Humidity and perceived temperature

[Furcifer]

I'm not so sure. As a former spelunker I can say that in caves it is usually 100% humidity; one's breath is often seen while speaking. But it is not cold, even with light clothing, even given that where I caved the temperatures were about 50 degrees F. The clothing used, if worn outside at that temperature and much lower humidity, would have been too light to stay warm. Now, I admit that caving is somewhat strenuous and 50 degrees isn't all that cold, but I never really felt cold in a cave like I sometimes did being outside at similar temperatures.

That makes sense, with that level of humidity your breath would be steam. At 100% humidity the dew point would be 50F, your breath would easily be above that and condense.

from wiki: Lower dew points, less than 10 °C (50 °F), correlate with lower ambient temperatures and the body requires less cooling. A lower dew point can go along with a high temperature only at extremely low relative humidity (see graph below), allowing for relative effective cooling.

From that article you'll notice a dew point of 50-54F is "Very comfortable". From a human standpoint what you're describing is ideal.

eta: wiki link http://en.wikipedia.org/wiki/Dew_point

 

[shadron]

Humidity is a factor in computation of the wind chill factor; it's effect is that rising humidity increases the negative chill value.

I was working on the eastern plains last week in 101 degree weather, 40% humidity with a constant 10 mph wind. The drying effect was extreme; lots of water was consumed, but it never felt really hot until the wind stopped, and the sweating started becoming noticeable.

30 degrees is relatively warm, after acclimatizing to 0-10, as can happen for weeks at a time in Denver. Likewise, 50 feels very cold in the autumn after 90 degree days.

And the bad snowball packing is not a humidity effect, but a temperature effect. Ask any skiier.

 

[aggle-rithm]

And the bad snowball packing is not a humidity effect, but a temperature effect. Ask any skiier.

So when it gets warmer, shouldn't the snow become easier to pack?

It doesn't.

(Of course, it could be a temperature effect at the time the snow crystals are formed, which lingers after the temperature rises. That would make sense.)

 

[aggle-rithm]

Another interesting characteristic of the snow in Steamboat Springs: I saw a big snow bank and decided to fall into it backwards, letting the cushy snow absorb my fall. The first two feet of snow that I passed through crumbled away, offereing absolutely no resistance at all, while the snow beyond this point was packed into solid ice. It was not a nice moment.

 

[Skeptic Ginger]

Another interesting characteristic of the snow in Steamboat Springs: I saw a big snow bank and decided to fall into it backwards, letting the cushy snow absorb my fall. The first two feet of snow that I passed through crumbled away, offereing absolutely no resistance at all, while the snow beyond this point was packed into solid ice. It was not a nice moment.

[sidetrack] Mmmmmmmmm, Steamboat Springs. One of my most favorite places I have lived. Of course that was before all the condos and freeway were there. [/sidetrack]

That would be the place I lived when I wore long sleeves and a vest if the Sun was out and it was 20⁰F

 

[Furcifer]

First humidity, now snow, from a Texan? I think the other Canadians are too shell shocked to respond...

So when it gets warmer, shouldn't the snow become easier to pack?
It doesn't.

Another interesting characteristic of the snow in Steamboat Springs: I saw a big snow bank and decided to fall into it backwards, letting the cushy snow absorb my fall. The first two feet of snow that I passed through crumbled away, offereing absolutely no resistance at all, while the snow beyond this point was packed into solid ice. It was not a nice moment.

Using my powers of deduction, from the above two posts I've deduced you were in a thaw. That's the only way it makes sense.

The latticed snow you speak of is old thawed snow. Round these parts it's usually brown and resides primarily in banks along driveways and in parking lots. The top snow melts, but the bottom snow it compressed from it's own weight. Usually a sub zero night freezes the bottom into ice pack while the top melts into some crazy looking patterns.

You can't make a snowball out of that snow, it's actually more of a crushed ice. It's usually like little tiny ice ball bearings, very round. That makes it hard to pack.

This is why the Inuit have 47 different words for snow. Or so I heard.

 

[Damien Evans]

So when it gets warmer, shouldn't the snow become easier to pack?

It doesn't.

(Of course, it could be a temperature effect at the time the snow crystals are formed, which lingers after the temperature rises. That would make sense.)

Wouldn't it be more mushy and harder to pack since it's closer to melting?


Disclaimer: I haven't seen snow for 7 years.

