Wind chill

Is the object to get something like the "official" numbers? If so, then there *is* a mathematical formula- and the OP can just measure the required variables, plug them into the official forumula and spit out the number. That's easiest and probably best.

If the object is to get some new number that (perhaps better) reflects how cold it "feels", that's something different. My favorite number, although it's probably not very scientific, is the minutes (or seconds) before exposed flesh freezes. ;-)

What's the equivalent in Phoenix? Minutes to fry an egg on the sidewalk in midsummer? ;-)

Best regards, Spehro Pefhany

On Sun, 30 Jan 2005 14:54:36 +0000, Guy Macon wroth:

That's been my take on wind chill from the beginning.

Jim

In your case a much more literal measurement of WCT is required: paste a temperature indicating strip to your forehead and stand outside for an hour.

I read in sci.electronics.design that Spehro Pefhany wrote (in ) about 'Wind chill', on Sun, 30 Jan 2005:

Just hold the bag. Your canine friend provides you with a lovely squishy hand-warmer. (;-)

On Sun, 30 Jan 2005 11:48:50 -0700, Jim Thompson wroth:

Nope. Never been in Arizona at any time either.

Wind chill as a number that means anything is ridiculous. If you know the air temperature and the wind speed you know enough. You don't need a formula to tell you that the faster the wind blows, the more uncomfortable you may become. And what about humidity? That's a large factor in how comfortable or uncomfortable you may be.

Tell me the temperature, the wind speed, the humidity, the precititation (if any), and I'll know what I need to wear and do to feel OK. I don't need a fictitious wind chill number.

Jim "the other one" Meyer

They did that a few years ago.

Before a few years ago, the windchill reported on the news was the one for bare skin. And it took something like -30 degrees F on that scale to achieve a windchill advisory. A really bad windchill that did not happen most winters (in Philadelphia) was -40 degrees F and a day with both strong wind and temperature slightly below zero managed around -50.

In recent years, they have been using a different windchill scale based on wearing clothing. Now -10 achieves a windchill advisory. A recent day (with a windchill advisory) when the windchill in Philadelphia got to about -10 to -15 F felt the worst to me since a day in 1994 when the windchill on the old scale was in the -40's F.

- Don Klipstein ( snipped-for-privacy@misty.com)

I read in sci.electronics.design that Spehro Pefhany wrote (in ) about 'Wind chill', on Sun, 30 Jan 2005:

We had some of that a few years ago, and it was fine enough to get through the vent grilles of our electric train motors, putting them out of action. Some railway PR droid achieved immortality by describing it to the media as 'the wrong sort of snow'.

My observation is that the flake size is inversely proportional to some direct function of the difference between the air temperature and the freezing point. We had a small snowfall here the other day with BIG flakes. It melted within an hour.

I'd suggest a sensor at body temperature, and measuring the power neede to keep it warm.

Thomas

I read in sci.electronics.design that Spehro Pefhany wrote (in ) about 'Wind chill', on Sun, 30 Jan 2005:

No. Midwinter.

Better than Pittsburgh last Monday. That must have been a depressing place! ;-)

It's hotter than hell here today. It got to 27F (-2C for the Canuckistanis here), and there was a big bright thing in the sky. We're kinda wondering what it was, but it left about 5:00PM.

Wait until all that stuff in _The Day After Tomorrow_ starts to happen-- then you'll be singing a different tune. Destroying the Capitol Records building was a nice touch.

Best regards, Spehro Pefhany

Content-Transfer-Encoding: 8Bit

Spehro Pefhany wrote:

I really ought to mention that it has been between 72 and 75 degrees here in Los Angeles all week... :)

Glad to hear that they are giving better answers. Mmmm. Let me check to see when the last time I travelled to somewhere cold other than the usual surf in the morning ski in the afternoon trick... Ah, Here it is. Indiana, winter of 1997.

Thanks to all who replied. After reading thru the various responses I've reached the conclusion the simplest solution to the problem is to stay inside :).

Howard.

I know, I was having great sport teasing the client's travel lady about our mid-70's temperature.

Beware the "big bright thing in the sky", AKA the slush monster ;-)

...Jim Thompson

I suppose you aren't prepared for "the wrong sort of snow". When you get in your car and turn on the defroster and it snows *inside*, it's "the wrong sort of snow" too. ...happens all the time, perhaps 30-40 mornings a year.

Sure. The colder the flakes the less they stick to each other making for smaller "flakes" when they reach the ground. I always thought it was "too cold to snow" when it got below 0F (-18C), but since I moved to Vermont I'm repeatedly reminded at the folly of that observation. I had never seen a foot of snow at -20F (-29C). I have now! Several times.

Wind chill was originally meant to express how rapidly uncovered flesh would freeze. It's since been hijacked into a "touchy, feely" number that does include humidity (e.g. Accuweather's "real feel").

It's not fictitious. Though I agree, I listen to wind-speed far more. At -30C (as it was last week), I was happy to hear that it was dead calm (even the wind was frozen ;-).

Yes. It's in the JS code from that windchill calculator page that was previously posted. I started to post it, but the line wrap crapped it up.

Probably the best way as you said. Even the new formula isn't perfectly linear and it says they've adjusted the wind speed for the height above ground of the human face. That takes a lot of work out of the project.

LOL. My observation is that in winter, wind does more to make it feel colder than a summer wind does to make it feel cooler - at least during physical activity in the sun. The summer wind sometimes appears to keep me from sweating, but IME that's just the air keeping the skin dry That may lead you to believe it's not as hot, but the whole time you're dehydrating. Normally, if you stop sweating when you should be, you're headed for danger. If the wind keeps the skin dry, you can't tell anything's changed until you black out.

I was referring to their non-show at the stadium the day before. The Pats kicked their donkey, and at home. ...no snow even! Forget the 70F! It was far colder there than the temperature would indicate, last Monday! ;-)

Naw! I gotta get my driveway cleaned off. Early January we had a "little" wet snow on a Monday morning. By the time I got home in the afternoon it had dropped 20F and was frozen solid. I'm just now getting down to the black. ...Another few days and I may not need 4WD to get up my short driveway.

Mud season is at least six weeks off. if we even have one this year.