Complex sentence: It was the largest single day tornado outbreak in Ontario since May 31,1985, with two F2, three F1, three F0 strength confirmed tornadoes and one additional (as yet unconfirmed F0) bringing the total to 8 (or possibly 9).
Split into simpler sentences: It was the largest single day tornado outbreak in Ontario since May 31,1985. The final reports counted two F2, three F1, three F0 strength confirmed tornadoes and one additional (as yet unconfirmed F0) bringing the total to 8 (or possibly 9).