Not sure about the cricket analogues here, but they are using a different approach , using a model to predict the winter pattern. Here is an extract from a paper cited in the recent Nature article

'The forecasts used here were produced using the Met Office Global Seasonal forecast System 5 (GloSea5). The climate model at the core of this forecast system is Hadley Centre Global Environmental Model version 3 with atmospheric resolution of 0.83° longitude by 0.55° latitude, 85 quasi-horizontal atmospheric levels, and an upper boundary at 85 km near the mesopause. The ocean resolution is 0.25° globally in both latitude and longitude with 75 quasi-horizontal levels. This resolution is necessary to reduce key biases in the ocean and atmosphere and give a realistic winter blocking climatology in the model [Scaife et al., 2011]. A 24-member ensemble of forecasts was run for each winter in the period 1993 to 2012 with lagged start dates centered on 1 November (25 October, 1 November, and 9 November) and eight members initialized on each of the three start dates. Members from the same start date differ only by stochastic physics [Arribas et al., 2011]. Initial atmospheric and land surface data were taken from ECMWF Re-Analysis (ERA)-Interim observational reanalyses, and initial conditions for the global ocean and sea ice concentration were from the Forecasting Ocean Assimilation Model (FOAM) system [Blockley et al., 2013]. This configuration allows very skillful predictions of various slowly varying components of the climate system to be made for the coming winter (Table S1)'

In other words they are saying that they have a much better method of predicting NAO now certainly for the upcoming winter and indeed as they have now shown a year ahead.

That's all well and good but I still don't see how this improves on the May SST NAO correlation which was being discussed 17 years ago. Am I missing something here? 

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That's all well and good but I still don't see how this improves on the May SST NAO correlation which was being discussed 17 years ago. Am I missing something here? 

 

I would say 2 things:

 

1. They aren't just predicting NAO but the other factors, temperature, rainfall etc relevant to winter weather


2. These prediction are more accurate than from May SST and then inferred from the NAO forecast.

 

 

I would say 2 things:

 

1. They aren't just predicting NAO but the other factors, temperature, rainfall etc relevant to winter weather


2. These prediction are more accurate than from May SST and then inferred from the NAO forecast.

How do you know? They haven't made any yet. And please don't say it's because their system has had a 62% success rate in hindcasting.

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According to their paper using hindcasts

I think the MetO are expecting a cold, dry start to winter but they dare not say so for fear of prompting 'Mega Freeze' headlines in the media.

The cold start to winter theme has even now appeared in the updated MRF which indicates the real possibility of a cold November, that's a rare beast indeed apart from a few notable exceptions ie 2010.

The ability to predict the winter NAO well in advance is a clear advantage for the Country's planners and those on TWO of a nervous disposition.

At least it has more science behind it than the OPI! Ok I'll get my coat.........

Andy

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How can the meto predict a whole season based soley on the NAO,when clearly there are many other factors that influenze the uk`s weather??

Also coming out and saying the start of winter will be colder and drier than 2015 is stating the bleedin` obvious

How can the meto predict a whole season based soley on the NAO,when clearly there are many other factors that influenze the uk`s weather??

Also coming out and saying the start of winter will be colder and drier than 2015 is stating the bleedin` obvious

 

It is the bleedin obvious and it is said with the knowledge that Joe Public probably won't remember just how wet and warm December 2015 was. 

The NAO is huge for us though and I think one of the reasons we have runs of mild/very mild winters is the NAO reverting to the base state of the previous winter until the cycle is broken.

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How can the meto predict a whole season based soley on the NAO,when clearly there are many other factors that influenze the uk`s weather??

Also coming out and saying the start of winter will be colder and drier than 2015 is stating the bleedin` obvious

there's colder and drier and there's 'cold and dry'

I haven't seen the latest MRF but I'd interpret the 2 things differently.

NAO is a good general forecast indicator (more so when combined with AO) More useful than QBO and solar activity but these factors favour a colder scenario anyway this winter. 

Seeing the Met office saying that they  can predict the NAO type a month ahead set me examining the frequency and persistence od NAO winter types.The data set in monthly NAO's from 1826 to 2015 a total of 190 years.

