Snow rolled into neat bales moving across the field was spotted this week by residents of the province of Nova Scotia in eastern Canada. This amazing anomaly requires specific weather conditions, according to The Weather Network.
“It is a rare case when all the ingredients necessary for the formation of snow rolls come together. You need enough wind to push and roll the snow,”Kevin McKay, meteorologist to The Weather Network, told The Weather Network.
This phenomenon requires matching of suitable humidity, snow, wind and temperature. There should be light dusting of snow over a slightly frozen layer at the very surface of the earth, often on a hill or in a valley without tall vegetation.
You need snow dust that is moist enough so that the particles can adhere to each other, but not stick to the ground. It takes a wind at a speed of about 48 km / h to roll the snow into a cylindrical shape, and the temperature should be from +3 to +5 ° С. This temperature level allows the snow to form amazing regular cylinders, but prevents them from melting.
Snow skating rinks are found in open fields as well as on gentle slopes where sunlight and shaded areas alternate, and snow density can vary.
In 2014, snow rolls were seen in the US Midwest. In January 2018, this phenomenon was reported in Scotland.