RealFeel of Temperatures re-evaluated

[blizzard]

This is kind of long, but overall, an interesting read:

Scientists work to determine 'RealFeel' of temperaturesWEATHER: Some meteorologists say temperature must take into account variables beyond wind chill, such as humidity and the amount of sunshine.
BY JAMES GORMAN
NEW YORK TIMES

For tens of thousands of years, nobody knew how cold it was. They knew about ice and snow and the danger of freezing to death, but no one had thermometers. Instead, they used metaphors, often vulgar, to describe what the cold could do.

In the 16th century, the thermometer was invented. But it wasn't until the 18th century that Fahrenheit and Celsius came up with their numerical scales, making polite conversation about the weather possible for the first time. General satisfaction reigned, if not with the weather itself, at least with how to talk about it, until the 20th century, when the wind chill factor was invented, complicating things. The start of the 21st century has brought even more complicated attempts to describe how hot or cold it is, by academic researchers, government agencies and private companies.

Once again, nobody knows how cold it is.

The thermometer outside the kitchen window may read 20, but then a voice on the radio announces that because of the wind, humidity and a fast-moving nonsense front it feels like 127,000 degrees below zero, that in fact the entire universe has ground to a halt because of the wind chill.

When the authority of the thermometer is undermined, confusion can threaten social bonds. If two people in the same bed can say, at the same time, "I'm freezing!" and, "It's an oven in here," without faith in an objective measurement, the whole point of science is called into question.

Meteorologists, aware of the crisis, are searching for a solution. The United States and Canada revised the wind chill chart a couple of years ago when critics pointed out that it had been developed using small plastic bottles of water in Antarctica. New studies used human beings in Toronto, walking on a treadmill in a cold laboratory, wind blowing in their faces.

An Australian scientist, Robert Steadman, has created fiercely complex formulas to measure the apparent temperature. The forecasting giant, AccuWeather, has developed a proprietary way to determine what it calls the "RealFeel" temperature (patent pending).

Commission 6 of the International Society of Biometeorology, a group under the auspices of the United Nations, has a committee working on a temperature measure that will serve in cold, heat, wind, rain and sun.

Robert Henson, a meteorologist who is an editor at the nonprofit University Corp. for Atmospheric Research in Boulder, Colo., wrote a history charting the changes in television weather forecasting. In the late 1940s, he said, members of the military did some forecasting. In the 1950s, forecasts turned more toward entertainment, and the tone has gone back and forth.

"It feels to me," Henson said, "in the last 10 or 15 years, there has been a swing back to harder science."

That has, of course, meant more and more numbers that the public has to interpret. And the desire to announce record highs and lows has led to varied parsings of the data.

"There are so many ways to assess weather records," he said. "There's always a way for a weathercaster to grab a statistic." And there's always a number for the public to puzzle over, wind chill being one of the most obvious. But despite the emphasis on the wind chill by forecasters, the index has long been known by scientists to be inadequate to the task of presenting an accurate account to the public of what the temperature feels like.

Dr. Joel N. Myers, founder and president of AccuWeather Inc. in State College, Pa., said that since the wind chill did not take into account sunlight, humidity or other factors, it was obviously flawed. It could, he said, produce the same result for a day at noon in the sun in downtown New Orleans or a night on a beach, as long as temperature and wind were the same.

The RealFeel, Myers said, takes into account eight parameters -- not only temperature and wind, but also "precipitation, cloudiness, density of air -- all the factors that affect human comfort." His company has applied for a patent on the method used for calculating the RealFeel, which raises the possibility of competing private temperature interpretations -- letting the market decide what the temperature is. Keeping the method proprietary also leaves other scientists with nothing to say about the method, because they cannot see the calculations.

Myers said that after the patent was granted he would let scientists, and anyone else who was interested, see how it was done.

OPTIONAL END

In 2001, shortly after the introduction of RealFeel, the United States and Canada introduced a revision of the wind chill equivalent temperature, making the temperatures significantly warmer than they had been in the old calculations, from 1945.

Dr. Maurice Bluestein, a professor of physics in the School of Engineering and Technology at Indiana University-Purdue University Indianapolis, and Randall Osczevski, an environmental physicist at Defense Research and Development Canada in Toronto, cooperated in research to develop a new wind chill chart. They conducted a series of experiments with 12 people, male and female, measuring heat loss from the face because of cold and wind. After the researchers plotted the data, they confronted the essential difficulty of all attempts to say just how frightful the weather feels to the average person.