The first  observation is that NA0+winters (DJF) occur in 68%of the years.Another way of saying this is that NAO- winters occur only once in three years sowing the strength the default NAO + position.No wonder cold lovers get frustrated!

The second observation is that there are different levels of frequency in the three winter months.The % for NAO % are Dec 56%,Jan,68% and Feb 66%.This is somewhat surprising result because it shows December as the most blocked month.There  is thought to be a singularity of a mid December Anticyclonic spell so maybe that is showing through in the December figures.

The more blocked nature of the month of December and its position as the first month of winter led me to look at what followed the December NAO types.

NAO + Decembers were followed by NAO + 76% NAO+ Jans and 73%  NAO + febs these being small amount greater than  expected frequencies. NAO -Decembers were followed by 60% NAO + Jans and 61% Febs slightly lower than would be expected.

However here is the fascinating figure .If we look at the entire winter NAO (DJF) than NAO + Decembers are 85% likely result in 85% NAO + for DJF..For NAO- Decembers the figure for DJF is NAO + is just 45% with NAO at 55% forming the majority.These results show strong variation from expected levels.

Could it be that the December NAO sign is the bell weather for warm/cold winters? Given that we can track the NAO through the month ten we have an early indicator of what December may turn out to be

 

 

 

Thanks Roger. So the MetO claimed 62% accuracy rate more or less ties in with your findings which no doubt the MetO will have accessed through their own data, so it's hardly groundbreaking stuff as first proclaimed by them and more a simple case of looking through records and coming up with a number.

Seeing the Met office saying that they  can predict the NAO type a month ahead set me examining the frequency and persistence od NAO winter types.The data set in monthly NAO's from 1826 to 2015 a total of 190 years.

The first  observation is that NA0+winters (DJF) occur in 68%of the years.Another way of saying this is that NAO- winters occur only once in three years sowing the strength the default NAO + position.No wonder cold lovers get frustrated!

The second observation is that there are different levels of frequency in the three winter months.The % for NAO % are Dec 56%,Jan,68% and Feb 66%.This is somewhat surprising result because it shows December as the most blocked month.There  is thought to be a singularity of a mid December Anticyclonic spell so maybe that is showing through in the December figures.

The more blocked nature of the month of December and its position as the first month of winter led me to look at what followed the December NAO types.

NAO + Decembers were followed by NAO + 76% NAO+ Jans and 73%  NAO + febs these being small amount greater than  expected frequencies. NAO -Decembers were followed by 60% NAO + Jans and 61% Febs slightly lower than would be expected.

However here is the fascinating figure .If we look at the entire winter NAO (DJF) than NAO + Decembers are 85% likely result in 85% NAO + for DJF..For NAO- Decembers the figure for DJF is NAO + is just 45% with NAO at 55% forming the majority.These results show strong variation from expected levels.

Could it be that the December NAO sign is the bell weather for warm/cold winters? Given that we can track the NAO through the month ten we have an early indicator of what December may turn out to be

 

 

 

The MetO report is about predicting the NAO a year ahead though

However I take the point about the percentage accuracy. The MetO are saying they can get a correlation coefficient of 0.62 with the new model and supercomputer. If as you say the DJF NAO is +ve for 68% of winters then I could get a coefficient of 0.68 just by saying +ve every year

I suspect though that they are comparing the actual ups and downs of the graph with their model  and not just the overall sign.

 

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Just remember what the media say the Met Office are saying is not what the Met Office are saying   

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Here is the original Nature Geoscience paper un-paywalled:

http://sci-hub.bz/10.1038/ngeo2824

There's no claim of "62% accuracy" that I can see. That might be the result of the hack at the Telegraph thinking an r-value of 0.62 means 62% accuracy. (it's an expression of the scatter between actual values and modelled values.) To be fair to the hack, rather too many climate/weather "scientists" in recent years have been silent when values with a specific statistical meaning have been misinterpreted to mean percentages, especially when the misinterpretation suggests their models are going to predict the future, when in fact they're simply modelling the past (as here).

