5 people died and 45 were injured on Saturday Evening, August 13th, 2011 at the Indiana state fairgrounds as damaging outflow winds struck the fairgrounds causing a stage set-up for the Sugarland concert to collapse. Governor Daniels called the incident a “fluke” in a statement he made following the disaster and also stated, “I’m not clear how anyone could have foreseen a sudden, highly localized blast of wind.”
Here is the official local storm report issued by the NWS Indianapolis:
This blog entry will look into the events that occurred across Indiana and at the State Fairgrounds on Saturday, August 13th, 2011 as a line of severe storms swept across the state.
There have been numerous comments including the ones from Indiana Governor Mitch Daniels describing this as a “fluke” event or an event with no warning. That is far from the case. The National Weather Service issued hazardous weather outlooks and severe weather outlooks as early as Friday morning indicating the potential for severe storms with damaging winds across Central Indiana on Saturday. The private sector, including myself, began noticing the potential very early on in the week. In fact we at SWAT began monitoring for a potential chase day on Saturday, August 13th as early as Sunday, August 7th. The pattern was prime for potential severe weather and our forecast models along with pattern recognition should have allowed any meteorologist to see the potential several days prior to Saturday. The image below shows the posts I made in our SWAT group on Facebook (notice the dates).
By Saturday morning, the Storm Prediction Center had placed nearly all of Indiana including Indianapolis under a slight risk for severe weather. The severe weather outlook even indicated a higher probabilities of damaging winds from Indianapolis and points North and West.
Early in the morning a surface low and an associated boundary were located across portions of Northern Illinois. This low was forecast to move into portions of North Central Indiana by late Saturday Afternoon. Temperatures climbed into the middle to upper 80’s with low leve moisture increasing and pooling ahead of the boundary. Thunderstorms began to develop by late afternoon across Eastern Illinois and the storms quickly developed into a squall line with CAPE values (convective available potential energy) climbing to well over 2,000 J/K. A 40 knot jet undercutting the trough helped promote storm organization and enhanced the potential for damaging winds.
At 5:57 PM, the Storm Prediction Center issued a Severe Thunderstorm Watch for all of Central Indiana including the Indianapolis metropolitan area and the Indiana State Fairgrounds. The Severe Thunderstorm Watch called for damaging winds up to 70 mph, 1″ hail and dangerous lightning. The watch was issued over 2 hours prior to the stage collapse at the Indiana State Fairgrounds.
Here is a radar snapshot of the developing squall line at 7:45 PM (approximately 1 hour prior to the line hitting the Indiana State Fairgrounds.
By 7:45 PM, the radar image above shows the developing squall line and also a developing gust front. The image on the left hand side of the radar snapshot above shows a thin line of green echoes about 15 miles out ahead of the main squall line. This is called a gust front. A gust front is the leading edge of gusty, cooler surface winds from thunderstorm downdrafts; the strong winds along the gusty front are often associated with a shelf or roll cloud. The image on the right hand side of the radar snapshot above shows velocity data or wind speeds. As the squall line continued to organize, enhanced winds were noted within portions of the squall line (noted with the brighter green velocities).
The squall line continued to intensify and the gust front continued to surge several miles out ahead of the squall line. At 8:39 PM as the squall line began to enter far Western Marion County, the National Weather Service issued a Severe Thunderstorm Warning for Marion County calling for damaging winds up to 60 mph.
The warning was issued 10 minutes prior to the Indiana State Grandstands incident which was adequate notice for public safety officials and event planners at the fairgrounds to get the concert attendees to shelter. In my opinion, the two things the National Weather Service did not accurately portray in the Severe Thunderstorm Warning were the fact that the damaging winds were well ahead of any precipitation (the gust front) and the storm arrival times listed in the warning were several minutes off. It appeared that the National Weather Service was timing the squall line itself rather than the gust front as the warning has the storms hitting Zionsville at 8:55 PM when in fact the gust front went through Zionsville at approximately 8:45 PM.
Shortly after the Severe Thunderstorm Warning was issued, hurricane force winds of 77 mph were reported (measured) in Plainfield. An estimated 70 mph wind gust was also reported in Speedway.
The radar image above from 8:45 PM shows the gust front surging well ahead of the squall line. The stripe of green and blue reflectivity outlined by the black circle shows the gust front just West of the fairgrounds extending from Western Madison County through Northwestern Marion County and farther Southwest towards Speedway & Plainfield where the 70+ mph wind gusts were reported.
At 8:49 PM, the gust front struck the Indiana State Fairgrounds, 10 minutes after the Severe Thunderstorm Warning was issued. The gust front was accompanied by a significant amount of blowing dust. Gust fronts sometimes produce gustnadoes (gustnadoes form due to non-tornadic cyclonic features in the downdraft from the gust (outflow) front of a strong thunderstorm) and some of the high definition video from the fairgrounds shows what could have been a developing gustnado. Either way, winds at the fairgrounds and at the Sugarland Concert were likely close to 70 mph. The video screen capture below shows the blowing dust and reduced visibility as strong winds associated with the gust front struck the State Fairgrounds.
