-49c - PeachParts Mercedes-Benz Forum

Graplr · #1 01-28-2008, 04:19 PM

Quote:

Originally Posted by Bio300TDTdriver

"The original wind chill formula was derived from experiments conducted in 1939 by Antarctic explorers, Paul Siple and Charles Passel. These hardy scientists measured how long it took for water to freeze in a small plastic cylinder when it was placed outside in the wind. Over the years, the formula was modified somewhat, but remained based on the Antarctic experiments."

This formula was obsolete and in certain circumstances created confusion. Thus in april 2000 Environment Canada held an Internet Workshop [sic] on wind chill for it to be better adapted to reality. Rather than be based on a water cylinder, "the new index is based on a model of how fast a human face loses heat. We chose the face because it is the part of the body most often exposed to severe winter weather, assuming the rest of the body is clothed appropriately for the weather". Reading of the assumptions taken into account for this new index is relevant. Here is an example of these assumptions: "It [the wind chill] uses a calm wind threshold of 4.8 km/h; this value has been obtained by observing the speed at which people walk at intersections."

In case you want to read more: http://ptaff.ca/humidex/?lang=en_CA

Yes, as you stated, THE ORIGINAL WINDCHILL!!

Paul Douglas, a meteorologist for the Twin Cities and big player in the industry was part of the REVAMPING of the original windchill for the newer system. He has stated this several times on his forecasts.

Windchill is bogus. There is NO reason for the numbers other than to shock people. Otherwise not just say, the temp will be -20F and very windy. I can figure out it will feel bitter if it is cold and windy. I don't need some arbitrary number along with the ACTUAL temperature.

Brian Carlton · #2 01-28-2008, 06:06 PM

Quote:

Originally Posted by Graplr

Windchill is bogus. There is NO reason for the numbers other than to shock people. Otherwise not just say, the temp will be -20F and very windy. I can figure out it will feel bitter if it is cold and windy. I don't need some arbitrary number along with the ACTUAL temperature.

Clearly, you don't understand what the windchill number represents. The wind causes more heat loss by any object that is warmer than the current ambient air temperature. In the case of an object that's at 98°, the heat loss with wind is significant. Therefore, the windchill number represents the effective temperature that would be equivalent to the the heat loss absent of wind.

Naturally, you can believe what you wish..............

TripWagner · #3 01-28-2008, 08:56 PM

Let's flip this around ... I agree w/ Graplr that windchill is simply for shock value.

My reason, when it's 90 out and we have a stiff breeze, do the talkingheads say - "The breeze will cool us down, and you'll be comfortable outside" OR do they say "This is the 19th day of this oppressive and dangerous heat wave"?

I can assure you of one thing ... If I did as poorly with my assessments at work as the weather dorks do with theirs ... I'd be fired. Think about it!

Quote:

Originally Posted by Graplr

Yes, as you stated, THE ORIGINAL WINDCHILL!!

Paul Douglas, a meteorologist for the Twin Cities and big player in the industry was part of the REVAMPING of the original windchill for the newer system. He has stated this several times on his forecasts.

Windchill is bogus. There is NO reason for the numbers other than to shock people. Otherwise not just say, the temp will be -20F and very windy. I can figure out it will feel bitter if it is cold and windy. I don't need some arbitrary number along with the ACTUAL temperature.

Brian Carlton · #4 01-28-2008, 09:02 PM

Quote:

Originally Posted by TripWagner

Let's flip this around ... I agree w/ Graplr that windchill is simply for shock value.

Whether it's "bogus" or whether it is factual has nothing to do with the intentions of the forecaster.

The forecaster may use wind chill for shock value. However, this does not diminish the fact that a warmer object will cool faster in the presence of convection.

Bio300TDTdriver · #5 01-28-2008, 09:06 PM

Quote:

Originally Posted by Brian Carlton

Whether it's "bogus" or whether it is factual has nothing to do with the intentions of the forecaster.

The forecaster may use wind chill for shock value. However, this does not diminish the fact that a warmer object will cool faster in the presence of convection.

I'm not sure, but I believe you are needlessly waisting the skin on the ends of your fingers. I don't think any amount of proof will convince them.

Chris

Brian Carlton · #6 01-28-2008, 09:15 PM

Quote:

Originally Posted by Bio300TDTdriver

I'm not sure, but I believe you are needlessly waisting the skin on the ends of your fingers. I don't think any amount of proof will convince them.

Chris

I post not to convince those that will not see.

I post to show others the fallacy of their argument.

