Raining snowballs

I was planning on looking this up elsewhere, but instead I thought
I'd give the amateur meteorologists here a chance to strut their
stuff. Saturday afternoon, we were under a threat of rain all day, and
the lake effect moisture off Lake Ontario was promising to deliver.
The sky was both interesting and menacing; and the occasional rumble of
thunder in the distance kept our attention skyward more than usual.

Then the precipitation started. Just like a summer downpour, it poured
from the sky in mass quantities; no lightning, no thunder, very little
wind. The odd part is, it wasn't rain, it was snow. Not a regular
"thundersnow" like I've seen plenty of times. No, it was a
veritable downpour of snowballs; little round snowballs about a quarter
of an inch in diameter. It wasn't hail, it was far too soft. It
wasn't exactly sleet either, at least not like sleet I've seen
before. It was little balls made up of tiny little snow crystals. If
you squeezed one, it would easily crush just like a snowball.

Because of the thunderstorms in the area (we never got one), I have to
assume those updrafts had something to do with the formation of this
stuff; but I've never seen anything like it. It was brief,
beautiful, and even a bit funny to watch bouncing off the ground and
the fishermen. Air temps at the time were probably in the low to mid
40s if that helps. Anybody have a name for this stuff or how it's
formed?