2026-04-13 EVENT: OK, KS, MO, IA, MN, WI

[Mike Smith]

SPC has a pretty good outlook for the Upper Midwest Monday. I would not be surprised if they upgrade it to moderate due to wind or, possibly, tornado risk.

Of more curiosity to me is the potential for "day before the day" supercells with a tornado risk from central OK to NW MO. The HRRR ((18Z) shows the dry line gets to just east of the Flint Hills and then retreats after 23Z. Significantly, there is no diurnal pressure rise over the area and the SIGTOR is 3 to 3.3 with backing winds (~30°) east of the dry line. At 02Z (Tuesday in UTC) the 18Z HRRR shows an impulse from MHK to FSI moving over the threat area. I have attached the 23Z surface inhibition.

The 18Z HRRR does not convect anywhere from the central Plains to Upper Midwest (including SPC's "enhanced" area). Nor do any of the 12Z CAM's and I may be way off base. But with 3000+j of CAPE, no significant inhibition, and a source of lift, I think Central and NE Oklahoma, the eastern third of Kansas and west central and NW Missouri are worth keeping an eye on. The 01Z (8p Monday) sounding for MKC is pretty impressive if that impulse can create enough lift.

One thought about Tuesday: Some well known chasers have forecast a "tornado emergency" and another is forecasting a "historic outbreak" based on what they are posting on Twitter/X. While I certainly believe tornadoes are possible, I'm just not seeing a super big day.

I certainly invite others to post their thoughts. I may be way off-base.

 

[Zack Ruddle]

One thought about Tuesday: Some well known chasers have forecast a "tornado emergency" and another is forecasting a "historic outbreak" based on what they are posting on Twitter/X. While I certainly believe tornadoes are possible, I'm just not seeing a super big day.

Hype for the hype machine. I expect 10 videos already posted with "THIS SETUP CHANGES EVERYTHING" as the title. Click driven income.

I'll likely be on this mostly because it's right in my backyard in MN, but the tornado risk seems much more conditional than wind/hail and I have little interest in being caught up in those... If things initiate early it could be a nice chase day, but much of the current northern target area is in the "driftless" region, not a fun area with lots of hills and poor road grid.

I think we had a very similar setup around this time last year that ended up being mostly a wind/hail event. Hard to get everything right in April up here...

Great write up Mike!

 

[Boris Konon]

SPC has a pretty good outlook for the Upper Midwest Monday. I would not be surprised if they upgrade it to moderate due to wind or, possibly, tornado risk.

Of more curiosity to me is the potential for "day before the day" supercells with a tornado risk from central OK to NW MO. The HRRR ((18Z) shows the dry line gets to just east of the Flint Hills and then retreats after 23Z. Significantly, there is no diurnal pressure rise over the area and the SIGTOR is 3 to 3.3 with backing winds (~30°) east of the dry line. At 02Z (Tuesday in UTC) the 18Z HRRR shows an impulse from MHK to FSI moving over the threat area. I have attached the 23Z surface inhibition.

The 18Z HRRR does not convect anywhere from the central Plains to Upper Midwest (including SPC's "enhanced" area). Nor do any of the 12Z CAM's and I may be way off base. But with 3000+j of CAPE, no significant inhibition, and a source of lift, I think Central and NE Oklahoma, the eastern third of Kansas and west central and NW Missouri are worth keeping an eye one. The 01Z (8p Monday) sounding for MKC is pretty impressive if that impulse can create enough lift.

One thought about Tuesday: Some well known chasers have forecast a "tornado emergency" and another is forecasting a "historic outbreak" based on what they are posting on Twitter/X. While I certainly believe tornadoes are possible, I'm just not seeing a super big day.

I certainly invite others to post their thoughts. I may be way off-base.

Last week I saw a post from a well-known chaser stating this period would be like April 2011. What a crock, and I know this particular person knows better from meteorological perspective, but all this person seems to care about is generating engagement/rage bait to monetize.

Ever notice when a historical wx comparison is made now on social media from the hype-masters, it is *always* the absolute benchmark extreme example from history? Pure click-bait.

April 2024 and 2025 rank #2 and #3 for the most U.S. tornadoes in April, so what are those? Chopped liver?

