A step forward in forecasting cold winters?

Thursday 11 October 2012, 16:16

Paul Hudson Paul Hudson

Sudden stratospheric warming (SSW) has been the 'in' topic in meteorological circles in the last couple of years, ever since the severe winter of 2009/2010 in which December was the coldest since the late 19th century.

SSW is linked to sudden large increases in temperature over a few days in the stratosphere over the Arctic.

This temperature change cause winds to reverse their normal direction.

For some time, forecasters have noted that a sudden weakening in high altitude winds in the stratosphere was often followed in winter by blocking surface weather systems.

These blocking weather systems tend to bring much colder conditions across Europe and the UK from the east, stopping milder air pushing in from the Atlantic.

There have been notable successes from observing this phenomenon on shorter time scales.

A week before the onset of severe cold that begun at the end of November 2010, stratospheric warming was observed, which led to a forecast which successfully included a risk of cold conditions developing across the UK.

The cold weather which occurred in 2006 and 2010 also coincided with sudden stratospheric warming.

But it would be much more helpful if the onset of such severe weather could be forecast further ahead, and that is what researchers at the Met Office have been working on, publishing research in Environmental Research Letters last month.

A breakthrough came last year when scientists at the Met Office demonstrated a clear link between stratospheric influence on climate during a sudden stratospheric warming, with easterly winds burrowing down through the atmosphere to affect the jet stream.

Following on from this, researchers at the Met Office have produced a model that is better at simulating stratospheric warming, which may give forecasters a better chance of signalling cold winters in future.

By using this new model with data available from autumn 2009, the Met Office showed that they could have seen the cold coming well in advance.

But blasts of cold weather are not always due to SSW.

There are several competing influences each winter, such as Atlantic sea surface temperatures, volcanic eruptions, snow cover and solar forcing.

For example, the research highlights the deep solar minimum as a contributory factor to the observed severe weather conditions in 2009/2010.

But separating their effects, and establishing which has the largest impact, remains a big headache for forecasters.

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  • rate this

    Comment number 1.

    Well, well. About time they noticed that a warming stratosphere pushes the climate zones equatorward so that the polar air masses expand and spill out across the middle latitudes.

    When the sun was more active the stratosphere cooled and the climate zones shifted poleward.

    When the sun became less active following the peak of cycle 23 the stratosphere stopped warming and we have since seen more so called SSW events with a negative Arctic Oscillation and more surges of cold air equatorward.

    Full description of the processes involved and the implications here:


    "How The Sun Could Control Earth's Temperature"

    and more here:


    "CO2 or Sun?: Which one really controls Earth’s surface temperatures ?"

    As they admit:

    "the research highlights the deep solar minimum as a contributory factor to the observed severe weather conditions in 2009/2010"

    On that basis they must logically accept that the level of solar activity does indeed affect stratospheric temperatures and in turn the net position of the climate zones as I have been pointing out for several years.

    The trouble is that an active sun COOLS the stratosphere and an inactive sun WARMS the stratosphere which is the opposite of established climatology.

    That pretty much does for the CFC scare too in the process.

    I do believe they are getting there.

  • rate this

    Comment number 2.

    1. Stephen Wilde wrote:

    "The trouble is that an active sun COOLS the stratosphere and an inactive sun WARMS the stratosphere which is the opposite of established climatology."

    By what mechanism does increased solar output cool the stratosphere? Is this mechanism described in the peer reviewed literature?

  • rate this

    Comment number 3.

    #1. - Stephen Wilde wrote:
    "That pretty much does for the CFC scare too in the process."
    Does that mean that CFCs didn't cause the hole in the ozone layer?

  • rate this

    Comment number 4.

    Indeed, how does it happen?

  • rate this

    Comment number 5.

    uhh..I'm confused...surely you're not suggesting this isn't related to the extra amount of C02 humans are pumping into the atmosphere? The author of this piece should be dismissed summarily.Please get a competent global warming fanatic to analyse the weather in a rational and objective fashion.

  • rate this

    Comment number 6.

    Read my articles.

    The mix of wavelengths and particles from the sun varies when solar activity varies and alters ozone concentrations differentially at different heights.

    The consequent changes in stratospheric temperatures then allow the climate zones and jetstream tracks to shift so that global cloudiness and albedo changes thus altering the amount of solar energy able to enter the oceans to fuel the climate system.

    When the sun is active the thermosphere and troposphere warm but the stratosphere and mesosphere cool.

