CheeselandSkies

***Edit: Added tomorrow (Monday) to the thread title as there is broad agreement among the CAMS in an MCV-driven setup along the IL/WI border region tomorrow (SPC added a small slight risk to the updated SWODY2 to account for this). These events are subtle with generally modest parameters depicted beyond Day 1, but if everything comes together just right they are capable of producing some prolific localized outbreaks in this area, such as 8/9/21 and 7/12/23.*** Guidance has been in good agreement for several days now that a compact, negatively tilted shortwave will impinge upon the IA/MN/WI/NW IL region on Tuesday with strong southwesterly flow at 500mb. At the surface, a low will deepen throughout the day with warm sector dewpoints well into the 60s, if not upper 60s by 00Z Wednesday. Basic pattern recognition suggests a very high ceiling and I'm frankly baffled why SPC's day 3 outlook does not at least include an all-hazards hatched area for wind potential if nothing else. That said, strictly in terms ofchase potential, there are several potential flies in the ointment as it seems there always are. One of them is, exactly how many rounds of storms initiate, where and when? For example, models have EXTREME levels of SRH along the warm front in southern Wisconsin, but suggest late-morning/early afternoon convection preventing that area from destabilizing. Other models suggest supercells might initiate in western Iowa, but might not be colocated with the best tornado parameters until they have begun to congeal into a QLCS (of course, this was also a concern with 3/31/23). Regardless, I think this day will end up a noteworthy regional severe weather event and worthy of its own thread.

The 30% contour alone (doesn't need a hatched area) drives an "Enhanced" category; but pattern recognition alone (compact, negatively tilted shortwave, deepening surface low with rich moisture in the warm sector) suggests this event will be capable of producing significant severe weather of some type, perhaps widespread.

Either way, I don't understand SPC's lack of even a hatched area for any hazard on the Day 3 outlook...

Just like the days that align for MI/IN/OH are too far east for me...

Next potential round coming up and this time it looks to be timed right for E IA/WI/IL. SPC has a large Day 5 area highlighted for Tuesday 5/21. Lots of important details yet TBD of course but moisture/instability doesn't look to be much of an issue.

2012 sucked. Too stupid hot for March and even early April; but also bone dry which set us up for the drought that summer...and despite all that early season warmth there was no severe weather to go with it. When we got 80s into Wisconsin in March I fully expected an abundance of Rochelle, Winterset or Keota type setups (although we were years prior to knowing what those were)...instead it was just straight .

GFS suggests Sunday/Monday in KS/possibly down the dryline into OK, Tuesday further east somewhere in the MS and/or OH Valley, somewhat more localized potential in the southern Plains Wednesday followed by another potentially big round Thursday-Saturday. All subject to how each day evolves on the mesoscale of course; but can't complain about another string of chances like this if you're out chasing.

Yep. That's exactly what happened. I had committed to following 169 north (which involved going east on 34 from Afton) after the storm that produced the second of the three Creston-Afton-Macksburg area EF2s. Here is a lightning-backlit and contrast enhanced 500% zoomed-in grab from my GoPro as I was passing through Afton. I think I have a distant glimpse of it here, but that's it. As I said in my earlier post, by the time I finally got a good view under the base near Lorimor, the tornado was gone (as evidenced by the relatively weak couplet in your RadarScope grab) and the storm didn't produce for me again before dark. Meanwhile, the view toward the third couplet was completely blocked by hills and trees west of 169, so I just considered it as something to avoid getting run over by rather than try to catch.

It is rather rare. Only used when an abnormally significant derecho (such as 8/10/20) appears imminent and the tornado threat is relatively low enough to not warrant a tornado watch.

Great shots! I am still scratching my head as to how I managed to be in pretty much the same area at the same time and get jack squat for quality shots. I was on the storm that produced the initial Creston tornado when it first went tornado-warned southwest of Bedford, and observed this nice wall cloud just west of IA-148: Taking 148 north through Bedford, I had to drive practically underneath it to get to my next east option. It was here that road options quickly became an issue, as I became trapped in a maze of unpaved roads trying go as fast as possible without sliding off as the base outran me and started producing. With some white knuckle driving I managed to make it back to pavement and emerge onto US-169 just east of Shannon City, a little ahead of the longitude of the couplet according to RadarScope. Blasting north and cresting a hill near Arispe at 7:34 (per timestamp of cell phone pictures I took which did not turn out through the raindrop-spattered windshield), this was my view ahead. One of those lowerings under the base is surely the first Creston tornado, but which? Hindsight being 20/20 I should have taken a left instead of a right where 169 intersects US-34 and then I would have easily been able to see the second tornado. Instead I pursued the original cell to north of Lorimor and by the time I finally got a good view under the base, the tornado had lifted. Hills and trees to the southwest obscured my view of the base of the second cell; so noting that it was also tornado-warned with an intense couplet I viewed this more as something to avoid getting run over by rather than try to see. I followed the base of the original cell a little further to the northeast, IIRC it later produced additional tornadoes but I broke off due to darkness rapidly setting in. I went back to 169 and found a spot that looked to be clear of the path of any couplets to pull over and wait out the RFD with blinding rain and strong, but fortunately not too crazy winds to clear the highway before heading north to Winterset and then toward home.

