I'm not going out this youth day,(my daughter's 17 now) but we did that every year. The farm in andover has a resident flock that roosts on a particular hill. They always hit the nearby fields in the morning. We just set up the ground blind the day before where we find new tracks in the field, and show up before sun up. Lots of times the Tom's would pitch off the trees on top of the hill and fly down right in the field in between the decoys. But even when they don't, eventually they show up. A D.S. with the sound off often helps pass the time for the kids too. Just make the experience as fun as possible.
And yes they will still be gobbling in the rain