Severe weather, such as a sudden weather change, strong winds, or lightning, is always one of the biggest safety risks for large outdoor events. When a storm approaches while thousands are enjoying themselves, their safety and health is your responsibility. It is important to quickly assess the situation, to be able to take the necessary actions and to be able to switch quickly with the local authorities and emergency services. Support the effectiveness of this response with a Decision Support Matrix.
It’s not hard to imagine that extreme weather is a scenario that any major outdoor event should be prepared for. The risk is foreseeable and eliminating the risk completely is impossible. Iconic events having to deal with severe weather include Falls Festival (Australia), where the camping had to be evacuated in 2019 due to extreme weather, Lollapalooza (Chicago), which as evacuated due to storm in 2012, 2015 AND 2017, Rock am Ring (Germany), which was hit by lightning in 2015 and 2016, and the deaths and wounded due to an unforeseen storm at Pukkelpop in Belgium (2011). Many more other festivals and events may be added to this list.
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Anticipate and prepare
The arrival of severe weather need not take you completely by surprise. There is a great deal of scientific knowledge about the characteristics and consequences of risky weather, and much can also be learned from the experiences at the events mentioned above. ESI’s workshop ‘Hazardous weather’ offers good tools to better understand weather scenarios. This knowledge helps you to prepare thoroughly for the consequences and possible decisions.
Approach per weather type
In ESI’s ‘Planning for Hazardous weather’ course, Meteorologist Klaas Dros explains that the approach for each weather type can be thought through and worked out in advance. He distinguishes the weather types; Wind, Precipitation, Thunderstorm, Heat and an extreme value of the “Wet Bulb Globe Temperature” (WBGT). In the case of wind, for example; up to what wind force ae conditions pleasant enough for revelers? Which cloths must be removed from high structures at which wind indicators? In the case of precipitation, for example; what will visitors do if it starts to rain heavily? How much holding capacity do we have in festival tents and is there a chance of overcrowding? Will parked vehicles get stuck? In the event of a thunderstorm, consideration can be given to the possibilities of executing a timely show stop or the way in which the public on the field can remain as safe as possible. With a high value of the WBGT, health risks can be expected, among other things, and risk communication can be considered in advance.
Decision support tool
In ESI’s “Introduction to Crowd Science” course, delegates gain insight into the use of the “Decision Support Matrix” (DSM). This is a very helpful tool, in which three variables are compared. The purpose of a DSM is to support those who have to make decisions about Safety Management during an event with targeted information that originates from the risk analysis. For example, are there risks due to expected crowds at certain places at the event at predictable times? Then the variables time, location and busyness can be compared against each other in a DSM.
The Decision Support Matrix can also be used for risky weather scenarios. By placing the weather types in the vertical axis and comparing them horizontally with the most important benchmark moments before and during the event, you as an organization can already think in advance per weather type which measure should be used and when. Below is a “blank” example.
In order to fill this Decision Support Matrix, the organization will have to analyze the risks and consequences of the weather types and the influence options it has to manage the risks at its event. This requires thinking beyond the direct consequence of the weather type; after all, the behavior of the crowd itself as a result of the weather can also form a risk that needs to be anticipated.