Scientists fly into winter storms to better understand crazy weather: NPR

Up in some clouds full of ice, sitting inside an airplane full of scientific instruments, Christian Nairy looked at the images flashing on his computer screen. This high-altitude slideshow shows real-time images of cloud particles sampled by a device on the wing of an airplane — and some of the ice crystals look like perfect little snowflakes.

“They look amazing. Especially when they pop up in front of you on the screen, it’s amazing,” said Nairy, a Ph.D. student at the University of North Dakota.

He was just one of the scientists aboard a research plane earlier this month as it took off from NASA’s Wallops Flight Facility in Virginia to travel through a winter storm — part of a research campaign called IMPACTS, or the Investigation of Microphysics and Precipitation for Atlantic. Coastal Hurricanes Mission.

It gathers the kind of information that in the future will help weather forecasters better predict when a winter storm will cause adverse conditions that require school closings, road closures, and cancellations. on trips.

Until this mission, which began in 2020 and ended on February 28, there had not been a major wind study of winter storms in the eastern half of the United States in about 30 years, said Lynn McMurdie, a scientist in the atmosphere of the University of Washington. in Seattle.

“We’ve had some really good storms,” ​​McMurdie said. “Whatever Mother Nature throws at us, we’ll fly it. We’ll go out and try to get the whole range, from a super snowstorm blocking all traffic up and down the East Coast to ‘oh, it’s just normal it’s a storm, why do you care?’ “

The biggest storm they weathered was a blizzard in January of 2022 that dropped about 2 feet of snow on parts of the Atlantic coast. “It was a fool,” Nairy recalled. “We hit a crazy mess on that flight.”

This year, however, eastern snow storms have been a little harder to come by. “But you know, this is what we have and we’re going to make the best of it. And I think we have very good data,” McMurdie said. “So there are a lot of studies from all these different storms, even if they’re not the most beautiful snow storms.”

One of the goals of this project is to better understand the bright “snow bands” that often appear on radar maps of winter storms east of the Rocky Mountains.

Scientists have known about these distinctive radar patterns for several decades, but it’s still unclear how the bands form or what’s actually happening inside the clouds, McMurdie explained. .

That’s why scientists with IMPACTS plan their flight paths to pass through storm bands.

Instruments mounted under the wings of P-3 aircraft can directly sample cloud particles. Researchers inside the aircraft can also send dropsondes, small probes that parachute into the storm and send back data on things like temperature, pressure, relative humidity and wind speed.

Meanwhile, another research plane, ER-2, always follows the same flight path, but at a higher altitude of more than 60,000 feet. It has instruments that also take data about the storm, from above.

“I think what makes it so special is that we’re coordinating these two planes,” McMurdie said, “and looking for this many storms.”

One thing the researchers hope to understand is the role of supercooled liquid water in storm clouds. Under certain conditions, water can remain in a liquid form down to minus 34 degrees Celsius – about minus 29 degrees Fahrenheit.

Small droplets of this supercooled water sometimes stick to snow crystals. “Imagine a beautiful snowflake, and then it has all these little dots. It looks like it has a case of measles, or something,” McMurdie said.

What they’ve seen so far, he said, suggests that this type of water is an important aspect of snow bands, perhaps bringing more water content, more ice particles, and eventually more snowfall to the ground.

The amount of data gathered from above, below and within this diverse range of winter storms should give meteorologists much to think about in the coming years, and hopefully feed into models of forecasting, so future weather reports can give a better sense of what a storm might do.

“I’m always in awe every time we go up and fly,” McMurdie said. “Every time, there’s something like, ‘Really? What’s going on there?’ “