Why does it say we got 21 inches of snow?

Question

I live in rochester, NY. The recent Valentines Day storm cancelled our college classes and that was great... but me and my roomate have been debating for a few days now exactly how much snow fell. He is looking at reports from the area which say we got 21 inches... I have been outside walking through the stuff and the deepest i have been in is no where near that or so it would seem. (deepest was about at my knee... and im about average height) this would lead me to assume we got about 12, maybe 13 inches at the most.

There was some blowing... but could that really cause a 9 inch discrepency all over?

Answer 1

If you're average height, then if your knees are only 12-13 inches off the ground, you must look really peculiar. Your knees are more likely about 18-20 inches off the ground, depending on your footgear.

The real answer is that there is one particular place they measure in each city for the "official" precipitation, windspeed and temperature. YMMV.

Answer 2

Snow packs as it rests on the ground, and falls vary across the reporting area from the airport or weather station where it is measured hour by hour.
The number of inches of snow reported in urban areas is not done by measuring the actual snow (because it blows and drifts and falls unevenly) but by capturing the snow, melting it and measuring the water and multiplying by a fixed factor or by measuring the snow density to get an average figure. The souce points out that 10 inches of snow = 1 inch of water is used at times while actual snow can be from 3:1 to 100:1.

Answer 3

I live in the Buffalo area.The measurments are taken from an area that is not suspectible to the wind etc.They measure it from an undisturbed area.Snow totals can differ from across the road! The amount you see, if it was that high, can have been compressed by the weight of the snow above it.Alot of times they take the largest amount from a similar area.We could have gotten 7 inches but 15 inches in the next town over.Lake effect is hard to measure.I would say it was probably an undisturbed area that has seen compression if any.