Huge Snowfall Caused By Rare Clash Of Weather Events

[DR Hosking]

By analysing 60 years of snowfall measurements and satellite data, researchers concluded the anomalous weather conditions were caused by an unusual combination of an El Nino event and the rare occurrence of a strongly negative North Atlantic Oscillation (NAO).

http://www.bbc.co.uk/news/science-environment-11152077

[Tim Bland]

Interesting read. Unfortunately it's not what most people on here will want to read - That last winter was a once in 200yrs experience! It has seemed to me that over the last 3 winters there has been an increase in snow events. Hopefully this year won't bring us back down with a bump!

[4wd]

[cold] "Weather will continue to be weather. You have to average over a lot of weather to get the climate trends

Unless it's warm, or windy, or wet, and then it's a clear sign of global warming.

[stewfox]

Interesting read. Unfortunately it's not what most people on here will want to read - That last winter was a once in 200yrs experience! It has seemed to me that over the last 3 winters there has been an increase in snow events. Hopefully this year won't bring us back down with a bump!

It seems to refer to both ........'Scientists have shown that a severe snowfall in North America and Northern Europe in the winter of 2009-2010 '

I like the more scientific approach what has 1947,63,81,87,09 got in common

All odd years, bodes well for 2011 ?

I dont care if it doesnt snow in Washington

[NorthantsSnow]

How can it be a once every 200 years event? We had a colder winter as recently as '63.

What utter balderdash.

[Optimus Prime]

Would be helpful if they provided a reason for the exceptionally prolonged severe winters of 1895 and 1963. I read somewhere the 1963 winter was caused somewhat by the Tsar bomb, the world largest and most powerful nuclear test in October 1961 that caused an unusual weather pattern to emerge.

The winter of 1979 was a bit more straightforward as most of the very cold weather came from unsettled conditions from the Atlantic whereas 1963 was from almost unbroken Easterly winds and 2010 from light northerlies/north westerlies and easterlies and north easterlies.

The NAO 2010 was remarkable. In that sense it was perhaps a rather mild winter overall.

How can it be a once every 200 years event? We had a colder winter as recently as '63.

What utter balderdash.

They were referring to the state of the NAO which was record breakingly low. So a once in a 200 year occurrence.

[Thundery wintry showers]

Aye, they mean that the combination of atmospheric indices (ENSO, NAO) was a 1 in 200 year event, not that winters of similar severity are a 1 in 200 year event. Some of the other famous cold winters arose as a result of other combinations of factors.

But last winter was certainly an exceptional winter. For persistence of snow cover across the southern half of England it may not have been that exceptional, but in the north it was, and taking the country as a whole my snow events index suggests that the amount & significance of snow events was the second highest (after 1979) since 1947 (the discrepancy largely resulting from a large number of marginal snow events in February).

[SteveB]

Would be helpful if they provided a reason for the exceptionally prolonged severe winters of 1895 and 1963. I read somewhere the 1963 winter was caused somewhat by the Tsar bomb, the world largest and most powerful nuclear test in October 1961 that caused an unusual weather pattern to emerge.

The winter of 1979 was a bit more straightforward as most of the very cold weather came from unsettled conditions from the Atlantic whereas 1963 was from almost unbroken Easterly winds and 2010 from light northerlies/north westerlies and easterlies and north easterlies.

The NAO 2010 was remarkable. In that sense it was perhaps a rather mild winter overall.

They were referring to the state of the NAO which was record breakingly low. So a once in a 200 year occurrence.

How far back do NAO records go (I really don't know) surely not 200yrs. Its another case of "since records begun"

[Neilsouth]

Snow that covered most of the UK was caused by a rare weather system bringing down cold air from the Arctic

Rare weather system?

This is exactly why i have no faith in the met office or anybody from the climate change camp!

[Geordiesnow]

Rare weather system?

This is exactly why i have no faith in the met office or anybody from the climate change camp!

I think they mean by rare weather system is that the NAO was hugely negative and that only occures very rarely(every 200 years according to the scientists) but the language could be better i have to admit.

I don't think we will get as cold winter as last year but you just can't rule out a 3 day Northerly or a cold biting easterly from height rises which lasts a while.

[Snowmadsam]

lol I'll get snow becuase im going skiing to france this winter

But I hope we get a cold winter

[AderynCoch]

The NAO 2010 was remarkable. In that sense it was perhaps a rather mild winter overall.

