A thunderstorm produced severe hail over northern Thayer county on this Saturday evening. Just before 7 PM CST, a lone thunderstorm developed near Davenport. Shortly thereafter, other storms rapidly formed as well, creating a continuous narrow line of storms from northern Nuckolls county east along the Fillmore-Thayer county line. This west-east oriented line moved east. Between 750 and 800 PM CST, a storm within this line produced severe hail in the town of Bruning, and to its east, with hail the size of quarters, half dollars and golf balls being reported. As the storms continued moving east, their western edge reached the eastern border of Thayer county by 9 PM CST. Other scattered storms formed over the central and southern parts of the county through 1030 PM CST, but none of them were strong or severe.
These storms formed just north of a warm front that had been moving north through Kansas during the day, but had slowed its northward progress by 6 PM CST. Late in the afternoon, a weak 1008 mb low had formed along this front over north central Kansas. In the upper-levels, the Westerlies were fairly weak, zonal, and confined to the northern half of the U.S. A weak shortwave trough was over the Dakota's. These storms formed in a zone of warm air advection. Around the time of convective initiation, temperatures were in the middle 70s, with dewpoints in the upper 60s. The mid-level lapse rate was poor, but the MLCAPE was still around 2000 J/kg. Effective deep layer shear was 35-40 kt.