NWS Confirms August 11 Storm Was a Derecho; Hail Reported in Blackford County

From National Weather Service and regional news reports on August 11-12, 2026

The National Weather Service has confirmed that the severe storm system that swept through northern Indiana on August 11 was a derecho — a widespread, long-lived windstorm that stretched 331 miles from Iowa through northwest Indiana and into Ohio.

Peak winds reached 100 mph in far northwest Indiana and 75 mph in Marshall County. At least six tornadoes were confirmed across Iowa and Indiana. In Blackford County, the NWS recorded golf-ball-sized hail — 1.00 inch in diameter — three miles west of Mill Grove at 7:55 a.m. on August 11.

The storm's intensity diminished as it moved into north-central Indiana, meaning Blackford County experienced the weakened tail of the derecho rather than its worst. However, repeated heavy rainfall triggered a flash flood advisory for the county early on August 12, and a severe thunderstorm watch remained in effect through the afternoon — marking the third consecutive day of NWS severe weather actions for the area.

The storm's effects were felt at Hartford City's Property Standards Board meeting on August 12, where multiple property owners cited weather delays in repair timelines. One owner's roofers were unable to work due to storms earlier in the week.

Source: NWS Northern Indiana (weather.gov/iwx/SevereWx_Derecho_Aug11th2026); IndyStar (Aug 12); WNDU (Aug 12)