Too cold to snow?

VicDaring

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VicDaring
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It's freezing here in Pennsylvania right now. And I mean temperatures in the single digits (farenheit).

So, the last couple days I've heard the line about how it's "too cold to snow" a few times and it just rings untrue to me somehow.

Doesn't it snow at the North Pole, when it's considerably colder than anything we're experiencing?

Problem is, I know nothing about the science involved. So I'm asking anyone here with any knowlegde in this area. Is there anything to this idea? Or is it just a popular wrongheaded cliche?
 
I always took that to mean that it it lowered the water vapour content in the air and made snowfall less likely or lighter.

For example, at the extreme, the atmosphere couldn't hold any moisture, so no snow.
 
VicDaring said:

Doesn't it snow at the North Pole, when it's considerably colder than anything we're experiencing?
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No. The artic and antartica are both deserts
 
VicDaring said:
Doesn't it snow at the North Pole, when it's considerably colder than anything we're experiencing?

Not very much, no. It's been said that the high arctic is drier than the Sahara (maybe just another cliche, but it is dry up there).

Problem is, I know nothing about the science involved. So I'm asking anyone here with any knowlegde in this area. Is there anything to this idea? Or is it just a popular wrongheaded cliche?
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Like Drooper said, cold air holds less water (can't wait for the pedants to jump on that one), so when it's really cold, there's less water vapour available to form snowflakes. I've seen temperatures down to -46C (-50F), and it's always been extremely dry, and crystal clear, at those times. I did a little experiment once, when it was about -40C outside: I boiled some water in an electric kettle, poured it into a cup, and tossed it into the air. It instantly created a thick, brown cloud, which slowly settled and dissipated.
 
Re: Re: Too cold to snow?

arcticbiker said:


Like Drooper said, cold air holds less water (can't wait for the pedants to jump on that one), so when it's really cold, there's less water vapour available to form snowflakes. I've seen temperatures down to -46C (-50F), and it's always been extremely dry, and crystal clear, at those times.
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Don't confuse cause and effect here. Yeah, it is often the case that those very cold days (-40) are clear and sunny. But is it clear and sunny because it is cold, or is it cold because it is clear and sunny?

I argue the latter. Water vapor has a much greater heat capacity than does just air. Thus, if you have water around, it will stay warmer. Without the clouds, it can get much colder.

Of course, blizzards will have the combination of it all, clouds, wind, snow, and cold.
 
Just to echo the other fine responses.

The colder air is, the less moisture it can hold; and less moisture there is, the less likely the meteorological conditions will be for the moisture to condense out.

That is why the South Pole is one of the most arid places on the planet.
 
Thanks all. Great link, Harry. Shared that one with co-workers who've had this conversation.
 
I have personally been in falling snow, with an air temperature of minus 40 (C or F, makes no difference). Wind was zero. (Thanks be). North Caspian , January 2002.

It didn't snow much, but it did snow.
 
Crossbow said:
Just to echo the other fine responses.

The colder air is, the less moisture it can hold; and less moisture there is, the less likely the meteorological conditions will be for the moisture to condense out.

That is why the South Pole is one of the most arid places on the planet.
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What he said. The poles are deserts, because they so cold. So, your local weatherman is (essentially) right. It is too cold to snow.

Snow is most common and abundant in the 20-32F range.

Another factoid to boggle over. Road salt doesn't really work if the temp gets too low. In fact, below 17-20F, it has little effect at all.

We Michiganders know all about cold stuff.



:D
 
Re: Re: Too cold to snow?

arcticbiker said:
I boiled some water in an electric kettle, poured it into a cup, and tossed it into the air. It instantly created a thick, brown cloud, which slowly settled and dissipated.
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You don't wash your cup very often, do you? :D
 
Soapy Sam said:
I have personally been in falling snow, with an air temperature of minus 40 (C or F, makes no difference). Wind was zero. (Thanks be). North Caspian , January 2002.

