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Barry95

Are our Winters changing?

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Before 2008, the last 10 years had featured predominately mild winters with little or no snowfall, in February 2009 we were unexpectedly hit with extreme weather, with huge depths of snowfall and very low overnight temperatures like we had not seen at the time for nearly 20 years. I was watching 'Extreme Snowstorm' on channel 4 which went through the February 2009 event caused by Sudden Stratospheric warming, there was an interview with Boris John, and he said 'It's a one in 20 year event'. Then come the middle of December 2009 our weather changed and we were again hit with extreme weather with again huge depths of snowfall and very low overnight temperatures, the cold didn't relent until the middle of February. 'This was the most widespread and prolonged spell of this type across the UK since December 1981/January 1982.' We had 2 extreme weather events in 2 years, and it didn't stop there! During the end of November we were again hit with extreme weather, and this time it was even worse. The coldest December in 100 years as we all known followed on from there.

Last Winter overall was mild, but we were so close to again having extreme weather yet again, but it just missed us putting Europe in the freezer instead. Although places were still pretty cold in February 2012, with very cold overnight lows in the SE and Yorkshire. We got 15cm here as the Atlantic tried to break through, that snow depth before 2008 in the previous 10 years just never happened for low level England. This Winter has been average so far up until a few days ago, although nowhere near as severe so far it's still pretty cold for the last Decade. There is a chance that we could get some heavy snowfall and more extreme weather this weekend/next week and if this happens then we will yet again get more extreme weather.

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UkSnow_7thJan2010.jpg

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Are our Winter's changing?

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I would love if it of they were going to get colder (and our summers to get a little warmer too) but can offer absolutely no input technically to this thread. What i can say is i can remember the really good winters on one hand at 32 years of age and two of them were in the last few years.

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I would love if it of they were going to get colder (and our summers to get a little warmer too) but can offer absolutely no input technically to this thread. What i can say is i can remember the really good winters on one hand at 32 years of age and two of them were in the last few years.

I think you have hit the nail on the head...your age will have an effect on your perception of Winters..im old enough to remember the harsh winters of the late 70s and 80s and the events of 2009 -10 were nothing to extreme compared to the winters back then..just a case of swings and roundabouts.

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Yes there has been a significant change in our weather for the Uk, in the last six years, Cooler wetter Summers here "generally" but colder snowier Winters here "Generally" Spring and Autumn in this time have been extreme in temperatures and rainfall in comparison! ...and this goes for the Uk. Some folks are on the global warming band wagon, but myself, I think we are in for a cool down upon our planet, various reasons for this, but I do think that our Summers will be cooler and wetter, Winters very cold, and Spring and Autumn quite extreme with rainfall and temperature!blum.gifsorry.gifgood.gif

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I think you have hit the nail on the head...your age will have an effect on your perception of Winters..im old enough to remember the harsh winters of the late 70s and 80s and the events of 2009 -10 were nothing to extreme compared to the winters back then..just a case of swings and roundabouts.

Definitely agree and these things, like many natural phenomena are probably cyclical and it could be that the trend will now be for colder than average (i've experienced enough warmer than average ones). I am still waiting for the one winter where I can shut my dad up about being able to jump from the upstairs window because the snow was so deep, actually able to skate on ponds because the ice had a chance to become so thick, and breaking the ice in the toilet was a regular occurrence.

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We had a large change in the Arctic in 2007, the PDO switched to it's negative phase and the prolonged solar minimum began to get into its swing.

It's likely that these have come together to cause some modifications to the weather. It's likely that things will continue changing in the future too.

Best enjoy things while they're cold and snowy, whatever the cause!

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The 'event' that got people initially thinking was the unusually cold and snowy northerly that hit us in October 2008;

Rrea00120081028.gif

Local minimum records and national low maxima records were achieved. Snow fell in most areas (2 days of settling snow here)

I remember there were some discussion due to how intense that blast was it might be a subliminal message to what might be in store for the winter 2008/2009. The October cold snap was more severe than some northerly's that occurred in the middle of winter. Whether or not it had any connection to what was to come we will never know (I do doubt it) but that was a real shock.

And despite this being a 'mild' start to the winter December was still bang on average (0.4c below 71-000 normal) this winter does seem to be showing signs of a continuing cold pattern. Last year was mild (February was a little colder than average for SE) but still contained a very cold spell of weather and some snow.

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A warning, this thread will not be going down the way of the rest of the climate forum. Any postings of that nature will be immediately removed.

Thanks

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I have recently read about the Milankovitch cycles on the web. This link stood out http://chiefio.wordpress.com/2012/12/29/annoying-lead-time-graph/ very interesting and very relevant to this thread.

