How no snow cover amps up our temps

MINNEAPOLIS (KMSP) - The first victim of any warm up is our snowpack. The snow shrinks to a point where the ground is exposed and the landscape looks more like fall or spring than the dead of winter. As we continue with the 2016-2017 winter season, the Upper Midwest continues to see dismal, if not nonexistent, snow cover. Its not just February, last year on Valentine’s Day we have 2 inches of snow cover and in 1967 we had a record breaking 31” snowpack.  Below is the latest snow cover as of Valentine’s Day 2017.

You will notice that I have drawn a few arrows on that map. This is to point out that when we receive our warmer wind flows out of the south and southwest, that those winds as of lately are blowing in over bare ground. Why is this important you ask? Well, it all has to do with albedo, the reflection of the sun’s energy, aka heat.

The blanket of snow can zap as much as 10-12 degrees from the warm air mass passing over it. This depends on snow depth and the area of coverage, but nevertheless, 10° is a lot of warmth this time of year. Just think, if we had a normal snowpack, this upcoming warm up would have only taken us to the upper 40s to near 50° and not to the threshold of record breaking temperatures near 60°.

The lack of snowcover also helps us at night as the warmer ground gives off enough heat to add a few degrees to the temperatures.