"Cold-core" setup?? I am planning to chase far eastern NE/extreme western IA tomorrow as it looks like there could be a localized sweet-spot near or just north of the developing surface low by early-mid afternoon… as a powerful upper low ejects northeastward. The NAM and RUC models both depict a north-south quasi-stationary front position north of the surface low which may act as source of rich vertical vorticity which seems to be a very important ingredient for tornadoes near closed cold-core upper lows. I am heading to Kansas City this weekend anyway, so this chasing location really won’t be all that bad for me… as I’ll be heading back "home" home (Overland Park) after this chase to spend the rest of my 3-day weekend with fam and friends. Below is a surface forecast chart from this evenings NAM model run with the white transparent oval indicating my first-guess target area:
