The weather will remain seasonable in terms of temperatures through the weekend, with occasional cloudiness breaking over the ridge of high pressure that will remain just off the coast of California keeping us dry. High temperatures will stay in the mid-60s with overnight lows near the freezing mark through the weekend.

But as the holiday approaches, a very cold winter storm is looking more likely to move through the region, bringing snow to all elevations and causing the temperatures to plummet, not even reaching the freezing mark for the high on Thanksgiving Thursday.

I get this type of question a lot: “I have been running comparisons between three thermometers, two digital and one mercury, and they have as much as 10 degrees difference at times. In plotting the graph on each one they start out pretty much the same, but change throughout the day, one being higher and then the other being the high. Is this normal? Which are more accurate, digital or mercury?”

I’ll tackle the latter part of the question first: As long as they are calibrated, either type of thermometer should be accurate as the other, usually within a degree or so. But his problem isn’t with his instruments. I’ll explain tomorrow.