"So that happened." Or perhaps, "We now return you to our otherwise uneventful lives." Had anything so definitive as titles appeared on the screen at the conclusion of Aaron Katz's third feature, Cold Weather , either of those statements might have served the purpose quite well. As it happens, one of the strengths of Mr. Katz's films, as well of those of his contemporaries, is a lack of definitive resolution. There are not so much stories as a day's or week's events. Lives don't dramatically intersect, but drift together and perhaps eventually apart. Rather like life. The first portion of Cold Weather begins in the unassuming manner of Katz's first two, brief features, Dance Party USA and Quiet City . It's a family dinner, though it's unclear at first whether the two 20-something participants are children of the parents in attendance or a couple....