GFS continues to predict monster storm, and oft-conservative NAM12KM predicts 10 inches of snow

UPDATE: Latest NAM12KM put totals up. NWS forecasters are still waiting for observations off the Pacific which will feed mid-range models to help determine true intensity/track of the storm, but the chances of this forecast changing by a great deal are slim. Biggest factor will be temperatures, and whether or not they warm enough to cause the mixing ratio to drop and/or cause rain for a period. Latest image below.

Confidence on this one is going in one direction: up.

The NAM usually doesn't put as much down as the GFS and winds up underballing heavy snow events. It's predicting 10 inches of snow for parts of SE Michigan as of this morning's run. The above image reflects this forecast. Here's what the GFS says:

Keep in mind that snow to liquid ratios are assumed at 10:1 in the above images. They can go up or down based on temperature. They also may or may not be properly gauging what effect the warm Lake Huron will have on the storm.

A Winter Storm Watch (or possibly a blizzard watch) is almost certain to be issued sometime today or tomorrow morning.