Snow Rollers: The Rare and Fascinating Natural Phenomenon

Some Interesting Facts

• Snow rollers form under unique weather conditions
• Have been found in other countries as well, including Europe and Canada
• They come in sizes from a few inches to several feet in diameter

For much of the country this winter, it has turned out to be quite harsh, with outbreaks of arctic air pushing southward, creating dangerous conditions. And as is usually the case, the cold is accompanied by periods of snow and ice.

After a fresh snowfall, many find it beautiful as it covers the landscape in a white blanket. However, in the urban areas especially, road grime and dirt quickly turn the pure white snow into an unsightly mess.

However, sometimes a strange phenomenon can appear in the countryside. Snow structures resembling rolled-up carpets or jelly rolls can seem to suddenly appear out of nowhere in open fields. What are they, and how in the world did they get there?

How they form

Snow rollers are a fascinating meteorological phenomenon that occurs under very specific atmospheric and surface conditions. Their formation is governed by physics, particularly the interplay of wind force, friction, and gravity. They are most commonly reported in open fields, hillsides, and mountainous regions during late winter or early spring.

Wind plays a crucial role in initiating the rolling motion. However, it must be strong enough to push the snow, but not so strong that it scatters or breaks it apart. If the wind isn’t sufficient, gravity can also cause snow to roll downhill, forming a natural spiral as it picks up more layers.

Temperature and snow properties

The snow must be in a semi-wet state, meaning it has enough moisture to stick together but not too much that it collapses under its weight. The presence of an ice crust underneath ensures the rolling snow does not adhere to the ground, allowing continuous movement. The temperature should be around freezing or slightly above (32°F or 0°C), which allows the snow to remain cohesive.

Types of snow rollers

Small Rollers – Resemble compacted snowballs, often just a few inches wide.

Large Rollers – Can reach several feet in diameter and may be hollow in the center because of the way they form.

Snow rollers in other countries

United States:
• In 2009, a large number of snow rollers were spotted in eastern Washington after a storm created perfect conditions.
• In 2014, residents of Ohio and Pennsylvania reported fields full of snow rollers after a unique weather event.

Europe:
• Snow rollers have been recorded in the Scottish Highlands and parts of Norway, where wind-driven snow is common in open landscapes.

Canada:
• The Prairie provinces and parts of Ontario have occasionally reported snow rollers, typically after warm snowfalls followed by high winds.

Because of their rarity, snow rollers often surprise people who are unfamiliar with them, sometimes leading to mistaken reports of “alien activity” or unusual natural events.

Conclusion

Snow rollers are a unique and fascinating phenomenon that can be observed in certain conditions. While they may seem mysterious, their formation is governed by natural processes and can be explained by the interplay of wind, friction, and gravity.

FAQs

Q: What is the ideal weather condition for snow rollers to form?
A: Snow rollers require a semi-wet state of snow, an ice crust underneath, and temperatures around freezing or slightly above.

Q: Where are snow rollers typically found?
A: Snow rollers are commonly reported in open fields, hillsides, and mountainous regions during late winter or early spring.

Q: Can snow rollers be found in other countries?
A: Yes, snow rollers have been reported in the United States, Europe, and Canada under specific weather conditions.