One of the very basic stats that would concern me wrt to potential for a cold winter is this:

Month CET Anomaly notes
January 4.0 0.1
February 6.1 2.3
March 8.7 3.0
April 8.9 1.0
May 13.2 2.1
June 16.0 1.9
July 16.8 0.7
August 15.6 -0.2
September 13.5 -0.1
October 13.8 2.3 provisional, to the 17th

https://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

In finance they say "past performance provides no guide to future performance". I don't think that's true in the case of the weather. Yes a disturbance in the Indian Ocean may punch a hole in the global pattern but underlying forcing mechanisms and background warmth are clearly pointing in one direction. Let's see what November brings.  

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One of the very basic stats that would concern me wrt to potential for a cold winter is this:

Month CET Anomaly notes
January 4.0 0.1
February 6.1 2.3
March 8.7 3.0
April 8.9 1.0
May 13.2 2.1
June 16.0 1.9
July 16.8 0.7
August 15.6 -0.2
September 13.5 -0.1
October 13.8 2.3 provisional, to the 17th

https://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

In finance they say "past performance provides no guide to future performance". I don't think that's true in the case of the weather. Yes a disturbance in the Indian Ocean may punch a hole in the global pattern but underlying forcing mechanisms and background warmth are clearly pointing in one direction. Let's see what November brings.  

Once could have said pretty much the same thing back in 2008/09. As Andy W mentioned, the MetO went for a mild winter in 2009/10 presumably with the underlying forcing mechanisms and background warmth that you mention in mind. Yet in the end, they couldn't have been more wrong with their forecast.

I might be wrong about this, but I think that at the time, 2010 turned out to be the warmest year on record globally. Yet that didn't stop us having our coldest December for 120 years that year plus I think 2010 was the UK's coolest year of any since 1986 or thenabouts. Not that this year is going to turn out like 2010 did, but it shows that the unexpected can never be totally discounted, "modern era" or not.

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Well I always prefer the stats, if you take the winter months of 87/88,88/89,97/98,98/99,07/08 & 08/09 then you have 18 winter months - 16 were above average, many crazily so.  

 

So for a period between 1987 and 2009, you cherry-pick a selection of 6 winters and point out that a majority of months were milder than average?

1) Even excepting your selective choice of 'stats', has a run of generally milder-than-average winters never happened before?

2) What happened after the 2008/9 winter?

 

The fact is, you use a statistically inadequate timeframe to try to give credence to your favourite trolling method of mentioning 'modern winter' with the insinuation that we won't get proper winters any more (you used to say more directly that we would no longer get proper winters but then the winters of 2009/10, 2010/11 and 2012/13 widdled all over that line).

 

 

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Once could have said pretty much the same thing back in 2008/09. As Andy W mentioned, the MetO went for a mild winter in 2009/10 presumably with the underlying forcing mechanisms and background warmth that you mention in mind. Yet in the end, they couldn't have been more wrong with their forecast.

I might be wrong about this, but I think that at the time, 2010 turned out to be the warmest year on record globally. Yet that didn't stop us having our coldest December for 120 years that year plus I think 2010 was the UK's coolest year of any since 1986 or thenabouts. Not that this year is going to turn out like 2010 did, but it shows that the unexpected can never be totally discounted, "modern era" or not.

To a degree Brian is indeed correct if we’re basing weather on predictive sequencing, however as we know weather doesn’t follow a format and generally makes a fool out of all of us at some point in time. 😁

Hey all, this is a somewhat cherry picked stat but 2017 has joined the 10 Atlantic hurricanes in a season club. Here is a list of years in chronological order where 10 or more hurricanes formed, 1887, 1916,1933, 1950,1969,1995,1998,2005,2010 and 2012.

What stands out from from that list is firstly only one of those winters was mild and that was the strong la Nina year of 1998. Secondly and more importantly what shows up is early winter cold. In fact the list is pretty much a rogues gallery of the coldest Decembers of the last 100 plus years. The average December C.E.T. of those years is around 2.7, 2 degrees below normal. 

For the record 1981 was classed as an active hurricane season and 1996 saw the joint highest number of major hurricanes with 6. 

