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Heat Wave Expands to the East Coast; Flash Flooding Likely in the Central Plains into the Midwest; Severe Thunderstorms in the Northeast

Dangerous, prolonged heat is ongoing in the Mid-South to Mid-Mississippi Valley and heat expands into the Northeast for a brief period today. Widely scattered instances of flash flooding due to heavy rains are forecast from northeast Kansas to much of Indiana. Scattered strong to severe thunderstorms are possible across parts of New England, northern Mid-Atlantic, and North Dakota. Read More >

Overview

A supercell thunderstorm produced a long swath of significant hail across portions of north central and northeastern South Dakota into west central Minnesota during the morning of August 28th. The storm produced hail to the size of tennis and baseballs, and led to extensive damage to houses, vehicles, and crops within its path.  Initial estimates of the severe hail path (areas with hail of 1" or greater) show a path length of around 225 miles, stretching from Lake Oahe to west central Minnesota. This storm persisted uninterrupted for about 6 hours, from ~2:30 am to 8:30 am. During that time, the average width of the severe hail was around 6-7 miles, with the peak width around 11 miles. Additional severe thunderstorms developed as well, leading to further reports of damaging winds and large hail before exiting the area shortly after 10am. 

We want to thank you for all of the hail reports and pictures that you have sent to us! 

Hail damage to a house in Edmunds County - Photo shared by Edmunds County EM
Hail damage to a house in Edmunds County - Photo shared by Edmunds County EM
MRMS Maximum Estimated Size of Hail (MESH) Tennis ball sized hail in Grant County, South Dakota - Photo relayed by Grant County EM
Video of the radar and maximum estimated hail size. From 11PM CDT on August 27, 2021 to 11am CDT August 28, 2021 MRMS Maximum Estimated Size of Hail (MESH) for the 24 hours prior to 1pm CDT on August 28, 2021.  Hail Estimate Scale: Green = 1-2" hail, Yellow = 2-2.5" hail, and Orange/Red/Purple = 2.5"+ Hail scar as seen on the 29th via satellite
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