Forecast Discussion - May 17, 2026 - Severe Weather Outbreak Likely Today/Tomorrow

Added: 2026-05-17

[00:00:00]Hey everybody, Trey here. Welcome back to another video. We have reached the peak of our multi-day severe weather sequence as today and tomorrow could feature some widespread robust severe weather that could include some significant severe hazards. Starting with today, Sunday, May 17th, we have a large level three out of five enhanced risk in the orange shaded region here.

[00:00:21]That's going to stretch from northeast Colorado through parts of northern Kansas, much of Nebraska, southeast South Dakota, southwest Minnesota, and western Iowa with a large level two out of five slight risk in the yellow shaded region stretching from the Great Lakes all the way down into the southern plains. So folks in the enhanced risk the greatest threat for severe weather today places like Makook, Lincoln, Omaha, Sou Falls, Sous City, Columbus, Nebraska, Northfor, Nebraska, you are in that greatest severe weather threat for today. Folks in the level level two out of five slight risk places like Milwaukee, Lacrosse, Minneapolis, De Moine, Witchah, down toward Woodward and into the eastern Texas panhandle. You are in that greatest threat uh in that level two out of five threat for today.

[00:01:03]So a a lot of folks under the gun today.

[00:01:05]A widespread severe threat is expected with the potential for all severe hazards. The tornado risk is going to be maximized in the 10 and 15% regions.

[00:01:13]Those yellow and red areas there across northern Kansas into eastern Nebraska, southeast South Dakota, southwest Minnesota, and western Iowa. That's where the greatest threat of tornatic activity is expected to be. And we do have a 5% that does extend all the way down into the southern plains for a threat along the dry line today. These areas are coincident with a SIG one hatched area which could include some uh the threat for strong tornadoes up to about EF2 in intensity. Of course, doesn't mean we can't get stronger tornadoes today in that area. Doesn't mean that all the tornadoes in that area have to be EF2 or greater to verify that risk. Just means that we have a threat for some strong tornadoes on the table for today. We have a separate area that's been added for about the the central corridor of Michigan there, a 5% SIG one there um ahead of an MCV. We'll talk about that here in just a second.

[00:02:01]going to focus on the main risk area today from the central plains southward into the southern plains. But uh there is a risk up there in Michigan for a few tornadoes as well. Uh damaging wind is also going to be a threat today maximized in the yellow and especially the red shaded regions. Significant hurricane force or greater wind gusts are possible and large to very large hail that stretches across the enhanced risk area especially in the red shaded region. We could see some 2 to 4 inch in diameter or greater hailstones with some of the more robust supercells today, particularly in this corridor out here from northeast Nebraska into c northeast Colorado into central Nebraska with a threat down there along the dry line as well. So all hazards on the table for today. But then we go to tomorrow which has an even higher risk for severe weather. They at the SPC has added in a level four out of five moderate risk in the red shaded region here really encompassing much of eastern Kansas into far southeast Nebraska. Basically Witchah northeastward up to the I7 corridor sneaking into southeast Nebraska. That's where the greatest threat of significant severe weather is expected to be tomorrow with a large level two out of five slight and level three out of five enhanced risk. Uh the slight risk stretches from the Great Lakes all the way down into the southern plains with the enhanced risk from northern Oklahoma into Missouri and Iowa. So a another day of widespread severe weather is expected with the greatest threat maximized in the orange and especially the red shaded regions tomorrow. Significant severe weather uh severe hazards are possible. We have a 10 and 15% area for tornadoes in the yellow and red respectively with a SIG 2. So that includes a reasonable max intensity for any tornadoes in this solid hatched area of EF3. Again, doesn't mean we can't get stronger.

[00:03:42]Doesn't mean all have to be EF3 in that corridor. Just means that a reasonable max intensity for any tornado that does occur in that solid hash corridor is about EF3.

[00:03:51]Sig one surrounds that in the stippled region from uh Iowa southwestward into Oklahoma. uh could see some strong tornado potential there. But the greatest threat of tornatic activity is expected to be in the yellow and especially the red shaded regions there with strong tornado potential. Strong to intense tornado potential evident.

[00:04:09]Damaging winds, possibly hurricane force or greater maximizing the red stippled region there. Uh and then large to very large hail. We could see some giant hailstones tomorrow. 30 and 45% areas have been added across that northern Oklahoma to eastern Kansas and southeast Nebraska corridor in the red and pink shaded regions with a SIG 2. That means that we could see some giant hailstones in excess of 3 and a half inches in diameter across these the solid hatched corridors with some 2 in in diameter or greater hailstones possible in these stippled region there across the entirety of the risk area. So a very potent severe weather setup is on tap for tomorrow, Monday, May 18th. Then we go into Tuesday. Slight risk level two out of five from the Great Lakes down into the southern plains. Not going to talk too much about Tuesday in this video, but we could see a few instances of significant severe weather in the stippled region there. Likely more of a large hail and damaging wind risk on Tuesday, but a low-end tornado threat does exist. Want to focus today on our two very potent severe weather days coming up today and tomorrow. Let's go ahead and start off by what is going on as we speak. Let's take a look at the radar here. We had a lot of storms overnight across the central plains into the Midwest. A very, very widespread area of convection that continued into the overnight hours. Uh that has since dwindled today. We do see some of the remnants of that here across the central plains into the Midwest. You even see an MCV here, a messcale convective vortex.

