Fair warning: How the Minnesota State Fair handles severe weather

The Minnesota State Fair is a city within a city, with hundreds of thousands of people packed into an outdoor venue over 12 days.

So what happens when severe weather threatens? The answer starts well before the first raindrop falls.

As a meteorologist, I wondered: How do you monitor a rapidly changing storm and communicate that threat to a massive crowd spread across an outdoor venue?

My curiosity led me to the State Fair itself, where I interviewed Mike Hagen, the Minnesota State Fair's senior manager of operations.

One of the most important pieces of that operation is the National Weather Service.

Meteorologists from the National Weather Service's Chanhassen office are stationed inside the fair's emergency operations center throughout the fair. They provide regular weather briefings and remain in direct communication with fair officials as conditions change.

Hagen says having a meteorologist physically inside the operations center gives fair officials immediate access to weather expertise.

“Anytime our operations center is open, we have a representative from the National Weather Service that we can turn to and have that one-on-one conversation with.”

The fair also has its own weather-monitoring capabilities, including lightning detection software and wind-monitoring devices around the grounds.

But there's not one universal weather threshold that shuts down the entire fair.

Different rides, entertainment stages and other operations have different criteria based on the type of threat and how much time is needed to respond.

For example, a large ride like the Great Big Wheel takes much longer to unload than a smaller ride. That means operators need more advance notice when severe weather is approaching.

The decision-making process also involves multiple people, including ride operators, inspectors and safety personnel.

“There's ride inspectors. There's safety people. There's all sorts of layers that are influencing those decisions as well.”

When the forecast calls for trouble, the State Fair has a plan

If the public needs to take action, the fair has several ways to get the message out.

Warnings can be delivered through PA announcements at free stages in English, Spanish, Hmong and Somali. LED boards can display messages, while police officers can drive around the grounds using their squad-car PA systems.

The fair can also send a Wireless Emergency Alert (WEA) directly to cell phones on the grounds, a tool officials have used during previous severe-weather events.

There are six designated severe-weather shelters at the fair: the Grandstand, food building, Agriculture & Horticulture building, Lee & Rose Warner Coliseum, 4-H building and the water tower and campgrounds area.

The fair also has numerous other buildings where people can get out of the elements, depending on the severity of the weather.

For Hagen, the goal is to make sure those decisions are based on much more than a single forecast or weather app.

“This is not just a person looking at their phone and taking their best guess. We're working with the National Weather Service. We're working with our partners. We're working with all sorts of people to really be on top of whatever is coming at us.”

At a place where weather can change the plans of rides, concerts, vendors and hundreds of thousands of visitors, preparation starts long before the first warning is issued.

So as you enjoy the cheese curds, carnival rides and all the Great Minnesota Get-Together has to offer, know that someone is always watching the skies, just in case Mother Nature decides to join the fun.