231%

legion · 01-06-2010, 05:02 AM

That was the relative humidity this morning. Too bad it's still damn dry when the temperature is -1º. This marks the sixth day in a row that the temperature has been below zero when I got up. Tomorrow it's supposed to hit 20º--a freakin' heat wave! (It has to warm up to snow tomorrow.)

masraum · 01-06-2010, 05:33 AM

Uh, humidity can't be over 100%.

Yeah, we've had some REALLY cold weather here too lately. It got down to 27.6°F at my house yesterday morning. Brrrr.

Yes, our winter has been much colder all ready this year. I think we've had colder temps than we've had for several years. This Global Warming is killing us.

kaisen · 01-06-2010, 05:35 AM

Yeah, how do they get more than 100%

legion · 01-06-2010, 05:40 AM

Super-saturation. Don't you guys know anything?

Seriously if the relative humidity is at 100% at 40º, and then the temperature cools to 20º, then the relative humidity will be over 100%.

The relative humidity measures how much water can be absorbed by the air at a specific temperature. If the temperature has dropped, the air can still carry the more moisture than it could absorb at that temperature without precipitating the difference.

kaisen · 01-06-2010, 05:42 AM

I thought it had to precipitate? But it's been 20 years (exactly) since I took a meteorology course in college.

masraum · 01-06-2010, 06:07 AM

Yeah, I've not been able to find anything that says that it's possible to have more than 100% humidity. WHen the temp drops, the water will condense out.

masraum · 01-06-2010, 06:31 AM

I found someplace that says that it's possible. (and several places that says that it's not)

USATODAY.com

Quote:

Q: Is it possible for relative humidity to be higher than 100%?

A: Yes, it is possible. In Elements of Meteorology the authors Albert Miller and Jack C. Thompson explain that in extremely clean air which contains no "foreign" particles, water droplets, or ice crystals it is extremely difficult for condensation to occur even when supersaturated conditions are present. Supersaturated conditions refer to relative humidities much greater than 100%. C.T.R. Wilson invented an instrument called a cloud chamber in which clouds can be manually made. He discovered that in pure, clean air the relative humidity must reach 800% before water drops form. Realistically, air is not pure and clean. There are many particles that are small enough to remain suspended in the atmosphere such as salt particles from sea water, combustion products, meteoritic dust, volcanic material, and soil. These particles, prominent as they are, act as nuclei for water to condense upon and, hence, are an easier means of condensation. This means that condensation in real air can usually produce humidities just barely over 100%.

So, there's 1 vote for.

There are several votes against.

widebody911 · widebody911's Garage

If you're not part of the solution, you're part of the precipitate!

sammyg2 · 01-06-2010, 07:08 AM

Tell me about it.
A couple of nights ago it got down to 48 degrees here, I had to put on a jacket in the morning!

legion · 01-06-2010, 07:10 AM

Eh, the TV said 231% humidity this morning. I know that super-saturation is possible in any solution. I'd never heard that it was supposedly impossible in the atmosphere.

Pazuzu · 01-06-2010, 07:50 AM

Anything else the TV tells you that seems wrong, but you believe anyways?

M.D. Holloway · 01-06-2010, 08:17 AM

its all relative

legion · 01-06-2010, 08:24 AM

Quote:

Originally Posted by Pazuzu

Anything else the TV tells you that seems wrong, but you believe anyways?

Something about Hope and Change...

sammyg2 · 01-06-2010, 09:09 AM

This isn't my field of expertise but I had some education on the topic years ago. I could see 102%, maybe 105%, but 231%? Nope. Not for more than a very short time.

relative humidity is by definition a percentage of capability. How much moisture is the atmosphere capable of retaining under given temperature, barometric pressure, etc.
In other words it's a scale of zero to 100. It's actually more complicated that that but that's an easy way to remember it.

Having said that, it is possible uncer certain conditions to go over 100% but that capability is projected or estimated. It isn't perfectly accurate under all conditions. If the air cools quickly it might take time for the moisture to condense so for that time it would be over 100% but not much.

Heel n Toe · 01-06-2010, 11:03 AM

Extra, extra... read all about it:
"humidity higher than 100%" - Google Search

BeyGon · 01-06-2010, 11:06 AM

That Global Warming is going to kill you.
I would post a picture of Dana Point today but,

sammyg2 · 01-06-2010, 11:19 AM

Quote:

Originally Posted by Heel n Toe

Extra, extra... read all about it:
"humidity higher than 100%" - Google Search

I checked the pages listed in that search.
Several of them referenced "relative humidity above 100%" but did not elaborate.
One of them even suggested it was impossible to go over 100% (which I do not agree with).
how much higher than 100%?
Was there a specific page you were referencing or just results of a search?

sammyg2 · 01-06-2010, 11:25 AM

I found this which is of interest and seems reasonable:

Quote:

Q: Is it possible for relative humidity to be higher than 100%?

A: Yes, it is possible. In Elements of Meteorology the authors Albert Miller and Jack C. Thompson explain that in extremely clean air which contains no "foreign" particles, water droplets, or ice crystals it is extremely difficult for condensation to occur even when supersaturated conditions are present. Supersaturated conditions refer to relative humidities much greater than 100%. C.T.R. Wilson invented an instrument called a cloud chamber in which clouds can be manually made. He discovered that in pure, clean air the relative humidity must reach 800% before water drops form. Realistically, air is not pure and clean. There are many particles that are small enough to remain suspended in the atmosphere such as salt particles from sea water, combustion products, meteoritic dust, volcanic material, and soil. These particles, prominent as they are, act as nuclei for water to condense upon and, hence, are an easier means of condensation. This means that condensation in real air can usually produce humidities just barely over 100%.

USATODAY.com

Heel n Toe · 01-06-2010, 11:34 AM

Quote:

Originally Posted by sammyg2

I checked the pages listed in that search.
:::::
Was there a specific page you were referencing or just results of a search?

Nuttin' specific... I looked briefly at a couple of them and decided to leave the in-depth analysis to the chemical engineers and meteorologists amongst us.

I'm an artist... all that stuff is Greek to me... beyond a certain point... I usually made decent grades in science class.

sammyg2 · 01-06-2010, 11:40 AM

Quote:

Originally Posted by Heel n Toe

Nuttin' specific... I looked briefly at a couple of them and decided to leave the in-depth analysis to the chemical engineers and meteorologists amongst us.

I'm an artist... all that stuff is Greek to me... beyond a certain point... I usually made decent grades in science class.

LOL, I understand. I'm an engineer and don't have an artistic bone in my body

The curiosity was really getting to me because I THOUGHT I understood it but wasn't 100% sure.

Is it possible to be more than 100% sure?