The Glossary of Meteorology and the Handbook of Applied Meteorology do not contain the term “gustnado.” It’s a constructed word, embraced by the National Weather Service that refers to a short-lived, ground-based, shallow vortex that develops along a gust front. A gust front is the leading edge of a thunderstorm downdraft that enhances existing storms and forms new ones. It is believed a gustnado caused the deadly stage collapse at the Indiana State Fair. Wind gusts of 50 mph were logged at Indianapolis International Airport, 20 miles southwest of the fairgrounds. Radar-estimated wind speeds could not be measured due to ground clutter as meteorologists reviewed video of a large flag indicating winds in excess of 50 mph. The gust front was 3 miles ahead of the storm.

Fastcast: Dry.

Sunny and hot. High about 97. Calm winds becoming northerly at 5 mph. Tonight: Mostly clear, low about 71. Northerly winds 5 mph.