Giant nature-made snowballs have been spotted across Pennsylvania and Ohio this week, mystifying onlookers unfamiliar with the meteorological phenomenon.
The rare snowballs, called snow rollers, are formed when gusty winds roll snow along the ground, similar to how snow might be rolled to create a snowman. The result, however, is typically cylindrical and hollow.
Snow rollers do not form after every winter storm because they require specific conditions.
First, the ground must be covered by a layer of ice, then have wet, loose snow on top, with a temperature near freezing. Next, winds need to be strong enough to get the snow rolling, but not too strong that they dismantle the weak inner layers of the roller.
Gusty winds after a big storm help to create snow rollers like this one found in Stow, Ohio. (Facebook Photo/Angela English)
An open snowy field provides a conducive environment for the formation of snow rollers, like these found in Lexington, Ohio. (Facebook Photo/Benjamin Lee)
Snow rollers have been being reported across parts of Ohio consistently over the past week. (Facebook Photo/Mike Fuerst)
Snow rollers can vary in size, depending on the strength of the gusting wind, the type of snow and other factors. (Facebook Photo/Mike Fuerst)
Gusty winds Monday morning helped create these rollers in northwestern Pennsylvania. (AccuWeather Photo/Jordan Root)
Rollers were spotted across Crawford County, Pa., this week. (AccuWeather Photo/Jordan Root)
The next round of thunderstorm downpours will swing into the Appalachians with the risk of isolated flash flooding on Monday.
Following a rain-free weekend for many in the Northeast, residents may be wondering if this is a sign of things to come for July.
A persistent storm track will keep summer warmth out of the United Kingdom through much of July.
Rounds of drenching thunderstorms could bring drought relief to parts of the southern United States into July.
Severe storms will bring large hail and damaging wind gusts to parts of Colorado, Nebraska and Kansas on Monday.
The uptick in spotty, drenching thunderstorms, associated with the southwestern United States monsoon, will continue in the coming days and weeks.
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