Night-time minimums offer the best picture because they are now into the long nights.
This air mass is moving very slowly, and may freeze the US East. Then natgas prices will go up. We are being saved by Hudson Bay, which has been very warm and is now finally freezing up. This is just weather, since it is cold.
ps. the one in Europe is building a core, as well.
pps. if the core moves down, then this is a 'hybrid' of clairslide, and stagnant blob.