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.