That's what worries me: should last winter have been colder? Winter 1783/4 was certainly a good deal colder (about the same as 1946/7).

I dislike it as much as any cold-lover, but the even larger teapot theory isn't completely dead and buried just yet - we need more time to see if the cold weather of 2009/10 was a one-off or if the coming years will bring more frequent wintry blasts compared to previous years (exceptionally -ve NAO or otherwise). What I would say was a one-off last winter was the prolonged lack of mildness - there may be colder winters to come but I don't expect to see such a dearth of mildness for a long long time.

[Weather-history]

- there may be colder winters to come but I don't expect to see such a dearth of mildness for a long long time.

You only have to go back to winter 2005-06 for a distinct lack of mild weather. The lack of mildness actually ran from mid November 2005 through to after mid March 2006. The issue was the lack of real cold within the winter months. That wasn't the issue with last winter.

I remember some pundits suggesting the winter of 2005-06 could be the lower limit of cold for the current age. That of course can be scoffed at now.

[Thundery wintry showers]

I think last winter will have had about 0.5C or so of background global warming added to its mean temperature, so yes, maybe it "should" have been a bit colder. This, however, wasn't the main reason why temperatures were not outstandingly low in southern areas. The vast majority of last winter's cold snowy weather came from the north, which is very unusual for a cold snowy winter with frequent prolonged cold spells- usually it tends to be either a mix of northerlies and easterlies (e.g. 1979) or predominantly easterlies (e.g. 1947, 1963). Easterlies favour the southeast for the coldest weather, northerlies favour the north.

Another factor was the high frequency of "west based negative NAO" setups which saw the coldest air occupy northern and western regions while towards the southeast the airmasses were much more modified. For these same reasons, Scotland had its second coldest winter for over a century.

[weathe20]

"This was a once in a century type of event"

Rubbish..There has been more severe winter weather over the last 100 years than the winter of 09/10.

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

I think people are ignoring the fact that Mid Atlantic and New England area of the US had a number of extreme snow events, 5 separate events gave snowfall totals over 3 feet. I think its fair to say that even in the good old days of cold, snowy winters there wasn't as much snow as last winter in this region. Just because your back garden didn't see record snowfall doesn't mean other places didn't.

[AderynCoch]

Exceptional snowfalls don't have to occur during particularly cold winters though: February 1978 springs to mind. Similarly, very cold winter months tend to be dry and blocked (February 1986 being an extreme example, but January 1963 was a notably dry month).

2005/6 definitely had fewer mild days than average, but not on the same scale as 2009/10. When can we next expect to see much of southern Britain not to record 10C for three months?

[Guest]

Interesting read. Unfortunately it's not what most people on here will want to read - That last winter was a once in 200yrs experience! It has seemed to me that over the last 3 winters there has been an increase in snow events. Hopefully this year won't bring us back down with a bump!

"Once in 200 years" - where did you get that from? - CET for winter period 2009-10 accordinging to Hadley was just under 4C - in the previous century we had 1917, 1929, 1940, 1947, 1963 and 1979 all with CET's for the winter period of below 2C and in fact for 1963 it was -0.52C.

[SNOWPLOUGH]

Exceptional snowfalls don't have to occur during particularly cold winters though: February 1978 springs to mind. Similarly, very cold winter months tend to be dry and blocked (February 1986 being an extreme example, but January 1963 was a notably dry month).

2005/6 definitely had fewer mild days than average, but not on the sa

me scale as 2009/10. When can we next expect to see much of southern Britain not to record 10C for three months?

Managed to record three months here without it hitting 10c, but just about! 11th of December 09 til the 11th of March 10...

I am living in hope that the last few winters are the start of a trend rather than a rare clash of weather events.

SP

[damianslaw]

Last winter indeed was notable for its persistantly cold weather with no mild air to speak of between mid december to mid march. 2005/2006 brought similiar conditions in many respects however, the cold was nowhere near as potent with maxes often in the 3-6 degree range.

Winter 09/10 was very unusual for the negative NAO and a west based NAO- I can't help but look at how things changed dramatically in the space of a few days between the 10th-14th dec, with the high suddenly building over the country and anchoring to our east - something very odd happened around these dates,before then the atlantic was in firm control and there was no indication of a prolonged cold spell setting up, indeed the whole period from mid nov was very odd with the jet stream - the record rainfall totals in nov in Cumbria a case in point, strange forces at hand.... In this respect it was a joy to see the cold synoptics unfold just as we were entering the immediate pre-christmas period - if I could have such a synoptical pattern change around the same time of year every year I'd be a very happy man.

