REPORT: Watch Out for Wind Chills Today

The National Weather Service has issued a hazardous weather outlook for the Burr Ridge area. Wind chills as low as -1 are expected. Winds will be moving at 5 to 10 mph and could gust as high as 15 mph.

Tonight it will be mostly cloudy, with temps rising to around 30 degrees by 2 a.m. South southwest winds are expected to be between 10 and 15 mph, with gusts as high as 25 mph.

A few questions and answers about windchills from the NWS:

Q. What is wind chill temperature?

A. The wind chill temperature is how cold people and animals feel when they are outside. It's based on the rate of heat loss from exposed skin caused by wind and cold. As the wind increases, it draws heat from the body, driving down skin temperature and eventually the internal body temperature. Therefore, the wind makes it feel much colder. If the temperature is 0 degrees Fahrenheit and the wind is blowing at 15 mph, the wind chill is -19 degrees Fahrenheit. At this wind chill temperature, exposed skin can freeze in 30 minutes.

Q. How is the Windchill is calculated?

The wind chill temperature is calculated using the following formula:

Windchill (ºF) = 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16)

Where: T = Air Temperature (F)
V = Wind Speed (mph)
^ = raised to a power (exponential)

Windchill Temperature is only defined for temperatures at or below 50 degrees Fahrenheit and wind speeds above 3 mph. Bright sunshine may increase the wind chill temperature by 10 to 18 degrees Fahrenheit.

Q. Can wind chill impact my car's radiator or exposed water pipe?

A. The only effect wind chill has on inanimate objects, such as car radiators and water pipes, is to shorten the amount of time for the object to cool. The inanimate object will not cool below the actual air temperature. For example, if the temperature outside is -5 degrees Fahrenheit and the wind chill temperature is -31 degrees Fahrenheit, then your car's radiator will not drop lower than -5 degrees Fahrenheit.

Q. How should people dress during cold weather?

A. Wear several layers of loose-fitting, lightweight, warm clothing. Trapped air between the layers will insulate you. Remove layers to avoid sweating and subsequent chill. Outer garments should be tightly woven, water repellent, and hooded. Wear a hat, because half of your body heat can be lost from your head. Cover your mouth to protect your lungs from extreme cold. Mittens, snug at the wrist, are better than gloves. Try to stay dry and out of the wind.

Q. Will moving around and participating in activities (such as shoveling the walk help me stay warm?)

A. People should avoid overexertion in cold weather. Your heart is already working overtime when the weather is cold. The strain from the cold and the hard labor of shoveling heavy snow, walking through drifts or pushing a car could cause a heart attack. Sweating from overexertion could lead to a chill and hypothermia.

Q. What is the difference between windchill factor and wind chill temperature?

A. These terms are almost the same. The wind chill factor describes what happens to a body when it is cold and windy outside. As wind increases, heat is carried away from the body at a faster rate, driving down both skin temperature (which can cause frostbite) and eventually the internal body temperature (which can kill).

Windchill temperature is a unit of measurement to describe the wind chill factor. Windchill temperature is a measure of the combined cooling effect of wind and temperature. Since you and your husband ride motorcycles, you can insert your driving speed to estimate the wind speed and the outside temperature. These two parameters combined will give you the wind chill temperature, or how it feels to you skin. On the bottom of the wind chill chart is the updated wind chill temperature formula.

Q. Is it possible to get frostbite if the temperature is above freezing but the wind chill is below freezing?

A. The air temperature has to be below freezing in order for frostbite to develop on exposed skin. Wind chill can bring the temperature to below freezing for humans and animals.

Q. When does the National Weather Service issue a Windchill Advisory or Warning?

A. Criteria for issuing Windchill Warnings and Advisories are set locally. For example, in the Rochester, New York area, Windchill Warnings are issued when the Windchill Temperature is expected to fall at or below -25 F. Windchill Advisories are issued when the wind chill temperature is expected to fall between -15F and -24F.

Q. Does wind chill only apply to people and animals?

A. Yes. The only effect wind chill has on inanimate objects, such as car radiators and water pipes, is to more quickly cool the object to cool to the current air temperature. Objects will not cool below the actual air temperature. For example, if the temperature outside is -5 degrees Fahrenheit and the wind chill temperature is -31 degrees Fahrenheit, then your car's radiator will not drop lower than -5 degrees F.

More information on wind chill terms and definitions can be found on the National Weather Service website here.