Hail — Cass, Illinois

2021-05-03 · near Bluff Spgs, Cass, Illinois

Wider weather episode

A Mesoscale Convective Vortex (MCV) generated by a large cluster of convection across Kansas during the pre-dawn hours tracked eastward into central Illinois by the late afternoon and evening of May 3rd. Despite weak instability and deep-layer synoptic shear, the MCV was able to enhance the low-level shear and trigger a broken line of convection. One of the cells on the east-southeast flank of the MCV became a supercell and tracked across central Illinois from Cass County southeastward to Coles County before dissipating after dark. That particular storm produced five brief tornado touchdowns and hail as large as half dollars along its path. Another thunderstorm cell further south dropped 2-inch diameter hail in southern Christian County.

View location on OpenStreetMap → (39.9399, -90.3283)

Source: NOAA Storm Events Database, event_id 950835. Narrative written by the NWS forecast office that issued the report.