Apparently a giant snowball fight is being organized on Facebook to take place starting at 2 p.m. on Sunday. Participants are encouraged to build snow forts a day earlier, and to abide by various rules of fair play (adults only, no ice, no ink, no shots to the face)
The event page says Jeanne-Mance Park, but they actually mean Mount Royal Park, near the Georges-Étienne Cartier statue near the corner of Park Ave. and Rachel St. (Jeanne-Mance Park is the one on the East side of Park Ave.)
The Facebook event page has 280 “confirmed” in attendance, but those numbers are always heavily inflated. Expect a few dozen to show up.