Clearer Days Ahead for National Weather Service Maps

Looking for a 10-day forecast for the American South? A map showing a distractingly pixelated view of the fjords of Baffin Island in far northern Canada with a retro computer font could mean an outlook of partially confused with a chance of headache.

Last week, the National Oceanic and Atmospheric Administration’s Climate Prediction Center (CPC) left these and other design choices behind to launch decluttered and more user-friendly long-range U.S. temperature and precipitation forecast maps—widely used by weather forecasters, media outlets and decision makers whose industries rely on accurate weather.

The center did so with the help of University of Maryland researchers, who for several years delved into how to make the maps—part of the National Weather Service’s suite of forecast products—more useful and useable, not to mention easier on the eyes.

“These are maps that haven’t changed in a long time,” said Michael Gerst, an associate research professor at the University of Maryland’s Earth System Science Interdisciplinary Center (ESSIC). “As the federal government's official forecasts for temperature and precipitation over the next one to two weeks and the coming season, a lot of people see these maps, and a change isn't taken lightly.”

Gerst is the lead author of the research study that underpins these forecast design changes. In 2017, the CPC embarked on an effort to diagnose problems with readability and understandability in its outlook maps and teamed up with Gerst and other collaborators from ESSIC’s Cooperative Institute for Satellite Earth System Studies to analyze forecast maps and look for ways to more clearly communicate long-term forecasts.

The redesign represents a considerable multi-institutional achievement, said Jon Gottschalck of the Chief Operational Prediction Branch for CPC.

“After considerable research and collaboration with partners and users, we are pleased to offer these now-operational upgraded climate outlook maps for our partners and the public,” he said. Jon Gottschalck, Chief Operational Prediction Branch for CPC.

Gerst and his colleagues evaluated the six- to 10-day, eight- to 14-day, monthly and seasonal outlook maps. The team incorporated comments from map user focus groups along with guidelines from data visualization science that stem from an understanding of how users perceive and interpret images.

“Our results showed that there were some features of the original maps that people found really confusing. Visualization science theory predicted these would be the most challenging to understand, which points to the theory’s practical utility for making good designs,” Gerst said.

Gerst and colleagues adjusted the design and compared the usability of the new versions with the original maps by surveying a group of volunteer test users from four sectors that rely on accurate weather information: agriculture, emergency management, water resources and energy.

The results of the surveys shaped the final redesign. One of the most significant changes included removing Canada from the image and depicting Alaska on its own beside the continental U.S. In addition, new fonts, a less ambiguous representation of forecast probability scales and a clearer, more user-friendly legend make the new version cleaner and less cluttered.

CPC says these maps are just the first to get a new look. More maps from the NWS suite of forecasting products will be getting a visual upgrade in the coming years.

This story was adapted from text provided by the Climate Prediction Center.