[00:05:30]You see the swirl in the rain there across eastern Iowa moving into the Great Lakes states. That is what is going to prompt the severe threat across central Michigan today ahead of this MCV as it tracks off to the east northeast with time. So that's going to be uh that all hazards threat in Michigan that is due to that MCV. We are starting to see the dissipation of these rain and storms here this morning across that Nebraska corridor across that central plains corridor. Very clear radar to the south as well across the central and southern plains. So we are likely to see very robust recovery in the wake of that overnight convection. Skies are starting to clear very nicely across Nebraska and southward into the southern plains. not a ton of cloud cover at all to the south of the that lingering uh shower and storm activity across northern Nebraska.

[00:06:16]So, we are expecting instability to really become very strong today and that's going to set the stage for a very robust thermodynamic environment for intense updrafts and intense supercells um going into our upper air pattern today. So yesterday we were kind of dealing with somewhat of a uh of a sort of minimal uh change in the geot potential height contours. Not a ton of change, perhaps a little bit of a short wave out there in the uh northeast Colorado vicinity and then in that Missouri vicinity to help us out there, but overall very subtle features and that's going to be much of the same today. Our our trough is still well back here to the west. This main big trough is still back here to the west. strong jet streak rounding the quoteunquote base of the trough based on its orientation. Kind of looks like the side of the trough, but it's kind of rounding the base of the trough based on its orientation right now. And that'll be more in play for tomorrow's setup as it finally starts to eject into the central plains. For today, we're still relying on very subtle features, namely this little short wave that is expected to uh shortwave and jet streak that is expected to move off to the northeast slowly going into the afternoon. It's kind of tough to tell because it is so subtle right now, but you can see a very, very subtle little kink in the height contours there out across Colorado into New Mexico associated with a belt of slightly enhanced flow there, 40 to 45 knots or so within that area.

[00:07:36]That is a little bit of a short wave that is expected to amplify maybe ever so slightly going into the afternoon and then eject off to the northeast by the late afternoon to early evening.

[00:07:46]probably located somewhere here from west central Nebraska into sort of the central Kansas vicinity um by late afternoon to early evening. That's going to be our main synoptic mechanism for storm initiation in today's setup. We are going to see a lot of our we're going to see our surface boundaries come into play as well. We have a pretty robust surface pattern at this point. A fairly decent surface cyclone has developed out here across the southwest Kansas vicinity. warm front draped across northern Kansas here. Uh perhaps up into Iowa probably has been reinforced somewhat by convection overnight, but that is somewhat that is kind of the position of the warm front at this point. It is expected to lift northward as we go through the day today. This surface low will traverse off to the northeast as well up into somewhere near the southern Nebraska, northern Kansas vicinity by the afternoon. And ahead of that, we'll be focusing uh the main threat for the most robust severe storms in this setup. kind of northern Kansas up into that eastern Nebraska, southeast South Dakota, western Iowa corridor for today just ahead of that surface low. We also will have a dry line down to the south somewhere somewhat draped across the Texas panhandle into eastern New Mexico at this point. Um, and we we'll refine that here in just a second as we look at our surface observations. Uh, going back up here to 850 millibars as you might expect with this uh stronger strongish low-level cyclone. We have a decent low-level jet across this region. uh 30 to 40 50 knots across this region from the southern plains all the way up into the Midwest. A little bit of a lobe up here into the northern plains as well.

[00:09:17]This should persist as we go into the afternoon because we're going to have this low kind of maintain itself move into the southern Nebraska, northern Kansas corridor. We're going to m and not really lose intensity too much.

[00:09:29]We're going to maintain this lowle jet out here across the Midwest into eastern Nebraska and southward across the southern plains going into today. So our kinematic support for robust storms today is quite good and we're going to see that low-level jet maintain itself and maintain those stronger those more looped large low-level photographs going into the afternoon across the area.

[00:09:50]What's going to be the main factor in determining how intense the overall severe threat's going to be today is the storm mode. We are expecting a bit of a cold front to develop up here across the northern portions of really the main portions of the risk area, but up there into Nebraska, uh, eastern South Dakota, Minnesota, Iowa. There will be somewhat of a cold front that develops. It starts to surge at some point, perhaps by the late afternoon into the early evening, and that may eventually congeal storms into somewhat of a line, especially with northward extent up there. So, the duration of of discrete supercells today is in question. uh along the dry line of the south forcing is going to be weaker and shear vectors will be a little bit more perpendicular to the initiating boundary. So we could see more discrete supercell development with southern extent. But up here across eastern Nebraska it remains a question of how long those supercells will be able to stay somewhat discreet before they really line out. Regardless, we're going to see an intense batch of severe storms. Whether that's discrete supercells or a line uh producing those significant severe hazards and we could even see some strong tornadoes embedded within the line as it moves off to the east given the kinematics at play as we go into the early evening hours uh today. Let's take a look at our surface observations right now so we can kind of pinpoint where our features are. So clearly we have a low pressure area here in southwest Kansas. You can see the counterclockwise rotation of the wind barbs here. a little bit maybe elongated across this area, but it's somewhere perhaps in that region there kind of east uh western Kansas uh near the Scott City area perhaps.

[00:11:20]Warm frontal zone draped off to the north. You can see a clear windshift and temperature gradient up in this vicinity here. Becomes a little bit more diffuse up with northward extent as we go into Nebraska, but there does maintain a a bit of a temperature gradient up in here. Uh and then you see a better um windshift as we go into southern uh Iowa. Uh, and that'll be kind of good enough for our purposes there. So, the warm front is somewhere in that vicinity. Just kind of eyeballing it this morning. Um, you can see mid to upper 70s, temperatures to the south, due points in the mid60s or so, uh, with temperatures in the 60s off to the north. So, clearly a warm front, some sort of frontal boundary, a warm front is in that vicinity there. Again, it's going to lift northward today. the surface low will develop off to the northeast and end up somewhere here by early evening, late afternoon, early evening in that southern Nebraska, uh, northern Kansas corridor. And ahead of that's going to be where our main focus for severe storms is. The warm front may even lift as far north as into southern South Dakota, uh, and southern Minnesota, but we it remains to be seen with some of that lingering shower activity uh, here across this corridor.

