this, me not being a Meteorologist at all – aww shucks, it comes from the Daily Telegraph :)
Now, after being formed, the rolls eventually become too large and heavy for the wind to move, or are halted by rising ground or a tuft of vegetation.
They are often hollow because the weak inner layers which form first can easily be blown away, and the fragile formations can collapse in the slightest change of temperature or gust of wind.
Liz Bentley, of the Royal Meteorological Society, said despite their rarity in the UK, there is a chance of more snow rolls appearing over the next few days. (Whoo wooo!)
“These rolls are unusual here because we don’t tend to have major snow events like the one we’re experiencing now. They happen with the combination of lying snow and high wind speeds, mostly in North America and Northern Europe, and they can be as small as a tennis ball or they can be as large as two feet across – depending on how strong the wind is and how smooth the surface of the snow is,” she said.
“There are quite strong winds predicted this weekend as well as more snow, so if people keep a look out they might see a few more of these appearing around the country over the next few days.”
