February 11, 2015: Last Friday, the official snow depth for Rockford (measured at the Rockford airport) was measured at 12″. Heading into today, the depth is down to half that value.
The above freezing temperatures over the weekend went a long way to melt off some of the snow. That is the primary reason for losing plenty of snow pack. The difference between this weekend’s melting and ones previous this winter is the added influence of a higher sun angle and the increase in daylight. This is why we were able to melt 6″ of snow in roughly 3 days rather than taking more time than that.
In the heart of the winter, the sun is low on the horizon, so the sun’s energy is coming in at an angle, and isn’t all that intense. The daytime hours are also very short, so there isn’t much time to provide a lot of energy.
Now, the sun is higher in the sky, so the sun’s energy is more directed at the ground rather than at an angle to the side. Because the energy is more directed at the ground, the energy can be more intense, helping heat the ground or snow up quicker. The longer days means more energy being put into the atmosphere.
This post was written by Alex Kirchner on February 11, 2015