Web Extra: When Will the Snow Melt?

The short answer: it could take awhile!

Temperatures will climb into the mid 40s over the weekend and there should be plenty of sunshine. Without a doubt, that will help. However with so much snow packed in, the snow won't just immediately melt.

There are two primary factors control the melting of snow, according to researchers at Shuswap Lake in Canada:

• Air temperature
• Intensity of the sun

Secondary factors are

• Wind, wind speed and wind temperature
• Rain, rain water temperature and quantity
• Heat absorption properties of the ground (i.e. rocks, vegetation, loose soil)
• Angle of the sun in relation to the snow surface
• Snow density and consistence

Snow on the ground melts from top to bottom. Heat converts the snow particles into water and gravity pulls the water to the ground. Ignoring topics like energy and temperatures of the converted water the process is as follows.

The top layer of the snow pack absorbs the heat energy and causes the snow crystals to break down. At first surrounding snow crystals are able to bind the fine water drops. As they grow the gravitational force is gets stronger than the adhesive force and the drops start flow to the ground. This progress is actually far more complicated but not of importance here. The warmer water drops cause some pre-melting in the upper layers but eventually leak through the snow with no major effect to its consistency. The air temperature should be at least 5 degree Celsius to initiate that process. Heat absorption from direct sun light is usually much larger than from the surrounding air.