The weather

[Gary_C]

Betcha didn't know wet air (higher water vapor) is lighter than dry air. ;D  Nice snap'n cold dry day has the coldest spots in the river valleys, as cold air flows like water down them valleys and is heavier air.  ;)

No I didn't know that, and am trying desperately to follow your logic, without much success.  ??? 

What are you smoking??   

[Warbird]

Betcha didn't know wet air (higher water vapor) is lighter than dry air. ;D  Nice snap'n cold dry day has the coldest spots in the river valleys, as cold air flows like water down them valleys and is heavier air.  ;)

That I did know.  We get what they call inversions here.  Usually it is 5 - 20°F warmer in the hills.

It is -45°F in town this morning, -38°F here at the house, and -32°F at work.  Good example of what you are talking about, SD. 

We also have a lot of ice fog and the air quality is real bad with the extreme cold, as particulate cannot rise.  Oh, and they are calling for -50°F tonight again.  Good thing I planned on torching off a bonfire while I'm outside lighting off the fireworks this evening!!  I'll try to get some pictures.

[Woodcarver]

Oh, and they are calling for -50°F tonight again. 

Think what it might be like if the National Weather Service hadn't predicted milder than average temperatures for Alaska this winter.   

[Warbird]

Betcha didn't know wet air (higher water vapor) is lighter than dry air. ;D  Nice snap'n cold dry day has the coldest spots in the river valleys, as cold air flows like water down them valleys and is heavier air.  ;)

No I didn't know that, and am trying desperately to follow your logic, without much success.  ??? 

What are you smoking??   

Gary, if you want an explanation, this site gives it a whirl:

http://www.theweatherprediction.com/habyhints/260/

*EDIT*  This site gives a much more succinct explanation: http://answers.yahoo.com/question/index?qid=20080906154058AA67UVA

The "inversions" I was talking about may be related to what SD is referring to but I don't know for sure.  And I have to head into work for a bit so can't google it right now.

Oh, and they are calling for -50°F tonight again.

Think what it might be like if the National Weather Service hadn't predicted milder than average temperatures for Alaska this winter.   

Don't get me started, sir.  ;D

[Gary_C]

Betcha didn't know wet air (higher water vapor) is lighter than dry air. ;D  Nice snap'n cold dry day has the coldest spots in the river valleys, as cold air flows like water down them valleys and is heavier air.  ;)

Warbird, my problem with those two sentences is they are unrelated and not clearly defined. The first has to do with the density of air with varing moisture contents with the atmospheric pressure undefined. The second has to do with the density of air at different temperatures with the atmospheric pressure still undefined. While both statements may be true under defined pressure conditions, the first statement does not prove the second or vise versa.

And inversions which are normally temperature related are a completely different subject that may pertain more to solar radiation than moisture content of the air.

So now that is all clear, why does the very cold dry air in the upper atmosphere not flow down to the earth's surface like water as SD described?   

[sharp edge]

Just to clear thing up I would like to add...thermal mass... enters in here (density of air with varing moisture content). 

SD is just talking about H and L weather systems. Hes right about H going down rivers.

Also will add the size of air...when H get warm they get a lot bigger and cause wind.. Don't know what causing all the wind in this thread, think there a little uncle Al in all of us. :

SE

[Tom]

So.....   If we are trying to make a point, which way do we move it?

[Gary_C]

Tom, we are trying to move that point up into the stratosphere. If you don't know where that is here is an explanation:

The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler higher up and warmer farther down. The border of the troposphere and stratosphere, the tropopause, is marked by where this inversion begins, which in terms of atmospheric thermodynamics is the equilibrium level. The stratosphere is situated between about 10 km (6 miles) and 50 km (31 miles) altitude above the surface at moderate latitudes, while at the poles it starts at about 8 km (5 miles) altitude.

The problem is that the point keeps sinking down into the valleys as SD predicted, or caused, which ever came first.   :D :D

[stonebroke]

Gary

You lost me a long time ago. This is way more than my little brain  can absorb.

Stonebroke

[Gary_C]

Gary

You lost me a long time ago. This is way more than my little brain  can absorb.

