It is underway. I know because a couple days ago saw an UFB (unidentified flying bird) that was a Warbler on the yellow side.
Today on the porch as Kelly Flint sings, have seen 2 UFBs. One on the yellow side and one on the grey side.
I could guess at them, but no need. In time they will return.
Post your sightings, and if possible - photos.
One year some of us had great fun with Fall Migration.