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But it's a dry heat....



 
 
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  #1  
Old July 19th 05, 01:40 PM
Matt Barrow
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"Dan Luke" wrote in message
...

"Matt Barrow" wrote:

The same day it hit 104 in Chicago and ...the humidity was 90+/-
percent.


Baloney.

Look at a psychometric chart:

http://www.rfcafe.com/references/gen...tric_chart.htm


I guess all those people didn't really die, huh?

Same thing when that heat wave hit France a couple years ago.

First, it was mainly elderly people and secondly, they don't have A/C.


  #2  
Old July 19th 05, 01:43 PM
Matt Barrow
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"Matt Barrow" wrote in message
...

"Dan Luke" wrote in message
...

"Matt Barrow" wrote:

The same day it hit 104 in Chicago and ...the humidity was 90+/-
percent.


Baloney.

Look at a psychometric chart:

http://www.rfcafe.com/references/gen...tric_chart.htm


I guess all those people didn't really die, huh?

Same thing when that heat wave hit France a couple years ago.

First, it was mainly elderly people and secondly, they don't have A/C.

So, yes, you're right in that respect...



  #3  
Old July 19th 05, 02:04 PM
Matt Barrow
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Posts: n/a
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"Dan Luke" wrote in message
...

"Matt Barrow" wrote:

The same day it hit 104 in Chicago and ...the humidity was 90+/-
percent.

Baloney.

Look at a psychometric chart:

http://www.rfcafe.com/references/gen...tric_chart.htm



Ever hear of "Heat Index"?




  #4  
Old July 19th 05, 02:32 PM
Dan Luke
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Posts: n/a
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"Matt Barrow" wrote:
The same day it hit 104 in Chicago and ...the humidity was 90+/-
percent.

Baloney.

Look at a psychometric chart:

http://www.rfcafe.com/references/gen...tric_chart.htm



Ever hear of "Heat Index"?


Yes.

What's that got to do with your made-up statement that the temperature was
104 F. and the humidity was 90%?

Did you attempt to understand the chart?

--
Dan
C-172RG at BFM


  #5  
Old July 19th 05, 05:31 PM
Doug Semler
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"Dan Luke" spewed this drivel:
"Matt Barrow" wrote:
The same day it hit 104 in Chicago and ...the humidity was 90+/-
percent.
Baloney.
Look at a psychometric chart:
http://www.rfcafe.com/references/gen...tric_chart.htm

Ever hear of "Heat Index"?

Yes.

What's that got to do with your made-up statement that the temperature was
104 F. and the humidity was 90%?

Did you attempt to understand the chart?


First off, it's psychRometric.

Do you understand relative humidity?

According to NOAA, July of 1995 (about which I presume Matt is talking)
had the following (from
http://www.crh.noaa.gov/lot/science/jul1395/jul1395.htm)
quote
In the immediate Chicago region, surface dew points held in the upper
70s to near 80 however the temperature exceeded 100 degF for several
hours. Heat Index values were greater than 115 degrees for much of the
midday and afternoon hours...reaching 125 degrees for the 2145UTC
observation from Midway (MDW). In fact, the mercury remained at or
above 100 degF at MDW for seven hours, from 13/1800UTC to 14/0100UTC.
This extraordinary length may be partially due to the more urban
location of the field.
/quote

Now, I am going to use the following readings:
104 degrees F for the temperature (the "official" high)
80 degrees F for the dew point.

According to the formula RH =~ 100((112 - .1T - Td)/(112 + .9T))^8,
where T = observed temperature and Td = dew point temperature, I get a
relative humidity of 88.32%.

P.S. A heat index of 125!?!? That's definitely "stay at home and hope
the AC doesn't go out on me" weather!

  #6  
Old July 19th 05, 05:48 PM
Doug Semler
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Why can't my buttons work right.


mea culpa. That should be 37.4 % RH.

Grrrr.

Still, a heat index of 125 is insane....:-/

  #7  
Old July 19th 05, 06:19 PM
Doug Semler
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Or even 46.9% .....First I don't hit the exp(8), and then I fudge up
and forget to convert to deg C the second time around...