[00:12:22]It is dissipating. So, I do expect recovery in that warm front to lift pretty far northward into the southern South Dakota, northern Iowa, southern Minnesota corridor today. Um, and to the south of the surface low, you can see our dry line here. Very dry air to the west. Due points in the teens and 20s out here across eastern New Mexico into the Texas panhandle with 60s off to the east. So clearly a dry line setting up here to the south through the Oklahoma and Texas panhandles down into the eastern or western Texas panhandle, far southeast New Mexico and down into West Texas. Looks like that that's the approximate location of our dry line today. These features will mix off to the east. The dry line will mix off to the east today with that drier air coming in. Um, as that surface low moves off to the northeast, we'll tighten that dry line going into the day and it should end up somewhere in that south central Kansas vicinity southwestward through southwest Kansas, western Oklahoma, the eastern Texas panhandle.

[00:13:18]And that could be a focus for severe storms today. Although the position of the short wave is going to make that a little bit more conditional with southern extent because we might be behind that short wave just a little bit battling a little bit of subsidance, but we could see strong enough surface heating along that dry line uh and strongest strong enough strong enough convergence along that dry line to support a few storms uh down into southwest Kansas, northwest Oklahoma uh and toward the I40 corridor in western Oklahoma. So that remains to be seen. We have seen a signal for that. Uh but that could be a potential as well for maybe some slightly more discrete supercells there going into the late afternoon and early evening hours today. In our warm sector, uh quite a robust air mass here.

[00:13:56]Due points in the low to upper 60s.

[00:13:59]Temperatures already in the um low to mid and upper 70s across this region. So we're going to see those temperatures warm pretty significantly through the day. and that that will move off to the north as well as we get that warm front to lift off to the north into eastern Nebraska going into the afternoon. Uh and that should be a favored corridor for robust uh severe storms today.

[00:14:20]Thankfully, we do have some soundings from across our area of interest today unlike yesterday. Uh starting with the Topeka sounding uh thermodynamically pretty impressive today. We have some fairly decent moisture here going up to about 800 millibars or so, maybe just above that. a little bit of a saturated layer there in the um low levels of the air mass beneath a stout cap inversion at the base of a very stout elevated mix layer. That layer kind of homogeneous strong lapse rates there between about 500 and 700 millibars lapse rates over 9° C per kilometer. We we've talked about this in the previous couple of videos detailing this overall severe weather sequence. This EML is pretty persistent with this persistent wests southwesterly flow uh transporting that uh strong heating off the higher terrain there. Steep lapse rates on the higher terrain there um out into the areas of the the Midwest and the plains that are going to see this severe weather and that is going to set once again set the stage for robust instability today with that strong surface heating as well. We get those temperatures up into the 80s.

[00:15:21]Very strong instability a loft. Now, the degree that this capping inversion erodess is a little bit in question.

[00:15:27]Some of the forecast soundings are showing a little bit of that inversion sticking around. That is perhaps one signal that may keep the storm mode at least slightly more semi-discreet for a little bit longer before that cold front starts to move off to the east across that eastern Nebraska corridor today.

[00:15:42]Um, but I still think we'll get upscale growth fairly quickly. But if if this cap hangs around a little bit longer, then we could see uh storms are forced up as the short wave moves in um and along the boundaries, we could see a slightly longer window for semi-discrete storms, but overall quick upscale growth is expected today, but no doubt we're going to see very strong instability within this environment. We already have some elevated instability here um thanks to this elevated mix layer. As we get that surface heating and continued warming and moistening off to the north, we should see a very robust thermodynamic profile take shape. And we'll show you some forecast soundings here in just a second. Kinematically, not all that surprising given the low-level jet in place that we have very strong looking low-level photographs.

[00:16:22]Very uh large effective storm elephality or storm felicity in the lowest few kilometers of the atmosphere this morning. Somewhat weaker mid and upper level shear. So that could mean a tendency if that continues toward more high precipitation supercells. Not going to see a huge change in the overall mid and upper level flow today. uh perhaps a slight increase as that short wave comes in, but weaker mid and upper level shear does tend to mean a little bit more high precipitation supercell characteristics uh because of slightly weaker precipitation venting away from the mesocyone region of the storm. So something to watch today. If if supercells are somewhat semi-discreet, they may have a tendency to be a little bit more on the high precipitation side given weaker mid and upper level shear.

[00:17:06]Low level shear should be fairly strong going into the afternoon across the broader risk area from the Midwest down into the southern plains with the maintenance of that low-level jet ahead of the low-level cyclone down here at Oklahoma at Norman. Uh you see again very steep uh lapse rates there indicative of that elevated mix layer. Strong instability expected along the dry line to the south. A lot more dry air here um in the low to mid levels of the atmosphere compared to Topeka.

[00:17:35]Uh, so that'll be something to watch as well. Will Updass be able to sustain in somewhat of a slightly drier mid-level environment. Um, shouldn't be too much of an issue. I think the lack o of forcing overall, uh, it may be a little bit of a bigger issue down along the dry line there. Um, but the we do have some dry air to speak of leading to really a loaded gun profile. So, thermodynamically should be very very good down here as well. And kinematically, we should maintain that strong low-level shear through the afternoon. uh to set the stage down there for perhaps some supercells along the dry line should they initiate.