Incidentally, the r-value is only 0.62 for the first winter, falling to a rather less impressive 0.42 for the much-vaunted 12-months ahead (an r-value of less than 0.5 suggests only a small relationship between model and reality).

If you want to eyeball how well the modelling in this case works in practice, have a look at the top two diagrams on page 2 of the paper. Notice how in the one on the right (the NAO 12 months ahead) their models backfit quite well until the most recent couple of years. Whatever caused the startlingly positive NAO and mild winter last year, this model missed it completely and predicted the opposite 12 months out.

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Seeing the Met office saying that they  can predict the NAO type a month ahead set me examining the frequency and persistence od NAO winter types.The data set in monthly NAO's from 1826 to 2015 a total of 190 years.

The first  observation is that NA0+winters (DJF) occur in 68%of the years.Another way of saying this is that NAO- winters occur only once in three years sowing the strength the default NAO + position.No wonder cold lovers get frustrated!

The second observation is that there are different levels of frequency in the three winter months.The % for NAO % are Dec 56%,Jan,68% and Feb 66%.This is somewhat surprising result because it shows December as the most blocked month.There  is thought to be a singularity of a mid December Anticyclonic spell so maybe that is showing through in the December figures.

The more blocked nature of the month of December and its position as the first month of winter led me to look at what followed the December NAO types.

NAO + Decembers were followed by NAO + 76% NAO+ Jans and 73%  NAO + febs these being small amount greater than  expected frequencies. NAO -Decembers were followed by 60% NAO + Jans and 61% Febs slightly lower than would be expected.

However here is the fascinating figure .If we look at the entire winter NAO (DJF) than NAO + Decembers are 85% likely result in 85% NAO + for DJF..For NAO- Decembers the figure for DJF is NAO + is just 45% with NAO at 55% forming the majority.These results show strong variation from expected levels.

Could it be that the December NAO sign is the bell weather for warm/cold winters? Given that we can track the NAO through the month ten we have an early indicator of what December may turn out to be

 

 

 

 

Thanks Roger, certainly mild Decembers in the modern era have usually been followed by mild Jans and Febs, though the story was different in the early to mid eighties.

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Here is the original Nature Geoscience paper un-paywalled:

http://sci-hub.bz/10.1038/ngeo2824

There's no claim of "62% accuracy" that I can see. That might be the result of the hack at the Telegraph thinking an r-value of 0.62 means 62% accuracy. (it's an expression of the scatter between actual values and modelled values.) To be fair to the hack, rather too many climate/weather "scientists" in recent years have been silent when values with a specific statistical meaning have been misinterpreted to mean percentages, especially when the misinterpretation suggests their models are going to predict the future, when in fact they're simply modelling the past (as here).

Incidentally, the r-value is only 0.62 for the first winter, falling to a rather less impressive 0.42 for the much-vaunted 12-months ahead (an r-value of less than 0.5 suggests only a small relationship between model and reality).

If you want to eyeball how well the modelling in this case works in practice, have a look at the top two diagrams on page 2 of the paper. Notice how in the one on the right (the NAO 12 months ahead) their models backfit quite well until the most recent couple of years. Whatever caused the startlingly positive NAO and mild winter last year, this model missed it completely and predicted the opposite 12 months out.

 

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Here is the original Nature Geoscience paper un-paywalled:

http://sci-hub.bz/10.1038/ngeo2824

There's no claim of "62% accuracy" that I can see. That might be the result of the hack at the Telegraph thinking an r-value of 0.62 means 62% accuracy. (it's an expression of the scatter between actual values and modelled values.) To be fair to the hack, rather too many climate/weather "scientists" in recent years have been silent when values with a specific statistical meaning have been misinterpreted to mean percentages, especially when the misinterpretation suggests their models are going to predict the future, when in fact they're simply modelling the past (as here).

Incidentally, the r-value is only 0.62 for the first winter, falling to a rather less impressive 0.42 for the much-vaunted 12-months ahead (an r-value of less than 0.5 suggests only a small relationship between model and reality).

