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Winter 2010/2011


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Posted
  • Location: Aldborough, North Norfolk
  • Location: Aldborough, North Norfolk

The video is definitely plausible and well thought however the whole warning and little ice age OTTness ruined it a little for me.

Couldn't agree with you more Adam. I saw some reports that said that statistically, we would be unlikely to get a winter as severe as last year. I know the saying "Lies, Damned Lies and Statistics", but I think too many people see a single bad winter and jump on the "We're All Doomed" bandwagon.

Personally, I think we will have another cold one, probably not quite as bad as last year, and these may be the forerunners of some rather more severe winters over the next 10-20 years. Just another cycle that we only see via records.

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Posted
  • Location: W. Northants
  • Location: W. Northants

I found the video really hard to read. Almost got double vision for a few minutes afterwards. :)

The point about all this is that nobody can really say one way or the other whether we can still get a severe winter. Remember, up until December 2009 most people thought a winter as cold as 2009/2010 was out of the question (where is Ian Brown BTW?) And if you suggested in November 2009 that we were just days away from the coldest winter for 30 years, most people would have been VERY skeptical.

But by the same token, just because we've proved we can still get impresively cold winters in the UK doesn't mean we can get an even colder one. It may be that 2010 is our generations 1963 and thats as cold as we can get it now? Or maybe not? The truth is the weather is endlessly surprising us.

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2010/11 Winter Weather Forecast

Last winter saw below average temperatures and heavy snowfalls for a large part of December and January, before becoming slightly milder through February. But what are the indications for this winter? Will we see a return to the Atlantic driven, mild winters? Or will the cold and snowy weather continue?

The reason last winter was so cold was due to an exceptionally negative Arctic Oscillation (AO) this meant that high pressure developed across Greenland and something known as Northern Blocking developed, this allowed freezing air to flood across Europe and over to us here Ireland in the UK. This winter? The indications are looking promising for another cold and snowy one.

Firstly, we’ll take into account the Sea Surface Temperatures or SSTs, the chart below shows us both the warm and cold anomalies

sst.gif?w=481&h=361
Sea Surface Temperatures Anomaly

We also have areas of blue in the Mid Atlantic, this suggests that we’re likely to see high pressure developing and building up into the Atlantic, when this happens low pressure systems get stuck in the North Atlantic and subsequently, cooler air from the Arctic heads Southwards.

Another thing to take into account is the low sunspot activity in the last 2 years or so. Historic data show that during times of low sunspot activity, the UK experiances unusually cold winters, 1962 being one of them.

The Arctic Oscillation and North-Atlantic Oscillation are other things we should take into account, however because these are more variable and can change on a day to day basis, it’s much harder to use these to help forecast more than 5-10 days out, although we’ll take a look to see how they’re doing anyway.

nao.gif?w=481&h=641
North Atlantic Oscillation

ao.gif?w=488&h=650
Arctic Oscillation

We also must take into account the fact that the Arctic has had one of the coldest summers on record, meaning we’re unlikely to have a problem with getting an embedded cold pool into place, ready to flood Southwards.

Taking all these factors, and more into account. I think we’re likely to see a generally damp and dull start to Autumn, before things begin to turn increasingly cold as we move through October and into November. I’m forecasting another cold, and snowy period of weather, particularly from the middle of November through until the middle of January, before we see the Atlantic kicking into gear again bringing some mild, stormy weather to end the second half of winter.

The Gulf Stream

I don’t think I could create this forecast without mentioning the current state of the Gulf Stream. It’s something that’s been a hot topic amongst weather forums in the last few weeks, and here’s one of the reasons why. This graphic shows what the Gulf Stream was like in September last year.

2009.gif?w=432&h=288
September 2009

2010.gif?w=449&h=299
September 2010

Winter 2010/11 Overview

So just to summarize, I’m predicting a cold start to winter. I believe the first cold spell to take hold during the second part of September with frosts becoming more frequent across the United Kingdom and early snowfalls pushing down from the North and into Scotland and perhaps higher hills in Northern England.

