Stop me if you’ve heard this one, but there are two areas of significant tornado risk today, one across the Midwest and another in the South.

The comparisons to last Friday’s setup are natural because we humans can’t help ourselves, but this setup is a completely different thing altogether. Let’s take a look.

The Setup

A large trough is ejecting out towards the middle of the country today, with rich moisture screaming north along a warm front. However, a pretty stout capping inversion is evident this morning across the Central U.S.

  • In the north, thermodynamic profiles point to a pretty stout cap that’ll need upper air support to arrive in order to break. This should happen late in the afternoon.
  • To the south, a more shallow moisture airmass has taken shape across Texas, which is advecting into Oklahoma and Arkansas through the day. This is strengthening the cap and also likely delaying storm initiation until possibly after sunset.
The shallowness of the moisture profile is evident by the dryness at 850mb across much of Texas and Louisiana this morning.
The morning sounding from DFW shows this shallowness in the moisture profile with a pronounced cap situated below 850mb.
Further north, there is also a stout cap in place. This would require temperatures to reach the mid-upper 80s to break without some type of upper lift and cooling. However, there is lots of instability rooted above the surface pointing to a potentially volatile scenario as temps warm at the surface and cool aloft.

Northern Target

Let’s break down the northern target in a bit more detail.

  • Storms should begin forming across Northern Missouri into Illinois and Iowa no later than 4-5 p.m.
  • Storms will form in two areas it looks: to the west along a surging front and in the open warm sector a bit further east. The eastern storms have my attention if they were to take shape.
  • Initially the storm environment isn’t fully supportive of big tornadoes, but if storms can maintain a dominant supercell mode with clean inflow towards sunset the atmosphere rapidly improves.
  • Tornadoes seem to be the most likely with any isolated, dominant supercells in the 6-9 p.m. hours.
  • This tornado risk area to me seems like it is conditionally significant, but it would be unsurprising if that risk doesn’t fully materialize.
The initial supercells will form in an environment that doesn’t have a ton of turning in the lowest 1 km. Despite seemingly adequate 0-1km SRH, the hodograph shape indicates storms may struggle to really wrap up early on in the day.
However, the turning in the 0-1km layer looks more pronounced just after sunset, with large values of 0-1km SRH nearer the warm front.
A storm interacting with the warm front could be especially dangerous. But the orientation of the warm front relative to storm motion suggests that these interactions would be very short lived. I would bet on a storm or two producing a tornado as they interact with this boundary through the day. The temps on the north side of this boundary are so cool, I just don’t know how a storm can maintain a robust low-level mesocyclone after they cross it.

Southern Target

To the south, the setup looks much different. Storm initiation before dark is far less certain, but the environment looks favorable for severe weather if a storm could form.

  • I only expect the cap to break in one or two areas max before dark along the dryline today.
  • An important note: the dryline begins retreating across large sections of it, especially in Oklahoma, well before sunset. This likely means that storms in this segment are a bit more of a longshot.
  • My eyes are on Texas for a dryline storm or two. Here, the dryline stays stationary with strong surface convergence through the afternoon.
  • The most likely time for storms to form on the dryline are after 4 p.m.
If a storm were to form before dark, the radar would probably look something like this with the storm location TBD. Anything forming before dark would have to be in the area of maximum surface heating and surface convergence.
The setup in the southern target loosely resembles the setup from the past several days. And the caveats are the same. If a supercell can maintain a dominant mode (this means it isn’t struggling with capping or subsidence), then it will pose a tornado threat near/just after sunset.
The most likely scenario today is that the zone for tornadoes before dark is very small. I think in the Midwest, only the storms ahead of the surging front will pose a robust strong tornado threat.
The tornado threat further south is much less certain even after dark. However, the tornado threat across Arkansas and portions of Texas may peak near or just after midnight.

Final Thoughts

There is certainly a conditionally significant risk of tornadoes, especially across the Midwest. But this setup comes with a lot of caveats. First off is storm mode, as always. Secondly is how will the storms interact with the warm frontal zone. These are very big questions. Given the area storms look to form, the orientation of the warm front, and the speed storms will likely move — the threat zone in the northern target is pretty narrow in both time and space.

To the south, I just don’t see a robust tornado threat unless robust supercells can form after dark, and there is mixed messaging about that on models. This is certainly possible, and it is a worrying possibility. Please, if you live in the Southern Risk area or know someone living in the Southern Risk area, make sure there is a weather radio on site and your phone emergency alerts are on. The tornado threat will likely peak while most people are sleeping.

This is a setup where I wouldn’t be surprised to wake up with lots of tornado reports tomorrow, but I also wouldn’t be surprised to wake up with few to almost none. The forecast bust potential is evident, but so is the outcome that results in many tornadoes.

We’ll be updating throughout the day on our Facebook and Instagram with our thoughts on which scenario seems more likely.