Yeah, it looks HUGE! I don't know what kind we have around here. I hear them at night but this is the closest that I've gotten to seeing them before. Except juveniles. You'll catch them out in the afternoon every now and again, which always shocks me because I thought owls were nocturnal. But I guess when you are newly out on your own and hungry, you try to go look for a meal, no matter the time of day.
ETA: After some quick research... It is probably a Barred Owl.
This is a better look at it and what it sounds like. Is a distinctive call. I've definitely heard this call.