It didn't snow much, but it did snow.
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That sounds like what around here is known as "lake effect" snow. Requires temps colder than 14 F, and very light winds (if it blows too hard it doesn't have time to collect moisture) from the north. The cold air gathers moisture from Lake Michigan (which is warmer) and it condenses over land. Not real common here as the wind has to be from the north, which is unusual as prevailing winds in winter is from the west or northwest. But western Michigan and the UP get gobs of it, as well as northwest Indiana. It's a very light fluffy snow.
 
WildCat said:

That sounds like what around here is known as "lake effect" snow. Requires temps colder than 14 F, and very light winds (if it blows too hard it doesn't have time to collect moisture) from the north. The cold air gathers moisture from Lake Michigan (which is warmer) and it condenses over land. Not real common here as the wind has to be from the north, which is unusual as prevailing winds in winter is from the west or northwest. But western Michigan and the UP get gobs of it...
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Oh yeah, does it ever. This marker is on US41 north of Houghton MI in the Upper Peninsula.
SnoGage.jpg

That top marker is over 32 feet up ...yeah, they get snow up there...
 
ok if it is too cold or dry to snow at the poles where did all the white stuff comes from?

Thanks


Virgil
 
Virgil said:
ok if it is too cold or dry to snow at the poles where did all the white stuff comes from?

Thanks


Virgil
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this is what my grade school science teacher told me...

it snows less than a few inches a year but it doesnt melt so it just builds up.

dont know if that's right or not. especially since the ice in the ice cube tray in my freezer get smaller and smaller, (i'm guessing due to evaporation) i would think the same would happen to the snow.
 
Virgil said:
ok if it is too cold or dry to snow at the poles where did all the white stuff comes from?

Thanks


Virgil
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Well, it does snow at the poles, just not very much and that little bit of snow rarely melts.

So, if say a place like the South Pole were to get about 2 inches of snow every year, and the temperature has not exceeded 0 C for the last ten of thousand years, then the snow pack could be hundreds of feet thick.
 
Crossbow said:


Well, it does snow at the poles, just not very much and that little bit of snow rarely melts.

So, if say a place like the South Pole were to get about 2 inches of snow every year, and the temperature has not exceeded 0 C for the last ten of thousand years, then the snow pack could be hundreds of feet thick.
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Arctic Climatology and Meteorology


In some parts of the Arctic, warm ocean currents bring heat and moisture to the air and frontal activity results in increased precipitation. For instance, southern Iceland, southern Alaska and parts of the Norwegian coast receive in excess of 3000 mm of precipitation per year. In contrast, inland areas of the Arctic with continental climate and lower temperatures receive less than 150 mm ( 6 inches ) of precipitation per year.
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Arctic Climatology and Meteorology



Compare the 6 inches above with an average of 3 inches for subtropical areas of the Sahara...


Here is a chart about Antarctic Precipitation


It shows years 80 - 94 with a range of 0 to 300 mm per year..
It looks like the average might be about 150 mm ( 6 inches ).. Not very much at all..



I found the average annual rainfall in Cairo in the years 1903 to 1990 to be about 1 inch.. It didn't say anything about snow, though....:D
 
Re: Re: Re: Too cold to snow?

wayrad said:
You don't wash your cup very often, do you? :D
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Only with boiling water when it's -40!

Seriously, though, I think the brownish tinge is due to the density and/or size of the airborne ice crystals. I don't think any of the 200mL of boiling water actually hit the ground (at least, not before it turned into very fine ice crystals).
 
I live in a place where we get very cold temps (-30C and colder but rarely colder than -45C) and plenty of snow. As a general rule the temps are warmer when we get most of our snow. When it is bitterly cold it is almost always clear (high pressure arctic air). Just like rain you won't get snow from a clear sky. When it snows it is cloudy and warmer. I always chocked up the warmth to greenhouse effect from the clouds (just a guess).

Having said all that I have seen it snowing with ambient air temps around -40C but that is very rare. It can't be a lake effect because we are not near any large bodies of water and everything is frozen anyway.

Typically when it is very cold there is almost zero humidity. At -45C it can feel like your lungs are being sucked out of your body when you breathe. If you start to move you create more wind chill. If you stand still you freeze very quickly. Probably explains why we mostly stay indoors when it gets cold.
 
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