30” is tough for any given one spot. For ORH, there’s 3 such storms on record. If you want to count 1888, that makes 4 (they had 32” in that storm but the official records didn’t begin until 1892 there).
BOS has zero 30” storms on record. Though they have come close on a number of them. Parts of SE MA have had several (1978, 2005, 2015).
Then you have NE MA where some spots have had a few...Feb ‘69, Dec ‘03 (in a narrow swath), Jan 2015 a little further west toward northern 495 belt. But you’d be hard pressed to find a single point that has more than 3 I’d imagine.
Now, there’s definitely no shortage of 20”+ storms in eastern areas. Most places have double digit storms in the 20”+ range.