Issue of measuring snow the RIGHT way

[Planetsnow]

What is the issue? There are many, but here is just one of them: Snow, it turns out, needs to be "cleared" every 6 hours or so during a storm, NWS standard. The reason is because snow settles onto itself. Here is a snowplow paradox to help illustrate this.
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Say a snowplow operator plows a driveway 2 times in a 12 hour period. Each time there was 10" of snow that he measured right before he plowed it. How much snow fell during the storm? The correct answer, is of course 20".

However, on the neighbor's driveway that was NOT plowed during the storm at all, there is only 17" of snow on the driveway, if that! What happened to the missing 3"??? Did it melt ? Possibly, but not necessarily! The answer is that the snow settled as it fell on itself. Just like taking a fluffy feather pillow, 10" wide, and dropping another feather pillow 10" wide of top of the first one. Yeah, they were two 20" pillows.. but when the 2nd falls on the first one, it crushed the first feather pillow down just a tad, so the two pillows stacked together are now more like 17", right?
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Finding the snow in your town can be therefore tricky. The National Weather Service cooperative observers are getting pretty good at it, but don't always follow through to the end of a storm, and there is a mixture of good ones and bad observations. In addition, they don't report amounts under 2".

[vbhoutex]

Measure what snow? What is a snowplow?

Sorry, I couldn't resist!!