I count 14 if we add today since 2016.
I think the discrepancy is likely because Portland Airport did hit 98 on 6/11/1940, one degree higher than the 97 on 6/11/2019, but that was technically at the old airport location at Swan Island so it falls outside of PDX's period of record. The PDX station didn't officially go online until October 1940.
The 12z Euro has a 985 mb surface low on Wednesday. That's pretty ridiculous for the middle of June.
There's almost always potential failure mode(s) in a severe weather setup, but if things come together, this could get really ugly with a plethora of strong-intense tornadoes... more like what you would expect in the spring.
As far as somewhat recent events, this setup reminds me a bit of 6/5/2010. There's a stronger system and better wind fields this time though, so if anything, the ceiling may be higher.