The Ultimate Lightning Guide for Airport Operations

The ultimate guide to help airports, airlines, and fixed-base operators (FBOs) navigate lightning’s many safety and operational challenges.

Jump through this helpful guide using the links below or scroll down to read the guide in its entirety and learn everything there is to know about lightning in airport operations.

Time to read: 🕒 30 minutes

All About Lightning

Airport Operations and Lightning

Severe Weather Safety at Airports

Airport Lightning Alerting Rules

Lightning Accidents at Airports

Free vs. Commercial Weather Data

Key Takeaways

Airport Operations and the Weather: An Overview

We don’t have to tell you that weather greatly impacts airport operations. Conditions associated with thunderstorms, winter storms, and extreme events impact various key stakeholders in the industry. According to the Federal Aviation Agency, weather is responsible for 69% of all air traffic delays in the National Airspace System.

But did you know that the majority of these delays are from convective weather, like thunderstorms?

The below image shows the various weather conditions identified by our meteorologists that impact airport operations.

Severe thunderstorms include many of the threats illustrated above, including:

Wind gusts

 Hail

 Heavy rain/flooding

Fog

Lightning

All About Lightning

Close your eyes and picture a lightning strike.

We bet you’re picturing a bolt that seems to extend from the clouds down to the ground or a tree. Maybe, given our discussion of airport operations, your bolt of lightning is striking a plane or an air-traffic control tower.

These types of lightning strikes, called cloud-to-ground lightning strikes, only make up approximately 20% of all lightning strikes. What type of lightning makes up the other 80%?

It’s the type of lightning you don’t always see: in-cloud lightning. In-cloud lightning strikes jump from cloud-to-cloud up in the sky.

The combination of in-cloud lightning and cloud-to-ground lightning is called total lightning.

Total lightning is the complete picture of lightning activity in a region. Total lightning networks detect the most at-risk areas and are able to prompt advanced warnings for thunderstorms and other severe weather events.

Why is that important? When you break it down, lightning is the most reliable indicator of storms. In fact, lightning is detected in an overwhelming majority of storm reports within a 30 km radius and 45 minutes before and after a severe weather event:

90% of high wind reports include lightning

94% of all tornado reports include lightning

99.6% of all hail reports include lightning

Lightning Development

So how does lightning develop? While scientists aren’t completely sure why lightning happens, we do know how it happens. This electric current forms in a cloud. When the ground is hot, it heats up the air above it. As warm air rises, the cloud gets bigger and bigger. However, the whole cloud isn’t warm. In the tops of clouds, temperatures are actually below freezing. It’s so cold that the water vapor turns into ice!

When this hot air and cold air meet, a thunderstorm forms. Lots of small pieces of ice bump into each other as they move around. This is what starts a lightning bolt. These particles hitting each other create an electrical charge.

As the cloud fills up with electrical charges, lighter positive-charged particles form at the top of the cloud. The heavier negatively-charged particles sink to the bottom. When both charges grow large enough, lightning occurs between them.

Lightning heads towards the ground and becomes a danger to those outdoors when a build up of positive charge happens on the ground beneath the cloud. This is attracted to the negative charge at the bottom of the cloud, so it concentrates around anything that sticks up into the air. That’s why trees, air-traffic control towers, and even people make great lightning conductors! The positive charge from the ground connects with the negative charge from the cloud, creating cloud-to-ground lightning.

Lightning sensors work to detect lightning both in-cloud and cloud-to-ground lightning at the end of the development.

Threat of Lightning Casualties

Believe it or not, there is a “sweet spot” of sorts when it comes to lightning incidents. This is when the most injuries and deaths occur as a result of lightning. Knowing this sweet spot can help you protect your airport and ground operations from a lightning strike.

Most people would think that they’re most at risk during a thunderstorm when it’s directly overhead. However, that’s untrue. By the time a thunderstorm is overhead, most people have already sought shelter.

The greatest number of lightning casualties happen right before a thunderstorm arrives and right after it begins to depart. Oftentimes, people do not seek shelter or stop outdoor operations quickly enough to protect themselves from the lightning strikes that occur before the storm. On the other hand, the sun may lure people out of shelter to resume outdoor activities when lightning is still within striking distance. Automated lightning alerts and all clear signals from a system that relies on total lightning detection is the best way to reduce the injuries, casualties, and property damage caused by lightning and stop them from happening in the first place.

The Thunderstorm Challenge

As we know, thunderstorms mean lightning – whether or not you can actually see it. This hazardous form of severe weather is a threat to people both indoors and out from over 10 miles away. When thunder roars, go indoor isn’t just a catchy saying. If you can hear thunder, lightning is close enough to strike you.

