Happy Holidays to All and Stay Warm; but if You Cannot, Beware The Consequences
Illustration by Ivan Bilibin
This time of year, Winter has arrived in the Northern Hemisphere, the Wind Chill Effect can hasten damage to unprotected humans and animals, depending on conditions, especially the wind speed.
The USA’s National Weather Service (NWS) Windchill Temperature (WCT) index uses advances in science, technology, and computer modeling to provide an accurate, understandable, and useful formula for calculating the dangers from winter winds and freezing temperatures. The index:
- Calculates wind speed at an average height of five feet, typical height of an adult human face, based on readings from the national standard height of 33 feet, typical height of an anemometer
- Is based on a human face model
- Incorporates heat transfer theory, heat loss from the body to its surroundings, during cold and breezy/windy days
- Lowers the calm wind threshold to 3 mph
- Uses a consistent standard for skin tissue resistance
- Assumes no impact from the sun (i.e., clear night sky).
NWS Wind Chill Calculator Online (since 2009): www.nws.noaa.gov/os/windchill/index.shtml
Plus, The USA’s northern?? neighbors, Canadians, who sustain, and evidently survive even colder conditions than most US?? residents, have a slightly different view of the matter, show below, too:
Just what is Wind Chill? How did it start? Does it pose a real problem or is it just a “passing” fad?
(Note: This is a rehash of our 2o12 article, Wind Chill 2012 which, in turn was a rehash of our page 2010 article on the subject – so, some may have seen this before.)
The USA National Weather Service (NWS) informative Wind Chill Page is online at: www.nws.noaa.gov/om/windchill/. On it it tells us:
The NWS Windchill Temperature (WCT) index uses advances in science, technology, and computer modeling to provide an accurate, understandable, and useful formula for calculating the real dangers from winter winds and freezing and subfreezing temperatures.
Environment Canada???s Wind Chill web page at: www.ec.gc.ca/meteo-weather/default.asp?lang=En&n=5FBF816A-1 tells even more (It more regularly gets a lot colder there than in the USA – In the Northeast USA we often speak about the “Alberta Clipper‘! Don’t cha know it comes from Canada?)
It’s not just the temperature that chills you, the combination of wind and low temperature produces the effects of much colder temperatures on humans and animals. The wind chill is the effective temperature.
There’s a lot of very useful information on the Environment Canada website including the table below showing the effects of windchill: (Credit: Environment Canada) but we added the temperatures to the nearest degree in F, the preferred units in the warmer, southern portion of the North American continent.)
I believe the Continental USA low Temperature Record is – 60 ??F, set in in Tower, Minnesota on February 2, 1996 (Interesting note: your Editor was there and has a thermometer-embellished hat to prove it!)
The Environment Canada Website also shows a Wind Chill table:
NOTE: 10 km/h = 6.2 mph, 20 km/h = 12. 4 mph, 30 km/h = 18.6 mph,?? 40 km/h = 25 mph,?? 50 km/h = 31.1 mph and 60 km/h = 37.3 mph
|Wind Chill||Risk of Frostbite||Other Health|
|What to Do|
|0 to -9 ??C (31 to 16 ??F)||Low|
|-10 to -27 ??C (14 to -17 ??F)||Low|
|-28 to -39 ??C (-18 to -38 ??F)||Risk: exposed skin can freeze in 10 to 30 minutes|
|-40 to -47 ??C (-40 to -53 ??F)||High risk: exposed skin can freeze in 5 to 10 minutes*|
|-48 to -54 ??C (-54 to -65 ??F)||Very High risk: exposed skin can freeze in 2 to 5 minutes*|
|-55 ??C (-66 ??F) and colder||Extremely High risk: exposed skin can freeze in less than 2 minutes*|
*In sustained winds over 50 km/h (31 mph), frostbite can occur faster than indicated.
Finally, the Wind Chill Canadian wap page has some very straightforward recommendations for those who may be subject to severe cold; to wit: