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Offline bruced  
#921 Posted : 12 January 2014 18:25:21(UTC)
bruced

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Posts: 141

Well, so far this winter has been one of the most unsettled and mildest for a long time (is it any coincidence that the solar cycle is very active?).  Some are saying this winter is a throwback to the winters of the 1990s - IMO, there is one subtle difference.  Correct me if I'm wrong, but the jetstream (extremely strong as it is) has been further south than it was in those mobile winters of yesteryear.  Instead of roaring away to the North of the UK near Iceland and allowing higher pressure over the near continent, this winter has seen it flow across, or just to the south, of the UK...bombarding the whole of the UK with wind and rain.  The jetstream has also dug a comparatively long way south in the mid-Atlantic.

Now that a large Scandi high has/is forming and is projected to linger, would that lead to increased wave activity, as we saw last winter (IIRC), which would then lead to warming pressures in the stratosphere?? 

David, Northallerton

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Offline Stormchaser  
#922 Posted : 13 January 2014 23:44:36(UTC)
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Location: West Hants

After a serious fail in predicting December 2013, I gave CFS a wide berth for a while.

I couldn't resist glancing at it tonight though, in light of the models trending towards a stronger and stronger block to our east. I kind of expected to see raging zonality from CFS, and yet...

http://www.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd3/glbz700MonInd1.gif

That has Euro troughing and easterlies written all over it, there's even scope for some regression towards Greenland...!

http://www.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd3/glbz700MonInd2.gif

March resembles 2013's ordeal, but maybe less blocked to our NW with more of an Atlantic influence.

http://www.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd3/glbz700MonInd3.gif

Blocking is signalled to peak in April and give a soggy month.

 

Make of it what you will - and don't take it too seriously. The February chart does make a lot of sense based on current trop/strat projections, though... 

 

If you have any problems or queries relating to TWO you can Email twomoderationteam@gmail.com :)

Homeland: Rural Mid-West Hants nearly 10 miles S of Salisbury (near Fordingbridge). More insights: https://twitter.com/peacockreports

2018's Homeland Extremes:

T-Max: 30.9*C 8th July | T-Min: -7.7*C 28th Feb | Wettest Day: 19.2mm 14th October | Ice Days: 4 (28 Feb - 2 Mar & 18 Mar)

Keep Calm and Forecast On

Offline Essan  
#923 Posted : 14 January 2014 12:35:46(UTC)
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Originally Posted by: Saint Snow Go to Quoted Post

Whilst last March's cold & snow was interesting, I'm not sure I'd want a repeat. For one, the snow didn't stay around for that long each fall - and the roads especially cleared quickly (). Secondly, by March I'm looking for some spells of sunny & warmish weather to set the scene for hopefully a sweltering & drought-filled summer.



Aye, whilst I observed snow falling on 7 days in March last year, there was 50% snow cover at 09z on exactly zero days.   Hardly wintry!   I preferred the previous March - spring is the best time of year for warm sunny weather, IMO, cos it's not too hot and humid to be able to enjoy, and nights continue to be reasonably cool

Andy

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Offline Gooner  
#924 Posted : 15 January 2014 21:55:32(UTC)
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Remember anything after T120 is really Just For Fun

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Offline KevBrads1  
#925 Posted : 16 January 2014 20:30:14(UTC)
KevBrads1

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Originally Posted by: Essan Go to Quoted Post

Aye, whilst I observed snow falling on 7 days in March last year, there was 50% snow cover at 09z on exactly zero days. Hardly wintry!

There's more to wintriness than snow, there's frost as well.

I suggest a wintry index as I do and compare it to past winter months then you can judge whether it was "wintry".

Timelapses, old weather forecasts and natural phenomena videos can be seen on this site

http://www.youtube.com/c...z2feWDTydhpEhQ/playlists

Offline Quantum  
#926 Posted : 17 January 2014 00:33:03(UTC)
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Originally Posted by: KevBrads1 Go to Quoted Post
Originally Posted by: Essan Go to Quoted Post
Aye, whilst I observed snow falling on 7 days in March last year, there was 50% snow cover at 09z on exactly zero days. Hardly wintry!
There's more to wintriness than snow, there's frost as well. I suggest a wintry index as I do and compare it to past winter months then you can judge whether it was "wintry".

Can you explain the methodology behind your winter indicies and perhaps give us a few previous years for comparision. Thanks

 

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Offline KevBrads1  
#927 Posted : 17 January 2014 06:11:40(UTC)
KevBrads1

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Originally Posted by: Quantum Go to Quoted Post
Originally Posted by: KevBrads1 Go to Quoted Post
Originally Posted by: Essan Go to Quoted Post
Aye, whilst I observed snow falling on 7 days in March last year, there was 50% snow cover at 09z on exactly zero days. Hardly wintry!
There's more to wintriness than snow, there's frost as well. I suggest a wintry index as I do and compare it to past winter months then you can judge whether it was "wintry".

Can you explain the methodology behind your winter indicies and perhaps give us a few previous years for comparision. Thanks

10 x [(number of days where minimum is at or below 0C) + ( number of days of falling sleet/snow) + ( number of days of lying snow at 9am)] divided by the mean winter maximum temperature.

The higher the value the more wintrier it was.

Last winter was 102

1988-89 was just 20

2006-07 was 21

2009-10 was 197

1978-79 was 262

Timelapses, old weather forecasts and natural phenomena videos can be seen on this site

http://www.youtube.com/c...z2feWDTydhpEhQ/playlists

Offline roger63  
#928 Posted : 22 January 2014 23:28:49(UTC)
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Location: Winchester,Hampshire



Rank: Advanced Member


Joined: 16/09/2006
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Location: Winchester,Hampshire

The strongest indicator this winter ha sbben the QBO

The QBO (Quasi-Bennial Oscillation) is a quasi periodical oscillation of the equatorial zonal wind between easterlies( -) and westerlies(+) in the tropical stratosphere.It is  measured at 30mb height.

The average length of the the oscillation is around 26-29months.It is  however asymmetric,with the amplification of the easterly being nearly twice as great as the westerly.In addition on average the easterly cycle lasts o about 30% longer than the westerly.

It is possible , looking at the data set to work out for each year (1953/4 to Dec 2013) to work out the type affecting each year and the strength and length of each cycle.

The summary of my analysis is

1.There is  no correlation beween postive and negative cycle years and the winter CET.The average across the series for easterly( -years) is 4.3 c and the + years are 4.3 too.!

2.If  a subset of years with particularly high +or - values is used the relevant CETs are 4.27 v 4.26.

3.Using a measure which  combines number of months in a cycle with values of each month  all mothst then selecting the higher value  years  gives an avearge CET of 3.8c for strong -ve years and 4.1  for strong +v years unlikely to be statistically significant.

4.The overall conclusion is clear.I seems that on its own it can't explain winter circulation patterns.It may be that this year in the absence of any other indicators then it has played a part but  could b  other little known facts as well.!  

originally posted in Model ouyput thread b uy really belongs here

 

Edited by user 22 January 2014 23:30:22(UTC)  | Reason: Addition

Offline KevBrads1  
#929 Posted : 25 January 2014 23:26:50(UTC)
KevBrads1

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Location: Irlam

I have never written a post as downbeat as this but in terms of notable cold and snow, I have personally written off this winter now. Some may say why

a) I am writing it off when next week looks interesting?

b] I am writing it off when I know of historical past examples of notable late winter spells?

Some places may get snowfalls next week but the cold uppers are mixed out during Monday, so it becomes increasingly marginal at low levels. Then when the winds go into the east, it's brief before we lose the flow and the uppers are not special anyway. The Atlantic threatens to move in at the end of next week. I'm not convinced it is going to bring a general snow event, it may not even bring in snow for low levels anyway by this stage but we shall see.

