Thunderstorm Wind — Johnson, Indiana

2021-12-11 · near Stones Crossing, Johnson, Indiana

Event narrative

Electric poles and some trees down by thunderstorm wind gusts in Johnson County. Transformer fire in southern part of the county.

Wider weather episode

A rapidly intensifying storm system tracking northeastward through the Quad Cities area produced strong low-level southerly flow over central Indiana, including a low level jet (LLJ) of 70 mph at the 850 mb level, during the evening and overnight of the 10th. These winds near the surface brought unseasonably high dewpoints as high as the low to mid 60s that destabilized the atmosphere, while the LLJ resulted in anomalously high vertical wind shear. Numerous lines of storms brought severe winds down to the surface, causing widespread wind damage, especially north of Interstate 70. Some locations saw several periods of heavy rain whose rainfall totaled 1-2 inches; which caused isolated flooding parallel to and about 20 miles north of Interstate 70.

View location on OpenStreetMap → (39.5700, -86.1400)

Source: NOAA Storm Events Database, event_id 988570. Narrative written by the NWS forecast office that issued the report.