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Offline roger63  
#1 Posted : 06 September 2013 08:19:28(UTC)
roger63

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Location: Winchester,Hampshire

Winter Indicators.

Here we are 3 months way from the start of winter,and asking the perennial question" will it be a cold winter? Four of the last five winters have been cold so does the law  of averages come into play to redress the balance or could it be cold again?What are the early signals from the key indicators?

 

1.ENSO.

The latest ENSO diagnostic discussion (Sept 5th) concludes "ENSO neutral is favoured through the northern hemisphere winter 2013/14."For DJF the various models show a split between weak negative and weak positive indices with the average trending slightly positive.Such years are slightly more likely to be accompanied by colder than average winters.

 

2.SST's.

 

End of May north atlantic SST,s are generally most closely linked to winter CET.Howebver I always have trouble idenitfying  a clear tripole pattern which is the cold indicator.Maybe Gavin P can give his verdict on what signal is coming from May SST's.The pattern seems to show cold anomalies off NE USA and Canada and to the east of Iceland with above average in Mid Atlantic.

 

3.QBO.

In autumn 2012 the QBO was in negative mode andthis npersoted though winter 2012/13.This Autumn the QBO is in positive territory normally supposed to indicate warmer winters.However this indicator is somewhat unreiable as the cold winter of 2010/11 was positive and the warm winter of 2011/12 was negative!

 

4.Sunspot Activity.

Cycle 24 is the weakest cycle since the early 20Th century.It now looks as if the peak was 96.7 in Nov 2011,witha secondary peak of 78.7 in May this year.Overall activity level is low and lower than fprecast.However work by the University of readind and METO suggest the strongest link to the CET is at solar minimum.

 

5.Models.

 

CFSv 2 shows broadly neutral temperature  conditions over the UK,with precipitationslightly  below average.The trend over th elast month or  seems to have been a shift on th ewarm anomaly towards SE Europe.

Meto tercile probability maps  shows no clear temperature sinal obver the UK although warmer than aveage probabilities in the Arctic region.Precipitation is broadly normal and a slight  tendency for higher than average pressure to ther north of the UK and slightly lower pressure towards southern europe.

 

6.Seasonal Pattern Matching.

The very cold dry spring has a 75% chance of being followed bya colder than average winter.The very dry very warm summer is not astrong indicator either way.

 

7.Conclusion.

 

Signals are variable  all rather weakand suggesting  a near average winter.It seems best to llok at the trends in the CFSv2 models and  the METO probability maps before making a conclusion at the end of November!

 

 

 

 

 

 

 

 

 

 

 

Edited by moderator 07 September 2013 11:38:46(UTC)  | Reason: Not specified

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Offline roger63  
#2 Posted : 07 September 2013 07:24:19(UTC)
roger63

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Some links for the indicator discussion above.

ENSO discussion.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.html

SST,s

http://www.ospo.noaa.gov/data/sst/anomaly/2013/anomnight.5.27.2013.gif

QBO

http://www.esrl.noaa.gov/psd/data/correlation/qbo.data

Solar Activity

 http://www.ips.gov.au/Solar/1/6

CFS V2 Forecasts

http://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2seasonal.shtml

 

METO probaility maps (nov-Jan)

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

 

So what do you make of the indicators.I,m particularly interested in your views on the SST signal- as i said I find the maps diifucult to interpret.Also I havent had achance to see ice cover data yet although possibly that's a bit early.

Could I ask vis this post for the mods to amke this topic a sticky.Thanks.

 

 

Edited by user 07 September 2013 07:40:54(UTC)  | Reason: Not specified

RavenCraven  
#3 Posted : 07 September 2013 09:05:01(UTC)
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As long as the Azores high keeps close to us we wont be seeing much in the way of cold, as seen in previous winters. That said I personally think that the weak activity of the sun will assist in any cold weather that gets to us, being very cold.

