I can give you some anectodal info: Thursday was the first day of the cold snap – I wasn’t around, but I think that’s right. Saturday afternoon I drove down to lake MacBride to see if anyone was fishing. It’s a 1000 acre impoundment with little or no flow during the winter. Easily 3/4 of the lake was open water still, and there were only a couple of shaded bays where people were on the ice.
Sunday I drove back down, and the whole lake surface was frozen. Where there had been a skim before, there was now about 4-5 inches of good ice. Where there was open water, it was still unsafe, but I would guess by tomorrow (Tues) the entire lake will be safe for walking.