If the PDO turns positive, then 1988-89 becomes the most obvious anti-log to this upcoming season.
1988 had a very warm summer, but a very cold fall, in the Eastern US.
This vacillation in the IPWP/PMM/PDO is intradecadal. This positive stretch likely lasts ~ 5 years, give or take a year.
The longer term/multidecadal elements of variability are driven by other factors/modes of interference.
Not sure I agree with pulling back the 5% tornado probs to west of the IL/IN border on the new SPC outlook. Indiana and the southern half of Michigan area looks largely free of precip by late morning or early afternoon (earliest with southward extent), so should get a chance to destabilize to a degree. Anything moving into those areas later in the afternoon into early evening could be more of a problem, imo. No guarantees, but if I'm looking for a "sleeper" area, that would be the area.