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
|NWS radar data at 7:30pm EST via University Corporation for Atmospheric Research, click to enlarge.|
|click to enlarge|
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.
But the weather near the Indiana State Fairgrounds was starting to get dicey. Backstage, State Police special operations commander Brad Weaver was watching an ugly storm moving in on radar via his smartphone. He and fair Executive Director Cindy Hoye decided it was time to evacuate the crowd.
But a minute later, when WLHK program director Bob Richards addressed the crowd, the word was that the show would go on, and that the crowd should be prepared to find shelter if things changed. Some of the crowd sensed the danger and left without further word. But the majority remained.
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,
Bursten said emergency personnel and fair officials were monitoring the weather because a severe storm had been expected to hit the area around 9:15 p.m. But the storm hit shortly before 9 p.m.
He said preparations were being made to evacuate the facility but that the "significant gust of wind" struck the stage rigging that holds lights and other equipment before the evacuation plan was activated.
"As we all know, weather can change in a very rapid period of time," he said.
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.