I expect the first half of winter to be generally cold and snowy, as cold if not colder than last year. I think it’ll be generally cold and snowy through November to the middle of January before high pressure begins to break down and the Atlantic takes over for the second half of the winter bringing spells of wet, mild and windy weather, with brief cold snaps as low pressure systems push Eastwards into the North Sea.

The oranges/reds on the image above show us where above average sea surface temperatures have developed. The blues/purples show us where below average temperatures. If you look at the Pacific Ocean, you can see a large area of dark blue and purples. This is known as a phenomena called La Nina, and it’s a cooling of the Pacific Ocean. Although not fully understood, it is believed to lower global temperatures and bring colder weather to certain areas and that usually includes the UK.

The NAO is currently forecasted to shoot up into a weak positive before slowly moving back down into a weak negative. This sudden change suggests we’re likely to see the Atlantic becoming slightly more active in the next couple of days, we’re likely to continue this unsettled and cool theme for the next week or so at least. When we have a negative NAO, we’re more likely to see high pressure developing in the Atlantic, when we see a positive NAO, we’re more likely to see low pressures developing, and in turn, turning our weather more unsettled.

The AO is currently forecast to remain in a weak negative, perhaps becoming increasingly negative during the next 5-8 days. When we have a negative AO (as seen last winter) we have high pressure developing across the Arctic where we want it then if the correct conditions present themselves, that cold air will flood Southwards towards the UK. A positive AO means we see something called the Polar Vortex, which is a system of low pressure systems across the Arctic which make it far harder to lock ourselves into a cold pattern for more than a couple of days.

And here’s what the Gulf Stream is looking like this year

If you compare the two images above you can see there has definitely been a slowdown and slight decay of the Gulf Stream over the course of the last year, and this is what has gotten so many people interested. Whether this will have any effect on the weather in the coming months is yet to be seen, however.

Edited by johncoolj
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Posted
  • Location: Horsham, West sussex, 52m asl
  • Location: Horsham, West sussex, 52m asl

2010/11 Winter Weather Forecast

where did you find this forecast?

Edited by reef
Removed huge quote
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Posted
  • Location: Lincoln, Lincolnshire
  • Weather Preferences: Sunshine, convective precipitation, snow, thunderstorms, "episodic" months.
  • Location: Lincoln, Lincolnshire

Netweather.tv has its own UK-only version, for instance here is Friday at 12:00:

http://www.netweather.tv/gfsimages/gfs.20100915/12/48/ukmaxtemp.png

You can get them freely at the Datacentre here:

http://www.netweather.tv/index.cgi?action=nwdc;sess=

I'm not sure if Wetterzentrale has a UK-only version, it definitely has a "more zoomed in" version but unfortunately I don't know where you get access to that.

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Posted
  • Location: Sunderland
  • Weather Preferences: cold
  • Location: Sunderland

Netweather.tv has its own UK-only version, for instance here is Friday at 12:00:

http://www.netweathe...8/ukmaxtemp.png

You can get them freely at the Datacentre here:

http://www.netweathe...tion=nwdc;sess=

I'm not sure if Wetterzentrale has a UK-only version, it definitely has a "more zoomed in" version but unfortunately I don't know where you get access to that.

TWS, you are a legend. Thanks!:diablo:

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

Here you go

Look at the winter forecast.

It is worth pointing out that the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO) are indices of pressure differentials between the Arctic and latitudes further south. They are derived from the pressure differences, as a result of the major weather systems, and do not drive the weather - a common misconception. The forecasts for the NAO and AO are derived from the models and are calculated using forecast pressure data from the models and their ensembles.

The state of the SST's, ENSO and stratospheric state etc will be the drivers of the major weather systems that influence the NAO, AO and other indices. These are the areas that need to be looked at when determining whether the AO/NAO will be positive or negative this winter.

