(WFXR) – Winter weather comes in many forms: Heavy, wet snow…frigid Arctic outbreaks…and the occasional Nor’easter which can bring a combination of the two.
When people think of winter weather, one aspect comes to mind – snow.
Here, we’re not going to talk at all about snow – at least not in any great detail because there’s another aspect of winter to examine and that’s ice.
Ice can be broken down into two primary forms of precipitation: sleet and freezing rain.
Sleet is simply ice pellets that fall from the sky – similar to hail but altogether different.
See, sleet differs from hail in one significant detail. Hail is formed by vertical updrafts in thunderstorms. With each ascent back into the cloud, the hailstone becomes larger until the vertical updraft can no longer support the weight of the hailstone.
Sleet forms as snow that falls from the sky that melts into rain as it comes into a layer of warm air between the surface of the cloud and the ground. But as it falls to the earth’s surface, it encounters a layer of cold air (below freezing) that allows the raindrop to completely freeze into a pellet of sleet.
Freezing rain forms somewhat similarly with one key difference.
It, too, starts as snow at the base of the cloud where temperatures are below freezing. Then, as it falls, it comes into a layer of above-freezing temperatures, allowing it to melt into rain.
The difference here is that the warmer air is broader and the pocket of below-freezing air is closer to the surface, so as it comes into that colder air near the surface, it doesn’t have enough time to freeze, so it only freezes when it falls and makes contact with anything that’s below freezing.
Let’s say you’re sitting in your nice, cozy living room watching tv. You know that the temperature outside is below freezing and you’re hearing pinging. That pinging is sleet so if you’re ever wondering if there’s a way to determine what’s sleet and what isn’t, remember…sleet has a beat.
Freezing rain sounds like rain when it’s hitting the ground because it’s falling as rain. It only freezes when that rain makes contact with something that’s below freezing. That’s why you never hear the term “frozen rain” because that would determine rain that is frozen before it hits the ground. In essence, frozen rain is sleet because the raindrop freezes BEFORE it makes contact with the ground.
Back to freezing rain now.
We’ve all seen those signs on the side of the road that read, “Bridge Freezes Before Road.” Because a bridge has air that circulates above and below it, its surface is able to cool down more quickly. Because of that, a bridge is almost always something that will develop ice accretion before things like a normal road or sidewalk where only the top portion of the surface is exposed to the elements.
As ice accretion develops, more problems can surface. Light ice accretion of 1/10 of an inch or lower, usually doesn’t have much in the way of significant effects. As accretion amounts increase, we can see more problems over a wider area.
So, severe thunderstorms and landfilling hurricanes aren’t the only types of weather that can produce damage and cause long-lasting effects. Winter weather certainly has its place and causes significant problems for a large group of people from whole neighborhoods to whole counties to even whole states.
In short, remember…if winter weather is in the forecast, gather your necessary supplies, go to the grocery store, prepare your generator (if you have one) and simply wait it out. If you don’t have to travel…don’t.
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