Online nsrobins  
#4 Posted : 07 September 2013 09:39:11(UTC)
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Thanks for the work on this and the links. I am not a great believer in trying to predict so far ahead but the data is out there for anyone willing to spend hours trying to determine whether there is a link between the myriad of parameters and the consequent anomilies season by season.
You say that looking again at the end of November for signals would be better. I agree, but it won't stop us discussing the prospects

Neil

Portsmouth, Hampshire 1m ASL (coast)

Stormchaser, Member TORRO

Offline Charmhills  
#5 Posted : 07 September 2013 09:49:05(UTC)
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Originally Posted by: RavenCraven Go to Quoted Post

As long as the Azores high keeps close to us we wont be seeing much in the way of cold, as seen in previous winters. That said I personally think that the weak activity of the sun will assist in any cold weather that gets to us, being very cold.

If a dry or very dry winter results than a drought is likely next year for sure.

Duane.

Offline roger63  
#6 Posted : 07 September 2013 11:00:51(UTC)
roger63

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Originally Posted by: nsrobins Go to Quoted Post

Thanks for the work on this and the links. I am not a great believer in trying to predict so far ahead but the data is out there for anyone willing to spend hours trying to determine whether there is a link between the myriad of parameters and the consequent anomilies season by season.
You say that looking again at the end of November for signals would be better. I agree, but it won't stop us discussing the prospects

Thanks Neil,agree plenty to discuss before November end -just that I dont feel signals are clear enough for me to nail my colours to the mast yet!

Offline Gusty  
#7 Posted : 07 September 2013 11:41:12(UTC)
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Here's hoping for a dry, very mild and quiet winter with a persistent area of high pressure close to the SW of the country. 

We are due one. 

Steve - Folkestone, Kent

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Online Essan  
#8 Posted : 07 September 2013 12:13:01(UTC)
Essan

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Gut feeling is a rather ordinary winter with no prolonged, widespread, cold or snow.

And using my patent Antipodean method, it's looking like a rather mild winter with probably at least one record warm month    Though this does not preclude some decent snow, especially in upland areas.

Andy

Evesham, Worcs, Albion - 35m asl

And, you know, there is no such thing as society. There are individual men and women and there are families. And no governments can do anything except through people, and people must look to themselves first. It is our duty to look after ourselves and then, also, to look after our neighbours - M Thatcher.

Weather & Earth Science News

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Offline Retron  
#9 Posted : 07 September 2013 12:54:59(UTC)
Retron

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Originally Posted by: Gusty Go to Quoted Post

Here's hoping for a dry, very mild and quiet winter with a persistent area of high pressure close to the SW of the country. 

We are due one. 

We're just as much due a cold, snowy winter.

Good job personal preferences don't affect the weather, isn't it?

Offline Gooner  
#10 Posted : 07 September 2013 13:12:56(UTC)
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Originally Posted by: Gusty Go to Quoted Post

Here's hoping for a dry, very mild and quiet winter with a persistent area of high pressure close to the SW of the country. 

We are due one. 

You what

Remember anything after T120 is really Just For Fun

Marcus

Banbury

North Oxfordshire

378 feet A S L

Offline springsunshine  
#11 Posted : 07 September 2013 14:58:54(UTC)
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Indeed 4 out of the past 5 winters have been coldand i would be suprised if this coming winter

will be cold as well although we are bound to get some cold spells.

We are long overdue a wet winter with well above average rainfall and that is what im hoping for

Offline Gusty  
#12 Posted : 07 September 2013 15:05:42(UTC)
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Originally Posted by: Gooner Go to Quoted Post

Originally Posted by: Gusty Go to Quoted Post

Here's hoping for a dry, very mild and quiet winter with a persistent area of high pressure close to the SW of the country. 

We are due one. 

You what

 Marcus, My job role these days means that snow and bitterly cold weather results in days and days away from home. In the last 4 years I reckon I've only played in the stuff a couple of times.

