What meteorologists need to know about data visualization

Picture of colorful weather system on a map

As a former on-air broadcast meteorologist, I can tell you that most weathercasters are not trained in graphic design. Most of what we know was taught by software trainers or handed down by other meteorologists. That’s why most weather graphics are usually designed based on what looks good, not necessarily on what best communicates the science of meteorology.

Data visualization is defined as the “graphical representation of data.” When you think about it, that’s what broadcast meteorologists do. They take meteorological data and produce a graphical representation, a weather visualization, if you will.

READ MORE: WHOLE BRAIN WEATHER COMMUNICATION

While there’s not a lot of published guidance on creating good weather graphics (until now), broadcast meteorologists can use some of the same techniques scientists and analysts use to create engaging data visualizations. Many of those techniques focus on one thing: reducing the cognitive processing required for the viewer to understand the visualization.

Deliver one message per graphic

“When we’re at the point of communicating our analysis to our audience, we really want to be in the explanatory space, meaning you have a specific thing you want to explain, a specific story you want to tell,” writes Cole Nussbaumer Knaflic, former manager of the Google People Analytics Team and author of the book, Storytelling with Data. “Being able to visualize data and tell stories with it is key to turning it into information that can be used to drive better decision making.”

Colorful, but cluttered and confusing weather map — One map with too many messages

Applying this to the daily weathercast, the information presented in each graphic should help consumers make decisions that keep them safe during severe weather and enable them to live a happy healthy life. Broadcast meteorologists can do that by avoiding a data dump and simplifying each weather graphic to deliver one message, tell one story.

Eliminate anything that doesn’t deliver the message

Weather graphics systems today can display multiple layers of data. Broadcast meteorologists sometimes add additional data layers thinking it will help explain the weather better. Instead, it makes the graphic more complicated for the consumer to understand.

Weather map cluttered with data — Remove non-essential elements to deliver a clear, concise message

“Every single element you add to that page or screen takes up cognitive load on the part of your audience,” Knaflic writes. “Identify anything that isn’t adding informative value and remove those things.”

This echoes the advice offered by graphic designer Kent Kerr. During a presentation at the AMS 43rd Conference on Broadcast Meteorology, he explained, “Good graphic design isn’t achieved when you have nothing left to add, but rather when you have nothing left to remove.”

What we need to ask ourselves is not: What else does this weather graphic need? We need to ask: What doesn’t it need?

Use color as a communication tool

Many weather graphics display data using a rainbow color table. While it might look pretty, there are many problems with the rainbow color table. The different colors are not consistently applied and, as a result, not intuitively understood. Furthermore, the colors can be misleading for 8.5% of viewers who are colorblind.

When used correctly, color can reduce cognitive processing by identifying trends, patterns, and outliers in the data. Color conveys messages, signals actions, and affects mood.

The colors used to represent different data types should be a deliberate choice based on what best communicates the message. If we’re not careful, the colors we use could communicate a conflicting message.

Avoid annoying arrows and abbrvs.

Abbreviations slow down cognitive processing. It’s one more thing for viewers to decipher. Standard abbreviations like months, days of the week, AM and PM are easily understood. We run into trouble when we abbreviate words to make them fit. For example, the abbreviation “scat.” could mean scattered, leave me alone, jazzy music, or something much more vulgar.

Arrows have recently become an annoyance because some of them are added automatically by the graphics computer to connect a text box with the corresponding warning polygon. Arrows are also used to show the movement of the weather like the direction storms are moving. As a result, it’s not uncommon to see confusing weather graphics showing multiple arrows pointing in opposite directions.

Map showing arrows pointing in two different directions — Multiple arrows pointing different directions is confusing

Write out the entire word or edit the phrase to eliminate the need to abbreviate. And consistently use arrows only to show the direction of movement. For weather warning polygons, displaying one warning per graphic eliminates the need for an arrow and simplifies the message.

Reduce the cognitive load

It comes down to this: how easy is it for consumers to understand, process, and act on the information being presented in each weather graphic? “Anything you can do to reduce cognitive strain will help,” writes Daniel Kahneman in the book, Thinking, Fast and Slow.

Knaflic says, “When our visuals feel complicated, we run the risk of our audience deciding they don’t want to take the time to understand what we’re showing, at which point we’ve lost our ability to communicate with them.”

Furthermore, for every moment viewers are trying to figure out the weather graphic, they are not fully listening to you.

While broadcast meteorologists spend all day looking at data, viewers see each graphic for maybe 10-15 seconds, at most. We can help consumers comprehend our weather visualizations by delivering one clear, concise essential message that looks good and is intuitively easy to understand.

Tim Heller is an AMS Certified Broadcast Meteorologist, Talent Coach, and Weather Content Consultant. He helps local TV stations and broadcast meteorologists communicate more effectively on-air, online, and on social media.