Stonebroke

Aw, don't worry about it, Donk will be along shortly to straighten out all the confusion.  8)

[Jeff]

Now how has all of this got to do with figuring out what the volume is in a board foot of lumber in relation to the current atmospheric conditions?  ;)

[Warbird]

Now how has all of this got to do with figuring out what the volume is in a board foot of lumber in relation to the current atmospheric conditions?  ;)

Here is how it relates...  If it is -50°F, it is too DanG cold to be outside milling.  Stay inside and have a cup of hot chocolate.  ;D

ps.  You guys would be proud of me...  I actually fired up the chainsaw last night at -40°F   (I love my Stihl) and cut up a dead tree that fell a couple of years ago.  It is what I'm using for the bonfire this evening.  ;)

[sharp edge]

SB
Don't worry just watch a camp fire a lot of the same things are going on in one.

Gary C
To move a point. Was wondering how oxygen gets all the way to the center and down in the coals of a campfire? Maybe you can help me out here.

WB and Jeff its less bf when its cold out.

PS.  or bonfire

SE

[SwampDonkey]

So now that is all clear, why does the very cold dry air in the upper atmosphere not flow down to the earth's surface like water as SD described?   

Is pressure up there the same as it is at ground level? What about density? Convection? Radiation? All those turbulent things. :D I think you are referring to the troposphere, where temp decreases with height, above that in the stratophere, the air temperature increases with height and there is no turbulence. Ozone and other gasses along with solar radiation causes this. "Oh no , not another global warming thread".   ;) There is equilibrium at the tropopause, which is the transition between the two layers. What is the jet stream, and how come when it moves south, it brings cold air? :D


Hi uncle Al.  _grin

I think we got our cue to move on to something more pleasant. :D

[Gary_C]

Now how has all of this got to do with figuring out what the volume is in a board foot of lumber in relation to the current atmospheric conditions?  ;)

Not much, but after sitting in this chair for most of three days and parts of the night trying to do a years worth of bookwork, it has helped with my sanity and entertainment.  8)
But be warned, I am not done yet, with the bookwork I mean.  :D :D

Donk, I thought you might just say it was because the pressure is much lower way up there and pressure has been somewhat forgotten in this enlighting discussion, but that would have been too easy to leave it at that.    :D :D

[SwampDonkey]

 ;D 

That's what your here for, to find the cracks and fill them.  I can't do all the hard work. Besides, I thought we talked pressure a long way back. :D :

If the dew point has been reached at 40 F, and the pressure at the dew point temperature is 27 in-HG , what was the pressure at 50 F as we are approaching the dew point? ;D

[thecfarm]

OK pigman,your turn.You did a great job with how great Al Gore is. :D    :   :

[Warbird]

*whew*  It's -38°F and dropping here at my house.  Just spent an hour outside wrestling that dead tree that fell a couple of years ago out of the woods, over the fence, into the yard, and onto the burn pile.  I'm telling you what...  working hard at these temps, no matter how dressed you are for it, really saps your energy.  I'm completely pooped.

Good thing the guests don't start arriving for another couple hours.  At the rate the temp is falling, we might even see -50°F here!  I hope not.

Will try to post some pics for you guys late tonight or tomorrow morning.  Have a HAPPY, SAFE, and WARM NEW YEARS everyone! 

[woodman]

  Cold here today about 20 and 8 inches of snow, Bobcat got a little workout happy newyear.

[SwampDonkey]

Cold, windy and no snow in the air here. NS has been getting most of this winter's snow and are getting the big New England snow. Moncton, NB in the southeast is a known snow magnet as well. We only had one storm this season a 15" incher and has rained a couple times since and two dustings of under an inch each. Saturday another inch expected from that Michigan storm. There might be 5 inches in the fields, but probably 16" in the woods where it is more sheltered from wind and rain. I walked out the woodlot the other day and I have a couple moose holding up in my hardwood, the ground is like a cow pasture with moose marbles and tracks all over a 5 acre area. Heard them running out of there when I snow shoed up. Ground ain't even froze under the snow, the tracks go into the mud.

[bull]

brrrrr -1 w/ -24 wind chill and blowing drifting snow!! Ah what a great start to 2009 real winter weather so much for global warming......

[Papa1stuff]

Really cold here this AM 52  ;D Had to wear a coat!!

[isawlogs]

Sunny but the breeze out there trumps the sun ....  its -22°C  .....

[Roxie]

So where are the pictures of the bonfire?  I want to see if the smoke froze or just stayed on the ground since it was drier.   

[DanG]

I didn't think fire would even burn at -50F!  If it got that cold here, I'd be wintering in New Zealand.