Particularly the thrushes. For a summary of status & distribution of Redwing and Fieldfare in the Northeast, check out my entry from this time last year.
Last year, that rare "Euro Turd" never materialized in these parts, but this year looks more promising. First we can go back to November when harsh early winter conditions in western Europe coincided with a mini-invasion of NORTHERN LAPWINGS into our region (one in Connecticut, one in Massachusetts, and several in the Maritime Provinces of Canada, particularly Newfoundland as expected). There was hope that other western European species with a history of crossing the pond would be found.
Recently there have been a few records of note. A Fieldfare in Quebec and a Common Chaffinch in Newfoundland. Multiple Redwings: Quebec, an unconfirmed report in Massachusetts, and THREE were found yesterday in Newfoundland. No idea when these birds actually arrived on our shores, but the recent Newfoundland spate of reports may be related to their weather. Newfoundland had apparently been enjoying a very mind winter until a couple weeks ago, and now the weather has become more typical for mid-winter including cold and snow. The recently-found rarities may have been hiding out for a while before being forced to relocate due to the harsh conditions...particularly the appearance of the Chaffinch at a feeder.
So, hopefully there's a European passerine somewhere in the eastern US just waiting to be found. For the thrushes, the best bet would be to check robin flocks.