[00:18:10]All right, let's take a look at some model data here. So, this is the 12Z NAM coming in as we speak uh at 500 millibars. And so, you see our big trough here out across the western US. A little bit of that secondary short wave out ahead of the main trough axis out there across Colorado into New Mexico this morning. As we go into the afternoon, you see it kind of becomes a little bit more apparent there in the main flow. Here's at 21Z, 4:00 p. p.m.

[00:18:36]Central Daylight Time. That short wave is kind of right in there out across western Nebraska, northeast Colorado into western Kansas. Uh so that may start to initiate storms right about that time ahead of our main boundaries there. And by zero Z, uh it kind of shifts off to the northeast. It is a very subtle feature, mind you, but still it kind of shifts off to the northeast kind of where we have it. We had it uh we had guessed it would be that west central Nebraska to kind of central Kansas corridor by zero Z and that's perhaps why the southern mode is going to be a little bit more conditional southwest Kansas into western Oklahoma.

[00:19:10]We might might be slightly behind this short wave. So, we're going to have to rely a lot more on the dry line uh dynamics, convergence along the dry line, the depth of the dry line circulation to initiate storms down there, making it a little bit more conditional uh in that area uh in the wake of that short wave, perhaps imparting a little bit of substance in that area. But ahead of this short wave, we should see um a an area from northern Kansas northward where storm development is quite likely by uh mid to late afternoon into the early evening along our boundaries. And that short wave kind of moves through into the Midwest going into the overnight hours tonight. And then it will be setting the stage for Monday as the trough finally starts to swing in. The main trough finally starts to swing in. Let's go down to 700 millibars. See if we can see the short wave a little bit better. So there you go. By 21Z, we have a nice little jet streak here. our more uh defined short wave up in here in in South Dakota, Minnesota, and then perhaps a little bit of another kink in the height contours down here across Nebraska into central Kansas. Uh setting the stage there for um supercell development. Um and so kind of on the same page there. This feature again is very subtle uh but it is there and will be our synoptic mechanism for today.

[00:20:22]Going down to the surface, um you'll see that surface low out there across the southwest Kansas vicinity this morning.

[00:20:29]warm front draped off through the pressure tongue and windshift there up into southern Iowa this morning. You'll see that low is going to start to lift off to the northeast with time kind of elongating as we go into the afternoon.

[00:20:40]I'll zoom in here to our central plains sector and you kind of see the more elongated nature of the surface low. Uh perhaps a little bit more of a center up in here into again into again that southern uh Nebraska northern Kansas corridor by mid to late afternoon. This is at 4 p.m. This is at 7 p.m.

[00:20:57]And you see our our the warm front does kind of lift off to the north. Dam has it a little bit farther south perhaps here into um it's kind of northeast Nebraska, central Iowa, and then down to our surface low here. Um and so definitely kind of a complex surface pattern here. The NAM does tend to be a little bit better with these cold air intrusions. We will have a little bit of a frontal zone here taking shape as we said. Uh so kind of a complex setup overall. The NAMA has the most robust air mass down here south of this frontal zone from eastern Nebraska into central Iowa uh and southwestward.

[00:21:32]Uh so definitely complex setup today, but all these boundaries may be focal points for severe storm initiation in today's setup. You do see that we we're getting very hot temperatures down here to the south ahead of the dry line into the upper 80s and 90s from Kansas into western Oklahoma. So that may lead to some more highbased convection that develops there going into the afternoon.

[00:21:53]Here's our moisture. And so this may outline our boundaries a little bit better. So you see that moisture going to rapidly invest low center somewhere in that vicinity there. Dry line down to the south into the eastern Texas panhandle. Warm frontal zone somewhere off in this vicinity here. We do see though we have kind of a a boundary in here. kind of that cold front that we talked about.

[00:22:19]Very complex setup at the surface and not one you see all that often here with these kind of multiple boundaries like this. The best air mass does look to be along and south of that sort of warm frontal zone there in eastern Nebraska, northern Kansas into western Iowa. By 21Z, that's 4 p.m. And then by zero Z, you start to see this frontal zone start to shift off to the east quite quickly.

[00:22:40]And that could uh be a factor that kind of lines things out if storms do initiate along that. Uh would expect all these boundaries to be initiation mechanisms here today. Um and so you know just we'll just kind of have to wait and see how that plays out. With such a complicated surface pattern, it is kind of difficult to pinpoint where things may initiate and all these boundaries likely will have some storm development along it. Perhaps up in here into southern uh South Dakota uh initially um in this main uh risk area.

[00:23:09]We may see storms develop there along this frontal boundary initially move off to the east kind of in a linear uh nature.

[00:23:15]Uh and then additional development down here kind of closer to this warm frontal boundary uh later on into the afternoon.

[00:23:21]Uh and then our dry line to the south uh starts to tighten up pretty significantly by late afternoon to early evening. Uh and that could allow for some storms there. Again, those temperatures are pretty warm out here even with due points in the mid to upper 60s. You have temperatures in the upper 80s approaching 90. It's going to lead to some higher based storms if any do develop down here. But by early evening, temperatures will come down. Moisture will continue to increase even with the dry line retreating back to the west. Um so that could lead to an increase in that all hazards potential for any supercell that does develop down here going into the afternoon and evening. We haven't talked about a separate regime that is possible out here today from eastern Colorado northeastward into northwest Kansas and southwest Nebraska.

[00:24:02]Uh models are are pretty gung-ho on robust supercells developing here.

[00:24:05]Mainly going to be a hail threat because our our low-level jet axis is well back out in here. But we will have an ups slope regime in place today with surface winds out of the kind of north and northeast here behind this frontal zone.

