Bill Burton: It's time for us to take a look at the Science Behind the Forecast as I am joined by WAVE 3 meteorologist Tawana Andrew. Good morning, Tawana.
Tawana Andrew: Good morning. Thankfully, everything's pretty quiet around here right now, but that hasn't been the case the past couple of weeks.
BB: No, it's been an active weather month or so and, well, it is winter, and it may come back at pretty much any time. So that kind of leads in to what we're talking about today, and that's taking care of the roads with salt and or brine. What do we need to know about that?
TA: Well, salt and brine, that's typically what you think of when we're thinking about what's happening to the roads, and how do we keep them clear during the winter months, right? And they're used, of course, before, during and after winter storms, to make sure that travel is safe across our area. So for salt, it is perfect for removing snow and ice, or at least keeping them from sticking to the roads in the first place, since it helps to lower the freezing point of water. So salt is best when temperatures are over 15 degrees. And by salt, I'm talking mainly about road salt that we're so used to. And when, when you have water that contains the max amount of dissolved salt, it actually helps to drop the freezing point down to zero. Beyond that point, salt doesn't really work that well. For salt brine, which is usually a 23% mixture of salt and water, that is way more effective in many cases than rock salt, because even though it works a lot like it's the plain old salt, since it's applied as a liquid, it actually works a lot more quickly. And brines also work very well in colder temperatures, because a 23% brine will actually freeze at negative six degrees Fahrenheit. And it's so good that it can help to lower the freezing point of water from 32 degrees to 18.
BB: Wow. That's a big difference.
TA: That is a huge difference, and that is why a lot of road crews use it, because it's so helpful when we are still in that slightly, well, I can't say slightly, because it is very cold, but not too cold range. So for temperatures below 20 degrees, both salt and brine are a whole lot less effective. Once you get below negative five, they don't really melt the ice or snow anymore. So what happens in those situations is that road crews will mix something else in to help lower the temperature of the ice and the snows on the roads. For example, the Kentucky Transportation Cabinet, they use calcium chloride when normal road salt doesn't really work anymore, and it works so much better in those colder temperatures that they mix it in with the salt when the temperatures drop too low. So it's very interesting to see what different parts of the country use to help clear their roads. There's some parts of the country that mix in beet juice. There's some parts of the of the country that mix in some extra stuff, like the residual from cheese making to help clear everything out. So, it's a little wierd. But if it works, it works.
BB: There you go. Better road care through chemistry.
TA: Exactly.
BB: And now we have a much better understanding of how all of this works when bad winter weather arrives, thanks to Science Behind the Forecast with WAVE 3 meteorologist Tawana Andrew. Thanks for the knowledge, Tawana.
TA: Of course.
This transcript was edited for clarity.