The radar image below was captured at 20:49 just as the gust front passed through the Indiana State Fairgrounds. The radar image shows where the gust front was located. You can see the precipitation associated with the actual squall line was still well West of the State Fairgrounds in Western Marion County.
Here is an even closer view of the radar which shows the well defined gust front moving towards and through the State Fairgrounds.
Radar imagery above courtesy of the NWS and Brad Panovich
At 8:58 PM, almost 10 minutes after the Indiana State Fairgrounds got struck by the damaging winds associated with the gust front, the Indianapolis National Weather Service issued a Severe Weather Statement calling for potential destructive winds in excess of 70 mph. The National Weather Service was obviously tracking the squall line and not the gust front as the warning text called for an estimated arrival time at the Indiana State Fairgrounds of 9:20 PM which would have been nearly 30 minutes after the fairgrounds had already been hit by the damaging winds.
A time line of events was released by the Indiana State Police showing the correspondence between public safety officials at the fairgrounds and the National Weather Service. It should be noted that the public safety officials and event planners at the fairgrounds made contact with the National Weather Service at 8:00 PM but no further contact was made after that point. The Severe Thunderstorm Warning was issued at 8:39 PM. The gust front and damaging winds struck the the fairgrounds at 8:49 PM. You can click on the picture below for a larger more detailed version.
So after a lengthy blog entry above detailing the facts and circumstances of the disaster at the Indiana State Fairgrounds on August 13th, 2011, what went wrong? Here’s my personal commentary.
1. There are apparently no building codes for outdoor temporary stages. In fact the Indiana Fairground incident is only one of three incidents that have occurred within the past two months. According to CNN, “Earlier this month, severe weather caused a stage to collapse before a Flaming Lips performance in Oklahoma. The August 6 incident occurred after heavy winds and rain pounded Tulsa, ending a block party music festival that featured Primus, the Flaming Lips and other acts. A lighting rig fell down and struck audio equipment and instruments. It was unclear whether there were any injuries. And last month, a severe storm toppled a stage when classic rock band Cheap Trick was performing. No one was seriously hurt during the incident at the Cisco Ottawa Bluesfest in Canada.”
There has been some debate that the winds that struck the Indiana State Fairgrounds might have not even reached “true” severe criteria of 58 mph. Some evidence to support these claims include the fact that there was little to no damage anywhere else across the Indiana State Fairgrounds. Between this incident, the Oklahoma incident and the Ottawa incident, it is quite clear that these temporary stages are not built to withstand even 50 to 60 mph winds which are somewhat common with thunderstorms during the summer months. Building and construction codes for temporary outdoor stages are critical and I would hope that we see legislation and law changes to require them!
2. The National Weather Service, as can be seen in my posts above, was obviously tracking the squall line itself rather than the gust front. Their timing of the storms arrival at the Indiana State Fairgrounds was almost 30 minutes off! The warning text also never made mention of the fact that the thunderstorm winds would arrive well before any precipitation. While the warning was issued prior to the damage at the Indiana State Fairgrounds, the warning text was not clear and somewhat confusing compared to what actually occurred.
3. Early reports indicate that the only person at the Indiana Fairgrounds monitoring weather conditions was a State Police Special Operations Commander who was using his smartphone to view radar data. The following quote comes from the Indy Star Press, “Backstage, State Police special operations commander Brad Weaver was watching an ugly storm moving in on radar via his smartphone.” If this is true, and the only weather and radar data was a state police officer using his smart phone, then obvious there was room for significant errors. A smartphone radar application does not have the proper resolution to view weather and radar data and a police officer likely does not have the training required to make educated weather decisions. Any time there is a large outdoor event, event planners and organizers should have a special relationship with expert meteorologists in order to help provide specific warning information. Generic National Weather Service forecasts and products are not enough because they don’t provide the information that the event planners need. Anytime there is a large outdoor event with thousands of people attending, there really should be some planning ahead of time to have a NWS meteorologist on site or to hire a private sector meteorologist to staff the event.
4. The Severe Thunderstorm Warning was issued at 8:39 PM and evacuations did not begin until 8:45 PM. The 6 minute delay is significant in this case. Evacuations should have begun as soon as the Severe Thunderstorm Warning was issued.
In closing, this was not a fluke or unpredicted event as indicated by the Indiana governor and other high ranking officials. The writing was on the wall for days and Severe Thunderstorm Watches and Warnings were issued prior to the stage collapse. While this event was extremely tragic, my hope is that it will serve as a wake up call for public safety officials and event planners. Weather has to be a priority at large outdoor events. The event staff typically hires law enforcement, Emergency medical personnel and fire personnel to be on site during the event, so why not a meteorologist? A meteorologist can provide valuable and detailed information as severe storms or even regular non severe thunderstorms are approaching. If a meteorologist was on site at the Indiana State Fairgrounds for the Sugarland concert, could it have saved lives? We’ll never know, but if I were a guessing man, I’d say there is a good chance that the meteorologist on site would have recognized the dangers well before the severe thunderstorm warning was issued and plans to evacuate the grandstands would have begun much sooner.