[00:24:18]So supercells are likely to develop across this corridor. Uh and they will likely be mostly large hailers uh with some damaging wind potential there. Um, but that is a separate area of severe weather risk that does need to be looked at for today. So, let's take some soundings from across the region. We'll take one here up in maybe southeast South Dakota. Then we'll take one here in eastern Nebraska and then one down here along the dry line kind of south central Kansas by this is at 4 p.m. So, here is up in southeast South Dakota. Uh, much more meager instability up in here. This is this may be a Nam Cork, but it does remain fairly cool up in here. uh going into the afternoon kind of north of that warm front. Um I do want to see some other models perhaps how they destabilize up there. So you see the RAP is kind of on board with the same situation. Cooler temperatures up there in southeast South Dakota with the best threat um at least in the afternoon hours uh kind of in that eastern Nebraska western Iowa corridor. And most models are are on the same page with that.

[00:25:20]So uh that is uh still enough to support some severe storms. may not be fully surface based for a while until we get into the early evening, but along that cold front, we may see uh storms congeal into a line there with that damaging wind, maybe some large hail potential for some more embedded robust embedded cores in there. This is eastern Nebraska at 4 p.m. And this is pretty interesting. So, uh thermodynamically that cap does kind of stick around a little bit. Uh and uh that may delay initiation as well going into the afternoon if this cap does stick around for a little bit. And the timing of that trough may mean a little bit later initiation by maybe four, five, 6 pm somewhere in that time frame. But we have destabilized quite a bit. 2,300 jewels per kilogram mixed layer cape 78 over 66 at the surface. Decently deep moist layer there up to about 800 millibars. But that cap is sticking around should we get storms to go.

[00:26:10]Plenty of thermodynamics there. But this is what we're dealing with in the afternoon. Very truncated uh sort of minimal photographs here. very very limited low-level curvature and all overall kind of small photographs in general. This is quite interesting here.

[00:26:26]So, we picked it there in eastern Nebraska. If we are going to outline our boundaries here, so our warm frontal zone is kind of in here, cold front back to the west, surface low here, dry line down to the south. I'm going to do that and I'm going to put in our 850 mibar winds. And you'll see that where storms may initiate uh here along these boundaries out along the cold front and then along the warm frontal zone, the low-level jet access at least on this Nam run is out to the east. You don't get to those 30 40 uh 45 knot winds until you get to far southeast Nebraska and southwest Iowa. So initially storms may pose more of a large hail and damaging wind risk. And this is going to be kind of a delicate balance today. Um, are storms going to be able to hold off until that lowle jet ramps up a little bit going into the evening or are we going to have storms initiate somewhat mid mid to late afternoon they line out quickly which is expected today uh and then move into the better air mass here that would kind of nyx the overall long track supercell tornado potential and lead to more of an embedded QLCS tornado potential. So very very complex setup today. Again with our warm frontal zone there we are expecting fairly quick upscale growth and then along the cold front as well. Um we are expecting fairly quick upscale growth today given that our shear vectors are pretty parallel to our initiating boundaries across this corridor. You see along the dry line to the south much more perpendicular nature to these shear vectors with respect to the initiating boundary. up here. It looks like we may see a little bit more of a tendency toward more uh of a linear storm mode up here. So, uh we're kind of again a delicate balance. Storms may initiate here in the weaker low-level sheer air mass, line out, and then move into this stronger low-level jet this evening. And then that would lead to more of an embedded QLCS tornado threat and damaging wind risk. If storms can hold off a little bit and that cap can maybe keep storms somewhat more semi-discreet or we can get some some warm sector activity down here or even along northern portions of the dry line that may act to be a little bit better for tornatic activity uh in a more robust sense with more discrete supercells. So we're it just that's one of the questions we're facing today that hasn't really been answered yet. We'll take a look at some cam data here in just a second and a lot of them are kind of on board with that um pretty quick transition to a linear mode up here. Uh and that may lead to less of a supercell tornado risk, more of an embedded uh circulation risk with the QLCS as we go towards zero Z though. Um so actually we didn't look here at the southern the dry line uh play here. So this is going to be at 21Z along the dry line southern Kansas. strong instability. That cap is a little bit uh noticeable there. 87 over 70. If we get those temperatures up into the 90s, uh that may lead to those higher temperature dupoint spreads. Overall, fairly truncated photographs. Deep layer shear. Interestingly, only about 27 knots there across all these areas. So, somewhat more marginal deep layer shear for supercells initially. Should increase going into the evening. Let's go ahead and take a look at zero Z here.

[00:29:29]We'll take one in eastern Nebraska.

[00:29:32]Then, we'll take one down here in southwest Kansas. This the dry line will be starting to retreat by this point. Uh if storms have not fired at this point, we're dealing with a retreating dry line that may be somewhat of an issue that may not initiate storms down there as well. Here is eastern Nebraska. We have eroded the cap by 0. Strong instability 3,300 jewels per kilogram mixed layer cape 74 over 71 at the surface. Decent low-level moisture. Uh this would favor a robust this is a robust thermodynamic environment for all hazard supercells paired with this kind of a wind profile.

[00:30:02]We do see an enlarging low-level photograph by early evening. Again, storm mode is a concern. Will we be lined out by this point? That remains to be seen, but maybe somewhat likely given the orientation of the shear vectors with respect to the initiating boundary, but that deep layer shear is increased.

[00:30:17]So, organized convection will become more likely with time. So, all in all, this is telling me that initiation up here may be a little bit later, maybe four, five, 6 pm uh before that Cappy roads uh espec at least in our main risk area there in eastern Nebraskan vicinity. And then uh that lowle jet, where do storms fire with respect to it?

