Before reading this posting, please keep in mind that information on this event is very preliminary and some of the media reporting on which this posting is based may be inaccurate or incomplete. I’m writing this because there are numerous State Fairs and other outdoor events in progress both now and during the rest of summer. My goal, as always, is to provide information that can save lives.
According to The Indianapolis Star, five have died and forty are injured — some very seriously — as a result of the collapse of the stage at the Indiana State Fair yesterday evening. Below is video of the collapse.
In the tape, we see lighting in the distance and blowing dust but no rain at the fairgrounds. That immediately suggested to me that a thunderstorm-generated “gust front” had moved through causing the very strong winds.
This is verified by radar. The thin light blue line is known to radar meteorologists as a “fine line” (arrows) which represents very strong winds out ahead of the precipitation (the green-yellow-red colors). At 8:30pm
EST EDT, the fine line is in northwestern Marion Co. (the county containing the Fairgrounds).
|NWS radar data at 7:30pm EST via University Corporation for Atmospheric Research, click to enlarge.|
The radar shows the fine line containing the strong winds passing the Fairgrounds two minutes before the collapse.
|click to enlarge|
If this was an isolated incident, it would be a tragedy. But, weather-related outdoor stage collapses have hardly been rare in recent years. Just in the last two months, according to CNN,
So, how are these events protecting their performers and customers?
In the case of the Indianapolis State Fair, if early reporting is correct, they used radar on a smartphone.
When I do my presentations across the country on weather risk mitigation, I talk about the difference between “consumer-grade” and “business-grade” weather.
Smartphones contain useful information about weather, but the information is not robust enough to be used for mass safety purposes. The radar on smartphones is often 5 to 7 minutes old before it is posted. It often does not contain the details (like “fine lines”) needed to get a complete picture of a threat. And, even if the radar is current and detailed, does a non-meteorologist have the expertise needed to make a correct interpretation?
According to Fox News,
This event was predictable. Our team at AccuWeather Enterprise Solutions was monitoring the weather for a client near the Fairgrounds. We issued a warning for 60 mph winds at 8:23pm EDT valid from 8:45 until 9:25pm. According to the National Weather Service’s preliminary report, the collapse occurred between 8:50 and 8:55pm.
Why did we get the warning out early? Because our meteorologists had the most detailed radar information available, ground truth as the storm moved in, and the expertise to recognize the fine line and threat it posed even though, to the untrained eye, the thin line of light blue color out ahead of the main area of storms appeared benign.
I do not have an opinion whether it is practical to design an outdoor stage that can withstand 60 to 70 mph winds (the speed estimated by the National Weather Service), but I do know the science and technology exist to provide advance warning in order to evacuate people when severe thunderstorms present themselves. Given the large number of outdoor stage collapses in the last three years, I believe it is time for the outdoor events industry to take a second look at their weather protection practices.