Snow, Snow, Snow

The last two days in the Kansas City area we've had quite a bit of snow, around 8 inches at my house. This comes after two previous weekends where weatherpeople were predicting massive ice sheets and snows ("the storm of the century" as one TV personality put it) only to receive a dusting each time. Understandably, they were a bit more cautious in their predictions this time and most stations underpredicted by 4 to 6 inches what ended up being our accumulation.

Apparently, in an effort to defend weatherpeople everywhere I saw a local forecaster last night hold up a 16 oz plastic mug like you'd get refilled at 7-11 and note that a cup this size when turned to snow would cover Arrowhead stadium's field to the depth of an inch. He pointed out that since small differences in precipitation can lead to major difference in snowfall, that it really is quite difficult to predict how much snow will fall.

Now, I'm not generally for bashing weatherpeople (except when they stand out in the snow to tell us its snowing) and I realize that weather is perhaps the most variable business you can be in. However, I was suprised by the comment and decided to check out his claim. According to my calculations....

1. To cover a football field to a depth of 1 inch would require 106 cubic meters of snow. I calculated the volume as (l*w*h) = 91.4 meters * 45.8 meters * .0254 inches in a meter
2. Snow is on average 1/10th as dense as water, in other words 10 centimeters of snow is equivalent to 1 centimeter of water. So the amount of water needed is 106 * .10 = 10.6 cubic meters of water
3. To figure how many gallons of water this is I found the conversion factor of 1 gal = .003785 cubic meters on a web site. This then calculates to 2,805 gallons of water (10.6/.003785)

This seems like a lot more water than our weatherman had in his cup. Since I may have misheard him I thought perhaps he had said "to a depth of 1 cm" rather than 1 inch but that of course would still take 1,104 gallons of water. Still, I may not have heard his statement correctly but...

The general rule of thumb is a 1 to 10 conversion. So, 8 inches of snow would be .8 inches of rain, certainly less but still a significant amount of rain. I think weatherpeople would be better served simply to blame it on the computer models and the fact that weather is just plain hard to predict and let it go at that.