AILSA CHANG, HOST:
If you live in a place where it snows, you probably know the drill. Forecasters will predict a massive snowstorm. Grocery stores are emptied. And then there's just a light dusting. It happens every winter, in part because we don't really understand how these storms work. But a new study from NASA hopes to change that. The IMPACTS mission wants to improve our understanding of snowstorms and, in particular, of what are known as snow bands. Here to talk about the program is Lynn McMurdie, principal investigator on IMPACTS.
LYNN MCMURDIE: Thank you. Happy to be here.
CHANG: So what exactly are snow bands? I have never heard this phrase before.
MCMURDIE: OK. Well, within a snowstorm, which you have heard about, the clouds associated with them span a large area. They can be, you know, as far as Florida up to Maine. But within those clouds, you have narrow regions where the snowfall is far more intense, and they often are organized in kind of a narrow band. And we could just call those snow bands.
CHANG: OK. And how do you examine closely these snow bands? I mean, I understand that you're using two airplanes.
MCMURDIE: Yeah. So this project - the way we were going to investigate these storms is fly two different aircraft. The first aircraft will fly high above the snowstorms. It will be equipped with remote sensing instrumentation.
MCMURDIE: And then the second aircraft will be flying inside the storm itself.
MCMURDIE: And inside, it's making a different kind of measurement, so it will be measuring the environment in which the snowfall occurs. And we have these instruments called probes, which actually take pictures of the snow crystals themselves.
MCMURDIE: In the different altitudes, you see different-shaped crystals. It's absolutely fascinating.
CHANG: OK. So how do these two planes help us understand how to predict snowstorms?
MCMURDIE: So what we're going to be doing is investigating the processes that create these snow bands, so trying to understand the science behind it. And then also, because the one that's flying high has remote sensing instrumentation, it will help us be able to sense it from space better. The information from the remote sensing point of view up above and inside the clouds will also help us improve our forecast models, which predict snowfall but need better information about how that forms.
CHANG: So how accurate do you think this study will help us get our predictions when it comes to snowstorms?
MCMURDIE: Well, hopefully much more accurate than we have now. Right now, we do OK with the track of the large-scale storm, certainly by 24 hours ahead of the storm. But we don't have a good handle on accurate predictions of the distribution of snowfall - where it's going to snow heavily, where it's going to snow not at all. And that's to do with these very small-scale, narrow bands of intense snowfall. So ultimately, we'll have better forecasts of whether Boston or New York will get the most snow.
CHANG: Lynn McMurdie is the principal investigator on NASA's IMPACTS mission.
Thank you very much for joining us today.
MCMURDIE: I'm happy to be here. Transcript provided by NPR, Copyright NPR.