    The opposite when the sun is less active.

    As far as I an tell that scenario fits all the available observations and the above post from Paul shows that some scientists are beginning to realise it.

  • rate this

    Comment number 7.

    #5. - kingkpp wrote:
    "uhh..I'm confused...surely you're not suggesting this isn't related to the extra amount of C02 humans are pumping into the atmosphere? The author of this piece should be dismissed summarily.Please get a competent global warming fanatic to analyse the weather in a rational and objective fashion."
    I can't tell whether you are being sarcastic or not!

  • rate this

    Comment number 8.

    There was never much an arctic ozone hole forming in the Arctic, at least not on the scale of the Antarctic.

    The reason is the temperature difference. The Antarctic is much colder and so more Polar Stratospheric Clouds form that are key because on these clouds chlorine reactions occur that are produce the molecules that break down ozone.

    When they flew a plane across the Antarctic ozone hole one summer in the 80s they found a strong anti-correlation between the levels of such chlorine molecules and ozone.

  • rate this

    Comment number 9.

    Horrific grammar in my last comment. sorry.

  • rate this

    Comment number 10.

    Related or the same?

    "Arctic summer wind shift could affect sea ice loss and U.S./European weather, says NOAA-led study"

    "Changes in summer Arctic wind patterns contribute not only to an unprecedented loss of Arctic sea ice, but could also bring about shifts in North American and European weather, according to a new NOAA-led study published today in Geophysical Research Letters."


  • rate this

    Comment number 11.

    6. Stephen Wilde wrote:

    "Read my articles."


  • rate this

    Comment number 12.

    Interesting piece Paul,

    Sudden stratospheric warmings (SSWs) are indeed vital events. They are essentially driven by certain shifts in the jet stream which are driven by PREDICTABLE changes in solar activity and sun-earth magnetic connectivity, and are associated with cold winter blasts in Europe and USA.
    Through this understanding at WeatherAction we, as you know, forecast the cold snowy blasts of 09/10 and the snowy and coldest Dec in 100 years in 2010 while the Met Office gave their usual misleading mildisms.

    Met Office 'long range' models however are of negative value. While recognizing the importance of the stratosphere they have no idea WHY the stratosphere changes and therefore can forecast nothing in long-range. They will never produce reliable long range forecasts and what they are doing will continue to mislead the public. What they do is not just a waste of taxpayers money but their consistent diabolically opposite to reality long range 'forecasts' are a massive BURDEN on the British economy because they point official bodies and farmers in the wrong direction. The bbq summers which came as floods, the mild winter months which turned to snowmadegons and the drought with floods (LOL!!) this Spring come to mind.

    The problem is they start from the premises that weather causes weather. This is true about one day ahead and reasonably true two days ahead but the further ahead you look the less true it becomes and solar influence rules all. Will they ever learn? To be frank the Met Office and the BBC are not interested in advancing forecasting science - ie by applying solar drivers - because to do so sounds the death-knell of their CO2 delusionism and 'weather drives weather' concepts. They will only change if forced to do so by the coming public revolt against massive energy price hikes which are a direct consequence of CO2 delusionism and government backed thieving from us all - electricity and gas users - to pay for prayer wheels (wind farms) and other silly green money wasters.

    THIS October is interesting both from the point of view of fine spells and cold/stormy blasts of interest in this post and I suggest people pop along to our WeatherAction(.com) website to get forecasts of some important events coming THIS MONTH.

    Happy weather, Piers Corbyn ARCS, MSc, FRAS, FRMetS

  • rate this

    Comment number 13.

    Piers Corbyn and Stephen Wilde on the same discussion, very good this blog is turning into Paul.

    I remember posting on a weather forum a few years ago about the solar impacts on the weather, starting with the soggy 2007 summer due to the jet stream sinking south (against the CO2 hypothesis). Ever since then we have been on a cooling trend in the UK.

    The reverse of this happened when the sun was very noisy during the 2nd half of the 20th century, causing the beneficial warming of the climate which improved crop yields and led to decent economic growth. Warmth is good for us; such a shame it isn't going to last now the sun needs a rest.

  • rate this

    Comment number 14.

    And if you're looking for a reason behind rising food prices, you can also look to the sun. The anti-correlation between sunspots and food prices was discovered over 300 years ago. http://www.bioedonline.org/news/news.cfm?art=686

  • rate this

    Comment number 15.

    Good to see Stephen and Piers here again.