Bio300TDTdriver · #7 01-28-2008, 09:17 PM

Quote:

Originally Posted by Brian Carlton

I post not to convince those that will not see.

I post to show others the fallacy of their argument.

AH, then the skin was not wasted!

E300TD99 · #8 01-28-2008, 09:52 PM

I don't want to offend anyone here. I respect everyone for having thier own opinions. And I am not saying this due to the fact that I WILL call on someone here to help me out in the future.

The Wind Chill Factor is a value used to help calculate what an ambiant air temperature would 'feel like' on your skin during the winter months.

With regard to objects such as an engine if that engine was cooling down. Yes, it will cool down quicker if there is a breeze or a wind blowing across it but the actual temperature will not reach a lower temperature than that of the ambient air temperature such as the Wind Chill Temperature.. If the engine was plugged into a block heater, it will take longer for the engine block to reach its temperature due to the fact that you have cooler air moving across the engine, resulting in heat loss being carried away as the block heater is working. The result will take more time to accomplish the same amount of work.
Hope this helps,
Mike

Graplr · #9 01-29-2008, 09:48 AM

Quote:

Originally Posted by Brian Carlton

Clearly, you don't understand what the windchill number represents. The wind causes more heat loss by any object that is warmer than the current ambient air temperature. In the case of an object that's at 98°, the heat loss with wind is significant. Therefore, the windchill number represents the effective temperature that would be equivalent to the the heat loss absent of wind.

Naturally, you can believe what you wish..............

However, this does not diminish the fact that a warmer object will cool faster in the presence of convection.

Brian,
I NEVER said ANYTHING about the rate of cooling. I talked about the air temperature itself which is what forecasters always associate wind chill with.

It sure will cool FASTER, but I can figure that out myself if the wind is blowing. I don't need some arbitrary number from a forecaster.

When I listen to the forecasters, they say for example "The temperature outside is 4F, but it FEELS like -15F. This is impossible. There is absolutely NO WAY it can be -15F if the air temperature is 4F!! The coldest possible temperature if the air is 4F is 4F!!!

They NEVER say the windchill will cause you to cool down faster, they say it FEELS like -15F, which is impossible.

Naturally, this is a fact, not me believing anything!

By the way, I am a science teacher. Specifically Earth Science which includes the area of meteorology.

Brian Carlton · #10 01-29-2008, 09:59 AM

Quote:

Originally Posted by Graplr

When I listen to the forecasters, they say for example "The temperature outside is 4F, but it FEELS like -15F. This is impossible. There is absolutely NO WAY it can be -15F if the air temperature is 4F!! The coldest possible temperature if the air is 4F is 4F!!!

Naturally, this is a fact, not me believing anything!

By the way, I am a science teacher. Specifically Earth Science which includes the area of meteorology.

See post #24.

Maybe that's why the education system is in the toilet...........

Graplr · #11 01-29-2008, 10:13 AM

Quote:

Originally Posted by Brian Carlton

See post #24.

Maybe that's why the education system is in the toilet...........

Wow Brian, didn't think you were that type of person.

You have yet to state anything about my point. You have simply talked about rate of cooling.

So then if you are saying I'm wrong you are saying that it is possible for the wind to cool you down past the air temperature?

Brian Carlton · #12 01-29-2008, 10:29 AM

Quote:

Originally Posted by Graplr

Wow Brian, didn't think you were that type of person.

You have yet to state anything about my point. You have simply talked about rate of cooling.

So then if you are saying I'm wrong you are saying that it is possible for the wind to cool you down past the air temperature?

Well, against my better judgment........here we go:

You made these statements:

Quote:

Originally Posted by Graplr

[B]When I listen to the forecasters, they say for example "The temperature outside is 4F, but it FEELS like -15F. This is impossible.

They NEVER say the windchill will cause you to cool down faster, they say it FEELS like -15F, which is impossible.

I have a couple of questions for you:

1) If you walk outside with an ambient air temperature of 10°F. with no wind, can we agree that the air temperature "feels" like 10°F?

This is important........and we must agree before we go to #2:

2) If you walk outside with an ambient air temperature of 10°F. with 30 knot winds, do you feel colder than you would feel without any wind?

And, if the above is in the affirmative..........

3) Since you do feel colder, what temperature would you judge the air to be when a 30 kt. wind is present? Would it be accurate to say that you might believe that the ambient air temperature is approximately -5°F.........using the baseline of no wind as your barometer?

Please limit your answers to simple yes and no for question #1 and #2.