Nighttime snowfall to play a key role Wednesday morning. We explain why.
It's fairly obvious that sunlight provides us warmth during the day. But, even in the heart of a snowstorm, with thick cloud cover and snow falling, it can have a dramatic effect on how snow accumulates.
The sun is always emitting energy and these effects can dramatically increase the later in the year that snow falls. That's why heavy snows can be so much harder to come by in late March and April.
The sun is up longer and it's at a more direct angle in the sky, preventing efficient accumulations.
When the sun emits energy, it's not only the ground receiving warming radiation, but the clouds and individual snowflakes get "treatment" as well.
When we see the milky gray color of the clouds, that is energy from the sun being reflected to our eyes.
The sun can also help warm snowflakes up as they approach the surface of the Earth. In some cases, especially when temperatures from the Earth's surface to the clouds are near freezing, snowflakes can partially melt. At that point, snowflakes are typically goners. Especially on roads and treated surfaces.
Elevated surfaces have more cold air to surround them and this can typically lead to some, albeit very slow, accumulations.
At night, incoming radiation greatly decreases. Anything left over will dissipate throughout the atmosphere, or be reflected back into space.
This loss of energy acts to cool the atmosphere, along with the snowfall (which acts somewhat like ice cubes in a drink to cool the air).
Another reason snow accumulates faster, particularly on roads at night, is due to a loss of vehicle traffic. Friction from car tires can help warm asphalt, slowing down snowfall accumulation.
Much like last week's snow event, snow accumulation on roads increased quickly when the sun set. Most of tonight's snow is expected to fall at night, too.
All of these factors will lead to greater impacts on the roadways by the time we get to the morning commute.
Stick with ABC 17 News as we continue to track the snow tomorrow morning with live team coverage starting at 5 a.m.!
-Luke