While lightning alone isn’t always the most disruptive weather condition when it comes to the airport operations (although it the top concern according to our 2019 industry survey), it is one of the most dangerous to workers on the ground. And it can be pretty terrifying when lightning strikes a plane in the air – a phenomenon that occurs approximately once per year with commercial aircraft.

One of the most dangerous aspects of lightning is that it can occur anywhere in the world at any time, on the ground (cloud-to-ground) and in the clouds (in-cloud). This differs from other types of severe weather like hurricanes that only impact coastal airports or tornadoes that generally only cause delays in areas like the Midwest of the United States.

Lightning can affect your airport operations no matter where your flights are taking off or landing, and like all weather-related delays, cause a ripple effect on air traffic globally. Lightning has been known to set fire to buildings at airports, strike (and knock out) air traffic control towers, and directly or indirectly hit ground crew workers. Lightning is extremely dangerous and most people think it won’t impact them until it does.

Reality Check: Severe Weather is a Billion-Dollar Problem

Safety and efficiency are among the top concerns for airport operations teams. Severe weather can strike a definitive blow to both.

In 2017 alone, there were a whopping 16 weather and climate disasters in the United States that exceeded $1 billion in damages. These threats, including hurricanes, tornadoes, and thunderstorms, collectively caused over $306.2 billion in damages. While 2017 was certainly an extremely active year for such disasters, 2015 and 2016 saw financial impacts of $200 billion and $175 billion respectively. Recent history proves that this is not an isolated incident.

While it might not cost your specific organization billions, per se, severe weather does have an extreme financial impact on aviation operations as a whole. According to a study commissioned by the FAA back in 2010, flight delays cost the airline industry over $8 billion a year. When you look at the big picture of delays costs the total number was over $32.9 billion back in 2007, with over half the cost borne by passengers.

Airport Operations and Lightning: It’s Everyone’s Problem

It’s clear that lightning is dangerous and expensive problem for airport operations and impacts everyone involved. Most of the industry understands this thanks to first-hand experience. Over 75% of professionals who took our audit admitted lightning has a large impact on their operations.

However, it’s difficult to decide when to stop and resume operations safely. There is a fine line between operational safety and operational efficiency. Both are important but balancing the two can be like walking a tightrope for airport operation professionals trying to meet scheduled flight times.

As part of this challenge, airport operations put lives at risk when airport personnel, airlines, and FBOs do not know the answers to critically important questions, like:

How do you decide when a thunderstorm or other severe weather event is a threat?

Who decides that: The airport, airline, or FBO? A local meteorologist? A team of meteorologists?

What qualifies them to make the call?

Where does your weather data and storm warnings come from?

How reliable is that information?

Other Risks

Even when an airport operations team is comfortable answering all of these questions, there are still things that can go wrong. A glaring example is the risk posed by outdated technology. An outdated lightning detection (or prediction) system can result in false or missed alarms, putting your ground crews, outdoor equipment, airplanes, and even passengers at risk.

Another risk comes from too manual of an alerting process. With manual alerts, there are delays with relaying the message that can waste precious time. When it comes to lightning safety, minutes make a difference.

Further complicating matters, operational suspension and resumption procedures typically vary from airport to airport, which can be confusing for airlines.

Making the decision to stop outdoor operations also varies based on the lightning detection method and technology in place, availability of meteorologists, and chosen safety buffers.

Severe Weather Safety at Airports: When to Stop Ground Operations

Based on responses to our 2019 Airport Weather Safety Audit, the current status of severe weather warnings regarding lightning at airports is troubling. In fact, most current protocols (or lack thereof) put everyone at risk. Over 20% of all respondents said they did not have a standard lightning radius they use to stop ground operations. This can lead to some very serious injuries, and even death, for ground crews caught outside when lightning strikes.

The lowest distance lightning must be from an airport to stop operations per our survey was 3 miles. More commonly, participants in our survey indicated a 5 miles radius for stopping ground operations.

54% of survey participants indicated they stop ground operations when lightning is detected within 5 miles of the airport

This seems to be the happy medium between safety and operational efficiency for most airports, however airport operations teams monitoring the weather should keep an eye on nearby storms outside of the safety radius as lightning bolts from the blue (i.e. bolts that extend from storm cells and strike when skies seem clear) can travel over 10 miles away from storm clouds.

Airport Lightning Alerting Rules

There is no requirement for airports or airlines in the U.S. to follow specific lightning alerting rules. According to research from the FAA, some best practices include:

Issuing a weather alert to the operations team at 8 miles

Stopping fueling & ramp operations at 5 miles

Resuming operations after a 15 minute all clear

Research conducted by an FAA working group on airport lightning policies suggests using a critical radius of 5 miles and waiting at least 15 minutes after the last lightning event to resume operations. Some airports and airlines use a critical radius of 3 miles and a shorter all-clear period but this generally leads to more inefficiency as lightning may not have completely moved out of the area and subsequent alerts may be triggered.