 

[aggle-rithm]

Using my powers of deduction, from the above two posts I've deduced you were in a thaw. That's the only way it makes sense.

During my week-long stay the temperature varied from -8 degrees F to about 35. There was unusually heavy snowfall at that time, according to the locals. I saw several backhoes clearing out parking lots and loading snow into dump trucks to be taken out of town.

This is why the Inuit have 47 different words for snow. Or so I heard.

That's a myth. Or so I heard.

 

[aggle-rithm]

Wouldn't it be more mushy and harder to pack since it's closer to melting?

That's what I thought, but no! The melting snow would be more drippy, but still couldn't be packed.

 

[aggle-rithm]

[sidetrack] Mmmmmmmmm, Steamboat Springs. One of my most favorite places I have lived. Of course that was before all the condos and freeway were there. [/sidetrack]

That would be the place I lived when I wore long sleeves and a vest if the Sun was out and it was 20⁰F

Ironically (or perhaps counter-intuitively), if you can get 100 feet or more above the ground in Steamboat Springs it gets warmer. The cold air settles into the valley leaving a layer of warm air above.

I learned this while taking a balloon ride there.

 

[aggle-rithm]

[sidetrack] Mmmmmmmmm, Steamboat Springs. One of my most favorite places I have lived. Of course that was before all the condos and freeway were there. [/sidetrack]

Close to the slopes it's a very different place, with lots of chain stores, condos, and modern conveniences. Move a couple of miles west, and it's like going into a time machine. The downtown area seems like it's been unchanged since the 50's.

 

[Skeptic Ginger]

Close to the slopes it's a very different place, with lots of chain stores, condos, and modern conveniences. Move a couple of miles west, and it's like going into a time machine. The downtown area seems like it's been unchanged since the 50's.

When I lived there only a highway went through town and I don't recall a single condo though there could have been some, they didn't dominate the scenery. I lived in the most incredible house, 3 stories, 3 balconies overlooking the valley, stained glass windows, my upstairs bedroom had a wood window that opened up into the main room, support beams that were still in tree trunk form, huge 2 story high central fireplace.... and lots of friends. We split the rent so it was cheap and there was plenty of room for everyone. You could ski from the house to the second chair lift. And Steamboat has the very best skiing of anywhere I've been. Every restaurant and bar in town was a different theme and had incredible food/atmosphere. The last time I visited we hiked up to about 10,000 foot level, when a lightning storm stuck making it a bit more exciting. Then we came back to a bar where we had drinks in the hot tub while it snowed.

Sigh.....

 

[Furcifer]

Just thought I'd say today was the first humidex warning, with the humidity at 60% it's 33C but feels like 45C.

It's hot.

 

[macdoc]

Wow that's useful since no one knows where you are tho it appears Windsor from an earlier post
.....but if it's Southern Ontario you are wrong.....there was an earlier humidex warning.

Tuesday May. 31, 2011 7:46 PM ET Toronto has patiently waited for summer's sunny arrival, but when it finally got here, it didn't disappoint.
A hot sun hovered over southern Ontario on Tuesday, leading the City of Toronto to issue a heat alert and residents to flock outdoors at every opportunity.
"That rain was driving me crazy, it was depressing. But this is lovely, this is really nice," one woman told CTV Toronto as she sunbathed lakeside on Tuesday.
City officials advised residents to stay cool during a sticky end to an otherwise rainy May.
Toronto reached a high of 31 degrees Celsius on Tuesday, a toasty temperature that hasn't been seen for eight months. With the humidex, it's likely to feel more like 40 C.
Soaring temperatures also prompted Environment Canada to issue a humidex warning for Tuesday. The advisory covers most of southern Ontario, stretching from Windsor and Sarnia, around the Golden Horseshoe to Ottawa and Cornwall and north to Algonquin and Grey-Bruce.

nothing new about that......you being wrong on the facts that is.....

 

[lomiller]

Dry air is generally feels cooler because evaporation/perspiration cools you more efficiently.


I'm not sure about the "feels cooler in winter" but I suspect it's basically wet vs dry cold. Wet cold tends to be more uncomfortable and dangerous because you and your clothing become damp which reduces it's insulating value. Keeping dry in wet-cold environments can be one of the most challenging aspects of winter survival making it more difficult to survive even when temperatures are not as low as dry-cold environments.

 

[quarky]

Its sunny in Colorado. Snow is very reflective. This plays a big part.