In June 2018 supercell thunderstorms brought tornadoes and large hailstones to South Dakota.
By Ivan Smiljanic (SCISYS) and Sancha Lancaster (Pactum)
On 29 June South Dakota experienced severe thunderstorms, the most intense of which produced tornadoes near the northern Black Hills, 11.5 cm diameter hail near the city of Newell, and winds of up to 145 km/h (90 mph). The storms travelled around 675 km (420 mi). It was reported that the large hailstones from the storm caused damage that could be seen from space (Figure 1, top right, click to expand)
The 5-minute Mesoscale Domain Sector GOES-16 (GOES-East) Dust RGB images (Figure 2) showed the development of large clusters of thunderstorms that moved from northeastern Wyoming into South Dakota during the afternoon and evening hours on 29 June 2018. Note: Black area on left is where data has not been rendered in the main area of the domain.
Figure 2: GOES-16 Dust RGB animation, 29 June 18:02 UTC–30 June 06:02 UTC. Download animation (MP4, 5 MB).
A synoptic ridge was suppressing cloud formation in most of the central and eastern US, with strong convective episodes at the western edge of a wide anticyclone (including South and North Dakota, and other neighbouring states) (Figure 3).
June 27+29th Hail Scar Storms (National Weather Service)
Severe thunderstorms in Wyoming and South Dakota (CIMSS Blog)
Three Derechos, 400-Plus Thunderstorm Wind Damage Reports Highlight 2018's Most Active Day of Severe Weather (The Weather Channel)