No, you were spot on. You measure and clear every 6 hours. Youre welcome to measure every 30 minutes, 40 minutes, hour, whatever you want to check on rates, you just don't clear it. If you clear less than every 6 hours you will be inflating your total and if you clear more than 6 hours you will be lowballing it. Of course this is if it is snowing, obviously as soon as a snowfall stops is the best time to measure it. In all of these rules apply when there's not a lot of wind, obviously when it's a windy storm snowboards maybe useless and you will need to just take a ton of measurements to get an average.
The storm really hurt lol, I think mainly because of the start we've had to this Winter. Most of the areas that got hit with this storm are areas that were definitely due based on recent years. The SE MI snowmagnet could not pull in a single flake with this one. Snow literally hit a wall, as expected.