The bird has a bright yellow breast/throat. The yellow does not extend to the upper head; noticeable white spectacles, dark beak, gray head and body. The back is almost gray/olive. Belly and rump are white.
An expert here thought it was probably a Pine Warbler but he not see my pictures. I question that since there are no white wing bars and the white at the eyes is pronounced. However. A Chat siting would be rare here in the winter months.
I'm new to this and would love to hear from more experienced birders.