If it was really the size of a blue jay, it was probably a juvenile Sharp-shinned Hawk. If it was the size of a crow, it was more likely a juvenile Cooper's Hawk. The size ranges of the two species do overlap a bit, so it is difficult to say for sure from this photo.
It is a juvenile Cooper's Hawk. Adults have a reddish brown and white breast with a horizontal scaly looking pattern. Juvie's like this one have dark, vertically oriented, teardrop shaped markings on white.
Common Yellowthroat is likely, but there might be other possibilities. Have you tried the Merlin Bird ID app or website? You can enter your description and it will offer photos that you might be able to match with your bird.