If you want to eyeball how well the modelling in this case works in practice, have a look at the top two diagrams on page 2 of the paper. Notice how in the one on the right (the NAO 12 months ahead) their models backfit quite well until the most recent couple of years. Whatever caused the startlingly positive NAO and mild winter last year, this model missed it completely and predicted the opposite 12 months out.

At long last an article on this without the media spin. 👍

UK winter forecast: Damaging windstorms to lash areas hit hard last year

"A stormy winter is in the offing for the United Kingdom this year with rain and wind set to batter the British Isles even before the season's official start.

AccuWeather forecasters are calling for 15-18 named storms between October 2016 and April 2017; however, the most active period will occur from December to February.

After a brief lull in windstorms during November, the threat will once again pick up in December, with some weeks bringing the potential for multiple named systems.

"The greatest wind threat is expected across Northern Ireland, Scotland, including Glasgow and Edinburgh, and Northern England," AccuWeather Meteorologist Tyler Roys said.

Significant but less frequent damaging wind events may also impact the remainder of the U.K."

http://www.accuweather.com/en/weather-news/uk-winter-forecast-damaging-windstorms-to-lash-hard-hit-areas-northern-england/60531022

UK winter forecast: Damaging windstorms to lash areas hit hard last year

"A stormy winter is in the offing for the United Kingdom this year with rain and wind set to batter the British Isles even before the season's official start.

AccuWeather forecasters are calling for 15-18 named storms between October 2016 and April 2017; however, the most active period will occur from December to February.

After a brief lull in windstorms during November, the threat will once again pick up in December, with some weeks bringing the potential for multiple named systems.

"The greatest wind threat is expected across Northern Ireland, Scotland, including Glasgow and Edinburgh, and Northern England," AccuWeather Meteorologist Tyler Roys said.

Significant but less frequent damaging wind events may also impact the remainder of the U.K."

http://www.accuweather.com/en/weather-news/uk-winter-forecast-damaging-windstorms-to-lash-hard-hit-areas-northern-england/60531022

Sounds like they're going for quite a mild Atlantic based winter. I've contacted Tyler to ask if that's a fair summary and will post here if I get a reply.

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UK winter forecast: Damaging windstorms to lash areas hit hard last year

"A stormy winter is in the offing for the United Kingdom this year with rain and wind set to batter the British Isles even before the season's official start.

AccuWeather forecasters are calling for 15-18 named storms between October 2016 and April 2017; however, the most active period will occur from December to February.

After a brief lull in windstorms during November, the threat will once again pick up in December, with some weeks bringing the potential for multiple named systems.

"The greatest wind threat is expected across Northern Ireland, Scotland, including Glasgow and Edinburgh, and Northern England," AccuWeather Meteorologist Tyler Roys said.

Significant but less frequent damaging wind events may also impact the remainder of the U.K."

http://www.accuweather.com/en/weather-news/uk-winter-forecast-damaging-windstorms-to-lash-hard-hit-areas-northern-england/60531022

Not what a  lot of us want this winter. Interesting thoughts given the  complete lack of Atlantic domination so far.

UK winter forecast: Damaging windstorms to lash areas hit hard last year

"A stormy winter is in the offing for the United Kingdom this year with rain and wind set to batter the British Isles even before the season's official start.

AccuWeather forecasters are calling for 15-18 named storms between October 2016 and April 2017; however, the most active period will occur from December to February.

After a brief lull in windstorms during November, the threat will once again pick up in December, with some weeks bringing the potential for multiple named systems.

"The greatest wind threat is expected across Northern Ireland, Scotland, including Glasgow and Edinburgh, and Northern England," AccuWeather Meteorologist Tyler Roys said.

Significant but less frequent damaging wind events may also impact the remainder of the U.K."

http://www.accuweather.com/en/weather-news/uk-winter-forecast-damaging-windstorms-to-lash-hard-hit-areas-northern-england/60531022

In fairness, their autumn forecast isn't holding much stock so far, which pointed towards a stormy one in this part of the world.

Still, I'd not say nope to a stormy winter. Hopefully there will be some real storms this time around and not the fluffy poodles of yokes that have become the norm since the start of the current century.

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