 

[Luke Penney]

SPC has a pretty good outlook for the Upper Midwest Monday. I would not be surprised if they upgrade it to moderate due to wind or, possibly, tornado risk.

I've been watching the area, and I agree that there's a note-worthy conditional risk for Minnesota and Wisconsin.
A lot of the earlier model runs weren't showing storm initiation happening at all (at least, not before dark), and I had plans to commit to on Monday, and that looks to be ultimately what's making the decision for whether I chase. However, it'll still be educational for me to watch how it'll turn out.
Recent HRRR and NAMST runs have put some nice supercells there. However, it looks like there's a decent risk of them not being surface-based. This might be more of a hail day than a tornado day, though a storm far enough south could find itself in a really nice parameter space - how far north/south storms are will affect what kind of show they'll put on. I also note there's a lot of high-altitude moisture, so HP-mode is something to watch out for.

One thought about Tuesday: Some well known chasers have forecast a "tornado emergency" and another is forecasting a "historic outbreak" based on what they are posting on Twitter/X. While I certainly believe tornadoes are possible, I'm just not seeing a super big day.

My analysis of Tuesday leads me to think that there's a high ceiling, but also lots of uncertainty. When looking at simulated soundings around storms, I ran into around a half-dozen PDS Tornado soundings (among many simulated soundings) in various models/runs. Yesterday's NAM was particularly enthusiastic. However, there was lots of variation between models and runs: Where conditions were good and how good they were, where storms initiated, whether storms where in the good conditions, etc., keeps changing. There has been a theme of lots of potential overall, so I'm definitely watching Tuesday, but I sure wouldn't commit to much specific in a forecast at this time.

 

[Luke Penney]

And yeah, I agree it's irresponsible/foolish to pick the highest possibility (or even higher) on an uncertain outlook and say "This is what's going to happen!"

 

[Luke Penney]

And now HRRR and RAP are suggesting a south-Wisconsin/north-Illinois target, and Minnesota storms getting down into Iowa

 

[Zack Ruddle]

Staged just south of Mankato. Strong sun, rising temps, and humidity building. Seems like good conditions are here and the cap is eroding

 

[Mike Smith]

Well lookie here......

The18Z HRRR kicks out a severe thunderstorm over eastern Kansas stating on the 6pm (23Z) panel along with a couple of non-severe thunderstorms in southeast Kansas.

Of course, this doesn't mean it is going to occur but I think the changes are decent for the same reasons as outlined at the top of the page.

Good luck and stay safe to anyone chasing.

 

[Mike Smith]

3:31pm satellite image: Dry line attempting to fire from north of Wichita to the KS border south of ICT. Nothing in northern Oklahoma yet. That area to TCU just north of ICT is moving NE.

3:56pm, SPC issues an "all hazard" mesoscale discussion for eastern Kansas. Image below which also show the TCU now NE of ICT showing up on radar. You will have to blow it up in order to see the outline in blue.

 

[Randy Jennings]

I told my chase partner this morning there was so little difference in direction and speed between the surface/850 mb and the 300/500 mb level along the dryline in TX/OK that I wasn't going to chase today as the storms would be raining in their updrafts. I didn't even look at the MN/WI target (out of range for us today). Looking at conditions now (5:25 PM CDT), we do have few storms along the dryline in TX but we still have the flow issues I mentioned above. I don't think these will amount to much in TX/OK. Looking quickly at the MN/WI target, the flow is much better in that area. If you are chasing up there you might have some luck.

 

[Matt Zumbrunn]

3:31pm satellite image: Dry line attempting to fire from north of Wichita to the KS border south of ICT. Nothing in northern Oklahoma yet. That area to TCU just north of ICT is moving NE.

3:56pm, SPC issues an "all hazard" mesoscale discussion for eastern Kansas. Image below which also show the TCU now NE of ICT showing up on radar. You will have to blow it up in order to see the outline in blue.

We nearly intercepted at my Son's track meet at Lyndon. We got south on 75 and pulled over on the south side of Melvern Lake. Ragged wall cloud formed then dissipated. We bailed for home. 15 min later it was cranking.

