Too cold to snow?

[AlexH]

I hear people say this very often, but have never believed it; actually got in a heated (no pun intended) debate with someone the other day who insisted its true, despite my argument killer (or so I thought!) of 'How cold is it at the North and South poles? Does it snow there?'. Anyone know anything about meteorology? Surely its a complete old wives tale?

[ZR1cliff]

Its a load of old bowlox,and always makes me tut when i hear it.

"Too cold to snow" :shakehead: tut tut

[scorp]

If it's too cold then there will be no humidity from which snow (or rain) normally forms.
I might be wrong though..

[pdV6]

Don't know enough about meteorology but its fair to say that you normally get decent snow when it warms up a little after a cold spell.

Google comes to the rescue:

www.theweatherprediction.com/habyhints/222/

METEOROLOGIST JEFF HABY said:

One phrase that is heard from time to time is that, "it is too cold to snow today". In actuality, earth's troposphere is not too cold to snow but rather it is "too dynamically stable to snow". Dynamic stability may be present due to low-level cold air advection, a lack of upper level divergence, and/or a lack of low level convergence. Also, if dynamic lifting does occur it may not produce precipitation that reaches the surface due to low relative humidity values in the lower troposphere. The ingredients for snow are: (1) a temperature profile that allows snow to reach the surface, (2) saturated air, and (3) enough lifting of that saturated air to allow snow to develop aloft and fall to reach the surface. In a situation when it is said "it is too cold to snow" there is in reality not enough lifting of air that causes snow to reach the surface. The phrase "it is too cold to snow today" probably originated as a misapplication of the relationship between temperature and the maximum amount of water vapor that can be in the air. When temperature decreases, the maximum capacity of water vapor that can be in the air decreases. Therefore, the colder it gets the less water vapor there will be in the air. Even at very cold surface temperatures significant snowfall can occur because: (1) intense lifting can produce significant precipitation even at a very low temperature, (2) the temperature aloft can be much warmer than the temperature at the surface. The relatively warmer air aloft can have a larger moisture content than air in the PBL, (3) Moisture advection can continue to bring a renewed supply of moisture into a region where lifting is occurring, (4) Even at very cold temperatures the air always has a capacity to have some water vapor. If the air cools to truly frigid Arctic temperatures such as -40 C and below then the moisture capacity of the air will be so low that likely not much snow can occur. Only at these extremely low temperatures is the phrase "it is too cold to snow" fairly valid. At the temperature of absolute zero ( 0 K, -273 C, -459 F) all air including water vapor condenses and loses all molecular energy. The temperature can not cool below absolute zero.

[Mikey G]

But shirley there must be other factors than temperature to make snow....

[thegreatsoprendo]

It's true that the ideal conditions for snow are when the temperature is around 0 deg celcius, but I can't remember the scientific explanation for it, I'm afraid...

[bga]

AlexH said:

despite my argument killer (or so I thought!) of 'How cold is it at the North and South poles? Does it snow there?'

I've yet to have any of the "too cold to snow" brigade come up with an answer to that one

the consensus is that it is unlikely to snow when below certain temps, but we are looking at -20C

some info here: http://starryskies.com/articles/2002/12/physics-snow & here: www.straightdope.com/mailbag/msnow2cold.html

pah, beaten to it.

>> Edited by bga on Wednesday 21st December 15:53

[scorp]

Mikey G said:

But shirley there must be other factors than temperature to make snow....

Air pressure and humidity i would of thought?

Oh sod it, too much thinking for me today. It snows because God makes it snow.

Taxi!...

[staceyb]

scorp said:

Mikey G said: But shirley there must be other factors than temperature to make snow.... Air pressure and humidity i would of thought? Oh sod it, too much thinking for me today. It snows because God makes it snow. Taxi!...

No its not its Angels dandruff.

