Winter Riddle - Snow Height

Thx guys. As a side note: In the last ten years, the worst snowfall here was ~12". It seemed to be very fluffy, but underneath it, on the 200' long, 21% grade concrete driveway, there was a thin sheet of ice; making it impossible to get completely home.

Declare war on ice give geomelt a try.

Good morning bwire. Thx for the reference. I was noticing on their website that it says it reduces salt by 30%, so I'm assuming to get all the benefit, I'd want to scatter salt as well. Also, I was wondering how much would remain on the driveway, since it has a steep slope.

For situations which salt is routinely applied adding geomelt reduces the quantity of salt necessary to accomplish the task. Adding geomelt to salt lowers the effective melt range of salt from 20°F to about 0° depending upon ratio.

Geomelt's effectiveness is not enhanced by adding salt.

Depends on how wet the snow is and how long it's been there. Freshly fallen, fluffy snow will be perhaps 4 feet high. Packed, it'll be maybe 2 feet.

As you can probably imagine - the density of snow varies greatly.

However, according to this site:

http://www.islandnet.com/~see/weather/almanac/arc2007/alm07feb.htm

Typically winter snowpacks have a density of 200-300 kg per cubic metre (12.5-18.7 lb per cubic foot).

Therefore, you need approximately 2 feet of depth for 30#/sq ft.

From CoronaCameraMan -

From my hydroelectric power days - it was said that a foot of new snow was an inch of rainfall / water.

A cubic foot of water is 7.48 gallons.

A gallon of water is 8.3453 lbs.

A square foot is 12x12= 144 in2.

A cubic foot is 144x12= 1728 in3.

30lbs-ft2 / 8.3453lbs/gal = 3.59ft2/gal

Ratio 3.59ft2/gal / 7.48gal/ft3 = 0.48 and 12in*0.48 = 5.76in water in a ft2 area

5.76in water * 1 inch water/ft of snow = About 5.76 ft of new snow for 30#/ft2.

Now determine what the run-off rate is in mountainous terrain on a sunny day versus a rainy day ?

The sun doesn't get below the pines so there is little run-off. If the ambient temp gets above freezing there is snow compaction due to surface melt trickling into base layer.

The rain gets soaked up by the snow, and released gradually, until snow saturation and then continued rain starts the flooding deluge where new rain plus stored snow and rain runs off which creates the 100 year and 500 year floods. Slopes have a lot more surface area per square mile.

Good morning Guest. Thx for the observation. It is very enlightening.