00:00Here on the forecast feed, we have plenty to talk about this time of the year, even on days without
00:05severe weather.
00:06There's always something on the horizon here in mid-April.
00:09We're stepping into the peak of tornado season the next six weeks or so.
00:13So let's take a quick look back at a preliminary look at our Friday and Friday night tornado reports.
00:20I say preliminary because the storm surveys are still coming in.
00:23More dots will be added.
00:25Some of these are from preliminary reports from the day of.
00:28Somebody saw a tornado or radar indications confirmed a tornado on their own based on various signals like debris in
00:37the sky.
00:38But in other cases, it's not always obvious until the storm survey crews get out there.
00:42And by the way, the National Weather Service in central Illinois, they've confirmed 18 tornadoes just from a chunk of
00:50Illinois here.
00:51So 18 confirmed in just one area.
00:54And Chicago office, they confirmed a handful more.
00:56We're going to end up with probably over 50 confirmed from this event.
01:01And the numbers continue to add up here.
01:03You can see from the northern part of, well, the upper Midwest all the way down to Oklahoma.
01:07But this time of the year, they ramp up in a big way here.
01:10And the tornado occurrence by day.
01:12Here you can see if we find approximately April 20th here around here.
01:18Again, by volume, the bulk of the tornadoes in any given year are from late April into early to mid
01:27-June.
01:27Now, moving forward to the present forecast, we're in okay shape here in the short term.
01:33We're not expecting tornadoes on this Monday in any widespread scale.
01:37But as we take a look at the storm system off the west coast here, we're dealing with a setup
01:44that's going to bring us, again, numerous tornadoes around the middle part of the week.
01:52At least a few may occur, even though it's primarily a straight-line wind setup.
01:56And the satellite loop shows that as we move through the early morning hours here, we're dealing with a Pacific
02:04storm, spiraling zone of low pressure out there.
02:08And that will become the concern for more storms in the plains.
02:14Mainly wind, some hail, but also some tornadoes.
02:17There was a bit of a data issue there, so we lost a little bit of the data.
02:20But you can see it spinning at the beginning and end of the loop.
02:23So let's take a look at what goes on with this.
02:24Here's our Pacific storm Monday and Tuesday.
02:27It's still primarily offshore.
02:29But jet stream energy associated with this will be moving into the plains Wednesday night and into the day Thursday.
02:35It's going to take some time for it to really roll fully in.
02:38So, again, these big dips in the jet stream and these bright colors here, which at face value are vorticity,
02:45spin in the atmosphere.
02:47Tuesday night, it's still off to the west, Nevada, California.
02:50It's Wednesday night.
02:52And, again, night is the operative part of this.
02:54It may not be Wednesday afternoon when this trough, and I'm connecting the dots here in the trough here, begins
03:01to cross the southern Rockies.
03:03And once we begin to see this big trough reach the high plains, the western part of the plains, we're
03:08going to begin to see a lot of extra lift in the atmosphere Wednesday night.
03:12It's going to be a late bloomer.
03:13But you can see by 2 a.m., here's a pretty aggressive trough digging into the western plains out of
03:19the northern Rockies.
03:20So, along with that, then into Thursday, you can see a little companion here to the south, the secondary disturbance.
03:27We have our northern disturbance.
03:29We're going to have a pretty significant trough crossing the plains on Thursday.
03:35Areas east of that will be the scene of some strong and severe thunderstorms.
03:40And we'll probably see at least a few tornadoes, but also a lot of damaging wind and some hail.
03:44Then into Friday, you can see this bit of energy here.
03:48Spoke of energy lifts through parts of the Mississippi Valley.
03:51So, what does all this do for us?
03:54As we take a look at the storms here, it's Wednesday night into Thursday, Wednesday night into Thursday, when these
04:02storms really break out.
04:03And Thursday into Thursday night, numerous storms in the plains.
04:06When it comes to this product here, this is CAPE, convective available potential energy.
04:11This is lift in the atmosphere, warm and humid near the ground, cold upstairs.
04:17And as a lobe of colder air, a loft moves over warm, humid air near the ground, we begin to
04:22see this signature here in the yellow zone.
04:25We're looking at probably 1,500 to around 2,000 plus joules per kilogram of CAPE.
04:31So, that is the impetus for those updrafts to get going, thunderstorm development.
04:35Now, in the Europeans, it's a little farther west.
04:38In the GFS, it's a little farther east, whether it's western Kansas or central Kansas.
04:42You get the general idea.
04:43It's going to be late, though, Wednesday night, when this is kind of maximized.
04:47So, I'm going to go back to our forecast graphic here.
04:50And here you can see in our forecast, we're going with a sun risk.
04:56And we're not saying Wednesday afternoon tonight.
04:59We're really playing up Wednesday night.
05:01This may be after 7 or 8 p.m., and it probably will be primarily after that time.
05:07In through the overnight hours, we're highlighting downpours, hail, and damaging wind.
05:13Damaging wind may be the biggest concern, followed by hail and flash flooding from any localized downpours.
05:20So, it's northwest Kansas, central western Nebraska, up into the Dakotas.
05:23We're highlighting a sun risk.
05:24That's Wednesday.
05:25As that trough enters more of the plains, we go back to this product, convective available potential energy.
05:32The lift in the atmosphere.
05:35Thursday, north Texas up into parts of Iowa.
05:37So, here's the European, similar signature there.
05:41North Texas up into parts of Iowa.
05:43And if we go back to this product showing the rainfall and, again, various different, you can see barometric pressure
05:51with the black lines.
05:52And the thickness lines in red or blue are the character of the air mass, whether it's warm or cold.
05:58So, storms move farther east.
06:00And the European depicts that pretty aggressively there through St. Joseph, Missouri, up into St. Louis, and beyond.
06:06So, going back to our graphics to end this out, to close this out.
06:10Wednesday night, Thursday, the next episode of this, during the afternoon and into the night.
06:15Thursday, north Texas, all the way up to Minneapolis, and maybe even north of there.
06:20We're going to have the risk of some damaging wind, hail, and then on Thursday, you notice we do begin
06:25to list isolated tornadoes as a potential hazard.
06:29Into Friday, we're playing this as a green map at this point, illustrating downpours, showers, thunderstorms, some severe weather.
06:37But as the main driver in this storm system lifts up into Canada, the severe weather potential may come down
06:43a notch.
06:43We need to keep an eye out for Friday, though, because it doesn't take much this time of the year.
06:47And that is your forecast fee.
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