Here goes: I have three candidates; borealis may winter there; coronatus may winter there; and trivirgatus trivirgatus shoud be resident. I will eliminate trivirgatus for the following reasons, of just about all Phylloscopus species trivirgatus has the smallest spiky-like short little bill of the genus - this one has too much bill. Moreover, I just can't see the amount of black on the head that I should see. The differentiation of the other two is more difficult. First, the photo itself has a flash-point right on the lower belly. This seems to wash-out any color existing near the vent, and throws the upper belly and breast colors into shadow. Another problem is that there is a twig intervening in the view of the caudad extent of the supercilium. The supercilium itself would appear to have a yellowish tinge, and not whitish or buff. I think I can possibly make out that there should be some yellow at the vent in spite of the flash point. Therefore, my guess is that this may be Phylloscopus coronatus.