Alaska could see more dangerous thunderstorms as Arctic sea ice melts and evaporation increases

Thunderstorm frequency could triple in Alaska by the end of the century because of ongoing climate change, according to new research.

Big thunderstorms, the kind that produce lots of rain, are not common in Alaska now. Some 30 occur in the state every year, said Andreas Prein, a research scientist at the National Center for Atmospheric Research who worked on the two papers, published in Climate Dynamics.

But the papers say melting sea ice could lead to more frequent thunderstorms across the state, with potentially devastating effects such as heavier rainfall and flash flooding, landslides and more wildfires sparked by lightning.

“The consequences could be manifold,” Prein said.

The cause of the more frequent thunderstorms is linked to a continued loss of sea ice in the Arctic Ocean, according to the research.

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Sea ice keeps the water below it from evaporating, essentially sealing it in. But as that ice continues to recede, larger tracts of ocean will be uncovered, which would lead to more moisture in the atmosphere and over Alaska.

That moisture feeds thunderstorms, Prein said.

The greatest increase in frequency of storms is likely to occur in the central part of the state, Prein said.

But also alarming is the potential in certain places, like parts of the North Slope that don’t get thunderstorms, to begin seeing them as well, according to Maria Molina, a research scientist at the National Center for Atmospheric Research who worked on the second study.

It’s important to not get hung up on the exact number of storms that could occur, said Andrew Newman, a project scientist with the National Center for Atmospheric Research, who worked on the first of the two papers. Rather, the research shows that such extreme events are likely to happen more frequently.

“There might be a year where you see a thunderstorm for the first time, and then you might get one the next year, and then all of a sudden, you’re realizing that that’s kind of the new normal,” Newman said.

One consequence of increased thunderstorms that should be studied more is the increased risk of wildfires due to lightning strikes, Newman said.

“Typically, the lightning that starts wildfires is associated with dry thunderstorms, so thunderstorms that don’t have a lot of rain,” Newman said. “Whether or not those conditions exist, or will exist in the future in Alaska — we didn’t necessarily look at that specifically.”

The predictions have the potential to impact several parts of life in Alaska, from small aviation to housing design, according to Rick Thoman, a climate specialist at the Alaska Center for Climate Assessment and Policy, who did not work on the study.

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“So what does this mean to Alaskans? Certainly, one of the core messages in this set of papers is that thunderstorms have the potential to become much more intense than thunderstorms are now, with much more rain in short periods of time. And those frequencies of those extreme rain events would increase quite dramatically,” Thoman said.

Whether Alaska is already seeing more frequent thunderstorms is hard to say, Thoman said. While there’s anecdotal evidence of more storms, there isn’t consistent data.

Newman, with the National Center for Atmospheric Research, said the studies point to the importance of continuing to discuss human-caused climate change and its potentially costly consequences to Alaska in detail.

“To me, it’s a call to action,” Newman said. “And (to) say ‘We need to figure out what we’re going to do.’”