[00:30:37]Are they lined out by the time they get into the better low-level winds? We'll have to kind of watch and see how that plays out. Down to the south across the dry line, you see that cap is fairly stout there. This could be a NAM quirk, but the cap does uh remain in place a little bit. Our moist layer up to about 850 millib bars. It is decently mixed given the higher temperature due point spreads. Some drier air loft there. So, this lends a little bit of uncertainty into the degree of coverage down to the south. If this cap does linger a little bit, this is again at zero Z. If storms can fire, they will be tapping into very strong instability. 3600 jewels per kilogram mixed layer cape. Wind profiles not all that impressive. Deep layer shear has increased enough to support supercells, but low level shear not super super strong. Some curvature in the low levels of the hodgraph, but hodgraph somewhat truncated as well with weaker mid and upper level shear. So um you know if a supercell can fire certainly would favor that all hazards threat uh down along the dry line, but it is quite conditional given the positioning of the trough. We may be a little bit dealing with a little bit of substance on the back side of the trough and perhaps this cap sticks around a little bit more uh as well. But should supercells fire, that all hazards hazards threat uh would be uh uh evident there with those storms. And then you see by the evening hours, the cold front really starts to crash there across the northern portions of the risk area. If we haven't lined out by that point, we certainly will uh going forward. And then we set up for tomorrow. Uh and those we'll talk about that here in just a second. Let's look at some some convection allowing model for uh data for today. So here is the 12Z her. So you see our convection dissipates. We kind of get that initial bout of storms across southern South Dakota, northern Nebraska from emanating from that the remnants of the morning convection. Uh that kind of lines out, clusters out hail and wind risk with those storms.

[00:32:25]And then by about 23Z, that's when we start to see robust supercell development along our boundaries. So initially um after that uh initial batch of storms there in southern South Dakota, we get supercell development near the Palmer Divide in Colorado.

[00:32:40]robust supercells there. Again, mostly a large hail and damaging wind risk given very straight line photographs in that area. We'll take a quick sounding just south of that storm and you'll see just very very straight line photographs there uh with decent instability for this region to support uh supercells, but tornado risk is going to be very very low across that region given very stick straight photographs there. But those supercells may be long track hail producers.

[00:33:05]By 56 PM, we start to see robust supercell development along the boundaries here in eastern Nebraska. We do see some semblance of some uh slight window for discrete supercells here. We are maintaining some semi-discrete supercells here. This is at 700 p.m. all the way down into northern Kansas. So, there is a bit of a window and then things kind of line out a little bit.

[00:33:28]somewhat more of a broken line down to the south closer to where our dry line is. But eventually we do kind of line things out completely especially with northward extent um up into eastern Nebraska, Iowa, southern Minnesota and then we kind of cluster and line things out there in northern Kansas as well.

[00:33:43]So, not a very big window according to the HER for discrete supercells in this mode uh there. Maybe eastern Nebraska southward into northern Kansas. Slightly longer duration period of uh robust supercell development possible there.

[00:33:56]But with northward extent, we should line things out along that cold front, especially as it starts to surge this evening. And the herd does remain dry in our southern mode here, southwest Kansas into western Oklahoma. Interestingly enough, let's take a look at our ARW model.

[00:34:11]Here's the warf ARW.

[00:34:14]So, you see we just get a lot of storms to fire there in that eastern Nebraska corridor. Just a lot of storms to fire, some embedded supercells, but things line up very, very quickly. Uh, and then you see the supercells back there in northeast Colorado, northwest Kansas.

[00:34:29]That is a viable play for maybe some photogenic supercells. And then we see some additional dry line development there along kind of the triple point there in northern Kansas by 6:00 7 p.m.

[00:34:38]or so. down here to the south. Not much to speak of as well. This is kind of a change from yesterday. Yesterday, last night's run had supercells here from the ARW in that southern Kansas western Oklahoma corridor. So now we don't really see that all that much. Uh and then uh you see just we kind of line things out to the north with time pretty quickly.

[00:34:58]An SSL WORF model.

[00:35:01]So once again, we see quite a bit of activity developing all at once there in eastern Nebraska, northern Kansas.

[00:35:07]robust supercells back to the west northwest Kansas and then we do see some semblance of development there along the dry line south southern Kansas to western Oklahoma but it is somewhat shorter lived so that may be a little bit stronger cap coming in not quite as long a duration for a severe threat there um and so but at least it is showing a signal down there in that area couple other runs here just to take a look at um this um actually let's just go ahead and leave it at that um the other models are are are on on some older runs here. So, all in all, a very difficult, tricky day to forecast, but the overall idea is that we'll see um supercell development in multiple areas here. Likely um from perhaps the remnants of that morning convection north of the warmfront along that southeast South Dakota corridor may become surface based with time going into the early evening. Mostly a hail and wind threat there. Supercell development then takes place in that northeast Colorado, northwest Kansas, southwest Nebraska vicinity. Mostly hail and wind threat there as well, but those could be longer track supercells per perhaps photogenic supercells. And then we get a lot of storms to develop there in that eastern Nebraska and northern Kansas corridor down to the triple point. Uh and it does look like from our CAM data from our meteorology that things may line out pretty quickly in that area. Uh, and so how long that supercell threat, discrete supercell threat lasts will dictate how intense our tornado threat is going to be, but we could still still see some embedded tornadoes that could be strong in the line and then the damaging wind threat will take over. And then a more conditional threat from southern Kansas into western Oklahoma uh with a little bit of uh conditionality there because of the capping inversion that may stick around and the overall lack of forcing uh and given the main shortwave might be a little bit north of that area. So, multiple regimes possible today. Here are the storm net probabilities for today for tornadoes. And you see it kind of likes that eastern Nebraska corridor pretty significantly going into the afternoon and evening. Uh, and this does not discriminate between discrete supercells or QLCS's. This is just for overall tornadoes. So, just because it has these enhanced probabilities here does not mean this is discrete supercells. This could be just a significant uptick in tornado potential with the line as it moves off to the east into western Iowa. And that's kind of likely the case there. Uh minimal probabilities down to the south as well.

