00:00In our forecast feed, I want to take a look at two storylines.
00:03One, daily severe thunderstorms through the plains.
00:06And number two, near record heat rolling into the mid-Atlantic, the eastern Ohio Valley,
00:11and ultimately the East Coast Tuesday, Wednesday, and Thursday of next week.
00:15So big picture here.
00:17Here we have the screaming message here with those two stories represented in one graphic.
00:22We are looking at rounds of storms on a daily basis through the plains
00:26and unseasonably warm weather building in, especially Monday and especially Tuesday and Wednesday into Thursday.
00:32There may not be many records on Monday, but there will be some this weekend in the southeast
00:37and then especially Tuesday, Wednesday, Thursday in the mid-Atlantic and the eastern Ohio Valley.
00:42First things first, though, in the short term, I do want to acknowledge some severe storms
00:46here from the Texas Panhandle region into northern Oklahoma, southern Kansas, southwest Missouri, northwest Arkansas.
00:52It's a somewhat modest risk, but we are concerned that there will be some cases into Friday night here
00:58with damaging winds, hail, flash flooding, areas like Amarillo, Texas, to Joplin, Missouri,
01:04and Springfield, Missouri, down to Miami, Oklahoma, all at risk.
01:08Just keeping us going here with the weekend, I'm going to jump into some computer models in a moment,
01:12but Saturday, Sunday, and Monday, each of these days somewhat similar in the intensity of the risk.
01:19Then there's a bit of a change for Tuesday that we become a bit more concerned about.
01:22So Saturday, some severe storms, mainly west of I-35.
01:26Sunday, we're going to take a step east with this.
01:29You'll notice that instead of it being mainly west of I-35, it really changes and disturbance rolls all the
01:36way up
01:36into parts of the Midwest here.
01:38So we're going to be tracking a relatively weak disturbance that's going to be driving up into the upper Midwest,
01:43and that will carry the severe risk there, then up through the Great Lakes.
01:46And Monday, somewhat of a similar area here with that severe risk.
01:51Before we go ahead to Tuesday, I want to jump into some computer models just to give you a big
01:55picture look at what's going on.
01:57Let's go to Saturday here.
01:58And this is the 500 millibar map, so we're 20,000 feet up in the atmosphere.
02:03These bright colors here are indicating areas of vorticity or spin in the atmosphere.
02:08And what your eye may be drawn to, and rightfully so, is this big storm system over the California coast.
02:14This is bringing us two to three feet of snow into some parts of the Sierra, which is great news
02:18after that warm, dry March.
02:21And we're going to be welcoming some snow back here in the early to mid part of spring there, which
02:26is good news.
02:26We also have an area of troughiness here across the New England states.
02:32There's a little spoke of energy here.
02:34I'm connecting the dots here with, there's a trough there, and then a weak ridge just to the east of
02:41that area,
02:41and a strong ridge over the southeastern U.S.
02:43But this trough, the dash lines, there's a little kink in the lines, in the thickness and height lines.
02:51That's where there's a little bit of vorticity.
02:53It doesn't take much in April to produce severe weather.
02:55So that little zone here where we have the vorticity, extra spin in the atmosphere into a warm, humid environment
03:04with colder air aloft,
03:06it's enough to produce some strong to severe thunderstorms.
03:09And as that rotates and pulls through the plains, lifting up into the upper Midwest on Sunday, highlighting that trough
03:16axis,
03:16that's why we carry the severe risk all the way up into parts of Wisconsin and southern Minnesota on Sunday.
03:22There will still be storms down in the southern plains here east of that trough axis, so the risk is
03:27still present.
03:28But we're going with some risk for Sunday afternoon and evening.
03:31And into Monday, here comes another disturbance.
03:34I didn't want to get too far ahead, but another disturbance here.
03:37And at this point on Monday, the primary trough axis, that California storm, is still back near Las Vegas.
03:45It has yet to really reach the plains.
03:48So another variable that we can look at here is, well, here's the actual precipitation forecast.
03:54Saturday, some storminess here in the southern plains up into the Midwest.
03:58Sunday, more of a push east through Wisconsin.
04:01Still some storms in eastern Oklahoma.
04:03And then into Monday, a new episode breaks out.
04:06It's pretty ragged.
04:07It does not look terribly widespread on Monday.
04:09Isolated strong storms in Kansas.
04:11That's the GFS.
04:12Let's go to the European.
04:13Similar message here.
04:14Kind of ragged and not very widespread, but spotty, strong storms possible on Monday.
04:20We look at CAPE.
04:21This is convective, available, potential energy.
04:24We're looking at that contrast of warm, humid air near the ground, colder air upstairs.
04:28Some on Saturday, not very impressive amounts.
04:31Here's the European, a little bit more impressive.
04:33Sunday, a bit more robust there into the plains and up into parts of the Midwest.
04:37Enough to get those storms going.
04:38Monday, similar story.
04:40There's some CAPE.
04:41There will be some updrafts and some storms going, but not a whole lot of wind shear.
04:45Things begin to change, though, as we get into Tuesday.
04:49Because look at what happens.
04:51That big western storm, it ejects into the plains.
04:54But look at this.
04:55The GFS, 8 p.m. Tuesday.
04:58The GFS has a strong vorticity here in western Iowa.
05:03The main trough axis over western Kansas.
05:05The European is slower.
05:07Same time frame.
05:08There's the GFS.
05:09Here's the European.
05:10European is about, what, a state farther west instead of Iowa, South Dakota with the first
05:15little impulse of strong vorticity.
05:17And the primary trough axis is still over the four corners region.
05:20So there's a bit of a disparity Tuesday and Wednesday, precisely how quickly the stronger
05:26storm system comes out.
05:28But regardless, there's more forcing.
05:31And when we look at CAPE here for Tuesday evening, European, a little slower, a little farther
05:37west of I-35.
05:38GFS, a little farther east.
05:40And then when we look at wind shear, now that you're going to see bright colors way up in
05:44Canada, but there's no instability there.
05:45So we need to find where the wind shear is going to be co-located with strong lift in
05:51the atmosphere, some of these areas.
05:53The shear increases compared to previous days where it's weak shear, Saturday, Sunday, Monday.
05:58It increases a bit on Tuesday and into Wednesday with that stronger storm system emerging.
06:03So because of that, going back away from the models to our forecast, we did introduce a
06:08moderate risk.
06:09That's two out of four on the AccuWeather four-tiered severe threat index for Tuesday from
06:13Oklahoma up into southeast Iowa.
06:15Tuesday is the day we're most concerned about.
06:17Wednesday, we got some questions because of the timing discrepancies between the European
06:21and the GFS.
06:22Regardless, the risk will be pushing east.
06:24And I wanted to end with just a few looks at some record highs.
06:27And I'll get myself out of the way here.
06:28Saturday, Tennessee, Mississippi, Alabama, Georgia, near record highs.
06:34Sunday, parts of Kentucky and Tennessee, near record highs.
06:38May not be many records on Monday, but on Tuesday, Virginia, West Virginia, Tennessee, Indiana, Dayton,
06:43Ohio, near record highs.
06:45That increases into the I-95 for Wednesday.
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