The current state of the Atlantic SST anomalies (from past experience) that we see now and by winter start will vary considerably and therefore will not be a good determinant for winter yet. Also any minor fluctuation in the gulf stream cannot be relied on at this point as things are liable to change again very quickly.

c

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Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

The above post raises some good points - the nature of the NAO and AO is a symptom of drivers such as ENSO and SST's not the other way around. Current SST's if they persist into and through winter in similiar fashion suggest we will escape a steep temperature gradient in the atlantic thanks to the colder than normal SST's in the mid atlantic and consequently less of a risk of deep depressions suddenly appearing the mid atlantic - if these SST'S begin to rise which seems unlikely SST's will be less favourable for colder conditions this winter especially if combined with increased warming of current warmer than normal SST's to the south east Greenland, developments with SST's need to be thus carefully watched over the coming weeks. The other supporting factor which combined with SST's will increase chances of colder than normal weather - is a weak jet which looks likely from forecasts - it has been in a weak state and unusual state for a very long period now. It could well be the weak jet which will be the key ingredient for enhancing prospects of colder than normal weather, combined with favourable SST's will send it o a southerly course providing plenty of opportunities for cold air to come sweeping down from the north and developments of cold 'heights' as we see once again a negative AO and NAO combo.

Edited by damianslaw
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OK, so can I do a trade with you all, don't mind a cold winter with some snow but prefer it to be sunny and dry, rather than the nasty damp cloudy conditions we get so often but after that I would really love a nice long fairly warm to hot summer lasting from May to October.

I am afraid that am continental in my preferences - who knows I may have been a Russian in a previous life - just love that music though. :D:rolleyes:

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Posted
  • Location: hertfordshire
  • Location: hertfordshire

It is worth pointing out that the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO) are indices of pressure differentials between the Arctic and latitudes further south. They are derived from the pressure differences, as a result of the major weather systems, and do not drive the weather - a common misconception. The forecasts for the NAO and AO are derived from the models and are calculated using forecast pressure data from the models and their ensembles.

The state of the SST's, ENSO and stratospheric state etc will be the drivers of the major weather systems that influence the NAO, AO and other indices. These are the areas that need to be looked at when determining whether the AO/NAO will be positive or negative this winter.

The current state of the Atlantic SST anomalies (from past experience) that we see now and by winter start will vary considerably and therefore will not be a good determinant for winter yet. Also any minor fluctuation in the gulf stream cannot be relied on at this point as things are liable to change again very quickly.

c

Sorry I don't agree with that a strongly positive or negative AO will determine roughly where the jet stream

lies and to some degree what type of weather we will experience, IE hot or cold.

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

Sorry I don't agree with that a strongly positive or negative AO will determine roughly where the jet stream

lies and to some degree what type of weather we will experience, IE hot or cold.

cc, how does this relate to my post? - I was just pointing out that the AO/NAO were not drivers but were sequelea of the drivers.

Also, I can read your post two different ways. Did you mean to put a full stop after 'that'?

Edited by chionomaniac
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Posted
  • Location: hertfordshire
  • Location: hertfordshire

cc, how does this relate to my post? - I was just pointing out that the AO/NAO were not drivers but were sequelea of the drivers.

Also, I can read your post two different ways. Did you mean to put a full stop after 'that'?

Yes sorry there should have been a full stop after that.

A strong positive or negative AO imo will be the main driver of the weather especially north of

40 degrees. Enso and other teleconnections may alter the state of the AO but a strong phase

+or - will dictate the weather.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

The posts by ch and Damian are first class posts and explain very well which comes first. As they have explained the main drivers are teleconnections prior to the AO and NAO not the other way round.

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The posts by ch and Damian are first class posts and explain very well which comes first. As they have explained the main drivers are teleconnections prior to the AO and NAO not the other way round.

its out folks joe bs winter euro forcast looks like a normal uk winter so mild and wet i bet

To My European readers.