[00:37:27]Um we do see perhaps a very subtle signal there along the dry line, but not really much pinging there. Uh and that does kind of highlight the conditionality of the setup overall.

[00:37:37]All right, let's talk about tomorrow.

[00:37:38]Now, tomorrow is going to be perhaps an even higher ceiling day than today. And the reason why is we're going to have not as many issues with the overall forcing. So going into the overnight hours tonight, the trough's going to really deepen across the western US. By tomorrow morning, that trough and the associated strong jet streak should be across the four corners region and then we'll eject very quickly into the central plains. Here we are by 21Z. Very fast translating jet streak here going into the Nebraska, Kansas vicinity. Uh and that's where our warm sector is expected to be located. we and that kind of ejects pretty quickly off into uh into the Midwest by the overnight hours Monday into Tuesday. So, this is a very fastmoving jet streak uh which as we know is is fairly good for tornado potential and tornado outbreaks overall.

[00:38:26]The question here has been the positioning of this trough where it ejects with respect to our warm sector.

[00:38:30]So, let's kind of zoom in here to our southern plain sector. Actually, let's go to the central plain sector here. So you see as we go forward with time, the cold front starts to surge a little bit, but we should see a renewed cyclloenesis as this strong trough starts to traverse the Rockies. We'll see a a new development of a surface low in southeast Colorado or or in vicinity going into tomorrow morning. And that's going to stall out that frontal zone.

[00:38:55]You see, it doesn't really move all that much going into Monday morning. And so that should perhaps um kind of sit there through the afternoon. And so we'll have a bit of a triple point that develops between that frontal zone that's going to kind of stall out and our dry line.

[00:39:07]So here we are by 4 p.m. dry line down to the south, frontal zone off to the northeast. And you have your your triple point there in this particular model kind of there in that west central Kansas uh vicinity. That is might change a little bit. Could be farther south, could be a little bit farther north.

[00:39:23]Just kind of depends on how things play out with our boundaries and our um our features going into tomorrow.

[00:39:30]So by tomorrow afternoon, you see where our boundaries are. Let's see where our our short wave is with respect to that.

[00:39:36]So here we are by 21Z 4 p.m. And you see it is quite a bit of a glancing blow. So this is a little bit of a glancing blow.

[00:39:45]You'd like to see this for a more robust event really over spreading the warm sector a little bit more, but still this we're this is going to provide a glancing blow as it passes by. um especially going into the evening, we might start to be in more of that right entrance region of the jet streak here.

[00:40:01]Uh and that could allow for some uh better uh activity there uh in the warm sector. But we should see enough of a glancing blow here to initiate storms across this region. Uh especially along the frontal zone near that triple point and then south along the dry line, it becomes a little bit more conditional given the we're separating from the forcing just a bit. But overall, the area of interest here for tomorrow is is in that moderate risk area and vicinity.

[00:40:25]Uh where that that that near that triple point and just northeastward along the frontal zone, it's where storm coverage should be highest.

[00:40:32]Now, how soon this front crashes is a question. You see it does start to crash there by early evening and that will line things out. It does remain stationary though through the uh much of the afternoon. So, uh, that could lead to some, uh, time where we have more of a discrete supercell risk. And then along the dry line, certainly a good discrete supercell risk there. Looking at our shear vectors with respect to our initiating boundaries. Let's take a look at that real quick.

[00:40:57]Uh, so again, this is at 400 p.m.

[00:40:59]tomorrow. You see along the dry line, no issues there. Pretty optimal look, optimal orientation of the shear vectors with respect to the boundary up here to the north, a little bit more uh, parallel to the initiating boundary. So even though the front is stalling a little bit, uh we may see a tendency toward um uh a a lining out of the storms as they develop along the cold front. And the better threat might be down here along northern portions of the dry line near that triple point, wherever it ends up sort of in that west central Kansas vicinity.

[00:41:29]But nonetheless, we're going to have a very volatile environment in place. You see a very, very juicy air mass in place from the cold front Iowa all the way down to the dry line into Oklahoma and Texas. Take a quick sounding here just out ahead of that. This is at 21ZZ um with we didn't take a look at the surface uh map, but you see we get renewed cyclloenesis here out across that Texas Oklahoma panhandle vicinity, southeast Colorado vicinity, and that will tighten up our boundaries. Low-le cyclone will be strengthening that at that time. So, we should have a strong low-level jet across the region. You see by zero Z here, we have a a you know 50 to 60 knot low-level jet across central Kansas. Coupled that with the thermodynamics that are at going to be at play, uh we should have a very volatile environment in place. So here is just ahead of that triple point at 21Z.

[00:42:17]So very strong instability over 4,000 jewels per kilogram mixed layer cape.

[00:42:21]Somewhat truncated photographs here in the afternoon. But as we go toward zero Z, that low-le jet ramps up significantly uh and we could have that significant to intense strong to intense tornado risk uh ramp up by early evening. So this is at 21Z. Here we are at 0. You see no change in instability.