As for February, I see two possible scenarios, more anticyclonicity of the Rex block type that limits precipitation or a continuation of what has plagued us a lot of this winter, Atlantic domination. I just don't see or feel a flip in the pressure pattern as has happened in the past for this winter. It feels a Sod's Law winter to me, when cold snowy scenarios have appeared in the charts and they have hardly been any it has to be said thus far, they have downgraded to virtually nothing such as the "northerly" during early December. Another example of the Sod Law nature of this winter is that around here it has dropped close to freezing but never actually got below, it has hovered about 1-2C at times.

I don't recall such lack of wintriness by this stage in a winter even by 1988-89 and 2006-07 standards. I saw lying snow in November 1988 and by this stage in January 2007 I have seen falling snow. Nothing thus far. Just looking at meteorological winter itself, it's on a par with 1988-89 if not as mild.

It just feels to me this winter is going nowhere, it's a non starter.

Timelapses, old weather forecasts and natural phenomena videos can be seen on this site

http://www.youtube.com/c...z2feWDTydhpEhQ/playlists

Offline Andy J  
#930 Posted : 26 January 2014 14:42:55(UTC)
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Location: Gainsborough, Lincolnshire

Certainly will be an unusually late start to Winter.  In my records for Gainsborough (going back 32 years), there is only one Winter that produced its first snowfall at a later date than today's date.  That was Winter 2011-2012, in which the first snow didn't arrive until Feb 3rd.  Yes, even all of the very mild late-80's and 90's Winters had already produced some snow by now.  

Having said that, there looks to be numerous possibilities for snow in the coming week, but we'll wait and see...

 

 

 

 

Gainsborough, Lincolnshire.
Offline Whether Idle  
#931 Posted : 26 January 2014 20:29:51(UTC)
Whether Idle

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Originally Posted by: KevBrads1 Go to Quoted Post
I have never written a post as downbeat as this but in terms of notable cold and snow, I have personally written off this winter now. Some may say why a) I am writing it off when next week looks interesting? b] I am writing it off when I know of historical past examples of notable late winter spells? Some places may get snowfalls next week but the cold uppers are mixed out during Monday, so it becomes increasingly marginal at low levels. Then when the winds go into the east, it's brief before we lose the flow and the uppers are not special anyway. The Atlantic threatens to move in at the end of next week. I'm not convinced it is going to bring a general snow event, it may not even bring in snow for low levels anyway by this stage but we shall see. As for February, I see two possible scenarios, more anticyclonicity of the Rex block type that limits precipitation or a continuation of what has plagued us a lot of this winter, Atlantic domination. I just don't see or feel a flip in the pressure pattern as has happened in the past for this winter. It feels a Sod's Law winter to me, when cold snowy scenarios have appeared in the charts and they have hardly been any it has to be said thus far, they have downgraded to virtually nothing such as the "northerly" during early December. Another example of the Sod Law nature of this winter is that around here it has dropped close to freezing but never actually got below, it has hovered about 1-2C at times. I don't recall such lack of wintriness by this stage in a winter even by 1988-89 and 2006-07 standards. I saw lying snow in November 1988 and by this stage in January 2007 I have seen falling snow. Nothing thus far. Just looking at meteorological winter itself, it's on a par with 1988-89 if not as mild. It just feels to me this winter is going nowhere, it's a non starter.

Good post, backed up with facts.  It has been a grim, wild, snowless and virtually frost free season (dare I call it winter?) thus far.  If we pay for it with another cold spring I will be pig sick.

With model watching its as much about remembering to forget things as it is forgetting to remember.
Offline KevBrads1  
#932 Posted : 27 January 2014 08:01:40(UTC)
KevBrads1

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Location: Irlam

Comparing 1988-89 with this winter: I had seen lying snow in November 1988, I have seen nothing so far. Further to that, at least the reason for the lack of wintry weather was the very mild nature of December 1988 and January 1989. We see Bartlett charts, no chance. Although December and January have been mild, they were not as mild as those two and we have had opportunities that seem to have gone AWOL, the northerly that vanished into thin air at the start of December, the polar maritime air around Christmas which brought a little bit of wintriness and a frost. Now we have been suckered by the high pressure to the east for the last few days, will it or won't it, suckered by polar maritime air coming in from the west.