This does give some credence to the idea that active hurricane seasons may retard polar vortex formation or disrupt it in some way. In summary every notably cold December I could find was preceded by an active or very active hurricane season.

A word of caution, the years with the highest total A.C.E. and the highest tropical storm formation were less interesting in terms of cold, so it is as I said cherry picked.

 

 

So for a period between 1987 and 2009, you cherry-pick a selection of 6 winters and point out that a majority of months were milder than average?

1) Even excepting your selective choice of 'stats', has a run of generally milder-than-average winters never happened before?

2) What happened after the 2008/9 winter?

 

The fact is, you use a statistically inadequate timeframe to try to give credence to your favourite trolling method of mentioning 'modern winter' with the insinuation that we won't get proper winters any more (you used to say more directly that we would no longer get proper winters but then the winters of 2009/10, 2010/11 and 2012/13 widdled all over that line).

 

 

Well in there, Saint. Nail hit right on head.

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Once could have said pretty much the same thing back in 2008/09. As Andy W mentioned, the MetO went for a mild winter in 2009/10 presumably with the underlying forcing mechanisms and background warmth that you mention in mind. Yet in the end, they couldn't have been more wrong with their forecast.

I might be wrong about this, but I think that at the time, 2010 turned out to be the warmest year on record globally. Yet that didn't stop us having our coldest December for 120 years that year plus I think 2010 was the UK's coolest year of any since 1986 or thenabouts. Not that this year is going to turn out like 2010 did, but it shows that the unexpected can never be totally discounted, "modern era" or not.

That's true but it doesn't change things. When producing a winter forecast as an "independent" the key things are:

1) Put aside your personal preferences
2) Try to resist the urge to produce something "interesting"
3) Look at all the evidence objectively and don't drown in confusion. For example, seasonal models have a low skill level but they shouldn't be ignored. 
4) Look at recent climatological trends
5) Put the forecast together and don't oversell it. 

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That's true but it doesn't change things. When producing a winter forecast as an "independent" the key things are:

1) Put aside your personal preferences
2) Try to resist the urge to produce something "interesting"
3) Look at all the evidence objectively and don't drown in confusion. For example, seasonal models have a low skill level but they shouldn't be ignored. 
4) Look at recent climatological trends
5) Put the forecast together and don't oversell it. 

Can't disagree with any of that Brian.

As Andy and myself mentioned earlier, the MetO went for a mild winter season in 2009/10 but my recollection is that you predicted a cold one, and you were vindicated with this prediction. I know that you always wait until the end of November each year before releasing your winter forecast to the public, However what I wanted to ask you is that back in 2009, would you have still predicted a cold winter had you released your forecast at this point in the autumn instead of the end of Nov based on the weather pattern that was in place at that time? Similarly in 2010, at this point that autumn did you believe it all possible that a couple of months later, we would have our coldest December since 1890 and our first sub-zero CET month since 1986? I'd be interested to hear your recollections of those two years.

I think you have said in the past that weather events during November are always an important factor to consider when producing a winter forecast, and I agree with this entirely. 2015 was a good example of a time when a pattern that took hold during November, i.e wet and very mild, then went on to dominate the winter season itself almost right up until the end of February.

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That's true but it doesn't change things. When producing a winter forecast as an "independent" the key things are:

1) Put aside your personal preferences
2) Try to resist the urge to produce something "interesting"
3) Look at all the evidence objectively and don't drown in confusion. For example, seasonal models have a low skill level but they shouldn't be ignored. 
4) Look at recent climatological trends
5) Put the forecast together and don't oversell it. 

Spot on Brian and that is why you command utmost respect. Your forecasts are never sensationalized never pushed too far and most importantly are published and kept online throughout any given season to be objectively scrutinised. Yours and Gavin P's forecasts are the only ones I take any credence from......they are not always right but they equally are not over hyped and never have been.

That's why you and Gav are the top two around.

 

(Just keep the polar bears off the home page though)! 😂😂😂

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I accept that recent performance may be an indicator of future weather trends, but does this work when comparing summer and winter months?  Summer months with higher CETs v average are likely (but not exclusively) featuring high pressure over the UK.  In winter, it's a zonal train of lows that is likely to bring milder conditions, albeit much wetter.  CETs should therefore be considered with precipitation?