Having said all that I will probably still get very excited when the beast starts to stir in those FI charts. 

Indeed Darren. It is a good job that preferences don't affect the type of weather we get.  

Steve - Folkestone, Kent

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Offline Matty H  
#13 Posted : 07 September 2013 15:11:32(UTC)
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Originally Posted by: Gusty Go to Quoted Post
Here's hoping for a dry, very mild and quiet winter with a persistent area of high pressure close to the SW of the country.

We are due one.

Approve Approve Approve

Yate, Nr Bristol

Offline Charmhills  
#14 Posted : 07 September 2013 15:20:12(UTC)
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Location: Loughborough.

Originally Posted by: Gusty Go to Quoted Post

Here's hoping for a dry, very mild and quiet winter with a persistent area of high pressure close to the SW of the country. 

We are due one. 

Steve, do I detect Physical warfare!

Duane.

Offline Matty H  
#15 Posted : 07 September 2013 17:12:39(UTC)
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Originally Posted by: Charmhills Go to Quoted Post
Originally Posted by: Gusty Go to Quoted Post

Here's hoping for a dry, very mild and quiet winter with a persistent area of high pressure close to the SW of the country.

We are due one.

Steve, do I detect Physical warfare!

Psychological I would have thought.

Yate, Nr Bristol

Offline Charmhills  
#16 Posted : 07 September 2013 17:19:54(UTC)
Charmhills

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Location: Loughborough.

Originally Posted by: Matty H Go to Quoted Post
Originally Posted by: Charmhills Go to Quoted Post
Originally Posted by: Gusty Go to Quoted Post
Here's hoping for a dry, very mild and quiet winter with a persistent area of high pressure close to the SW of the country.[/i]
Psychological I would have thought.

Yeah thats what I meant.

Duane.

Online David M Porter  
#17 Posted : 07 September 2013 22:53:26(UTC)
David M Porter

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Originally Posted by: springsunshine Go to Quoted Post

Indeed 4 out of the past 5 winters have been coldand i would be suprised if this coming winter

will be cold as well although we are bound to get some cold spells.

We are long overdue a wet winter with well above average rainfall and that is what im hoping for

I thought some places had that last winter, at least at the start.

"Sometimes what we accept as the truth may not be the full story".

Hercule Poirot (David Suchet)

Online Justin W  
#18 Posted : 08 September 2013 06:21:59(UTC)
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Location: North Downs, East Kent

The QBO is trending strongly positive now so it looks like we're looking at a strong polar vortex this winter increasing the likelihood of a mainly westerly flow over the UK.

Offline nickl  
#19 Posted : 08 September 2013 07:36:17(UTC)
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Originally Posted by: Justin W Go to Quoted Post

The QBO is trending strongly positive now so it looks like we're looking at a strong polar vortex this winter increasing the likelihood of a mainly westerly flow over the UK.

if only twas that easy justin. part of the jigsaw but not an overriding factor (neutral ENSO may give it a bigger piece though). i can confidently state that the upcoming winter will be colder than the summer just ended .

 

Online Justin W  
#20 Posted : 08 September 2013 07:53:29(UTC)
Justin W

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Originally Posted by: nickl Go to Quoted Post

Originally Posted by: Justin W Go to Quoted Post

The QBO is trending strongly positive now so it looks like we're looking at a strong polar vortex this winter increasing the likelihood of a mainly westerly flow over the UK.

if only twas that easy justin. part of the jigsaw but not an overriding factor (neutral ENSO may give it a bigger piece though). i can confidently state that the upcoming winter will be colder than the summer just ended .

 

 

 

As I said - "increasing the likelihood". Not guaranteeing. Neutral ENSO conditions (if that is what we end up with) will help but the state of the polar vortex is a major factor when it comes to western European winters. We end up relying upon significant SSWs to displace the PV and divert the Atlantic train.

 

 

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