The winter of 93-94 froze the river like that. Used to cross the Memorial Bridge every day. Stayed frozen for quite a while. Some of the saltwater inlets up here a frozen.
Maybe some sublimation. Back in 78 we had a 20 incher a couple weeks before the blizzard. Got wiped out by that big storm that buried the Midwest. Would have been a great pack if that didn't happen.