What is a 'gustnado' and how is it different from a tornado?

Gustnadoes can look similar to tornadoes, but they are not the same. AccuWeather's Geoff Cornish explains the differences.

Transcript

00:01We're going to jump into a close-in view here.

00:04We're going to zoom out a little bit so you get some perspective.

00:06This is southeast Massachusetts.

00:08Here we have Rhode Island, eastern Connecticut, Cape Cod's up here,

00:11Boston just off to the north.

00:13There was some wind damage tied to what is believed to have been a gust NATO.

00:19We're going to talk about what a gust NATO is in southeast Massachusetts.

00:22You can see a 1047 last night tree down, and at the same exact time,

00:271047 trees and wires down.

00:28The Weather Service in Boston investigated the damage,

00:31and they believe this was caused by a gust NATO,

00:34which is kind of associated with a tornado, but it really isn't the same exact thing.

00:39Let's take a look at radar here for this event.

00:42And, again, this is a radar loop that takes us through 7 p.m. to midnight last night.

00:49And there was a time right before 11 p.m. when this band of thunderstorms rolled through

00:54a line of thunderstorms east of the area of Rhode Island and into far southern Massachusetts.

01:00Right there, when this front, there was a cold front tied to this,

01:04produced something that kind of resembled a tornado, but it technically wasn't your traditional tornado.

01:09It was a gust NATO.

01:10So tornadoes are formed through an environment where there's a rotating updraft,

01:15and they generally form from the top down, where the circulation originates in the cloud,

01:21the base of the clouds, and it extends down to the surface.

01:24With a gust NATO, it's kind of the opposite.

01:26You typically have forcing near the surface, near the ground,

01:29that can lead to some convergence and some rotation and circulation.

01:33So it's surface-based, and it doesn't always extend all the way up to the clouds.

01:36So in this case, we talk about gust fronts, that really chilly push of cooler air,

01:41rain-cooled air, when there's a thunderstorm approaching.

01:44In this case, it may have been a true cold front that actually led to this zone of convergence

01:49and ultimately a little bit of a spin-up.