LANSING, Mich. (WLNS) – Even though we haven’t had to do it yet, we are all familiar with the task of scraping frost off of your car in the morning.
But did you know that sometimes frost can form even when temperatures are above freezing?
It’s that time of year when you head outside to your car in the morning and notice your windows are covered in frost, so now you have to take the extra few minutes to scrape it all off, or just sit inside your car with the defrosters turned on.
But when you get on your phone and check the current temperature on the StromTracker 6 app, you notice it’s a few degrees above freezing. Well, how does that work?
The sensors that are used to observe current conditions are sitting about four to six feet above the ground, and since cold air sinks the temperature below those sensors is likely cooler than what is being reported. Hence, even those on your phone might tell you it is 34 or 36 degrees outside, and when you turn on 6 News we’re probably telling you the same, but temperatures may be closer to freezing towards the surface of the earth.
That’s one reason why frost could form when temperatures are above freezing, but you’ll notice sometimes that there’s frost on your car and nowhere else. Not on the grass, not any plant leaves or trees; just your car. There’s a reason for that.
Both glass and metal, the two main materials that make up your vehicle, aren’t very good at retaining heat. Or in other words, they have a low heat capacity. So, they can absorb heat during the day, but once night falls, all of that heat that your car absorbed during the day is sent right back out to space. So, the temperature of the surface of your car decreases.
If other conditions are right, like having calm winds, and our temperature and dew point temperature are the same, we get that pesky frost to form.
