CheeselandSkies

12Z NAM is way slower, has the greatest threat back in central NE/KS at 0Z Friday (Thursday evening). Meanwhile Euro shows pretty meager moisture. GFS has looked pretty good over IA for a few runs, but it's really by itself with that. If the GFS is in fact being too progressive, I could see Friday actually being a significant day somewhere in the E IA/N IL/S WI region.

GFS suddenly looks pretty good over southwestern Iowa (last year's hot spot) on Thursday evening. However Euro is not nearly as aggressive with the moisture.

60th anniversary of Palm Sunday '65. The very definition of a Midwest regional outbreak affecting each IA, IL, WI, MI, IN, OH with significant tornadoes. Nothing else comes close for this part of the country, even though a few have flashed potential (like 3/31/23).

I really appreciate that despite chances repeatedly coming up in my local forecast the last few days, it hasn't actually snowed. Now can we get some real warmth and legit chances north of I-80, please?

It's the 10th anniversary of the Rochelle-Fairdale EF4. One of the few truly spectacular, high-end, Plains-style tornadoes in this sub north of I-80 (and especially for north of I-88) in modern memory. For me, it was the second demoralizing miss of a spectacular tornado event in as many years. These photos were taken between 3 and 4 PM along Illinois Highway 26 just north of Forreston, a little over 20 miles from where the tornado would touch down about 90 minutes later. Just as I thought I'd broken through the warm front, I kept encountering more showers (I now realize these were the incipient updrafts that amalgamate over time to form tornadic supercells in these type of events). Even as things cleared out and I started to see bubbly cumulus, I felt it was still too cool at the surface and too late in the day for sufficient destabilization. I decided it would probably play out similar to the previous year's April 28th, which I had also chased (apart from the moderate/later high risk down south, that day was also expected to be favorable for tornadoes closer to the main surface low in northern Illinois), with just a band of grungy, featureless outflow-dominant storms forming. On top of this, the "CHECK ENGINE" light in the car I had at the time (2005 Ford Focus hatchback) had come on during the drive down, and I didn't know how serious it was. I drove home only to pull up GR Level 3 on my desktop just as the monster hook and velocity couplet appeared. Pretty sure I literally banged my forehead into my desk several times.

18 degrees this morning and still saw my first robin of spring.

3K NAM hinted at this which is one of the reasons I didn't drive 4-5 hours into IL. I think if we got some heating a little earlier (and maybe less midday convection in IL interdicting the moisture return) we could have had something more significant up this way.

New warning with cell in northern part of Dane Co.

Tornado warning on small cell in southern Dane County. This is why I stayed home lol. Edit: Gone. Was based on an IMO suspect funnel cloud report, velocity never showed much of anything.

Suddenly a severe thunderstorm warning here.

Satellite showing clearing pushing in there as well as NW IL. If I'm still going to chase today it'll be because something promising fires there.

Annnnd the clouds have thickened up again. Vis sat looks like we should be almost clear, but looking out my window tells a different story.

Sky starting to brighten here. @madwx

I think I'm cancelling chase plans for today. Anything north of at least I-72/74 is going to be messy garbage, and moving at 60 MPH (per the warning currently in Knox/Peoria Counties). Got too used to these (sometimes ridiculously) early season setups performing after 3/5/22, 3/31/23 and 2/8/24.

1630Z outlook trimmed all of WI and most of northern IL out of any risk above Marginal. 3K NAM runs were showing high EHI values up to the WI/IL border.

Ah yes, the PDS wienerhead outbreak.

It's the first run to come in range, but 0Z HRRR washes out the northern IL portion of the setup with a big MCS (left over from what develops tomorrow evening) Wednesday morning. However, it does break out a few dangerous-looking supercells along the Ohio River by 23-00Z.

...and with more favorable timing, at that (triple point pushing in at closer to 21Z instead of 18Z). A frustrating amount of flip flopping for inside of 48 hours from the event.

As I suspected; latest NAM crashed way down on the forecast EHI/STP values over northern Illinois compared to just 0Z last night.

Again, still somewhat skeptical on this as a widespread/significant outbreak which is why I think SPC was wise to hold off on an initial Day-3 Moderate. I could easily see a scenario where the northern part of the risk area (a.k.a. us) gets borked by morning convection and the southern part by veered low-level winds and outflow interactions (like yesterday).

Well that sure turned around quick. Wasn't I just seeing a bunch of long range outlooks that had positive anomalies in the East/Midwest?

Fatality reported at Valparaiso, IN, apparently due to wind rolling a semi truck onto a person.

Tornado-warned supercell southwest of Centralia, IL. Low-level rotation doesn't look tremendous, but definitely present.

Severe warned cell rolling through the northern Chicago metro.

Had a nice couple hours of thunderstorms rolling through early this morning. That followed by this afternoon's 70s and sunshine ought to kickstart the greenup around here. @madwx