Isolated thunderstorms developed during the peak heating of late afternoon along and east of the Mississippi River on October 11, 2011. The storms formed in the deeper low level moisture axis where surface dew points were around 60F.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS DVN wrote it up.
Isolated thunderstorms developed during the peak heating of late afternoon along and east of the Mississippi River on October 11, 2011. The storms formed in the deeper low level moisture axis where surface dew points were around 60F. Negative theta-e lapse rates were present in the 850-500 mb layer along with marginal instability. There was a southwest flow aloft with short wave energy emerging out of the Plains and into the Midwest. There were several reports of pea size hail but one storm managed to produce penny size hail in Burlington, Iowa during the late afternoon.
The Quad Cities radar (KDVN), 101 km away, was scanning. The volume nearest the first event began at 21:11 UTC.
1 hail. Local standard time, as filed.
Trained spotter reported penny size hail at Hyatt and 65th Street in Burlington.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2011Every state in 2011This day in weather historyWarnings in Iowa, October 2011
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 349638.