Winter 09/10 didn't however deliver exceptional cold thanks to lack of clear skies in the main at night and no real deep seated continental easterly/north easterly. It had the potential to be a proper classic like 62/63 and 46/47 but never quite managed to get there especially in england and wales, but for Scotland it was a classic in terms of sustained cold. Also no major significant snowfalls were recorded apart from a couple of events in late dec and early jan and then on late feb (for scotland) this for me was a dissapointing factor of the winter.

[The watcher]

Yes, the -NAO was certainly something that rarely happens, but there is no doubt to me that colder spells can happen without this once in a 2 century event. There is no point looking at this article as a write-off for future cold winters, for all we know we could be on the edge of one of the coldest winters we have had for a VERY long time, without the aid of the -NAO. Weather does what the weather do...

[Cymro]

Last winter indeed was notable for its persistantly cold weather with no mild air to speak of between mid december to mid march. 2005/2006 brought similiar conditions in many respects however, the cold was nowhere near as potent with maxes often in the 3-6 degree range.

Winter 09/10 was very unusual for the negative NAO and a west based NAO- I can't help but look at how things changed dramatically in the space of a few days between the 10th-14th dec, with the high suddenly building over the country and anchoring to our east - something very odd happened around these dates,before then the atlantic was in firm control and there was no indication of a prolonged cold spell setting up, indeed the whole period from mid nov was very odd with the jet stream - the record rainfall totals in nov in Cumbria a case in point, strange forces at hand.... In this respect it was a joy to see the cold synoptics unfold just as we were entering the immediate pre-christmas period - if I could have such a synoptical pattern change around the same time of year every year I'd be a very happy man.

Winter 09/10 didn't however deliver exceptional cold thanks to lack of clear skies in the main at night and no real deep seated continental easterly/north easterly. It had the potential to be a proper classic like 62/63 and 46/47 but never quite managed to get there especially in england and wales, but for Scotland it was a classic in terms of sustained cold. Also no major significant snowfalls were recorded apart from a couple of events in late dec and early jan and then on late feb (for scotland) this for me was a dissapointing factor of the winter.

No significant snowfalls? We had nearly two feet of snow in the hills by the end of january and a good foot on the ground here then when the snow came in ont he tuesday january the 17th i think don't quote me on that though, we had drifts burying cars? Hardly not significant?

[Nights King]

I'd be happy enough to get an "average" winter like 2008/09 when we had more snow in 2 days(2 and half feet early feb) than last winter at any one point.

[damianslaw]

No significant snowfalls? We had nearly two feet of snow in the hills by the end of january and a good foot on the ground here then when the snow came in ont he tuesday january the 17th i think don't quote me on that though, we had drifts burying cars? Hardly not significant?

Perhaps I just have been clearer. What I meant to say is there were very few notable significant snowfall events in terms of quantity of events not necessarily quality.

For England and Wales the only really signficant fals above 1 foot came on the 5/6th Jan, other falls of equal depth were more sporadic and localised in nature, for instance NE Eng and Yorkshire on the 8 Jan, Cumbria on the 20/21st Dec.

The high total depths were mainly due to cumulative snowfall events. Many snowfall events brought 2-4 inches caused mainly by showers and weak frontal attacks from the SW, numerous occasions in late Jan and throughout Feb and early March when this occured. Exception was late feb in Scotland and late March in Scotland/N Ireland.

In this respect the winter was not a patch on 46/47 or even 78/79 for that matter when snowfall events were more frequent in terms of quantity. Many parts of the midlands for instance only saw falls giving a few cms at best. Indeed take away the 5/6 jan event and for southern england away from Kent and east anglia the winter would have been devoid of significant snowfall. Here in Cumbria take away the events of 20/21 Dec and the best we would have seen was the 3 inch fall on the 5th Jan.

[Optimus Prime]

I think people are ignoring the fact that Mid Atlantic and New England area of the US had a number of extreme snow events, 5 separate events gave snowfall totals over 3 feet

Search the Blizzard of 1978 into Google....now that's end of the world stuff!