Hopefully airlines are canceling flights already. If the GFS verifies STL, IND, MDW, ORD, DTW, CLE, PIT will have a ground stop at some point on one of the busiest travel days of the year.
Going to be a fun day at O'hare on one of the busiest travel days of the year. When O'hare has to cancel flights it usually effects almost every other airport in the country.
The Euro has upper level support for it's initial coastal low. The 18z GFS does not. It forms just cause of an arctic high hitting the gulf stream and in an area of rising heights.