Best practices also include the use of a total lightning detection system that captures both in-cloud and cloud-to-ground strikes (as recommended by the NTSB).

More than 80% of lightning activity is in-cloud and these strikes are generally detected before lightning strikes the ground. By using a system that detects both in-cloud and cloud-to-ground lightning, airports can be proactive in their efforts to protect employees and assets from severe weather. Alternatively, waiting until lightning strikes the ground or someone hears thunder nearby, puts everyone at greater risk from the storm.

It is also recommended that airports use an automated warning system with some human oversight to minimize downtime and inefficiency. When lightning notifications are triggered manually, the FAA found that it sometimes took longer to issue an all-clear notification to resume operations because the person in charge had moved on to other tasks.

What does IATA say about airport lightning rules? The International Air Transport Association (IATA) says to issue lightning alerts at 5 miles (8 km) and stop operations at 3 miles (5 km). They suggest using a 3-mile critical radius and resuming operations once the lightning activity has moved beyond this radius.

To be clear, a safe distance from lightning is at least 10 miles. Period. But most airports seek to find a balance between safety and efficiency to keep air traffic from becoming a heaping mess.

Flip through this presentation from the FAA’s Randy Bass to learn more about their research and findings on lightning warnings for U.S. airports.

Reliable Monitoring & Alerting 

Some airports, airlines, and FBOs do not have a reliable method of monitoring and issuing alerting for severe weather. In some cases, airport operations personnel make the call to stop operations based on visual observations (ie, storm clouds overheard) or visible lightning flashes in the distance. These decisions are highly inaccurate and can put workers in even more danger. They’re also extremely inefficient.

For those that do have a process in place for issuing severe weather alerts, the best method seems to be text alerts and the least effective method is automated phone calls. This is likely due to the noise on the ground making it impossible to hear the phone call.

Other widespread problems in the aviation industry include use of outdated warning systems, like lightning prediction systems (see why that’s a bad idea) or free weather applications that don’t always update or use the most accurate information. When relying on a free weather service, there is also the chance the alerts are not issued automatically and could be delayed.  This can be a costly mistake.

Here are some important best practices for you follow if you want to minimize the risk of lightning disrupting your airport operations:

Rely on total lightning detection (not prediction) with automated alerts

Have a clear severe weather safety plan that includes all parties at your airport

Utilize real-time weather data and lightning detection warning systems – two of the best severe weather safety tools to protect those on the ground, in towers, and in any other high-risk areas.

Detect, Alert, Protect

You can take advantage of all these best practices by remembering Detect, Alert, Protect. This is the overall best practice for dealing with severe weather at any workplace that operates outdoors in any capacity.

Detect

The best way to know if lightning is nearby is by using a lightning detection solution. The best lightning detection tools detect total lightning, the combination of in-cloud and cloud-to-ground lightning strikes, and are network-based. Using a system that is supported by a network, rather than just a single-node, is important in the event that severe weather damages your equipment or you want to track incoming storms farther away from your airport.

We have an entire reference document outlining the differences between lightning detection and prediction that you can access for more information.

Alert

If lightning flashes are within your warning zone, typically 10 miles of your location, you need to alert everyone at risk to seek shelter.

Severe weather alerting has traditionally been a clunky, unreliable task. But unreliable is one of the last things you want to be in the case of severe weather approaching an airport. That’s why automated alerts are your golden ticket to operational safety. Any type of automated alert that relies on your lightning detection system is encouraged. Options range from horns or Outdoor Alerting Systems (OAS) to mobile alerts in the form of text messages, push notifications, and email.

Protect

Once you detect lightning and alert everyone following these best practices you can then protect all those at risk. Have a plan in place for what happens when your alerts go off that includes safety procedures for moving people to safe locations and securing property.

You can offer better protection by developing a protocol for each at risk party and reviewing it regularly, so everyone knows what to do and reacts quickly.

Weather tracking software also comes in handy when it comes to protecting individuals who are skeptical of the threat of severe weather. A real-time weather map will help you collaborate with different parties online and show them incoming dangers as they approach your location with data backed by highly accurate and targeted hyperlocal weather networks.

When Things Go Wrong: Lightning Accidents at Airports

Severe convective weather can cause big headaches for airports, airlines, and FBOs alike. Let’s take a look at three different cases where thunderstorms, and more specifically lightning caused big problems for airports across the United States.

Case 1 – San Francisco International Airport

These types of lightning incidents aren’t limited to Florida – the lightning capitol of the United States. On the other side of the country, San Francisco International Airport had a close call with lightning back in 2017. Located just 30 miles south of downtown San Francisco, San Francisco International Airport is the seventh-busiest airport in the United States. Since it also serves as the hub for United Airlines and Alaska Airlines, this is a very busy airport for operations on the ground.

While thunderstorms – and rain in general – aren’t very common in California, airports in the Golden State still need to be prepared when severe weather rolls in. The folks at San Francisco International Airport were reminded of this on September 11, 2017 when a cloud-to-ground lightning strike came uncomfortably close to a United Airline tug driver. Luckily, the tug driver was not harmed, but the results could have been a lot worse. There were plenty of cloud-to-ground lightning strikes detected in the area by the Earth Networks Total Lightning Network prior to the strike.

Case 2 – Baltimore-Washington International Airport

Lightning strikes don’t only threaten the people and equipment on the ground. They also threaten those in air-traffic control towers. In 2013, a lightning strike hit the air-traffic control tower at Baltimore-Washington International Airport. This incident injured a worker and prompted the temporary closure of the tower. No air-traffic control tower, no air traffic. The lightning reached the worker through a panel that was not properly ground and that he was leaning up. While the worker survived the lightning strike, the airport was shut down for nearly 3 hours. Nearly 120 flights were canceled at BWI alone that day due to severe thunderstorms.

Commercial Weather Data Helps You Prepare for All Weather Scenarios

It is easy to understand your lightning risk and how to protect your organization, but it’s hard to attain complete lightning and severe weather safety if you’re using the wrong data. Earlier we mentioned there’s a problem with relying on free weather applications when it comes to making sound operational decisions. These apps might be good (sometimes) for figuring out what to wear in the morning, how long your commute is going to be, and if you can go for a run in the afternoon, but they just don’t make the cut when lives are on the line.

Aviation professionals require professional-grade, commercial weather data. Commercial weather data is superior to freely-available consumer weather data in four key areas:

Top Four Benefits of Commercial Weather Data

1. Accuracy – Quality commercial weather providers use weather data from professional systems rather than turning to weather stations owned and operated by everyday weather enthusiasts

2. Proximity – Commercial weather data is hyperlocal, which means it represents local conditions at and around your airport and other key locations

3. Granularity – Weather watchers receive a standard package when they rely on free data, but commercial weather data providers give key decision-makers with options and access to professional meteorologists for expert decision-support. With commercial weather data you get the weather information that matters most to your operations.

4. Real-Time Updates – Inclement weather can go from bad to worse in a matter of seconds. Commercial weather providers update in real-time, on average 50% faster than freely-available applications. Those extra minutes of advanced notice can save lives.

When you have the right tools in place from a commercial weather network, you can improve operations at your airport by eliminating false alarms, never missing real alarms, to keep people and equipment safe from severe weather.

In our 2019 Airport Operation Safety Audit, 40% of respondents indicated they were going to increase severe weather safety measures for their operations this year. There are dozens of airports all around the country that are currently using lightning safety systems and seeing the advantages. Let’s take a look at a few examples below and see how they compare to your systems and procedures.

If you don’t already have a lightning safety plan in place, this example should give you a good place to start.

Example 1 – St. Pete Clearwater International Airport

St. Pete Clearwater International Airport (PIE) is a public/military airport in Pinellas County, Florida. Know as the “birthplace of commercial air transportation,” it is also a leader in the airport safety field. After growing discouraged by inaccurate reports and warnings from free weather apps, St. Pete Clearwater now utilizes a complete suite of weather intelligence products from Earth Networks.

Their comprehensive weather safety solution includes:

Meteorological support

Weather tracking software

Text message alerts

These tools come in handy nearly every day at PIE. In 2017, there were 283 cloud-to-ground lightning strikes at the airport. When you take in-cloud lightning into account, that brings the yearly total up to 4,423. That’s a lot of lightning as you can see in the graphic below.

PIE detected these strikes with the help of Earth Networks and made better weather-related decisions which resulted in:

Better on-time performance

Streamlined operations

Improved safety throughout the airport

Key Takeaways

We work with hundreds of other airports, airlines, FBOS, and air traffic control agencies to help them mitigate the risks of lightning and other severe weather events to their operations.

When searching for a weather intelligence company to power your safety and operational policies, look for the following features:

Automated, timely alerts that assist with making quick decisions

Network-based solutions that gives access to expert meteorologists and support

Accurate, cost-effective solution

Lightning detection, not prediction

Audible and visual alerts

Access to hyperlocal real-time weather observations on site

If you’re ready to combat lightning and other severe weather safety hazards, get in touch with the team at Earth Networks. We’ll craft a customized solution with your operations in mind to help you mitigate thunderstorms and other severe weather events.