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Lucky with our meetup timing
Posted: Sat Jun 23, 2007 3:59 pm
by Dem
It seems we were really very lucky with
choosing the meetup for early June.
Although in the week before the meetup
the weather in Greece was very bad and
I was worried it was great on Hydra during
our stay there.
Now we have a heatwave all over Greece
with scorching temperatures that are excpected
to rise well above 40 °C.
It says 37°C (=99 °F) right now on Hydra!.
Dem
Re: Lucky with our meetup timing
Posted: Sat Jun 23, 2007 4:26 pm
by Laura
Unfortunately I would prefer 37 in Hydra than 37 in Bucharest!
Laura
Re: Lucky with our meetup timing
Posted: Sat Jun 23, 2007 5:42 pm
by dar
I too would prefer 99 degrees in Hydra, than 110 degrees in the desert Southwest. (Although I'm not there, so shouldn't whine just yet.) The weather in Sacramento today is beautiful.
Nice to see you made the gathering in Hydra dem! You look surprisingly "normal". haha
Re: Lucky with our meetup timing
Posted: Sat Jun 23, 2007 10:38 pm
by Laura
Dar, if there is a choice... stay with us! No snakey hellish places... I'm getting rather worried for you.
Damn, it is so hot here now... I think my brain has evaporated already.
Laura
Re: Lucky with our meetup timing
Posted: Sun Jun 24, 2007 4:56 am
by Andrew (Darby)
It may interest you to know that we had our coldest day on record here during the week, when (with the wind chill factor added in) it got down to -16.7 degrees Celsius!!!
Could someone explain to me what way the wind chill factor works in terms of modifying air or ground temperatures - there must be some sort of universally adhered to formula.
Cheers,
Andrew (Darby)

Re: Lucky with our meetup timing
Posted: Sun Jun 24, 2007 5:49 am
by TomBohan
Well, I was in Athens last Sunday when the temperature was 99F (37C) and was not uncomfortable, just happy to still be in Greece, which I was not by the following day. As for wind chill, Andrew, it's a bunch of B.S. And I say this as a physicist who started professional life as a meteorologist. One cannot take two variables and represent them across them board with a single variable. Just to take one example: If the air temperature is above the freezing temperature of water, say 1 C, a closed container of water will not freeze even if the wind speed is high enough to drive down the "wind chill" to -100C. BTW, what was the air temperature the day it was supposedly -16.7C wind chill?--Tom
Re: Lucky with our meetup timing
Posted: Sun Jun 24, 2007 3:11 pm
by lizzytysh
The way it was explained to me years ago and I've never encountered active discussions of it since, so have had no reason to question it, is that the wind chill factor is simply how it feels on your skin vs. what it reads on the thermometer. It made sense at the time, as both breezes and humidity can make it feel colder than it is. How that could actually get calculated, however, seems mind boggling. With the breeze, if a thermometer is stuck out in the wind vs. in a 'protected' place, does it read differently?
~ Lizzy
Re: Lucky with our meetup timing
Posted: Sun Jun 24, 2007 7:29 pm
by Anne
Re: Lucky with our meetup timing
Posted: Mon Jun 25, 2007 12:11 am
by Mirek
TomBohan wrote: As for wind chill, Andrew, it's a bunch of B.S. And I say this as a physicist who started professional life as a meteorologist. One cannot take two variables and represent them across them board with a single variable. Just to take one example: If the air temperature is above the freezing temperature of water, say 1 C, a closed container of water will not freeze even if the wind speed is high enough to drive down the "wind chill" to -100C.
Dear Tom,
If you're a phycicist than you know for sure what is the difference between open and closed systems (thermodynamically speaking). Your example described above tells us about a closed system (water vapors cannot cross the boundary of the container). The wind chill factor, on the other hand, refers to the temperture 'felt' on exposed skin (i.e. - open system) due to combination of both temperature and wind.
Therefore - we're talking about two absolutely thermodynamically different situations. That's the physical point of view.
What's more - this description is a bit simplified, as we do not take into account humidity etc.
But there's another point of view, too. No measurements, charts, thermometers needed. If you come out of water during a stormy day - do you feel as comfortable as a person that comes out of the water on a perfectly calm day? We assume that the temperature is exactly the same. I am pretty sure many of us have felt the difference.
Mirek
Re: Lucky with our meetup timing
Posted: Mon Jun 25, 2007 1:22 am
by Byron
If the temperature is 21C and you are riding a motorbike at 70mph, without clothes on, you will feel that the temperature is -21C, therefore, that is why we motorcyclists always wear clothes on motorbikes.

Re: Lucky with our meetup timing
Posted: Mon Jun 25, 2007 11:28 am
by Dem
dar:
I look but I am not.
Dem