Ok, pop quiz hotshot. The weatherman just called for freezing rain... but do you know what that means? Many times when it comes to winter weather, people get sleet, snow, freezing rain, and ice all mixed up. And don't even start with hail or graupel.
Yes, there are some distinct differences between all these winter weather precipitations. What it all comes down to what is going on the atmosphere when the precip is falling. Let's discuss.
Whenever precipitation falls out of a cloud it falls as snow. In the summer, all the layers of the atmopshere are above freezing (above 32 degrees), so when those flakes fall down to the earth they melt into water and hit the ground as liquid raindrops. In the winter however, some layers of the atmospere are below freezing... and that's what distinguishes the different types of precip. When the snowflake is falling, if it runs through a warmer layer it will melt - like a raindrop. BUT if that warm layer is thin, it will encounter another cold layer of air and will have enough time to freeze into a small ice pellet. This is what we call sleet.
Freezing rain is similar, with one major difference. The snowfake will still fall, encounter the warm layer and melt into a raindrop. But the warm layer here is thicker... so it will stay a raindrop longer. The raindrop will eventually hit another cold layer, but it won't have enough time to freeze into an ice pellet. So it will end up hitting the ground as a raindrop, but as soon as it hits the ground it will freeze (because the ground is frozen). This is what we call freezing rain.
At this point, you've probably figured it out... in order for the precipitation to stay as snow, there has to be NO warm layer. The snowflake will fall from the cloud, stay in an atmosphere layer that is below 32 degrees, never melt, thus hitting the ground in that snowflake state. In case you were wondering.
It appears that overnight Thursday we'll see a chance for freezing rain AND sleet north of the lake. Friday doesn't look much better, with a chance for freezing rain north and west of the lake. Friday night we'll likely see some sleet again with a small chance for some snow flurries. So, no one wants to see any of it... but at least now you know the difference!
