"Yes - our long-term winter data support what I call an "echo effect", in which the only significant time series correlation in winter numbers of great gray owls from year to year is that in the year immediately after an invasion/irruption year, there is typically half as many great gray owls as the invasion/irruption year."
There's not been a huge amount of great grays reported as of yet, but we are getting strong reports of snowy owls. In the last month in Minnesota there have been reports of snowys in Duluth, St. Peter, Rochester and Eagan. The Raptor Center even had an injured one brought in from Albertville. Looks like Wisconsin is getting quite a few snowy owls too. Take a look at Mike's post today.
A few years ago we had a November with several snowy owls reported and in a two week period, eleven snowys were brought into TRC starving. It was predicted to be a good winter for seeing them, but at the end of December there were hardly any more snowys reported. I wonder if this year will be the same.