 

 

So for a period between 1987 and 2009, you cherry-pick a selection of 6 winters and point out that a majority of months were milder than average?

1) Even excepting your selective choice of 'stats', has a run of generally milder-than-average winters never happened before?

2) What happened after the 2008/9 winter?

 

The fact is, you use a statistically inadequate timeframe to try to give credence to your favourite trolling method of mentioning 'modern winter' with the insinuation that we won't get proper winters any more (you used to say more directly that we would no longer get proper winters but then the winters of 2009/10, 2010/11 and 2012/13 widdled all over that line).

 

 

 

I'm not sure that this is fair Saint, I was just making the point the other day that the years towards the end of each of the last 3 decades have seen some phenomenal CET returns, though of course there are many others within the last 30 years.

Of course we did see some below average months around the turn of the decade which were almost certainly linked to low solar activity. Of course there have been periods of generally milder than average winters before, but no matter how hard one looks at the numbers, there's never been anything like this. 

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It's just the same every year now which is why my autumn forecast has a 100% success rate so far.

 

1.Horrible wet dull summer

2.Horrible mild damp autumn

3.Horrible snowless and frost-free winter.

 

1. has already been satisfied this year and model output shows 2. on its way to becoming a reality so no reason to think the pattern will break at 3

Yes, but what about spring, eh? That's the question.

 

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I'm not sure that this is fair Saint, I was just making the point the other day that the years towards the end of each of the last 3 decades have seen some phenomenal CET returns, though of course there are many others within the last 30 years.

Of course we did see some below average months around the turn of the decade which were almost certainly linked to low solar activity. Of course there have been periods of generally milder than average winters before, but no matter how hard one looks at the numbers, there's never been anything like this. 

Given what I have bolded above, would you now concede that no matter how dominant mild/very mild winters have been in the past thirty years, it is still possible to get mostly cold winters (e.g 2009/10) or cold winter months in isolation (e.g December 2010) which pretty much flies in the face of what you were telling us a decade ago, Ian?

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Yes, but what about spring, eh? That's the question.

 

The words 'horrible', 'dull', 'mild' and 'dreary' will feature.....

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Given what I have bolded above, would you now concede that no matter how dominant mild/very mild winters have been in the past thirty years, it is still possible to get mostly cold winters (e.g 2009/10) or cold winter months in isolation (e.g December 2010) which pretty much flies in the face of what you were telling us a decade ago, Ian?

Exactly.

It is clear from a review of the CET record that the mean temperature is on the increase.  There is an argument that the weather patterns have changed as well and contributed to the warming. But there must and will be below average months and when these coincide with the winter months we will get the occasional cold/very cold months and certainly cold/very cold spells.

Then of course, as demonstrated by past patterns, periods of low solar activity (reduced sunspots) correlate with more blocked weather patterns and consequent greater continentality: warmer summers, colder winters.

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However what I wanted to ask you is that back in 2009, would you have still predicted a cold winter had you released your forecast at this point in the autumn instead of the end of Nov based on the weather pattern that was in place at that time? Similarly in 2010, at this point that autumn did you believe it all possible that a couple of months later, we would have our coldest December since 1890 and our first sub-zero CET month since 1986? I'd be interested to hear your recollections of those two years.

I can't remember what my thoughts were as we headed through autumn 2009 so I won't make up a load of retrospective babble. However I wrote a piece on my blog page (generally I use Buzz now instead) which is can be read here:

https://www.theweatheroutlook.com/twoother/twocontent.aspx?type=bg&id=1723&title=Winter+2009/10+early+thoughts

 

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CET monthly anomalies for 2009:

Month	CET	Anomaly	notes
January	0.1	-1.1
February	1.5	0.6
March	3.0	0.8
April	5.3	1.4
May	7.6	0.9
June	9.9	0.2
July	12.1	0.4
August	12.4	1.0
September	10.3	0.7
October	8.2	1.0
November	6.0	2.4
December	0.4	-1.6

Ten consecutive above-average anomalies, culminating in November 2009's whopper, then ... boom! The best pair of winters a lot of people in southern England at least will have ever experienced.

