CheeselandSkies

HRRR now shows us getting an additional 2" from now through 12Z Sunday (and up to nearly 6" in Sauk County, they always seem to get doused in these setups, with devastating flooding in 2008 and 2018). @cyclone77 is in the screw zone from SE IA through NW IL, though.

Interesting tidbit from SPC at the bottom of today's 13Z outlook: I'm glad they started putting this type of thing in there. A common mistake people make (and I used to make) when looking at those probability maps is to take them to mean that everywhere within that percentage zone has equal chances of seeing that type of severe weather threat, therefore in terms of chase targeting "one spot is as good as another."

That had to have been an extremely rare set of circumstances, it's almost unheard of in this part of the country apart from that one event. Dixie once in a while, but here by that time of night any discrete supercells have either died off due to boundary layer decoupling or upscale growth into an MCS/QLCS has occurred.

Smells and feels a like a tropical rainforest outside right now with a very fine/atomized rain falling. Sent from my Pixel 4a using Tapatalk

One pre-NEXRAD era event that I wish I could go back and look at on modern Doppler radar is the June 1984 Barneveld, WI F5 which struck around midnight. As we've seen, nocturnal significant tornado events in June occur from time to time in the upper Midwest, including this recent DuPage County tornado and the Wisconsin outbreak from June 2014. However, in those two the tornadoes were produced by a QLCS and the intensity max was low-end EF3. I'd be curious to see whether the Barneveld tornado was an exceptionally violent QLCS tornado, or came from a discrete, classic supercell that somehow managed to persist that late at night.

So the raw numbers may not be unprecedented, but I suspect that sort of longevity is.

That cluster late this morning (which killed instability around here for later) mostly missed Madison just to the north. Now getting missed to the north and south:

Rather prolific lightning on this cell coming towards me. Sent from my Pixel 4a using Tapatalk

Slight risk expanded some across southern WI at 13Z, I'm now solidly in the 15/15/2.

MCS up north of Stevens Point will miss us to the north/east, one in Iowa will miss to the southwest.

18Z models seem less supportive of a chase-worthy severe weather threat within my range either tomorrow or Friday afternoon. Sigh.

If these waves keep coming like this in September...watch out.

Models seem to be all over the place on where the most conducive environment will be Thursday and Friday afternoons. For quite a few runs central Nebraska looked pretty good (out of range for me unless I took tomorrow/Friday off). Now this morning's 12Z NAM suggests south-central to eastern Iowa (LIES!!!) to north-central and northeast Missouri (yuck!) and even west-central and northwest Illinois. Meanwhile the 3KM NAM highlights more eastern Kansas and west-central Missouri (likewise out of my range). NAM also paints a rather interesting/perhaps even ominous environment across parts of west-central Illinois (Jacksonville/Beardstown/Springfield area, roughly ground zero of the December 2018 outbreak) Friday afternoon/evening.

Latest NAM is a lot farther south with the favorable parameters (closer in line with GFS) on Friday afternoon. Gonna have to be ready to fly south as soon as I get off work if it looks chaseworthy.

2005 was extremely active (state record yearly total, state record outbreak on August 18 including the long-track, killer F3 Stoughton tornado). 2004 had also been very active. 2008 and 2010 were also rather busy but you are right in that ever since has been very quiet. We had an outbreak in June 2014 (actually, same day/evening as the Pilger family in Nebraska) but that was late at night and from a QLCS, not unlike the Chicago suburbs tornado that just happened. 2017 had a long-track EF3 in May but that was waaaaaay up in the unchaseable Northwoods.

Would be nice to see the NAM slow that front down for Friday, still, about 1500 j/kg MLCAPE progged at 12Z on the latest run. Even trips a PDS TOR sounding (although contaminated).

12Z NAM @ HR60 says HELLO!

I just realized yesterday was six years to the day from my 2015 chase in almost the exact same area of Iowa...didn't produce any visible tornadoes but did likewise produce a gorgeous sunset-lit mammatus display that is still my avatar pic (mainly because I haven't seen anything better since).

Attention now turns to late this week. SPC: Will these days provide any quality chase setups in the form of discrete supercells producing visible in the 22-01Z timeframe? Given the way this year has gone, the smart money is on "fat chance" but I haven't really looked at any model data yet. Probably still too early for it to be of much help pinning down things like storm mode/timing, anyway.

I chased the 15 hatched in Lie-owa that day and it was completely pointless, zilch in the way of visible, supercell tornadoes*, so comparisons to that day made me go "HELL no!". *Of course, a week later there was a gorgeous tornado near Traer without a watch even being in effect.

Ugh. I had all but written this event off for sig potential due to lack of afternoon recovery. Why do they have to happen at night, from a QLCS, in a city?

Storm looks to have lined out. Another tornado warning is east of Sigourney or near West Chester. Edit: New one near Fort Madison in far SE IA, actually looks decent on radar, at least reflectivity at 7,200' up. MKX has issued a SVR for Rock County, WI for a storm moving northeast out of Illinois.

Dang, was not expecting a warned cell there. Had written this day off per my earlier post. That said it looks fairly messy/HP on radar.

Insufficient recovery between rounds for WI/N IL/E IA...as I suspected. Sent from my Pixel 4a using Tapatalk