This photo shows various weather apps arranged on a smartphone in Glenside, Pa., on Thursday. (AP photo)

Smartphone weather apps that summarize their forecasts with eye-popping numbers and bright icons may be handy during mild weather, but meteorologists say it’s better to listen to human expertise during multi-faceted, dangerous winter storms like the one blowing through the U.S.

The multistate storm’s combination of heavy snow, treacherous ice and subzero temperatures shows why it’s best to seek out forecasters who can explain its nuances via local TV or radio newscasts, online livestreams or detailed websites, said meteorologists interviewed by The Associated Press. The data is changing rapidly before and during the storm, and the distance of a few miles can mean the difference between snow, sleet or dangerous freezing rain.

“Weather apps are really bad at storms that have multiple types of precipitation and it really makes messaging hard,” said University of Georgia meteorology professor Marshall Shepherd, a past president of the American Meteorological Society. “Apps don’t understand the details of why snow, sleet or freezing rain happens.”

University of Oklahoma meteorology professor Jason Furtado and other experts said humans are important in these cases, especially those with local expertise.

“For extreme weather events, it is especially important to know there are human forecasters interpreting the data and making the best localized forecasts for your area,” Furtado said. “Unfortunately, many of the weather forecast apps use AI methods to either make the forecast or ‘interpolate’ from larger grids to your hometown, introducing the potential for significant errors.”

But some apps can be useful, especially those that pair National Weather Service data with meteorologists’ expertise, forecasters said. And they are definitely getting used right about now.

The Weather Channel app, which is seeing booming traffic this week, uses numerous models, data sources, weather observers and staff, said James Belanger, vice president of its parent company, which also owns the Weather Channel and weather.com. That level of proficiency matters, he said.

“It’s an all-hands-on-deck kind of approach that we take,” Belanger said, adding that “not all weather apps are created equal.”

What apps can do

Apps get much of their information from the National Weather Service and some companies augment it with proprietary information and the well-regarded European forecast models. Many offer forecasts by ZIP code or geographic areas far from weather stations by using software that focuses broader regional forecasts to where the phone is located.

While there are good apps, especially those displaying National Weather Service warnings and information, many “oversimplify uncertainty and present highly precise-looking numbers that imply more confidence than actually exists,” said Northern Illinois University meteorology professor Victor Gensini. This type of storm is where apps are weakest because they don’t get nuances, he said.

Weather apps are good for forecasting nice warm summer days, but not days like much of the country is facing now, said Steven DiMartino of NY NJ PA Weather.

Be wary of social media

Forecasters also warn against another quick fix for weather information: social media, where hype, misinformation and short takes can spread quickly.

While social media can help amplify official sources like the weather service, “it’s also where misinformation spreads fastest,” Gensini wrote in an email.

“Weather is complex, and social media tends to reward confidence and drama, not nuance,” Gensini said. “That mismatch is a real challenge during major events like this.”

Kim Klockow McClain, an extreme weather social scientist at the University Corporation for Atmospheric Research, said people are “getting misled by hyped forecasts.”

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Borenstein reported from Washington, Webber from Fenton, Michigan.

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