    It's becoming obvious that the Met and climate scientists in general are taking greater notice of natural variability in a more open manner. Lets hope that this is translated into AR5 so that the advice to policy makers becomes more relevant to reality than theory.

    If the advice our government is being given is to develop and plant more drought resistant crops then the near future will not only provide an energy crisis but also a risk of reduced local growing capability leading to higher prices of basic requirements in a time when the opposite is required.

    Your thoughts gentlemen on how an extended neutral ENSO state combined with a more southernly jet stream and a quiet sun will translate into conditions for next years growing season locally?

  • rate this

    Comment number 16.

    Piers, you too forecast a continuation of the drought in the UK this year http://www.youtube.com/watch?v=bNVUroWwhJc
    You've also forecast white Christmasses that were green, coldest May in 100 years that was average, a complete washout for The Olympics that turned out nice. You're great at writing forecasts that cover every eventuality, but that seems to be the extent of your skills.
    Interesting blog post Paul and good to see how the Met Office are still striving for the holy grail of forecasting.

  • rate this

    Comment number 17.

    #8. - quake wrote:
    "There was never much an arctic ozone hole forming in the Arctic, at least not on the scale of the Antarctic."

    I took Stephen Wilde's comment in post #1, that "That pretty much does for the CFC scare too in the process.", to mean the Antarctic.

  • rate this

    Comment number 18.

    The usual lies and libel from warmist/modellers eg Athena2. Get a life guys! Anything but the matter under discussion! Anyhow rather than pathetic 'assessment' by selected errors and false claims from people who 'cherry-miss' our success and can forecast nothing in long range; some facts:

    1. Our WeatherAction long range forecasts have 85% success rate for extreme events independently measured, and are advancing in scope.
    - http://www.weatheraction.com/pages/pv.asp?p=wact45 pdfs
    How about you A2?

    2. My Xmas bets over the years (not always for snow btw) have made overall profit as have weather bets overall - £14,000 profit until we were banned by William Hill. How about your success rate 'Athena2'? Why do you prefer to be annon?

    3. Our forecasted extreme cold spell(s) in May were a tremendous success. Ask the bees and flowers and gardeners! The fact the cold stopped for a week at end of May 2012 does not negate this. See http://www.weatheraction.com/docs/WANews12No26.pdf
    As usual you people distort and do not fairly represent our full forecast(s).

    4. What you say about the Olympics (in London which is what the forecast was for under Boris's request, rather than events held outside London which were finer at times and obviously, because finer weather makes better TV, reported for relatively longer) is just a lie. Remember the downpour on the stadium on the opening evening (which Met Office 12 hours before had said would be dry all evening)? That fully confirmed our warning of a high risk of such events in the SouthEast that evening. Remember the cyclists crashing in the rain and the archers stopping the contest? Remember the 'brollies up again' on TV day after day. We said it would improve later ('Complete washout' was made up by you/some media/ both) which it did but sooner so eg 2 days (9th & 10th Aug) were fine not wet.

    For latest comments on coming + future weather and a video of what I said on Alan Titchmarsh show (eg about end Oct) see

    Thanks, Piers Corbyn

  • rate this

    Comment number 19.

    15. ukpahonta wrote:

    "Your thoughts gentlemen......will translate into conditions for next years growing season locally?"

    Do you remember this?:-

    "The hottest year since 1659 spells global doom"


    "The warmest April to October period was reported with a mean temperature of 14.6C. The warmest autumn was measured with a mean temperature of 12.6C.

    Central England had the warmest ever growing season, surpassing 1959 and 1995. Scientists say the year was probably the warmest on record in central England."

    Well this year April to October(to date) mean temperature stands at 12.6C, still a lot of October to come but as April to September is only 12.9C can't see much improvement in the seasonal number.

    Don't know what the next year is going to bring but as a "grower" on a very small scale much rather have 2006 temps than this year's.

    The chart of CET growing season shows a familiar pattern an increase from approx 12.5C to 13.5C - 1900 to 1950, back down to 12.5C in approx 1950 and flat till about 1970 then steady rise to 14.5C in 2006. Since 2006 there seems to be a step down similar to the one circa 1950, but much too early to confirm.

  • rate this

    Comment number 20.

    #19 Greensand

    Growing season length in days
    1961-1990 average 252

    2000 330
    2005 247
    2006 269
    2007 303
    2008 249
    2009 298
    2010 255
    2011 279


    2012 possibly around 230 days so far, 249 end of Oct, 279 end of Nov!


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