I feel like I have been made a mug by this winter, suckered by the charts. Every cold prospect has been downgraded next to nothing. Today is a prime example, a couple of days ago or so, it looked good for wintry showers, now it has turned into nothing.

Really has been a Sod's law winter. Everything has been just on the wrong side of marginal, even minima temperatures have been just on the wrong side of freezing.

I rather have a winter where you know where you stand such as with 1988-89, you see Bartlett, you know where you stand but not this type of winter, it's been horrendous compounded by the ruddy rain all the time.

Timelapses, old weather forecasts and natural phenomena videos can be seen on this site

http://www.youtube.com/c...z2feWDTydhpEhQ/playlists

Offline bruced  
#933 Posted : 27 January 2014 18:18:47(UTC)
bruced

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Posts: 141

I wonder if it's any coincidence that we are, and have been, around the peak of solar activity this winter...and it's been a very Atlantic-driven 'winter' thus far?  Of course, the extreme cold in N America interacting with the Atlantic waters has not helped and has fuelled the jetstream massively but without significant HLB (that is a possble spin-off from low solar activity), the jetstream has not been diverted well south into Europe and Mediterranean. 

By the same token, it hasn't been diverted well to the north of the UK as you might have expected in the 1990s and early 2000s - this is curious. 

Of course, winter is not over yet technically.

David

Northallerton

David
Offline Gooner  
#934 Posted : 27 January 2014 21:29:29(UTC)
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looking further ahead to October High Pressure builds to out East

http://modeles.meteociel.fr/modeles/cfs/runs/2014012518/run4/cfsnh-0-6654.png?18

 

Remember anything after T120 is really Just For Fun

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Banbury

North Oxfordshire

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Offline bruced  
#935 Posted : 27 January 2014 22:39:01(UTC)
bruced

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Posts: 141

Originally Posted by: Gooner Go to Quoted Post

looking further ahead to October High Pressure builds to out East

http://modeles.meteociel.fr/modeles/cfs/runs/2014012518/run4/cfsnh-0-6654.png?18

 

Setting us up for a colder winter than this winter!! 

David

Northallerton

David
Offline Stormchaser  
#936 Posted : 28 January 2014 11:35:32(UTC)
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On the face of it, we're living through another memorable winter...

...and a remarkable one too in terms of the strat and tropospheric vortex behaviour.

 

Shame it has meant so much rubbish for us. For the eastern U.S. the consequences have been very different!

If you have any problems or queries relating to TWO you can Email twomoderationteam@gmail.com :)

Homeland: Rural Mid-West Hants nearly 10 miles S of Salisbury (near Fordingbridge). More insights: https://twitter.com/peacockreports

2018's Homeland Extremes:

T-Max: 30.9*C 8th July | T-Min: -7.7*C 28th Feb | Wettest Day: 19.2mm 14th October | Ice Days: 4 (28 Feb - 2 Mar & 18 Mar)

Keep Calm and Forecast On

Offline Stormchaser  
#937 Posted : 28 January 2014 13:21:03(UTC)
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Location: West Hants

In light of the rather stormy longer-term outlook at the moment, with the potential for storm systems peaking as they reach the UK, this free article from 2004 is well worth a read for anybody looking to gain an insight into the workings of particularly intense cyclones and sting jets:

http://onlinelibrary.wiley.com/doi/10.1256/qj.02.143/pdf

 

This is the work of the University of Reading legend that is Keith Browning 

If you have any problems or queries relating to TWO you can Email twomoderationteam@gmail.com :)

Homeland: Rural Mid-West Hants nearly 10 miles S of Salisbury (near Fordingbridge). More insights: https://twitter.com/peacockreports

2018's Homeland Extremes:

T-Max: 30.9*C 8th July | T-Min: -7.7*C 28th Feb | Wettest Day: 19.2mm 14th October | Ice Days: 4 (28 Feb - 2 Mar & 18 Mar)

