Rochester, N.Y. – It has been described as being a pretty view of the natural landscape when there is a thin layer of ice.  However, it starts to get ugly when the ice gets thicker and heavier and brings down the trees and power lines. Many folks remember the great ice storm of March 1991 as a poignant example of this. In the worst ice storms, it is estimated that an average size twenty-foot evergreen tree has tons of added weight because of this ice.

What is the mechanism that actually develops this kind of meteorological scenario? It is best understood this is to imagine a three-dimensional view of the atmosphere when warm, moist that rises up over the top of the colder air. This movement of air is similar to a hot air balloon because the warmer air is lighter, less dense. In this case the air will rise. But the main focus is the ultimate depth of that cold layer located below, at the surface of the Earth. If that freezing air is shallow, any rain that falls into the cold layer will freeze on contact and over time produce a glaze over everything it touches. If the layer of cold air is a little thicker than it is more likely to produce sleet.  And if the most of that column is just cold air than we would likely see all snow. 

The problem occurs when these weather systems are moving and migrating across the country and ingredients change from one location to another.  Then these different types of precipitation will also change.  “Fun times” for the News10NBC First Alert meteorologists.