0Z has it as well, somewhat further NW and with a secondary EHI max near the Quad Cities.

Euro and to a lesser extent GFS have the left exit region punching right into southern WI/northern IL at 0Z Wednesday, but GFS has already put the front through with the best moisture shunted south/east. If the GFS's slightly too fast bias holds here, that could give those areas higher potential at the expense of IN/OH. Of course, my backyard bias is at play here since I'll be back home next week, but also back at work. Sent from my Pixel 8 using Tapatalk

I pulled up GR Level 3 about 6:30 and saw what appeared to be a bona fide supercell taking shape near Monticello tracking east. I grabbed my cameras and loaded them into the car; right as I was doing so is when the tornado warning went out. I had redemption for bungling yesterday's southwest Iowa chase on my mind. Not to be as by the time I got to where I would have had a view of the updraft base, the storm had essentially ceased to exist. Currently getting some nice boomers back at the house in Madison.

I think a little of both. However, to my point below; each potential threat recently has had some obvious limiting factors apparent in the model data within a few days out (moisture depth, wave timing, etc). I was under the impression that we were actually currently moving out of El Nino toward neutral and then La Nina (hence also the universally very high-end forecasts for the Atlantic hurricane season)? *** The models showing a big, amplified trough with moisture is one thing; however, details matter. Most of the prior setups this year have had significant caveats become apparent within the 3-5 day range. However the amateur social media hypelords either didn't know or didn't care to point them out. @andyhb is right, this one is not downtrending to any degree that I'm seeing. If anything; each subsequent model run is only reinforcing the idea that the ceiling is quite high and something significant could happen each day starting tomorrow through Sunday. Now, will it? Not necessarily, but confidence it's higher than it's been in quite some time IMO.

Couple of 1" hail reports in western Lower MI; nothing came of this elsewhere.

Sneaky marginal risk over SE WI/NE IL/NW IN/W lower MI today. Sent from my Pixel 8 using Tapatalk

That tornado wasn't photogenic for very long but you sure made the most of it!

Apparently record low (24) set at Dubuque today. Didn't think we were in any kind of noteworthy cold pattern for doing that.

Our @hlcater got some of the better footage I've seen of the tornado of the day (at least duration/impact-wise) which tracked from Houghton-Mediapolis, IA. Me, I was on the storm minutes beforehand but didn't think it looked about to produce and jumped on the southern storm, which was also tornado-warned at the time, and chased it across the river to near Little York, IL but it never did much of interest. Wall cloud looking west on 140th St., south of Houghton or near Mt. Hamill:

Pretty sharp dry slot pushing into SW IA/NW MO. Not a lot of lingering cirrus behind the first round. HRRR back on board with firing a second round after dropping it for a run here or there (notably the 0Z yesterday evening).

True.

And of course, 0Z HRRR now cap busts SE IA despite a pretty sexy parameter space. I don't necessarily buy it given how much forcing ought to be present, but not exactly what I was hoping to see.

Yeah, picture is becoming *a bit* clearer. Pretty much all 18Z CAMs agree on robust supercell development in a solid parameter space, most in the far SE IA vicinity (3KM NAM a little further west). Looks like it's going to be another drive to Mt. Pleasant, IA and evaluate kind of day, need to be more decisive than I was on 4/4/23. Getting my cameras charged...

Tomorrow certainly going to be very interesting...ought to be at least a couple strongsomewhere near the IA/IL/MO intersection. As to exactly where in that vicinity at this point... Picking a target on 3/31 last year was easy (except the morning of when the HRRR started to make western IL look really good; but fortunately I came to my senses). This is giving me unpleasant vibes of 4/4 when I sat in Mt. Pleasant just long enough to miss both the Pleasantville and Table Grove/Lewistown storms. Ended up going for the latter but was stuck on the wrong side as it coalesced and went tornado-warned, so I just threw in the towel and started driving for home. A chaser I've been acquainted with for a long time and long held in high regard was in a similar situation (probably only about 10-15 minutes ahead of me out of Mt. Pleasant), tried to core-punch to get a view, and ended up having a very bad time of it so I'm glad I didn't do that.

Hey, I kind of am. I grew up on '90s TWC tornado docs with tons of footage from 4/26/91 since it was THE recent major outbreak of record at the time (as well as one of the first, along with 3/13/90, to take place in the camcorder era with a lot of home tornado video, although still nothing like now when everyone's phone can record 1080p or 4K video). I like to armchair chase a good Plains outbreak if I'm not able to chase it myself. I stay the **** off social media, though. It's long been a wretched hive of scum and villainy and it's only getting worse. 4/26/91 was also considered a major coup for the comparatively primitive NWP of the time; but I now believe it could just as easily have gone the way this one has. It was just "luck" from a forecasting standpoint that a lot of meteorologists called for a major outbreak based on what they saw several days in advance, and it verified.