Keep Calm and Forecast On

Offline glenogle  
#938 Posted : 28 January 2014 13:30:16(UTC)
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Originally Posted by: KevBrads1 Go to Quoted Post
Winter 1914-15 is the wettest winter on record for England and Wales December 1914: 190.8mm (7.51") (2nd wettest December on record) January 1915: 108.7mm (4.28") February 1915: 123.5mm (4.86") (13th wettest February on record) Rainfall % of average England and Wales Dec 1914: 201% Jan 1915: 148% Feb 1915: 196% Scotland Dec 1914: 152% Jan 1915: 109% Feb 1915: 166% Ireland Dec 1914: 187% Jan 1915: 115% Feb 1915: 176% British Isles Dec 1914: 183% Jan 1915: 127% Feb 1915: 181%  

 

Interesting to note that 1914-1915 was one of the ones on the low hurricane season i updated back on pg44.

Is this our analogue year?

If so,  anyone looking for a sting in the tail of winter can probably forget if going by CETs of Jan 4.1  Feb 4.3  Mar 5.2   April 7.9  (although as per this week, it doesnt rule out any seasonal weather, just not an abundance of it)

That year was also a colder one overall in terms of the CET so might not bode too well for summer? (although it could have been a dry year for all i know)

On a brighter note 1916/17 appears to be a colder Dec,Jan,Feb so some hope for 2015/2016 

UserPostedImage

Offline roger63  
#939 Posted : 29 January 2014 10:45:57(UTC)
roger63

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Location: Winchester,Hampshire

Some additional stats on QBO.

Looking at the 60 winters from 1953/54 to 2012/13 and tkaing the mean QBO values October- Feb and  November -Feb the correlation coefficents are 0.04 and 0.06 respectively ie no correlation at all.

Just concenrating on the Novemeber -February period dta has been split into above mean value and below mean QbO value for both -ve and +ve years ie identifying weak and strong QBO's.

The relevant CET in terms s of variation from 60 year   mean is then used to  cassfiy cold(below  mean ) yeers and warm(above mean.

 

The results are as follows

Strong QBO - ve  16 years,6 cold,10 warm

Strong QBO +ve  14 years, 5 cold 9 warm

Weak QBO  -ve    17 years, 11 cold, 6 warm

Weak QBO +ve   13 years  7 cold 6 warm.

This produces the conclusions that

1.The strongest signal linking QBO and CET is the weak QBO -ve (65% cold)

2.Overall weak QBO's tend  more cold than warm(60%)

3.Strong QBO,s tend to be warmer than weakers ones (65%)warm.

Frankly I doubt these differences  are statistically significant.

It seesms clear to me that other influences than QBO are the main drivers of our winter circulation.

 

Offline Stormchaser  
#940 Posted : 30 January 2014 00:15:32(UTC)
Stormchaser

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Location: West Hants

Originally Posted by: glenogle Go to Quoted Post

Interesting to note that 1914-1915 was one of the ones on the low hurricane season i updated back on pg44.

Is this our analogue year?

If so,  anyone looking for a sting in the tail of winter can probably forget if going by CETs of Jan 4.1  Feb 4.3  Mar 5.2   April 7.9  (although as per this week, it doesnt rule out any seasonal weather, just not an abundance of it)

That year was also a colder one overall in terms of the CET so might not bode too well for summer? (although it could have been a dry year for all i know)

On a brighter note 1916/17 appears to be a colder Dec,Jan,Feb so some hope for 2015/2016 

 

I remember reading on wunderground during the Hurricane Season that the lack of tropical activity would lead to heightened barclonic activity during the winter season, and believe it or not... we got that. Big time.

So yeah... hopefully it was a nice dry summer that year.

If you have any problems or queries relating to TWO you can Email twomoderationteam@gmail.com :)

Homeland: Rural Mid-West Hants nearly 10 miles S of Salisbury (near Fordingbridge). More insights: https://twitter.com/peacockreports

2018's Homeland Extremes:

T-Max: 30.9*C 8th July | T-Min: -7.7*C 28th Feb | Wettest Day: 19.2mm 14th October | Ice Days: 4 (28 Feb - 2 Mar & 18 Mar)

Keep Calm and Forecast On

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