Hailstone in western Minnesota may have tied a state record

CHOKIO, Minn. (FOX 9) - There might be a new weather record in Minnesota after massive hailstones fell in western Minnesota on Wednesday night. 

Thunderstorms on July 31

Multiple rounds of thunderstorms occurred throughout much of central and southern Minnesota during the afternoon and evening on Wednesday.

The first wave featured a cluster of storms that congealed into a line over eastern South Dakota and western Minnesota, producing a wind threat for west-central Minnesota. This line of storms tracked northeastward, but development on the southern flank continued with a weakened severe wind threat for areas along the Interstate 94 corridor.

Eventually, the line reached east-central Minnesota and produced marginally severe hail and wind across portions of the Twin Cities metro during the evening rush hour.

The second wave featured isolated storms that developed over south-central Minnesota, producing a severe wind and hail threat that moved into southeastern Minnesota. This wave featured heavy rainfall, which led to flash flooding over portions of Goodhue and Dakota counties due to a combined impact from the first and second waves.

Most notably, the third wave produced extreme hail in Stevens County, measuring up to 5 inches in diameter. This cluster of storms developed into a line and tracked southeastward across central and south-central Minnesota, producing a hail and wind threat.

Severe storms bring large hail

Each line of severe thunderstorms consisted of hail. Most hail reports ranged from the size of a penny (0.75 inches) to a half dollar (1.25 inches) across Minnesota and parts of western Wisconsin. 

The largest hailstones were mainly found in western Minnesota. Interestingly, and a rarity for Minnesota, a giant hailstone was found just outside Chokio, Minnesota, in Stevens County. 

The largest hailstone measured just shy of 6 inches in diameter.

Matthew Benson shared images and videos of the large hailstones, which caused significant damage to two of his vehicles.  

Largest hailstone on state record 

The largest hailstone recorded in Minnesota is 6 inches, which fell in both 1968 and 1986, so there is a chance that the hailstone from Wednesday’s storm could at least tie the state record. 

The National Weather Service will investigate and make the official call in the coming days. 

Why did the massive hail form?  

FOX 9’s meteorologist Cody Matz explains why the large hail formed:

For a hailstone that large to be suspended in a cloud before falling, the updraft, or the air rising to create the storm, has to be traveling over 100 mph. This is why storms can seemingly develop "out of nowhere" or in just a few minutes because with air rising at 100 mph, it takes about five minutes for the air to go from the ground to the top of the atmosphere.

Also, hail is obviously just ice, so not a super strong object. This means that often times if you manage to collect a very large hailstone, it's quite likely that the stone was even bigger before it hit the ground because it's likely that it fractured as it impacted the ground.