ajohn

This bird looks to me very like Eastern Crowned Warbler: large size, heavy bill with totally pale lower mandible, bright green above, pure white below, yellow undertail coverts, pale legs, supercilium shape, etc. But the lack of crown stripe does not fit for Eastern Crowned and it would be an unusual date.
It doesn't look like Greenish in my opinion but I have no other idea about what it could be.