What is wind chill, and how does it make you feel colder?
An ABC 17 Stormtrack Weather Alert Day is in effect, starting at midnight tonight and lasting throughout tomorrow morning. This is for wind chills that could be below zero during the early morning hours. The thing is, the actual air temperature tomorrow morning will be close to 10 degrees, meaning it is actually a bit warmer outside than the estimated "feels-like" temperature. This is because the actual air temperature outside isn't changing; it is just the winds in place taking extra heat away from your body, making you feel much colder.
This concept can be illustrated by a freshly poured cup of hot coffee. Whenever you blow on that cup of coffee to cool it down, the room's temperature doesn't change. What is happening is that as you blow on the cup of coffee, the heat is just being moved away from the liquid in the cup at a quicker rate. This is what will be happening to your body during the morning hours tomorrow as frigid air takes over.
Our bodies are constantly radiating heat. On a calm day, this heat gets trapped just millimeters off our skin, creating a thin, invisible layer of warm air. This insulates our body, but when the winds pick up, it strips away that layer of warm air before it can protect you from the cold. Your body has to work extra to keep itself warm, but the wind is more efficient at stealing that heat. This accelerated loss is what is calculated as the wind chill.
Wind chill is calculated by two main features: air temperature and wind speed. With higher wind speeds, air temperatures do not need to be as cold to still create hazards for the human body. Tomorrow, wind speeds will be in the 5-10 mph range, and air temperatures will be near 10 degrees. This will lead to a wind chill in the -4 to 1 degree range. This means that the potential of receiving frostbite will be present tomorrow if exposed to this cold for as little as 45 minutes to an hour. In colder conditions, where air temperature is measured at 0 degrees, it only takes wind speeds to be in the 15-20 mph range to make temperatures feel like it is -15 to -20 degrees. Once wind chills enter this range, it only takes 30 minutes to receive frostbite on unprotected areas.
To stay safe in this cold, there are several precautions you can take. First, make sure to stay dry, as wet clothing can result in a much faster loss of heat from your body. Another important precaution to take is to stay covered, wearing items like gloves or hats. If your head is not covered, at least half of the heat from your body is lost. Layering clothing is also important, as trapped air between loose-fitting clothing helps to insulate.