[00:42:39]We maintain that very strongly unstable profile. But now our photographs look extremely favorable for significant tornatic supercells. Very strong low-level shear, very elongated photographs with deep layer shear above 45 knots. That would be a this is a classic environment for all hazard supercells with significant severe hazards including strong tornado potential.

[00:43:01]The question is though, what's our storm mode look like? So, um, do we have storm supercells that maintain a semi-discretet nature going into the early evening or do we have things that start to mostly line out across this corridor near the frontal zone? Uh, if so, again, that would lead to more of an embedded QLCS tornado threat as that low level jam ramps up. If we have more of a line, but if we have more discrete supercells and that is more likely near the triple point and southward into northern Oklahoma, then we could see a threat for that some long track intense tornadoes there persisting into the evening. And then the cold front really crashes going into the nighttime hours tomorrow and that will line things out.

[00:43:38]So questions still remain for tomorrow.

[00:43:40]It is far from a slam dunk, but the environment that will be in place, especially going into the late afternoon and early evening hours tomorrow, is going to be incredibly favorable for supercells with all hazards. But the storm mode remains a question. How fast will this front uh surge? Uh what will the storm mode look like by the time that lowle jet ramps up? That remains a question. storm net probabilities for tomorrow uh real quick here. So you see going into tomorrow, they start to ramp up pretty early in the day, 1 to 2 p.m.

[00:44:09]there across the kind of I7 corridor uh and then down into southern Kansas and they really maximize there along the Kansas Nebraska border by the early evening. So again, this doesn't discriminate between a line or discrete supercells. So, we don't really know that from this, but the tornado threat, according to this model, is going to maximize there in that northern Kansas to southeast Nebraska corridor uh with some probabilities extending down the dry line into southern Kansas going into the evening. And that continues likely aligned by this point by the evening there uh with that tornado threat continuing as the low-level jet ramps up via embedded circulations.

[00:44:45]Some convection allowing model data for uh tomorrow. Um, we're probably not quite out yet on most of our models.

[00:44:53]Just take a quick look at what the HER shows. We can look at some of last night's data as well. But here is tomorrow.

[00:45:00]So, you see we're clear clear skies tomorrow. And then by early midafternoon or so, robust supercells develop there along the frontal zone, southeast Nebraska into northern Kansas.

[00:45:10]And then they do kind of line out fairly quickly. We may have a couple hour window though of discrete supercells in that volatile environment. Still though, by this point might be more of a hail and wind threat and then by the time the lowle jet ramps up, it may be more of a line and then more of an embedded tornado risk and then not much there to the south along the dry line as well. So that is interesting. Uh a lot of our models from last night actually had quite a few robust streaks across that central Kansas corridor. I'll go to last night's run of the ARW and this was mentioned in the outlook for tomorrow.

[00:45:44]So you see tomorrow we get that development kind of farther south along a dry line closer to the triple point by 4 to 5:00 p.m. some semi-discrete supercells in there and then they kind of line out pretty quickly um going into the evening. So that is last night's ARW last night's NSSL as well.

[00:46:03]Then we go into tomorrow afternoon and you see quite a few supercells develop there by mid to late afternoon and they kind of line out pretty quickly. So the window tomorrow might be short as well, but the environment tomorrow is going to be very very favorable, especially by early evening for those long track all hazards significant supercells. So still not a slam dunk. Remains to be seen how that's going to play out, but that is what we're dealing with going into tomorrow. So just to recap here today, enhanced risk for now. Level three out of five in the orange shaded region, northeast Colorado, northeastward through much of northern Kansas, much of Nebraska, western Iowa, southeast South Dakota, southwest Minnesota. slight risk in the yellow shaded region from the Great Lakes down into the southern plains.

[00:46:45]Um again, the window today for discrete supercells here off to the north and eastern Nebraska and northern Kansas may be fairly short, but there is that significant tornado risk with those supercells um especially going into early evening. Will the storms be still discreet by early evening?

[00:47:02]Tending to be uh leaning toward no. We may see more of a line by that point, but should we have any discrete supercells by the early evening, they would have that significant tornado risk as well as a large hail and damaging wind risk. Uh and uh if even if we do get a line, embedded circulations within the line are likely. And then down here, a conditional threat into the southern plains for uh today uh southwest Kansas into western Oklahoma, eastern Texas panhandle. If a storm fires there, all hazards would be on the table, but it is quite conditional given the lack of forcing and perhaps a lingering cap down there as well.

[00:47:35]MCV all hazards risk there into central Minnesota uh central Michigan today uh this afternoon as well. Then we go into tomorrow. They have that moderate risk here. We'll likely see some shifts in the outlook lines going into uh the next outlook today and then into tomorrow's outlooks. But this is what they have for now. Level four out of f five moderate risk in the red shaded region across eastern Kansas and southeast Nebraska.

[00:47:57]Uh with a large level three out of five enhanced risk and level two out of five slight risks surrounding that. Again, same kind of the same questions as today. How long will storms remain discreet into the better environment uh the drastically better environment by early evening. If we do have discrete supercells going into the early evening hours tomorrow, they will pose that risk for all severe hazards including strong to intense tornadoes and giant hail. So, we'll just have to kind of wait and see how that plays out and we'll have a little bit more clarity hopefully tomorrow morning. Uh I do plan on being back tomorrow morning for an additional video as we have some more info in. So, that is the deal for the next couple of days. A couple of potent days on tap regardless of storm mode. Lots of folks are going to see some nasty storms today. So, keep those weather radios handy. Have multiple ways of receiving warnings. Have a safety plan in place.

[00:48:44]Uh, and you'll get through this just fine. So, with that, thanks for watching and I'll see you next