[r988]

some antartic site said:

6. Does it snow at the pole? The South Pole is located within a permanent polar high, making it possibly the most consistently cloudless place on Earth where there is a scientific station. Although there is lots of snow and ice around, the Pole is really a desert environment, because it averages less than 1 inch of precipitation yearly, about the same as the Sahara Desert. When warm moist air does make it all the way to the Polar Plateau, the air cools and becomes supersaturated with ice crystals. Ice crystals account for 90% of the accumulation on the plateau.

[apache]

r988 said:

some antartic shite said: 6. Does it snow at the pole? The South Pole is located within a permanent polar high, making it possibly the most consistently cloudless place on Earth where there is a scientific station. Although there is lots of snow and ice around, the Pole is really a desert environment, because it averages less than 1 inch of precipitation yearly, about the same as the Sahara Desert. When warm moist air does make it all the way to the Polar Plateau, the air cools and becomes supersaturated with ice crystals. Ice crystals account for 90% of the accumulation on the plateau.

that's a bit harsh

[Truckosaurus]

Isn't the simple answer that when it is especially cold in the UK, the weather has come from the East, so is drier adn therefore less likely to snow than the Wetter Warmer Weather from the West.

[NerveAgent]

Although I have no evidence to back this up, Im sure I have heard a few theories on why the statement can be true but this only applies to the uk

Generally it only gets really cold in the UK when we have high pressure systems hence no clouds and no snow. Also it could be something to do with wind direction when its really cold. Its coming off the continent hence its dry air.

As I say I have no evidence for any of this and its probably all wrong but for some reason I have this in the back of my mind from geoigraphy lessons many years ago or something!

[r988]

apache said:

that's a bit harsh

So's the antarctic, they can take it

[off_again]

Was in Finland yesterday. It is -10 C there and it snowed.... so frankly its rubbish...

Then again, at this time of the year they have a permanent frost - so what snow they get will stick and lay each and every time. This seems to be the killer in the UK. We need it to be cold enough to snow, but warm enough for them to be big enough flakes. But also we need it to be cold enough to lay.... like freezing...

All I know is that the UK is positively warm - so no complaining about it being cold please

[r988]

off_again said:

All I know is that the UK is positively warm - so no complaining about it being cold please

Even I think it's fairly warm (considering it's winter). I'm beginning to wonder what all the fuss is about being a soft southern hemispherian and all. (Cue -30 C cold snap to teach me a lesson...)

[Highway Star]

We get a lot less snow in Iowa than say New York does, but it is normally much colder as we are further inland and continentality takes effect. It's not very humid here and there are very few large expanses of water near us, so snow is not as likely as say even in Minnesota directly north of us.

Basically its just as cold as charity (was -26 degrees C last week) and the little snow we do get turns to ice.

[up-the-dubs]

Highway Star said:

We get a lot less snow in Iowa than say New York does, but it is normally much colder as we are further inland and continentality takes effect. It's not very humid here and there are very few large expanses of water near us, so snow is not as likely as say even in Minnesota directly north of us. Basically its just as cold as charity (was -26 degrees C last week) and the little snow we do get turns to ice.

Iowa: The corn State!


I love those licence plate slogans

[Highway Star]

up-the-dubs said:

Highway Star said: We get a lot less snow in Iowa than say New York does, but it is normally much colder as we are further inland and continentality takes effect. It's not very humid here and there are very few large expanses of water near us, so snow is not as likely as say even in Minnesota directly north of us. Basically its just as cold as charity (was -26 degrees C last week) and the little snow we do get turns to ice. Iowa: The corn State! I love those licence plate slogans

And also the Pig State and the Soybean State - lucky me!!!!

Edit to say - actually is the Hawkeye State, after Chief Black Hawk.

They don't have the slogan on the plate any more, just a picture of a farm instead....

- an old Chevy we used to have

Although some still retain the slogans, I always wonder why Missouri is called 'The Show-Me State'?

>> Edited by Highway Star on Thursday 22 December 03:06

[gbbird]

There is some truth in this i think. Basically, when it is really cold it tends to be when there are no clouds in the sky. So, as snow comes from clouds, if it is cold and there are no clouds, then it is too cold to snow!