"There's no average person," Osczevski said. "You have to decide who you're going to represent. We chose to represent the person who would have the most trouble keeping their skin warm in cold wind."

Because prevailing wind speed is usually measured about 30 feet above ground, they reduced that height for wind chill because the human faces are much closer to the ground. Even so, the old chart turned out to have exaggerated the effects of wind, in some cases by just a few degrees.

In other cases, however, the difference was large. At an air temperature of 5 degrees Fahrenheit and a wind speed of 30 miles an hour, the old chart put the equivalent wind chill at about 40 below zero. The new chart puts the wind chill at 19 below.

But even setting aside unpredictable variations, Bluestein said, the new chart he helped create is "still not the definitive answer." For instance, "What's the influence of the sun?" That is very hard to incorporate, he said, because it depends on the time of day and latitude and longitude. RealFeel is said to incorporate the effects of sunlight, but Bluestein said without seeing the whole method described he could not comment on its accuracy.

Bluestein is on Committee 6, the international group, with Steadman of Australia and a number of other scientists. The group is pursuing a sort of nonprofit "RealFeel," a single number to say what the temperature feels like, summer or winter, but it has not yet come to any agreement.

Bluestein also said the perception of temperature might not depend on physiology at all. It could be related to other factors such as personality, habit and custom. But, he added, the wind chill is inarguably real. One recent weekend, he said, he was visiting Chicago. "On Friday night we went to a show," he said. It was 6 below, supposedly, and then there was a wind. I would not go out in that weather unless I had $70 tickets."

There is, of course, a question of how much any of the scientific details matter to the average person listening to a forecast. Asked how he thought that people had responded to the wind-chill changes, Olczewski said, "The average person doesn't seem to have noticed."

[JCT777]

They should change the system to the following (for cold weather only):

Level 1: Cool - you might want to wear a sweatshirt or sweater
Level 2: Cooler - definitely light jacket weather
Level 3: Pretty cold - a slightly heavier jacket is needed
Level 4: Cold - a medium thickness jacket with gloves, maybe a hat
Level 5: Colder - might want to think about a heavy jacket, gloves and a hat are a must
Level 6: Very cold - go with the heavy jacket, the gloves, a hat and probably a scarf too
Level 7: Frigid - a heavy jacket over a medium jacket, gloves, a hat, and a scarf and probably long underwear
Level 8: Very frigid - at least 3 levels of jackets, 2 levels of pants, 2 layers of socks, gloves, a scarf and maybe a ski mask to cover your head and face (instead of just a hat)
Level 9: Extremely frigid - every jacket in your closet over at least 3 sweatshirts, 3 or more layers of pants, as many socks as you can put on and still get your winter boots over 'em, multiple pairs of gloves, 3 scarfs, 2 hats over a ski mask. Heck, the only thing that should be exposed to the cold is your nostrils!
Level 10: Intolerably frigid - Don't even go outside. By the time you bundle up enough so you won't get cold, it will be summertime.

[blizzard]

LOL John, good categories....lol

[Stormsfury]

They should change the system to the following (for cold weather only):

Level 1: Cool - you might want to wear a sweatshirt or sweater
Level 2: Cooler - definitely light jacket weather
Level 3: Pretty cold - a slightly heavier jacket is needed
Level 4: Cold - a medium thickness jacket with gloves, maybe a hat
Level 5: Colder - might want to think about a heavy jacket, gloves and a hat are a must
Level 6: Very cold - go with the heavy jacket, the gloves, a hat and probably a scarf too
Level 7: Frigid - a heavy jacket over a medium jacket, gloves, a hat, and a scarf and probably long underwear
Level 8: Very frigid - at least 3 levels of jackets, 2 levels of pants, 2 layers of socks, gloves, a scarf and maybe a ski mask to cover your head and face (instead of just a hat)
Level 9: Extremely frigid - every jacket in your closet over at least 3 sweatshirts, 3 or more layers of pants, as many socks as you can put on and still get your winter boots over 'em, multiple pairs of gloves, 3 scarfs, 2 hats over a ski mask. Heck, the only thing that should be exposed to the cold is your nostrils!
Level 10: Intolerably frigid - Don't even go outside. By the time you bundle up enough so you won't get cold, it will be summertime.

Nice!

[Anonymous]

You find this cold?



-Jeb

[JCT777]

Jeb - I know, you would be going outside in a T-shirt in level 10 cold. But the rest of us might want to stay in!

[blizzard]

You find this cold?



-Jeb

Find what cold?? we KNOW cold here...lol