wind chill

(redirected from Wind-chill)
Also found in: Dictionary, Medical, Wikipedia.

wind chill,

the cooling effect of wind and temperature combined, expressed in terms of the effect produced by a lower, windless temperature, also called wind chill factor, wind chill temperature, wind chill equivalent temperature, wind chill index, wind chill equivalent index, and wind chill temperature index. Wind chill is based on the rate of heat loss from exposed skin. Under windless conditions air provides an invisible blanket around the skin. As wind speed increases, this layer of heated air is carried away from the body at an accelerated rate, forcing the body either to work harder to generate more heat or cool down. If the actual air temperature is −5°F;(−21°C;) with a 20 mph (32 km/hr) wind, the wind chill temperature is −29°F;(−34°C;). Because wind chill is based the removal of heat from the human body, it does not reflect the increased rate of heat loss for inanimate objects such as automobile radiators under the same conditions but they also experience a faster heat loss with increasing winds.

The term wind chill was coined by the American geographer Paul A. Siple in his dissertation, Adaptation of the Explorer to the Climate of Antarctica, (1939). Subsequently, on the third Byrd Antarctic expedition, Siple and American geologist Charles Passel determined how quickly extreme conditions could produce frostbite on exposed skin. By 1945, Siple and Passel had published a set of numbers expressing heat loss as a function of temperature and wind speed.

A wind chill advisory is issued when the forecast projects a wind velocity of at least 10 mph (16 km/hr) producing a wind chill temperature of −15°F; or lower for 3 hours or more. At these values wind chill is more of a nuisance than it is life threatening. A wind chill warning is issued when the forecasted wind chill temperature is −25°F; or lower, which can be life threatening if the individual is not suitably dressed. Persons who go outside under such conditions may experience frostbite and other cold-related symptoms in a matter of minutes, even if properly clothed for normal winter conditions, and longer exposures may prove fatal.

The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved.

wind chill

[′win ‚chil]
That part of the total cooling of a body caused by air motion.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
( reports that wind-chill can pose dangerous risks to your health and one of the dangers of wind-chill is hypothermia.
That was the consensus at an online workshop ( hosted by the Meteorological Service of Canada in April, where scientists gathered to critique the prevailing Siple-Passel wind-chill formula.
So Bluestein decided to learn more about the wind-chill factor, and what he found out didn't impress him.
Emma, star of the film which will be released in March, said: "We were filming in the Dorset countryside and the wind-chill was wicked.
A secret Met Office report, leaked to the Mail, says the wind-chill factor in Scotland SHOULD be taken into account when giving out extra payments to old folks and poor people.
("Red") Whittaker of Carnegie Mellon University in Pittsburgh announced from Erebus' upper flank, where the wind-chill factor hovered around - 55 [degres] C
Temperatures with the wind-chill factor can reach minus 40C.
With the wind-chill factor, it is expected to feel like -9C in Kiev come kick-off.
Although coastal areas were warmer yesterday and last night, a vicious wind-chill is set to send temperatures across the region plummeting today, according to the Met Office in Cardiff.
Tory Nigel Evans tried to get wind-chill factor included in the decision to give pounds 8.50 a week to pensioners and the needy to help with fuel bills.
It seemed doomed on Friday when Pensions minister John Denham refused to take the wind-chill factor into account when calculating pounds 8.50 a week cold weather payouts.
A secret Met Office report leaked to the Mail urged that the wind-chill factor in Scotland should be taken into account when the extra pounds 8.50 payments are triggered.