pen_artist

If you play your cards right you might catch a few quality boomers today!

Got a good three week trip this May so somewhat glad for this lull while I am away

I feel like if there is really any chance at svr in NIL it would be late evening. 10 and 11z (haven't look back more) hint at at least thunderstoms with some rotation moving through the 9 PM -12 AM timeframe.

Large D4 30% contour for much of IL and parts of WI, IN, IA, MO, AR, TN and KY. Mention of strong tornadoes but not as strong of wording as I'd expect. Regardless, shaping up to be another all hazards possible event especially if things can remain more supercellular. ...DISCUSSION... Latest medium-range model output suggests that a significant short wave perturbation emerging from the Southwest will pivot northeast of the middle/lower Missouri Valley, into the upper Great Lakes region, Monday through Monday night. It appears that the warm sector of an associated sub-1000 mb surface cyclone will become characterized by at least moderately large CAPE, ahead of the dryline/cold front overspreading much of the middle Mississippi Valley during the afternoon into evening. In the presence of strong deep-layer shear, organized severe thunderstorm activity appears probable. It remains a bit unclear the extent to which sustained supercell development will be maintained, as opposed to convection quickly growing upscale into one or more clusters/lines, but there appears at least some potential for a few strong tornadoes, in addition to large hail and potentially widespread strong to severe wind gusts.

Very large warm sector with much of the western sub highlighted in the 15% for Day 5, Monday 4/27

90 mph warned winds headed toward Davenport

MD on that Rockford cell Mesoscale Discussion 0480 NWS Storm Prediction Center Norman OK 0442 PM CDT Fri Apr 17 2026 Areas affected...Southern Wisconsin and far northern Illinois Concerning...Tornado Watch 129...131... Valid 172142Z - 172345Z The severe weather threat for Tornado Watch 129, 131 continues. SUMMARY...Leading supercells across northern Illinois and southern Wisconsin will likely pose a tornado (possibly significant) and very large hail threat as they move downstream over the next 1-2 hours. DISCUSSION...A pair of leading supercells continues to precede a broken line of storms along the IL/WI border. Regional radar imagery continues to indicate that these cells are rather intense with a three-body scatter spike, a bounded weak echo region, and a recent 3-inch hail report noted with the southern storm. An improving downstream convective environment is noted in recent observations and analyses (0-1 km SRH values remain between 200-250 m2/s2 per the KMKX VWP, and STP values have recently increased to 2-3 per recent mesoanalysis). Additionally, the southern storm will also likely propagate along a subtle surface theta-e gradient draped across northern IL to southern WI. Given these trends and the presence of a well-established updraft/mesocyclone with the southern cell, the potential for very large hail (likely in excess of 2 inches) and strong tornadoes will likely persist for the next couple of hours downstream into southeast WI and far northern IL. ..Moore.. 04/17/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...MKX...DVN... LAT...LON 42138771 42158906 42268948 42378957 42608965 42798955 42968903 43188791 43108770 42848764 42588767 42138771 MOST PROBABLE PEAK TORNADO INTENSITY...140-170 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN

Pretty scenic live cam of the Rochester MN tornado

@andyhb What are your thoughts on QLCS tor threat in Chicago area?

One of the worst too when it comes to the overhype

Watch extended into DuPage and Cook counties

Good point, guess I was more so referring to sups but yes models have been consistent in showing that. Definitely some touch and go to it. 15z HRRR wants to fire a mean storm over N Lasalle Co around 00z, so first hints of maybe some more initiation in NE IL.

Feeling more like a Chicago split right now but will see

Bit of an appetizer ahead of likely busy next few days Mesoscale Discussion 0395 NWS Storm Prediction Center Norman OK 1103 AM CDT Mon Apr 13 2026 Areas affected...portions of extreme eastern Iowa into western...central...and northern Illinois Concerning...Severe potential...Watch possible Valid 131603Z - 131730Z Probability of Watch Issuance...40 percent SUMMARY...Some hail (possibly over 1 inch in diameter) may occur with gradually intensifying storms over the next few hours. It is unclear if these storms will pose the greatest severe risk this afternoon, or if the greater risk will occur with later storms. DISCUSSION...850 mb troughing is underway across the Plains states into the Midwest, with 15Z mesoanalysis showing the northeasterly terminus of a LLJ currently positioned along the IA/IL/MO border. Here, an 850 mb Td gradient exists, with modest WAA likely supporting the gradual intensification of elevated convection within this regime. The 12Z ILX observed sounding and 15Z mesoanalysis depicts 700-500 mb lapse rates in the 8-8.5 C/km range, contributing to MUCAPE approaching 2000 J/kg. These storms are encroaching on a region of stronger 500 mb southwesterly flow, driven by a departing upper trough over the eastern U.S., which is resulting in 30-40 kt of effective bulk shear ahead of the storms. If storms continue to intensify, it is plausible that at a hail threat may materialize over the next few hours, with some stones potentially exceeding 1 inch in diameter. Short-range high resolution ensemble guidance is providing mixed signals regarding the evolution of this convection. Some deterministic CAMS show that the ongoing storms eventually consolidate and develop into stronger supercell structures in northern IL by afternoon. Other guidance members depict the ongoing storms oscillating in intensity, while stronger storms develop later. As such, there is an appreciable degree of uncertainty as to the evolution of the longer term severe threat with these WAA storms. All this being said, convective trends will continue to be monitored for the need of a WW issuance. ..Squitieri/Guyer.. 04/13/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...LSX...DVN... LAT...LON 40829153 41349115 41809076 42269021 42318942 42178872 41918839 41478835 41028850 40608866 40238895 40058932 39988999 40039043 40249121 40829153 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

Illinois and warm fronts this year

And obviously still conditional but SPC covering the possibility of more robust severe tomorrow. Definitely all dependent on morning convection

White Sox have cancelled their home opener in anticipation of tomorrows svr threat and rain

Definitely can't complain about the weekly opportunities we have had for severe the last few weeks. To me, it is feeling more active than last year around this time. But I will admit I haven't actually gone back and verified. Speaking specifically for NIL.

Stoked for you!

Enhanced risk introduced. For LOT CWA essentially the Eisenhower and south. Figured it might be worth a thread.

Good breakdown by Trey on the Kankakee supercell

Man, would've been a lot of damage reports if things were leafed out. Glad that isn't the case

Thread here:

How much further north will the warm front nudge? Still about 36-48 hours to see but looking like our first crack at some true severe for Central and N IL. Also storm initiation a slight question with the latest 00z models, specifically NAM3km.

Insane radar presentation with that MI cell. Definitely something on the ground. Getting shades of the tornado supercells in Portage back in May '24. Edit: Confirmed, pretty large cc drop.