My brain is fried today. Must be the humidity....Too bad it's so humid
out that I don't feel like taking the rest of the day off and
golfing... g

  #8  
Old July 19th 05, 06:05 PM
Matt Barrow
external usenet poster
 
Posts: n/a
Default


"Doug Semler" wrote in message
oups.com...
"Dan Luke" spewed this drivel:
"Matt Barrow" wrote:
The same day it hit 104 in Chicago and ...the humidity was 90+/-
percent.
Baloney.
Look at a psychometric chart:
http://www.rfcafe.com/references/gen...tric_chart.htm
Ever hear of "Heat Index"?

Yes.

What's that got to do with your made-up statement that the temperature

was
104 F. and the humidity was 90%?

Did you attempt to understand the chart?


First off, it's psychRometric.

Do you understand relative humidity?

According to NOAA, July of 1995 (about which I presume Matt is talking)
had the following (from
http://www.crh.noaa.gov/lot/science/jul1395/jul1395.htm)
quote
In the immediate Chicago region, surface dew points held in the upper
70s to near 80 however the temperature exceeded 100 degF for several
hours. Heat Index values were greater than 115 degrees for much of the
midday and afternoon hours...reaching 125 degrees for the 2145UTC
observation from Midway (MDW). In fact, the mercury remained at or
above 100 degF at MDW for seven hours, from 13/1800UTC to 14/0100UTC.
This extraordinary length may be partially due to the more urban
location of the field.
/quote

Now, I am going to use the following readings:
104 degrees F for the temperature (the "official" high)
80 degrees F for the dew point.

According to the formula RH =~ 100((112 - .1T - Td)/(112 + .9T))^8,
where T = observed temperature and Td = dew point temperature, I get a
relative humidity of 88.32%.

P.S. A heat index of 125!?!? That's definitely "stay at home and hope
the AC doesn't go out on me" weather!


One aspect is that for people outdoors (homeless, for example) cannot get
out of the heat during the day (shade doesn't work) nor at night (temps stay
high). I suspect that can add to a death toll.


--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO


  #9  
Old July 19th 05, 06:26 PM
Doug Semler
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Matt Barrow wrote:
One aspect is that for people outdoors (homeless, for example) cannot get
out of the heat during the day (shade doesn't work) nor at night (temps stay
high). I suspect that can add to a death toll.


Of course. And of course, I was talking about for *me*. I have lived
in the desert, where the temperatures routinely rose above 100 in the
summer. However the humidity was low enough that air conditioning was
not required (well, for ME at least). Then one July 4th, there was a
95 degree day with something like a HI of 105...That was one of the
worst days...I did run the AC that day. Not so much because it felt
like it was 105, but because if you didn't, you would lose 5 pounds in
sweat.

There's a wikepedia article on the July 1995 chicago heat wave that
reads, in part:

quote
Because of the nature of the disaster, and the slow response of
authorities to recognise it, no official "death toll" has been
determined. However, figures show that 739 additional people died in
that particular week above the usual weekly average. Further
statistical analysis analyzed by Eric Klinenberg (author of Heat Wave:
A Social Autopsy of Disaster in Chicago) showed that blacks were more
likely to die than whites, and that Hispanics had an unusually low
death rate. This has been explained by the fact that many blacks at the
time lived in areas of sub-standard housing and were quite dispersed,
while Hispanics at the time lived in places with higher population
density. Thus demographics, rather than ethnic values, were shown to be
the reason for this disparity in deaths.
/quote

Note that I take wikepedia articles with a grain of salt; I don't know
the reference for the "figures" regarding the death toll, but it is
probably from the same book mentioned.

  #10  
Old July 19th 05, 08:36 PM
Dan Luke
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Posts: n/a
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"Doug Semler" wrote:

First off, it's psychRometric.

Do you understand relative humidity?


I thought so, but I foolishly trusted the spelling in the url.

Now, I am going to use the following readings:
104 degrees F for the temperature (the "official" high)
80 degrees F for the dew point.

According to the formula RH =~ 100((112 - .1T - Td)/(112 + .9T))^8,
where T = observed temperature and Td = dew point temperature, I get a
relative humidity of 88.32%.


We must be looking at different charts.


 




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