The (http://www.nws.noaa.gov/om/cold/wind_chill.shtml)
wind-chill chart by NWS uses only those two quantities while AccuWeather's "(http://www.accuweather.com/en/weather-news/what-is-AccuWeather-realfeel/7198202) RealFeel" index adds in effects such as cloud cover and sun angle.
The chief source of concern is the
wind-chill factor, which produced an air temperature of -6.5C at Kempton yesterday, is forecast to dip to -9C on Christmas Day night and is not predicted to improve until the following day.
"Sheep use substantial energy just staying warm, and lose a lot of heat when it's cool, especially when there's a
wind-chill.
"The Met Office tell uswe are due an estimated
wind-chill factor of minus 9C.
It is now 100mm longer, and a Macrolon screen now shields the operator from
wind-chill where warehouses are unheated, and document and bottle/cup holders are now supplied as standard.
Daytime temperatures are expected to dip as low as 1C (34F), with the
wind-chill factor making it feel even colder.
The temperature is a relatively balmy minus 21, but when you account for the
wind-chill factor, it feels about minus 40.
Scotland's Louise Scott and American Tom Ferrel provide the biggest threat to the Scandinavian over a course where temperatures can fall to the equivalent of -50infinityC with the
wind-chill factor.
We're speaking, of course, of the
wind-chill factor, and the perverse thrill to be had upon hearing it announced over the airwaves.
My skin wasn't freezing in 15 seconds," like the meteorologists had warned when advising of the super-low
wind-chill factor.
It stays out there until the Northern California fog and
wind-chill seize control of the field.