Festival and outdoor event organisers: the wind call, at your height

As an Event Manager, Production Manager, or Event Director, you make critical decisions daily during the build, show, and derig phases of any outdoor event. These calls directly impact operations and the event's viability. Your wind management plan guides you, with specific triggers at 60% and 80% of each structure's maximum wind load.

A wrong call can lead to significant disruption and financial loss. For example, a festival in Galway had its second day cancelled due to wind, impacting attendees and incurring costs. Similarly, a national agricultural show experienced marquee damage and a cancelled day, illustrating the real-world consequences of misjudging wind conditions.

Your primary decision points are to delay, hold operations, or evacuate an area based on these wind triggers. This requires continuous monitoring and a clear understanding of current and forecast wind conditions at the specific height of your structures. The information needs to be precise and easily digestible for your team and contractors.

Your responsibility is to ensure these decisions are made consistently, based on your documented plan, and that a clear record is kept for all stakeholders, including councils and insurers. This ensures accountability and demonstrates due diligence in managing wind-related risks.

For festival and outdoor event organisers, knowing the wind at 10 metres is typically what matters most. This is the common working height for many temporary structures, and where your wind management plan's limits are usually set. However, The Wind Agent interpolates wind speed for any height you specify, such as the peak of a particular stage or marquee.

Your plan will differentiate between mean wind speed and gusts. Gusts can exert sudden, intense pressure on structures, often exceeding mean speeds. The instrument displays both, allowing you to monitor against both types of wind events, as specified in your structure's rating.

Your limit is not a general figure; it is specific to each structure on your site. It is set by the structure's manufacturer or designer, often referenced from guidance like The Purple Guide. You will input these limits into the instrument, typically as a percentage of the maximum wind load, such as 60% or 80% triggers.

The competent person on site makes the final call, using the instrument's data alongside their own observations and your documented plan. The instrument provides the objective wind data, but never makes the decision for you.

The instrument provides the probability of wind exceeding your specific limit, expressed as P(above your limit) by the hour. This is derived from multiple ensemble members, showing the fraction of these models that predict wind above your threshold at heights of 10, 80, 100, and 120 metres.

This percentage helps you understand the likelihood of needing to act. For example, if P(above your limit) is 20%, it suggests a lower chance of exceeding your 60% trigger, allowing you to proceed with caution but without immediate alarm. At 50%, you might initiate preparations for a potential hold or delay, such as securing loose items or briefing staff.

If the odds reach 80% or higher, this indicates a strong likelihood that wind will exceed your limit. This would typically trigger immediate action according to your wind management plan, such as initiating an evacuation or calling a halt to operations. This allows for proactive decision-making rather than reactive measures.

The Agreement Spine feature also shows where different weather models agree and where they do not. When models largely agree, your confidence in the forecast is higher. Disagreement suggests greater uncertainty, which might prompt a more conservative approach to your operations.

It is an example: On Tuesday at 07:00, you check the forecast for the main stage. The instrument shows a 10% chance of wind exceeding your 60% limit by 14:00, and a 20% chance by 18:00, with gusts at 10 m forecast up to 15 knots.

At 10:00, during your morning briefing, you review the forecast with your team. The odds for 14:00 have increased to 30%, and for 18:00, they are now 45%. You decide to instruct stage crew to ensure all banners are securely fastened and to have a standby team ready for potential further action.

By 14:00, the P(above your limit) for 18:00 has climbed to 65%. This crosses your first action trigger. You contact the structures contractor to be on alert and begin to implement your wind management plan's 'hold' procedures, such as advising artists to prepare for a potential delay.

At 17:00, the forecast for 18:00 shows an 85% chance of exceeding your limit, with gusts now predicted at 25 knots. This triggers your 'evacuate' protocol. You make the call to temporarily clear the stage area and pause operations, ensuring everyone's wellbeing until conditions improve.

Your wind limits are crucial for event operations and planning. These are not arbitrary figures but are derived directly from your specific wind management plan and the technical specifications of each temporary structure on your site. The Purple Guide, for example, provides guidance on action triggers for temporary demountable structures.

Typically, these limits are expressed as a percentage of each structure's maximum wind load, such as 60% and 80%. You will input these values into the instrument. The instrument's default height is 10 metres, but you can adjust this to the specific working height of any structure, such as 12 metres for a particular marquee, to get precise data.

This customisation ensures that the instrument supports your existing protocols, providing actionable information tailored to your event's unique requirements and the manufacturer's specifications for each structure. It is essential that the limits you enter accurately reflect the guidance in your own documentation, as this forms the basis for your operational decisions.

The instrument will then compute the odds of exceeding these specific limits at your chosen height. This ensures that the forecast is directly relevant to your operational thresholds, rather than generic wind speed figures.

Keeping a dated record of wind forecasts, observations, and your decisions is a non-negotiable part of event management. The instrument provides a dedicated record page that captures what was forecast, what was observed, the specific limits you used, and the call you made at that time. This creates an auditable trail.

Councils, as part of their licensing requirements, and insurers, in the event of an incident, will often request these records. They need to see clear evidence that you adhered to your wind management plan and made informed decisions based on available data. A comprehensive log demonstrates due diligence and professional risk management.

Your own reasons for needing this record are equally important. It serves as a reference for post-event reviews, helping you refine future wind management plans. It also provides a clear defence against any claims of negligence, by showing that you followed established protocols and acted responsibly based on the information at hand.

This record is frozen, meaning it cannot be altered after the fact, providing an immutable log of events. This ensures its integrity and reliability for all stakeholders, offering peace of mind that your decisions are transparently documented.

Ireland's outdoor event season, particularly from May to September, can still experience significant wind events, including unseasonal storms. The Atlantic exposure means that even outside the typical October to March storm season, wind conditions can change rapidly and unpredictably, posing challenges for event organisers.

Met Éireann, as the national forecaster, provides general meteorological information, but your event needs specific, granular data. The instrument provides this by interpolating wind speeds to your exact working height, such as 10 metres, and calculating the odds against your specific operational limits.

Past events in Ireland, such as cancellations due to wind, underscore the importance of robust wind management. Councils licensing outdoor events increasingly scrutinise wind management plans, often referencing guidance similar to the UK's Purple Guide for temporary structures.

Having precise, height-specific wind data, coupled with a clear record of your decisions, helps you navigate these conditions. It supports your licensing requirements and demonstrates a proactive approach to managing the unique wind challenges of Irish outdoor events.