Snow And Ice In The Northern Hemisphere 2012/13

[feb1991blizzard]

Just a quickie from me. What is the actual reason that larger areas of snow cover in Arctic or near Arctic regions and Siberia are supposedly better for cold winters?, is it because they affect wavelength patterns further West or is it because there is a colder or bigger pool of cold air to call on during the winter if we get the right pattern in place, i suspect it must be more teleconnective based because any strong Atlantic / Greenland heights in wintertime or any strong and reasonably long lasting heights over scandinavia as long as they orientated favourably would ultimately bring potent cold into the uk, it takes a really short time for the cold air from polar regions to get advected southwards.

[Styx]

Just a quickie from me. What is the actual reason that larger areas of snow cover in Arctic or near Arctic regions and Siberia are supposedly better for cold winters?, is it because they affect wavelength patterns further West or is it because there is a colder or bigger pool of cold air to call on during the winter if we get the right pattern in place, i suspect it must be more teleconnective based because any strong Atlantic / Greenland heights in wintertime or any strong and reasonably long lasting heights over scandinavia as long as they orientated favourably would ultimately bring potent cold into the uk, it takes a really short time for the cold air from polar regions to get advected southwards.

It's due to a social telekinecticism.

Millions of weather enthusiasts get excited, and where there is a multiple-multiple will, there will often be a result in the affirmative .

[gottolovethisweather]

Just a quickie from me. What is the actual reason that larger areas of snow cover in Arctic or near Arctic regions and Siberia are supposedly better for cold winters?, is it because they affect wavelength patterns further West or is it because there is a colder or bigger pool of cold air to call on during the winter if we get the right pattern in place, i suspect it must be more teleconnective based because any strong Atlantic / Greenland heights in wintertime or any strong and reasonably long lasting heights over scandinavia as long as they orientated favourably would ultimately bring potent cold into the uk, it takes a really short time for the cold air from polar regions to get advected southwards.

Hi,

I don't really know either but i think it must due to less modification of the winds and subsequent air source, when the flow is coming to the UK from that direction. This is why, perhaps the colder snaps (5 weeks of bitter cold, late November-December 2010, a massive exception) we are accustomed to, are favoured by increases in the snowcover over parts of Scandinavia, for example. Simply, because the Arctic air then never has to travel over anything warm, bar the North Sea.

Edited October 2, 2012 by gottolovethisweather

[jethro]

Isn't it something to do with the NAO? More snow cover encourages a negative phase? Or have I got that completely wrong?

[gottolovethisweather]

Isn't it something to do with the NAO? More snow cover encourages a negative phase? Or have I got that completely wrong?

Yes, surely that is another factor too.

[BornFromTheVoid]

According to a link in the "Hunt for White December" thread posted by bobbydog, (my own interpretation of it is) it's because the Siberian snow cover changes affect the strength of the Autumn Siberian high pressure. This then influences the upward propagation of rossby waves in the jet stream. With a stronger Siberian high,more energy is sent into the polar stratosphere causing warming and weakening the polar vortex, which then affects the weather at the surface by modifying the wave amplitude and positioning of the jet stream.

Here's the link http://dotearth.blog...on-to-the-test/

Two papers explaining with more detail than the link

http://web.mit.edu/j...dsetal_JC12.pdf

http://web.mit.edu/j...henetal2007.pdf

[Interitus]

According to a link in the "Hunt for White December" thread posted by bobbydog, (my own interpretation of it is) it's because the Siberian snow cover changes affect the strength of the Autumn Siberian high pressure. This then influences the upward propagation of rossby waves in the jet stream. With a stronger Siberian high,more energy is sent into the polar stratosphere causing warming and weakening the polar vortex, which then affects the weather at the surface by modifying the wave amplitude and positioning of the jet stream.

Here's the link http://dotearth.blog...on-to-the-test/

Two papers explaining with more detail than the link

http://web.mit.edu/j...dsetal_JC12.pdf

http://web.mit.edu/j...henetal2007.pdf

One of the authors of the second paper has published more recent research that suggests that maybe it is not so much the snow cover extent (SCE) as the rate of change in snow cover which has a greater correlation on the arctic oscillation; they developed the snow advance index (SAI) as a measure of this (as used in the first paper above)

http://www.agu.org/j...011GL049626.pdf

Edited October 2, 2012 by Interitus

[BornFromTheVoid]

One of the authors of the second paper has published more recent research that suggests that maybe it is not so much the snow cover extent (SCE) as the rate of change in snow cover which has a greater correlation on the arctic oscillation; they developed the snow advance index (SAI) as a measure of this (as used in the first paper above)

http://www.agu.org/j...011GL049626.pdf

Cheers. So the rate of snow cover increase from now until the end of October is the most important period. The correlations between the SAI and AO are incredibly high for a natural system. Better keep our eyes peeled for the next few weeks!

Here's a link to the paper without a paywall http://web.mit.edu/jlcohen/www/papers/CohenandJones_GRL11.pdf

[Suburban Streamer]

It's due to a social telekinecticism.

