Not Feeling Quite So Cold?
Ellen Phillips, Extension Educator – Crop Systems, Countryside
Extension Center, ephillips@uiuc.edu,
(708) 352-0109
Wind chill factors are used to estimate how cold the weather
feels. If it is 20 degrees Fahrenheit with a 10 mile per hour
wind, it feels as if it were 2 degrees above zero with no wind.
The faster the wind speed the colder it feels outside. Are you
are feeling warmer now than a couple of years ago? It may be
due to a new wind chill equation that the National Weather Service
has been using for calculating the wind chill the last couple
of years. The new formula does not estimate as great a drop in
temperature as the previous equation predicted.
Specifically, the new WCT index: uses calculated wind speed
at an average height of five feet. This would be the typical
height of an adults face. This wind speed is calculated based
on readings from the national standard height of 33 feet (typical
height of an anemometer). The assumptions are based on the latest
heat transfer theory relating heat loss from the body to its
surroundings on a cold and windy day. Wind chill calculations
also do not take into account sunlight. If you want to try your
hand at calculating the wind chill where you are, try using the
NWS Wind Chill equation below:
Wind Chill (oF) = 35.74 + 0.6215T - 35.75(V0.16)
+ 0.4275T(V0.16)
- Where, T = Air Temperature (oF)
- V = Wind Speed (mph)
To learn more about wind chill, visit the National Weather Service
Wind Chill page at:
http://www.srh.noaa.gov/jan/wchill.html As temperatures drop or wind speed increases, the potential
for health problems increase. Frostbite develops at freezing
temperatures and can occur more quickly if the skin is wet. Frostbite
is damage done when the skin tissue freezes. Frostbite causes
a loss of feeling and a white or pale appearance in extremities
such as fingers, toes, ear lobes or the tip of the nose. Keep
safe this winter season by dressing warmly with many layers,
change clothing that gets wet and keep out of the wind when possible. |
