00:00As we approach the end of the week here on the forecast feed, we're looking ahead to the weekend.
00:04Severe storms will return to the plains and the Midwest this weekend.
00:08We have some big concerns out there, and that will become probably the big story of the weekend.
00:13One big headline here, severe storms return to the plains Saturday afternoon, evening into the night,
00:19and then more of the Midwest.
00:21The Ohio Valley enters the conversation on Sunday afternoon and evening, so we have big concerns there as well.
00:28Let's take a look at, before we get into the forecast and the modeling and what's driving our forecast,
00:34here is your historical average number of tornadoes by tornado reports,
00:39which is close to kind of a one-to-one actual number of tornadoes.
00:43And we average the most in Texas, big chunk of real estate, followed by Kansas, which has that tornadic reputation,
00:51and Oklahoma. This goes back through the past 25 years or so.
00:55So, and you can see Illinois is on the list, but that is actually, you know, a little bit of
01:00quick counting here.
01:01That is basically tied for fifth, for fifth in the most frequent tornadoes with Alabama in the fifth spot there.
01:11Well, take a look at how we've done this year.
01:14This is just data through May, through May.
01:17Are we above or below the norm January through May?
01:21Well, the data in the West is pretty slim.
01:23There's not too much frequent activity in the West, in the, you know, just the whole sheer numbers.
01:29But we're way quieter in Texas and in Georgia and in Florida so far and Tennessee,
01:35but way, way, way above average in the state of Illinois,
01:39and also Wisconsin and Iowa and Mississippi for that matter, too.
01:43And Michigan's seen a tough start as well.
01:46Now, that's through the end of May.
01:47If we go a little more recently, looking at the number of tornado reports by state through June 17th,
01:54look at this, 164 reports in Illinois.
01:58This doesn't fully encapsulate everything that happened on Thursday night.
02:03Some of those numbers are still kind of coming in,
02:04and retroactively in some cases, tornado local storm reports are being added to the tally.
02:10So, it's been a really tough time.
02:13And honestly, most of the action has been north of Interstate 70.
02:18So, it's been the northern 60% of Illinois where the overwhelming majority of this has occurred.
02:24Let's look at what's to come here.
02:26So, here we are in our, looking at some upper-level maps here for the weekend.
02:31And as we get into Saturday, we become more concerned about severe weather returning.
02:36It's a weak disturbance initially, but it doesn't take much to get trouble coming into the plains.
02:42And I'm looking at this dip in the jet stream, and there's a vorticity here in parts of Nebraska.
02:46But this dip in the jet stream is going to be coming down through parts of the high plains into
02:52the central plains.
02:53That digs pretty aggressively, eventually, late Saturday.
02:56Here's the NAM.
02:58You can see Saturday night, it ramps up.
03:01I think that's going to make this more of a late event, but still an impactful one.
03:05If you're east of those bright colors, measures of spin or vorticity in the atmosphere,
03:10you're going to be in a posture where there's extra lift in the atmosphere.
03:12And then here's the European.
03:13You can see the general agreement there.
03:15But watch what happens with this on Sunday.
03:18On Sunday, that digs a bit more Saturday night into Sunday morning.
03:23And it becomes a bit more amplified, a little bit of a sharper, negatively-tilted trough.
03:28And that sharpening, negatively-tilted trough there from Iowa into northeast Arkansas
03:34is going to scare up a new round of severe weather into Sunday into the Midwest and the Ohio Valley.
03:40And that lifts pretty quickly into the Midwest and the Ohio Valley through Sunday afternoon.
03:45That's the GFS.
03:46So here's the NAM.
03:48It digs in, and it becomes a bit more amplified on Sunday.
03:53And as that moves forward into the Great Lakes area, we will be facing some severe weather on Sunday in
04:00the Ohio Valley.
04:01Here's the final third opinion, European model.
04:04It may be a little less dramatic compared to the GFS.
04:08There's the European, 2 p.m. Sunday, with the strongest vorticity up near northeast Missouri.
04:14The GFS, some stronger signals all the way down near Paragould in Jonesboro, Arkansas.
04:19But the message here is that in both cases, we're going to be facing some extra lift in the atmosphere.
04:24So here we look at CAPE, Convective Available Potential Energy.
04:28This is the fuel for rising motion in the atmosphere.
04:32And Saturday evening, you can see some moderately strong CAPE values here in Nebraska down into Kansas.
04:37And then all the way down into Texas.
04:40Here's the NAM.
04:42And then here's the European.
04:43Now, you'll notice there's a lot of CAPE all the way down across the south.
04:46This is just simply warm, humid air.
04:47But in the absence of a sharp focusing mechanism, being that disturbance that we looked at in the jet stream,
04:54those would just be garden variety thunderstorms farther south.
04:57But when you couple CAPE with some strong jet stream energy, you get into trouble.
05:02And you can see that into Sunday, the CAPE values, they're not tremendously high in the Ohio Valley,
05:07but they're present.
05:08Here's the NAM.
05:09A little higher.
05:10A little higher there into parts of central Kentucky on Sunday evening.
05:14So the NAM argues more firmly.
05:172,500 to 3,000 joules per kilogram.
05:19That's more significant lift.
05:20And the European also a bit more bullish in the Midwest.
05:25I think the GFS was a little stronger with the shortwave plunging south.
05:29So stronger dynamics.
05:30But perhaps not a strong instability in the GFS.
05:34So they almost are related.
05:36If the shortwave digs farther south, it's not as warm.
05:38And therefore, the CAPE values are maybe a little more suppressed.
05:41But you have stronger wind fields aloft that would drive stronger storms.
05:45So again, different arguments for what might be the dominant driver.
05:50Is it strong CAPE with weaker winds aloft, like the European?
05:54Or is it weaker CAPE, not quite as warm near the ground of the Ohio Valley,
05:58but stronger winds aloft, like the GFS?
06:01And here's the dew point.
06:03You can see plenty of juice out there.
06:05When you get into that sea green color, this is Sunday evening.
06:08We're talking about really humid air getting up into the likes of 70 to 75 degree dew points.
06:15So that's a big factor.
06:17By the way, we will see some flooding out here as well, looking at Sunday through Sunday night.
06:20So Kentucky, potential for three or four inches of rain in the GFS.
06:25And here's the European, potential for two or three inches.
06:29Also, keep an eye out for Chicago, that area, earlier in the weekend.
06:33Sunday, Sunday night, we could see some flash flooding there as well.
06:36So we can end with just an early look.
06:39Saturday evening, as our in-house model shows, gusty wind and hail into the central plains.
06:45Set your forecast feed.
