If you’ve lived in the South for any amount of time, just the mere mention of freezing rain probably sends a shiver up your spine. Our winters are a mixed bag; sometimes we get a bit of snow here and there, sometimes it’s just several months of clouds and rain, but we’re in a special position, both geographically and climatologically – a position that makes this area of the country somewhat prone to ice storms of all kinds. Just a couple weeks ago as of writing this we saw the mayhem that can cause firsthand, with several days of shutdowns, road hazards, and bitter cold because of compacted sleet, snow, and… freezing rain. But how does that happen? If it’s below 32, shouldn’t it be snowing? The science behind this is really a pretty interesting case of “more than meets the eye”… so let’s dig in.
We can start with some fairly traditional knowledge with snow. As you may expect, snowfall is just the precipitation that occurs when a given column of air (up to where the precipitation forms) is below freezing.
Things start to get a bit more dynamic with sleet – we’ve seen plenty of these over the last several weeks, and the reason is that, in an example column of air, there is some WARMER air high above the surface that melts the snow into rain. It doesn’t need to be “warm” like we think of it – it can just be in the upper 30s, but that is enough to melt snow into water. BELOW this… it goes back to freezing! This freezes it the water again, but it’s now in the form of ice, and we see it as a mess of sleet and ice pellets. Sometimes, like we saw recently, that junk can compactify and cause ice trouble too.
Lastly, there’s the ever onerous freezing rain. The principle here is very similar to how sleet forms, but it requires that same relatively warmer mass of air to be much thicker in the atmosphere – everywhere but the surface, that is. It’s one of the most deceptive winter weather phenomena as well, due to it’s appearance as, well, rain; something people don’t typically associate with winter weather issues. However, if your surface temperatures (and ground “skin” temps, another fascinating topic for another time) are at or below freezing, the foundation is laid – and that water refreezes on your roads, your power lines, and your windshields.
Needless to say, these sneaky freezing rain events can be downright dangerous, so here are a few tips to consider ahead of time if you hear us ever talking about the chance of ice in the forecast –
1.) Consider investing in a generator! In a power pinch, even a cheaper unit can get you through the headache of power issues due to ice.
2.) Fill your prescriptions early! This is something a lot of people don’t consider until they’re all out and can’t leave the house, but doing this ahead of time could avoid a lot of problems and avoid putting you and others on the road during bad conditions.
3.) Hygiene products… stock up! Obviously, we all stock up on the “bread and milk” so to speak, but many people over look things like diapers, toilet paper, or even moist toilettes if water is in short supply.