Icy polar winds have been coming down from the north & sweeping over the (relatively very warm) Great Lakes. Those winds picked up masses of water, which they then promptly dumped as snow on the next available target (mostly, it seemed, Buffalo). It has been doing that for a week or so, and recently relented for a day or two.
Hah! Fooled you. The whole thing is due to start up again.
--------- Alex Kemp