The polar vortex made many headlines across the world this week, along with some fantastic images.
The phenomenon of the polar voretx was the source of many YouTube videos and one of the best is one from Lake Michigan.
Water temperature dropped to below freezing and hundreds of beach sized balls, weighing up to 75 pounds, washed up on shore.
Park ranger Annie Lipscomb said that the structures form when chunks of ice break off the large sheets of ice on the lake.
AccuWeather.com Meteorologist Jim Andrews added: ‘It’s possible that the ice is accreting like a snowball or like a hailstone, and that they keep growing.’
The wind pushes the boulders to the shore and they don’t sink because solid ice is less dense than liquid water.
Andrews also said that it’s not the first time such structures have appeared.
America has now begun to warm up but the vortex has left a considerable impact as it’s estimated to have cost the US economy $5 billion.
