Last year our launch was on the 12th. All signs were pointing to 4' until the freak rainstorm a week before launch combined with snowmelt to create 8+ historical highs around that time. By the 12th I think it was in 5-6' range but I had cancelled in favor of another river out of concern for members of the group. Thank god we were not launching 10 days earlier.
Hey, if you want me to take a dump in a box and mark it "guaranteed", I will. I got spare time.