After reading that, I rather hope(!) that everything globally is just warming gradually because of us humans and the cold winters are just variations on a long standing and quite normal theme.shok.gif

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Conversely the cold winters of today are seen as the norm for me. I properly got into weather (in other words viewing this forum) during the March cold snap in 2008 been the grand old age of 13 so the idea of mild winters came as a real shock to me last winter. I pretty much expect northern blocking and cold spells.

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Hi all im with BornFromtheVoid on this there was a sudden change come 2007.....what with the PDO now negative ...and solar factors...last 6 years the jet has often been south of us there has been more northern hemisphere blocking....but the weather for us will always change.

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With the way people are talking, you would think we never had cold set ups before 2009 or so when infact we did, and of course those exceptional blocking charts in Feb 2005 always made me believe those set ups can come along again despite what a certain member thought with his theories.

The reason why Feb 2005 does not get more of a menturn was that the set ups upper air temp wise did not deliver as you would imagine it should but that was a prolonged spell of cold weather with frequent easterlies wth nice northern blocking charts.

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It's still early to say but it so far seems to be trending towards cooler times. If Big Joe B's predictions prove correct then it's just the beginning. I was signed up to Weatherbell last winter (2011/2012) and he regularly spoke about how the negative PDO would cool things down and also warned that the worst has yet to come with the AMO going negative. which he predicts will happen within the next four/five years. A cold Atlantic/Pacific could put us back to 70s/80s style winters and hopefully summers. Also worth noting last year Joe B was calling for this winter to be a beast and next winter to be worse. He said last winter would be relatively mild so on the money there and the next few weeks should tell of this winter but so far looking good.

good.gif Cold snowy winters and hot thundery summers...good.gif

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There is zero evidence to suggest that decreasing arctic sea ice was the cause of changing weather patterns, however there is stacks of evidence to suggest that solar activity is responsible. So any arguments really are a chicken and egg variety. Also has our climate changed that much really, remember we now live in a media infested world where once such events would go rather unnoticed.

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A warning, this thread will not be going down the way of the rest of the climate forum. Any postings of that nature will be immediately removed.

Thanks

Apologies for my previous comment, it was meant to be tongue in cheek rather than an attack on other posters. I must learn to use the smilies more.smile.png

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Sadly it appears 'weather' is to be discussed and not the climate forcings behind such events? Take a look at Barrentsz and Kara Sea areas. Then look at the sst's from the S. of Greenland north. If you get the chance then look at the salinity plots for that section of ocean compared to the Bering side.

What do you see?

This is supposed to be winter and yet we see conditions that would have been unthinkable in summer 20yrs ago. Will such changes not impact weather?

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For me there is no coincidence. The solar perturbation cycle kicked in Feb 2007, this is an approximate 36yr cycle where ENSO is likely to have more La Ninas and less El Ninos 'overall'. Its linked to the PDO [Pacific Decadal Oscillation] which is characterised by the reverse C cold water anomaly in the North Pacific.

sst_anom.gif

Remember forecasts of a weak to possibly moderate El Nino for winter? Well above is certainly not an El Nino. Also note the reverse C...-ve PDO.

With these factors linked to this is the enhancement of a -ve NAO as these cycles tend to drive the jetstream on a more southerly and meridional pattern. Aligned to this is what many believe now [and I have for sometime as I have read Landscheidt's work and I am very very impressed with his accuracy as its all happening before us] we are heading towards a Grand Solar Minimum of at least Dalton or maybe Maunder proportions.

The jetstream has 'visually' moved south and has become much more meridional and this is likely to continue.

The ITCZ [inter Tropical Convergence Zone] was for last 100 to 150 years spreading out polewards from the equator [we are not talking 1000s of miles we are talking 100s as we see re the jetstream a small shift makes an enormous difference]. This in turn saw the jetstreams shift polewards and corresponds to a general slight 150 warming trend. The ITCZ stopped spreading in 2002 and remained so as of a report in 2009 [i haven't seen any further results on it]. I speculate its retreating hence we see the jetstreams moving. This IMO is solar driven and we are heading in to cooler climes 'overall' and interestingly enough so do the MetO now

BFTP

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And how do the changes we see across the Arctic, and the energy now available to the climate that was once employed in ice melt play into that BFTP?

We may all have different 'theories' on how and why we see change but they should surely include all the information available to us? The combination of 'Albedo Flip' (adding more energy into the system), ice loss (adding back energy once 'spent' on ice melt all summer) and First year ice predominance across the basin (allowing 3 times the energy into the basin than older ice) Must lead to an additional energy imbalance compared to the last time we saw your cycle come around to this juncture? How have you accounted for this 'new energy' and will it prove pivotal to the changes we see compared to what we have seen in past incarnations of your cycle?

