< Scientists are flying into snowstorms to explore winter weather mysteries -

AILSA CHANG, HOST:

Conventional wisdom dictates that while traveling in the wintertime, you should avoid bad weather and icy conditions, right? Well, one research team has been seeking out winter storms for the past few years, flying through storms in a plane loaded with special instruments. The goal is to unravel some of the mysteries of snowfall, like why a storm will sometimes dump a lot of snow in one place but hardly any in another. NPR's Nell Greenfieldboyce recently joined the team on one of its expeditions.

NELL GREENFIELDBOYCE, BYLINE: At NASA's Wallops Flight Facility in Virginia, a group of scientists is sitting in a conference room with some pilots studying a weather map that's projected onto the wall and trying to plot a course.

UNIDENTIFIED PERSON #1: Like, imagine going down...

UNIDENTIFIED PERSON #2: North Carolina...

UNIDENTIFIED PERSON #1: ...Going down West Virginia, like, right in the middle of it.

UNIDENTIFIED PERSON #2: Northwest North Carolina, Kentucky border, southwest Virginia.

GREENFIELDBOYCE: The radar map of this storm shows some streaks of red and yellow. These colorful streaks are called snow bands. They're a really common feature of winter storms east of the Rocky Mountains, but they're not well understood. Lynn McMurdie is a meteorologist with the University of Washington in Seattle. She says it's not clear what's in the clouds that creates these bright bands.

LYNN MCMURDIE: The assumption is that must mean there's a lot of snow there. But it's not so simple. And that's actually what we're trying to understand.

GREENFIELDBOYCE: They're trying to understand snow bands by flying through them.

MCMURDIE: That is it. Oh, it's fine. I didn't bring my coat.

GREENFIELDBOYCE: Come on. You're from Seattle.

MCMURDIE: I know.

GREENFIELDBOYCE: She takes me out to the plane. It's rainy and windy and cold. It's a four-propeller plane. Hanging from its wings are some science instruments. They look sort of like skinny jet engines. The inside of the plane is pretty stripped down. There's seats for about a dozen people and racks full of computers and equipment.

UNIDENTIFIED PERSON #3: If you'd like to do the takeoff in the cockpit, we could set you up.

GREENFIELDBOYCE: That'd be fun.

Once we're in the air, Claire Robinson gets to work at the back of the plane. She's holding something that looks like a brown paper towel tube. It's packed with sensors. She puts it into another tube that's a kind of launcher.

(SOUNDBITE OF TUBE EXPELLING AIR)

GREENFIELDBOYCE: The probe that's been ejected out of the plane will parachute down through the storm, sending back all kinds of readings.

CLAIRE ROBINSON: Temperature, pressure, relative humidity, wind speed, wind direction, and there's a couple other measurements as well.

GREENFIELDBOYCE: Outside the window, it's completely white.

CHRISTIAN NAIRY: Right now we're heading right towards a snow band. It actually looks pretty impressive on the radar.

GREENFIELDBOYCE: That's Christian Nairy, a Ph.D. student with the University of North Dakota. He and the others stare at their laptops, watching a radar map that has a big streak of yellow.

So we're basically flying right through this band. Is that the deal?

NAIRY: Yep.

GREENFIELDBOYCE: But where's the plane now? Oh, we're right in it. We're in it. Excellent.

I'm relieved it's not at all bumpy. Nairy shows me a strange kind of slideshow on his computer. Images are coming in from a device out on the wing. It's a cloud particle imager. It has lasers and a camera that take pictures of the tiny droplets and ice crystals in the cloud. Some look like bits of crud, but others are perfect little snowflakes, like the ones you'd cut out of folded paper.

NAIRY: They're amazing to look at, I mean, especially when they pop up right in front of you on the screen. It's just remarkable.

GREENFIELDBOYCE: Other ice crystals look like pencil-shaped rods or TIE fighters, those imperial spaceships from "Star Wars." Nairy says, sometimes he sees little spheres of extremely cold liquid water.

NAIRY: People don't really realize this, but water can stay in a liquid form up to around, like, minus 34 degrees Celsius.

GREENFIELDBOYCE: That's minus 29 degrees Fahrenheit.

NAIRY: We call it super-cooled liquid water. And that's a particular interest in this field campaign is studying when we see the super-cooled water and where we see it.

GREENFIELDBOYCE: While our plane is flying along the East Coast, another research plane is on the same flight path but higher - over 60,000 feet - studying the storm from above. It goes so high, the pilot basically wears a spacesuit. Tomorrow is the last day of this research campaign, which has gathered tons of data giving scientists an unprecedented look at these storms. Lynn McMurdie says over the last three winters, they've flown through all kinds of weather.

MCMURDIE: The whole range from, you know, the super snowstorm that blocks all the traffic for, you know, the whole up and down the East Coast to, oh, this is just a normal rainstorm, why do we care? But we need to know that whole range to understand all the structures that are in storms - what's common, what's not common.

GREENFIELDBOYCE: And what they learn should eventually get built into weather forecasts so that people can have a better sense of what a winter storm might do. Nell Greenfieldboyce, NPR News.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.

ncG1vNJzZmivp6x7r7zRZ6arn1%2Bpv6K60pypoqikqHxyfZRyaHJvZ26E