Lastchance, I’ve seen “snow flies” as well. Size 20s. They do not provide surface action of any consequence on the j. The fly that we eagerly await for late winter dry fly action is Taeniopterix, a size 16, with size 14 wings. It is not the emergence that produces action. The trout take them as the females return to lay eggs in the afternoon, usually when it is sunny and in the high 40s to 50’s air temp. My pattern (see fly of the month) is not fished in the film…it floats high and dry and is often taken on a twitch.