What's causing the severe storm threat in the Plains?

There's a threat for hail and even tornadoes in the Plains on the evening of Oct. 21, but why? AccuWeather's Tony Laubach explains.

Transcript

00:00We have the threat for severe weather in the central plains and well there's somebody who's

00:05always trying to sniff out severe weather even if it's not a major severe weather event and that is

00:09Tony Laubach who is joining us now live in Norton County, Kansas. And Tony you're on the prowl.

00:15So what have you observed so far? What do you expect for the next few hours?

00:21Well Jeff it's certainly going to be an interesting evening I think out this way. We've been talking

00:25about the potential for severe weather out in this area really for the last day or so.

00:29This has been a storm system that we've been tracking over the weekend. You heard about the

00:33floods down in New Mexico, the snow in the Rockies. This all responsible from this particular area of

00:38low pressure that we're tracking. I'm pretty much sitting right under that surface low. We're over

00:43my shoulder. You see one of the two storms I'm tracking here right behind me is US Highway 36.

00:48I'm just to the west of Norton, Kansas. What you're looking at right now this is what we call

00:53in weather slang term a whale's mouth. We're on the back side of this storm system right now. This

00:59storm cell that we're watching and you kind of see the rivets in the clouds. That's indicative

01:03of the cold air on the back side of this storm. It gives that blocky appearance and you kind of

01:08see how it just kind of curves in. Think of it like you were literally looking inside a whale's

01:12mouth. That is kind of where that term comes from. This area is kind of stable and you see the core

01:18behind me here. A little bit of small hail in that ran into some peas maybe some marble-sized

01:22hail. Nothing severe as of yet but that is something we are expecting to see ramp up over

01:26the next couple hours. You guys touched on this we'll show you that again that severe thunderstorm

01:30watch. That is currently in effect four areas across western Kansas into south central Nebraska.

01:36This watch goes until 11 o'clock central daylight time. So we are expecting the potential for some

01:42large hail maybe up to ping pong ball size and the potential for a couple of tornadoes. That is

01:47why I am out here today is to track that what we're calling more of a cold core type setup. So

01:53at the surface typically when you talk about typical severe weather events you need a lot

01:57of instability at the surface a lot of warm air. Honestly where I'm standing right now on the back

02:02side of that storm I just showed you it's a little on the chilly side but what makes this storm

02:07this type of setup different we call it a cold core because there's a lot of cold air up aloft

02:13and as you cool the air up higher that air rises quicker. So a lot of times what that does is offset

02:19some of the lack of heating at the surface that instability is generated in a different way. So

02:24instead of warm air at the surface rising you've got a lot of cold air up top that is what we are

02:29expecting. Now when we talk about that low you've seen some of the satellite loops of that is a very

02:33very tight low. So there's a lot of vorticity kind of think of it as a weak inland hurricane. We saw

02:38that with Milton all those tornadoes not expecting anything that significant tonight up in this way

02:43but certainly not out of the question that we do see a couple of tornadoes in there along with the

02:47potential for maybe a lot of small hail in some of these storms guys. All right Tony I know that

02:53in just a few minutes here Damien's going to dig back into the severe setup there and look at the

02:58radar and other issues. So thanks for being on top of that as always there Tony Law back

03:03in west central and central Kansas.