You may have noticed a marked decrease in my postings in the last month or two. This is because of new duties I have here that really mean I have very little time to put forth the kind of honest effort that ethically I feel bound to when making a forecast. I have never backed away from a challenge, but I find my position, as far as trying to get out and there and keep you up to date, impossible to maintain. There is only one of me, only so many hours in a day and while my first love is the kind of pattern dissection needed to give you hints on your weather, I am no longer capable of doing this in a consistent fashion, because of these other things.. for Europe

I have seen the emails wanting to know about the winter. Again, to put together a forecast and line things up the way I do, takes a long time, and what I now do takes away from that time. My gut feeling is the core of the cold this winter.. in relation to normals, runs from the Alps to the Balkans. I dont think Great Britain is as cold as last year, more or less a normal winter. But this will be a rough winter in areas in central and eastern Europe, the interior part of the continent. That is a thumbnail sketch, a rough look. One more things, precip will be a bit below normal for much of Europe this winter.

i actually feel a bit guilty about putting out something like this because it is not how I do things.. I have a code I live by. On the other hand, I guess I did not realize how many of you follow me over there, and I am moved. I will try my best to put together a forecast, that right or wrong, I can feel I did my best with. Again the amount of time that has to be devoted to these new work requirements is close to 10 hours a week and that is time I spent researching things.. and may I add enjoying myself while I did it. I cant say that I enjoy what I am doing in this other option, but as the great Christian minister Oswald Chambers said, it is those that can find glory in drudgery that are actually reaching for the highest ideal.. Anyone can do something when its all chocolate and roses, which is what the challenge of putting together a Euro forecast is too me, a labor of love.

Believe me I am trying.

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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

The posts by ch and Damian are first class posts and explain very well which comes first. As they have explained the main drivers are teleconnections prior to the AO and NAO not the other way round.

Indeed John.

I have always understood the NAO and AO are just a way of stating where the upper High and Low pressure areas are-- which as you say are driven by Teleconnections.

Edited by phil n.warks.
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Indeed John.

I have always understood the NAO and AO are just a way of stating where the upper High and Low pressure areas are-- which as you say are driven by Teleconnections.

Please enlighten an old ignoramus - what does the term "teleconnections" mean? I take it that the high and low pressures are not communicating with each other through broadband or dial up.

:lol:

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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

Please enlighten an old ignoramus - what does the term "teleconnections" mean? I take it that the high and low pressures are not communicating with each other through broadband or dial up.

:lol:

Basically it`s a general term covering the interaction of the Ocean and Atmosphere in their varoius states.

I am no expert Mike but i am sure one of the forecasting term can elaborate.

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Posted
  • Location: Stanwell(south side of Heathrow Ap)
  • Weather Preferences: Thunderstorms, squally fronts, snow, frost, very mild if no snow or frost
  • Location: Stanwell(south side of Heathrow Ap)

Just to say some great posts on this thread ,and thanks to those for explaining what things mean, i would like to join in but i really need to learn more first, its an exciting time leading up to winter, and i enjoy and learn all the way!

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Posted
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Weather Preferences: Sunshine and 15-25c
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)

Had my first snow of the season today...late day snow showers...here i have seen my latest snow..May 31st and the earliest today Sept 16th...also interesting it has been cool/cold since mid August and so far September is some 6c below normal.

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Posted
  • Location: hertfordshire
  • Location: hertfordshire

Indeed John.

I have always understood the NAO and AO are just a way of stating where the upper High and Low pressure areas are-- which as you say are driven by Teleconnections.

This is wrong.The AO and NAO are also teleconnections and at times can lead or dominate the pattern.

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

This is wrong.The AO and NAO are also teleconnections and at times can lead or dominate the pattern.

The NAO and AO may be loosely defined as teleconnections but they do not dominate or lead. They are calculated as a result of the pattern, cc. The underlying pattern may lead to a season or period of time when a particular positive or negative AO/NAO predominates but, I stress again that this is a result of the underlying other teleconnections. I see the common misconception still persists with you. I could, if I wanted work out the average pressure difference between Lands End and John o'Groats and call this indice the BI indice, and grade this positive or negative depending on the difference from average. These readings would no way influence the pattern of weather we receive. The NAO and AO are the same but over a greater and different area.

c

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Posted
  • Location: Bedworth, North Warwickshire 404ft above sea level
  • Location: Bedworth, North Warwickshire 404ft above sea level

Bar-stewardi's blog has been updated now and hes says a "normal" winter for the uk but drier, and with central/eastern europe having a very hard winter......mmmmmmmmmmmm :unsure:

http://www.accuweather.com/ukie/laminate floori-europe-blog.asp?partner=accuweather

Edited by cyclonic happiness
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