Wind chill can be, well, chilly
National Weather Service wind chill chart
Jack Hughes
We hear a lot about wind chill temperatures in our winter weather forecasts. Most will agree, the wind certainly makes it feel a lot colder when we are outside on a winter day.
This past Wednesday afternoon, I took a 45-minute walk with a 28-degree temperature and it actually felt comfortable. Winds were calm and the sun was shining. That same walk with a 15-20 mile per hour wind would feel very miserable. The National Weather Service (NWS) developed wind chill temperature values to help protect people who must be outdoors in the winter time. It can also apply to those of us who like to participate in winter sports, such as skiing or ice fishing.
The NWS wind chill Temperature (WCT) index uses advances in science, technology and computer modeling to provide accurate, understandable and useful formula for calculating the dangers from winter winds and freezing temperatures. It is based on a human face model and uses wind calculated from a height of 5 feet and incorporates heat loss from the body during cold windy days.
The wind chill information is important if one plans to be outside or if one is caught unprepared. The problem is that the wind can be variable from one location to the next. Walking down one street, the wind could be blowing in your face at 20 mph, while turning the corner there is hardly any wind and it feels completely different. A skier at the top of a windy mountain feels a lot colder than when she is skiing down a tree covered trail with little or no wind.
Some of the weather forecasts have added wind chill as a bit of hype to enhance the weather story. One TV channel is even using wind chill temperature instead of actual air temperatures. It is interesting to note that even with a wind chill temperature of 25 degrees water will not freeze unless the actual air temperature is also below freezing.
The advances in the design and manufacture of today’s clothing and outdoor apparel is also a big factor in being able to brave the outdoors. With the winter weather now settling into the area, it is a good time to put on a few extra items of clothing and a blanket in the trunk of the car in the event of an unforeseen emergency. The chart above was prepared by the National Weather Service to help in planning your days outside. When we approach the dangerous levels, it’s best to stay indoors, have a coffee and make that trip tomorrow.