On This Date: A Utah Snow Tornado And Historic One-Hour Snowfall

Choosing a single strange weather occurrence for the "On This Date" column can be tricky, so today we highlight two remarkable events. On December 2, 1970, a tornado was spotted in the mountainous region of northern Utah, just below the Timpanogos Divide, roughly 70 miles southeast of Salt Lake City. This F1 tornado, approximately 300 yards wide, uprooted trees up to 18 inches in diameter along its mile-long path near Provo Canyon and Sundance.

What made this tornado especially unusual was its high-altitude location, around 8,000 feet, where 38 inches of snow already covered the ground. The tornado lifted this snow thousands of feet into the air, creating a rare "snownado" effect. According to NOAA's storm events database, this is one of only two recorded December tornadoes in Utah since 1950. The other, an F0, struck Pleasant View north of Ogden on December 5, 1995, causing minor damage to trees and a few homes.

Another extraordinary weather phenomenon occurred four years prior. On December 2, 1966, a trained observer in Copenhagen, New York, recorded 12 inches of snow falling in a single hour. Weather historian Christopher Burt described this as the largest one-hour snowfall accumulation in the United States that he is aware of. Typical snowstorms yield only a few inches per hour, making a foot of snow in sixty minutes nearly unimaginable.

Copenhagen, located on the Tug Hill Plateau of upstate New York within the Lake Ontario snowbelt, frequently experiences persistent bands of heavy lake-effect snow. During December 1-2, 1966, the town accumulated a staggering 63 inches of snow over 48 hours.

Jonathan Erdman, a senior meteorologist at weather.com since 1996, specializes in covering both national and global weather events. Extreme and unusual weather phenomena are his particular areas of interest. He is reachable on Bluesky, X (formerly Twitter), and Facebook.

Author: Sophia Brooks