Millions of weather enthusiasts get excited, and where there is a multiple-multiple will, there will often be a result in the affirmative .

If that's the case then the winter 2012/2013 thread is gonna result is one epic winter

[Gavin Hannah]

If that's the case then the winter 2012/2013 thread is gonna result is one epic winter

Time to get in the snow shovels and batten down the hatches.

[quest4peace]

Current snow cover Do i spot a new good blob of snow?

Compared to the day before

Edited October 2, 2012 by quest4peace

[Gavin Hannah]

Indeed, and a very good sized blob at that.

[quest4peace]

It's a bit like torture this year Patience is a virtue as they say

[WhiteXmas]

The main area of snow at the top has also widened.

[BornFromTheVoid]

Should see snow cover in more western parts of Russia on tomorrows update. During the week, much of Siberia should get a good covering and snow cover could well extend down to the US/Canadian border. A large portion of central and eastern Canada will certainly get a nice wintry blast this week.

Hints of the first Scandinavian coverings around the 9th and 10th too, but that's a little way off.

t6

t72

[quest4peace]

Snow looking a bit sparse at the moment in Barrow Alaska, seems to be sticking at night and melting a little during the day? Should they have more by now?

[gottolovethisweather]

Maybe some early signs of colder conditions attempting to bite.

This sounds quite hopeful, courtesy of GP.

http://forum.netweat...20#entry2376727

[feb1991blizzard]

Isn't it something to do with the NAO? More snow cover encourages a negative phase? Or have I got that completely wrong?

Hi,

I don't really know either but i think it must due to less modification of the winds and subsequent air source, when the flow is coming to the UK from that direction. This is why, perhaps the colder snaps (5 weeks of bitter cold, late November-December 2010, a massive exception) we are accustomed to, are favoured by increases in the snowcover over parts of Scandinavia, for example. Simply, because the Arctic air then never has to travel over anything warm, bar the North Sea.

Thanks for the replies. I think both points have some merits but i still think if we got a long fetch wind from a cold direction we would still get bitter weather in winter, regardless of cover although as you say GLTW it would be moderated somewhat with less, if there is a correlation between ice cover and a -NAO then it is far more significant.

[damianslaw]

Canada looks like seeing its first proper arctic blast of the season by the end of the week, with many central/southern parts seeing some snowfall. Also northern parts of USA i.e. mid western states and northern states as far south as Kansas will see a cold blast from the north, with temps dropping from low-mid 20's presently to low single maxima by the weekend.. at this time of year you often see such swings in temperatures in these parts, a signal that the northern hemisphere begins to rapidly descend into its winter state during October.

[snowking]

I know this is specifically for the northern hemisphere, but thought this might interest people:

http://nsidc.org/arc...mer-and-winter/

Funnily enough, this could possibly co-incide with what bobbydog has just written in the winter thread -

as it slowly comes together it becomes ever more complicated! for example, we discussed the link between annual or, year round, (rather than just winter) ozone levels, having an influence on the arctic strat, (higher levels leading to warming) which could influence ice extent. which have been falling on roughly the same timescale. in recent years, ozone levels have been rising. which should mean that arctic ice should begin to recover. however as it stands now, a warmer strat and the potential increase in snowfall due to less sea ice, should point to a higher chance of a colder winter. one thing i have noticed is that some signals also have the potential to cancel each other out!

I remember Chio posting recently about the o-zone levels being rather high across the antarctic in particular in response to a post by GP about o-zone transportation from the tropics in the past few weeks, this could add further weight to the links between the two

SK

EDIT:

Heres the link to southern hemisphere o-zone levels from Chio's post

http://www.cpc.ncep.noaa.gov/products/stratosphere/sbuv2to/gif_files/sbuv16_sh_latest.gif

Edited October 2, 2012 by snowking

[LincolnSnowstorm]

Current snow cover Do i spot a new good blob of snow?

Compared to the day before

The blob of snow has got smaller but after today's snowfall maybe there'll be more on tomorrow's update.

[Gavin Hannah]

Heaviest coating so far this season on Summit of Glencoe Mountain. Temp at 10:30 recorded at 0.3 Deg C on summit.

And some white stuff on Cairngorm Mountain.

[quest4peace]

The blob of snow has got smaller but after today's snowfall maybe there'll be more on tomorrow's update.

I hope so too Kind of willing the ice forward as well Lol! Got too much time on my hands i think

Heaviest coating so far this season on Summit of Glencoe Mountain. Temp at 10:30 recorded at 0.3 Deg C on summit.

And some white stuff on Cairngorm Mountain.

Brilliant to see a good covering of snow so close all be it high up a mountain in scotland

Edited October 3, 2012 by quest4peace

[BornFromTheVoid]

September snow cover extent was the 9th lowest out of the 44 years on record, with Eurasian snow cover the 13th lowest.

http://climate.rutgers.edu/snowcover/table_rankings.php?ui_set=1

Eurasian snow cover though has more than doubled in the last week though.

[quest4peace]

Nice pic from ny alesund in svalbard from the mountain webcam from today