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Dare I say it: but I'm starting to think that Fred and Ian are maybe both right; and that the timings of both the drop in solar flux and the phenomenal recent ice-melt are more than just coincidences? It could be that these two phenomena, though probably unrelated to each other, are driving our climate in the same direction?

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This is probably the wisest stance to take Pete? We know natural has always ruled our climate but we also have instances where external forcings also play their part (eruptions/methane releases/impacts) and so we need to 'blend' both what we know of the 'natural' and of anything 'novel' to the system as this 'novel forcing' will rarely be mute and will rather augment or mitigate the 'natural'?

2010 had a large dose of solar min at play over the winter months and the Atlantic blocking this facilitates but somehow, in a warmer world than the last time we saw such, the impacts appeared more focussed?

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Bound to be many factors involved, but the pattern of cooler and milder winters are reflected in the long term winter plots of AO http://www.cpc.ncep....ason.JFM.ao.gif and NAO http://www.cpc.ncep....son.JFM.nao.gif

But what are causing these?

For me there is no coincidence. The solar perturbation cycle kicked in Feb 2007, this is an approximate 36yr cycle where ENSO is likely to have more La Ninas and less El Ninos 'overall'. Its linked to the PDO [Pacific Decadal Oscillation] which is characterised by the reverse C cold water anomaly in the North Pacific.

Remember forecasts of a weak to possibly moderate El Nino for winter? Well above is certainly not an El Nino. Also note the reverse C...-ve PDO.

With these factors linked to this is the enhancement of a -ve NAO as these cycles tend to drive the jetstream on a more southerly and meridional pattern.

The PDO doesn't match the series of warm and cold winters very well, nor the AO and NAO and this paper http://nzc.iap.ac.cn..._csbe_2006a.pdf suggests that the influence is the other way round -

The results indicate that AO plays an important role in the low frequency variability of PDO. When AO leads PDO by 7/8 years, the lagging correlation between them becomes the strongest with correlation coefficient 0.77.

However, the correlation between them always keeps low (r < 0.3) when PDO leads AO on decadal timescale.

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This is where I think it important to look at how changes across the Arctic may be lending a helping hand to both AO and NAO?

We do have a lot of studies , ongoing, into the role reduced sea ice/snow cover is having on the general circulation of the Northern Hemisphere and, at present, a link between the changes and the circulation appears to be strenghthening as more yearly data becomes available?

With current record N.Hemisphere snow cover it will be interesting to see how fast it clears come spring and whether the earlier dates still hold for snow melt even in record high snowfall years?

The problem arises in trying to then project these changes into future winters as the Arctic melt grows? Is what we see transitional or the blueprint for future winters? Does the sinuous jet continue or do we see the polar Jet die and the sub tropical jet swing north? (when you look at some of the jet plots this last summer wind speeds were so low as to 'disappear' lengthy sections of the Jet with only small streaks visible on the plots.....will this year show us similar?)

One thing is certain, we are not in a period of time with parallels to all the current climate ingredients to enable us to 'pattern match' with and , if the science is accurate, this gap is set to widen between what we know and what we now experience?

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There is zero evidence to suggest that decreasing arctic sea ice was the cause of changing weather patterns, however there is stacks of evidence to suggest that solar activity is responsible. So any arguments really are a chicken and egg variety. Also has our climate changed that much really, remember we now live in a media infested world where once such events would go rather unnoticed.

There is plenty of evidence for the impact of ice on weather in mid latitudes. I posted a explanation yesterday of why that was so, but unfortunately it was deleted. There is plenty of evidence that has nothing to do with the media or number of events we can observe nowadays.

Here are just a few peer reviewed studies for a start.

Evidence linking Arctic amplification to extreme weather in mid-latitudes

The influence of low sea ice on anomalously cold Eurasian winters

Winter Northern Hemisphere weather patterns remember summer Arctic sea-ice extent

I can get you much more if you like?

While it may not be a dominating factor, it certainly is a strong, noticeable and observable one.

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So this theory predicts that winters will get ever colder if ice continues to decline late summer.

Doesn't that seem a rather peculiar idea?

And quite an abrupt change in all that 'settled science' - being based on two or three somewhat colder winters in the UK.

How did we ever have similar periods with colder winters in the past when ice was higher?

Last winter in the US was almost a non event especially in the east but it seems fairly normal this year.

This was also pronounced as evidence of catastrophic AGW affecting weather patterns.

I'd consider this as normal cyclical variation, and we do not need invocation of deadly new AGW effects.

What is blindingly obvious is that weather is essentially chaotic and announcing short term trends as a new dominant pattern - over a few months let alone years and decades from now - is a mugs game.

It's also rather pointless since we will simply adapt and carry on perfectly well.

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