 

[Matt Zumbrunn]

@Mike Smith and others. I've been pondering today's events. I am 99% certain when I woke up this morning we were not in the "general thunderstorm" area. I was sitting at the track meet when they extended the marginal risk with the hatched area towards the Iola area. Then the storms popped on the dryline and it was "we might issue a warning". The storms hit the Reading, KS area and developed a hook (Reading was hit the day before Joplin back in 2011). I missed the first tornado by 15 minutes.

So why did it overperform? The cap not as strong as forecast? Temperatures higher than forecast breaching the convective temperature? Mesoscale accident? Convective Chronicles is working on a breakdown, but I am curious to hear your thoughts. Mods if this is the wrong place then I will take my lashings. Just trying to figure out what the meteorlogical community/myself missed.

 

[Mike Smith]

@Mike Smith and others. I've been pondering today's events. I am 99% certain when I woke up this morning we were not in the "general thunderstorm" area. I was sitting at the track meet when they extended the marginal risk with the hatched area towards the Iola area. Then the storms popped on the dryline and it was "we might issue a warning". The storms hit the Reading, KS area and developed a hook (Reading was hit the day before Joplin back in 2011). I missed the first tornado by 15 minutes.

So why did it overperform? The cap not as strong as forecast? Temperatures higher than forecast breaching the convective temperature? Mesoscale accident? Convective Chronicles is working on a breakdown, but I am curious to hear your thoughts. Mods if this is the wrong place then I will take my lashings. Just trying to figure out what the meteorlogical community/myself missed.

As indicated in my forecast at the top of this thread, there was zero forecast inhibition just east of the Flint Hills at 23Z -- as forecast by yesterday's 18Z HRRR. The MKC (downtown KC) forecast sounding for 01Z this evening was an impressive TOR sounding. When you add the instability in place to an impulse that moved over the area, it was fairly straightforward as a "day before the day" event.

I have an advantage as I have seen enough of these to use "pattern recognition" (age 74, one of the original OU/NSSL chasers) and thus to not have any hesitation when I believe the models are wrong. Now, you'll notice my confidence was not super high but adequate to post.

Unfortunately, SPC didn't even have the eventual path of the supercells in the general thunderstorm area this morning. While they added general thunderstorms at 20Z for E KS and W MO, it was still NO SVR even as towering cu were going up fast just north of ICT.

I did a special update on my blog at 3:10p calling for the potential of tornadoes: Today's Tornado Forecast - Updated 6:40pm (white base map with red lines). I'm pointing this out because of the Twitter/X comments today that "no one should differ from SPC's outlooks."

There has been no improvement in tornado watches the past decade. I think some of the older forecasters retiring (and losing the experience of pattern recognition, etc.) is hurting SPC significantly. I also think there is too much relying on the CAMs. The fact the CAMs, especially the HRRR, at 12Z today was still not convecting really threw them off. But, then, look above at what the 18Z HRRR did! Almost right on the money, just slightly too far north with the tornado's path. (scroll up)

If I woke up tomorrow as the head of SPC I would be (during slow periods) drilling forecasters on old (pre-1995) cases and teaching them pattern recognition and satellite interpretation (another skill not often taught).

My 2¢. Thanks for asking.

 

[Mike Smith]

In real-time, I posted this Monday 18Z HRRR track forecast that was stunningly correct.

But, here is something else that is stunning: the 17Z and 19Z versions of the HRRR (and remember, these days there are many balloons launched at 18Z) had zero convection forecast for the State of Kansas before tomorrow (Tuesday)!

Wish we could get the models to be more consistent.

 

[Zack Ruddle]

In the Southern MN area, I spent most of the afternoon looking for the clear sky and humidity. Initially sat south of Mankato but went down to Blue Earth and waited for things to finally kick off. Initiation happened almost right on time with the HRRR.

I was glad to be further south to catch the Truman cell as my only target of the day and boy did it pay off! This was my first Tornado ever after busting out all last year and it's going to be a tough one to beat. Very photogenic and was able to watch it recycle 3 times. Very proud I was able to stay out of the chaser convergence.

Once things started to get messy with storms starting to come up north from Iowa, I decided it was time to bounce before I put myself into a position to get pinched. I managed to dodge all the hail heading home which was a nice plus. There were heaps of baseball sized hail stones in the ditches, enough to create some fog in the lower lying areas.

Once it started, this system really cooked.

Pardon my grainy iPhone zoom