 

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Exactly.

It is clear from a review of the CET record that the mean temperature is on the increase.  There is an argument that the weather patterns have changed as well and contributed to the warming. But there must and will be below average months and when these coincide with the winter months we will get the occasional cold/very cold months and certainly cold/very cold spells.

Then of course, as demonstrated by past patterns, periods of low solar activity (reduced sunspots) correlate with more blocked weather patterns and consequent greater continentality: warmer summers, colder winters.

I remain of the belief that it is not possible to reliably forecast winter weather.However I do think that there is chance of  of forecasting broad weather type as indicated  by the NAO type.The issue is therefore the  advance forecasting of the winter NAO

The met office do there own NAO forecast and sometimes the values are mentioned in their seasonal contingency forecasts.I would be very interested to know how these validate.It should be possible to get a time series showing the forecast NAO value and the actual.At the minimum figures showing how many NAO + forecasts were right and how many NAO- were right could be produced.The actual CET for each winter could also be added as he NAO is not a perfect correlation with + or - CET  anomalies.(correlation is around 0.66)

Any suggestions about the best way of getting the winter NAO forecasts from METO?

I'll make a couple more observations. On the Met Office CPF it currently says:

1: Overall, however, there are increased chances of above average temperatures over the outlook period (see figure T2). This is a result of the higher-than-usual likelihood of mild westerly winds and the background warmth that has been associated with above-average UK temperatures throughout much of 2017 (see figure T1).

https://www.metoffice.gov.uk/binaries/content/assets/mohippo/pdf/public-sector/forecast-temp-ond-v2.pdf

On the background information it includes this:

2: The forecast presented here is for the average of the October-November-December 2017 period for the United Kingdom as a whole. This forecast is based on information from observations, several numerical models and expert judgement.

https://www.metoffice.gov.uk/services/public-sector/contingency-planners

To me:

1) Point 1 suggests recent climatology is factored into their forecasts 

2) Point 2 suggests an element of subjectivity is available in their methodology. 

 

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I remain of the belief that it is not possible to reliably forecast winter weather.However I do think that there is chance of  of forecasting broad weather type as indicated  by the NAO type.The issue is therefore the  advance forecasting of the winter NAO

The met office do there own NAO forecast and sometimes the values are mentioned in their seasonal contingency forecasts.I would be very interested to know how these validate.It should be possible to get a time series showing the forecast NAO value and the actual.At the minimum figures showing how many NAO + forecasts were right and how many NAO- were right could be produced.The actual CET for each winter could also be added as he NAO is not a perfect correlation with + or - CET  anomalies.(correlation is around 0.66)

Any suggestions about the best way of getting the winter NAO forecasts from METO?

Exactly a year ago the Met Office revealed that they could skilfully predict the winter NAO up to 2 seasons ahead, This got faithfully reported as such in the press. The paper in question was  paywalled in Nature Geoscience, but it did appear for a time on a Russian server, though the link is no longer working.

Basically there was an r-value of 0.62 for the coming season, which fell to just 0.42 for the following one. This does NOT mean 62% accuracy, as the press reports claimed (and which the Met Office didn't attempt to correct, as far as I know). It's just an expression of the scatter of actual past values from the ones the model would have thrown up. 

Thus an r-value of 0.62 means that their model can explain 38% of past variations in the NAO, which is fairly impressive as these things go (although the other way of looking at it - that 62% of what goes on with the NAO is still a complete mystery 3 months out - sounds a bit less impressive).

An r-value of 0.42 for the winter after is a lot less "skilful", as they say in these circles. That figure implies that just 18% of past variation is explained by their model, which is pretty useless on the face of it.

As to your question of how to get hold of MetO winter NAO forecasts, I have no idea, but the following figure, courtesy of the abstract to the above paper, shows how the model they use fared in terms of hindcasting, for what that's worth:

(The figure in the top left is for the year ahead, the figure in the top right is for 2 years ahead. The red line is the ensemble mean, the black line actual values.)

http://www.nature.com/ngeo/journal/v9/n11/abs/ngeo2824.html

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