Potential Sever Weather Outbreak 4/27/2026

[pen_artist]

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.

[nvck]

Really, really rare to see this highest level contour on the CSU maps this far out

[sbnwx85]

Thinking another QLCS tornado threat this far east is best case scenario.