The Curse Of The Modern Winter

[SMU]

EDIT in progress

[Glacier Point]

EDIT in progress

Steve, try the reanalysis for 30mb zonals as well Jan and Feb, pre and post..

[Paul Sherman]

Crikey Steve

You been Kidnapped and drugged by Ian Brown over the weekend and taken to Waco

[andy_leics22]

Well this Christmas we will have gold, frankincense and Steve Murr

All joking aside though... As an amateur model watcher my rough knowledge tells me that the curse of the even larger teapot is too many strong low pressure systems in the Eastern part of U.S.A and moving on towards the UK with a track of heading towards Iceland, therefor leaving us in a strong South Westerly wind?

[SMU]

Afternoon All-

I havent opened a topic in a long long time, but seeing as we have havent a great deal to talk about now, it is perhaps appropriate to open a thread which is close to the heart of everyone who posts both here & on TWO-

This will be a duplicate thread, The use of attachments is key though to illustrate the points & I dont think I can do that over on TWO-

We also all know Ian B, who used to post here & still resides on TWO- & whilst this post is certainly not on his behalf it does cover SOME of what he refers to in his forecasts & posts-

We all know that even larger teapot is a loathsome phrase- the mere mention of it gets most peoples backs up- however whatever we call it- is there some credit to it?

The background to all this is an 'assumption' that the Winter weather in the UK has somehow been effected in such a way either in a dramatic or subtle manner that Easterly/North Easterly winds Combined with very cold upper air do not, or more importantly cannot exist & be sustained any more-

So before we just jump to our usual conclusions ( which is what I always used to do) lets remember the last 2 occasions when these types of synoptics happened-

Feb 1991, & Dec 1996-

The critical 2 components to look at in these examples is where the Mean 500 mb height anomalies are & where the upper cold pool is-

Feb 1991-

Height anomaly to the Western tip of Scandi ( +VE) & the negative heights towards southern France-

http://www.wetterzentrale.de/archive/ra/19...00119910205.gif

http://www.wetterzentrale.de/archive/ra/19...00119910206.gif

Cold pool moving East to West-

http://www.wetterzentrale.de/archive/ra/19...00219910206.gif

http://www.wetterzentrale.de/archive/ra/19...00219910206.gif

Also Dec 1996- Very similar to above-

http://www.wetterzentrale.de/archive/ra/19...00119961230.gif

http://www.wetterzentrale.de/archive/ra/19...00119961231.gif

A wider cold pool but less depth-

http://www.wetterzentrale.de/archive/ra/19...00219961230.gif

http://www.wetterzentrale.de/archive/ra/19...00219961231.gif

both of these events - especially the 1991 example are with a deeper Cold pool generated snow & was sustained for more than 5 days-

Now how many times since those dates have we seen those conditions with a sustained upper cold pool- Maybe cold at the surface over 5 days, but not as a direct result from the persistence of cold upper air-

Its now, in times that have seen so many let downs, including model runs that for days point to Deep cold easterlies failing at the last minute I have begun to question & look at possible reasons why we have had nothing like these for getting on 17 years ( omitting the mediocre example in dec 96)

17 YEARS - that is 51 WINTER MONTHS & counting-

Something must have changed in the short term, all be it not neccasarily changing for the long term-

I got to thinking that maybe Ians date around the late 80's was a marker in the step change of our weather- even though this was PRE 1991, the change or transition could already be taking place-

To give you an idea of what the pressure patterns look like in terms of 'long term mean since 1948 ( first date available from reanalysis) here is the DJF long term mean at 500 MB for the Winter-

As you can see the Hemespheric pattern is driven by that tight ribbon of low heights to the North, & also the keen eyed will see that the 552 DAM line generally runs across the UK-

However we havent had any trouble before with getting an Easterly so whilst this is the long term mean there must be anomalous times that we can get that very cold Easterly flow which is against the westerly Grain-

infact, to illustrate this I use the data for Feb 1986- possibly the best month to use to demonstrate the total opposing flow to the Norm-

The key though is to show the difference in terms of anomalies from perhaps 1948-1988 & then 1988 to 2008, which would then highlight if any a change in patterns against the long term mean-

Well these 2 charts make compelling reading-

Firstly the height anomalies for 1949- 1987 -both charts below show the height anomalies against the 1948-2008 Long term mean-

Here against the pattern of long term mean the heights are lower to the South generally & Higher to the North 'generally'-

Now look at the last 20 years-

Oh dear The height anomaly in the worst possible place- directly to the South-

We need to establish what is driving this & where its coming from-?

Well if we look at the same timespan in terms of anomalies of zonal wind- we find the following-

We see that the pacific jet has been very strong for the last 20 years & the jet in General across the Northern atlantic has been +VE-

How does this effect Easterlies & cold pooling?-

Well to get these flows all the way from a starting point somewhere close to the russian steps the air to go to be driven westwards- that means the initial jet flow across the plain of from Eastern Greenland to Moscow has got to be vectored SW - this is against the norm of Eastwards-

If the predominent anomalous flow is vectored +VE south/South Eastwards then we are already fighting a losing battle-

Ive also noticed that if you follow the zones of +VE zonal winds there will always be areas of subsidence at the northeast points of the flow-

look closely at Northern Europe, the subsidence generates a point where cold air is filtering in from the pole-

this Area is pretty much the only area where that bitter air is penerating into Europe-

However now look at the wind vector anomalies for the same period-

You will see that the 200mb steering currents take ALL the cold air towards Greece & Turkey- Cheers-

I could go on with reanalyis starts, but basically they all say the same thing- the vector movements, zonal Wind & Height anomalies have all changed since the late 80's- 88 being the date I picked because of Ians comments & that wreched 88 Winter- Im sure the figures & charts would still be the same if we used 89, 90 etc-

For me I want to see whats happening here because im pretty sure that MOST of my love for Winter comes from the fabled Easterlies & without it we have lost MOST of our chances for the bulk of the UK to see sustained snowcover again-

If I look at every variable that I use in terms of factors into the Winter forecast I generally come up with these -

ENSO, Cryosphere, Stratosphere, PDO, OLR, QBO, Smaller Scale SST'A's-

Note I havent included the AO or NAO because these I believe these these teleconnection indices are phased +VE or -VE due to the overwhelming factors listed above-

These factors are large movements of Warm or cold water sea surface anomalies, Snow & Ice cover & temps in the Stratosphere & location of the stratospheric vortex-

Looking at all the variables they have ALL oscillated in magnitude & Phase/location since 1988 all except one-

the Stratosphere-

the gradual decline is observed temperature in the stratoshere has really only been documented recently, but we have observations dating back to the late 70's which covers our 'christmas pudding' since 88-

the attached picture is CLEAR in presenting that evidence-

It is my assumption that the strength of the Winter vortex across the pole has been effected by this decline in Stratospheric temps- this may only equate to a net of 3-5 M/S across the jet but that has had a proportionate effect on where the zones of high pressure are setting up-

It could also be that the stratospheric vortex has shifted away from the pole at Winter towards the pacific, although without proof this is an assumption-

One other thing that I do entertain is the index of the PDO effecting the strength of the pacific jet- Although not having time to post now thats one for later research-

It certainly seems that in Winter these days theres 2 variables kicking our aR*e in terms of wiping out the prospect of Easterlies, both culminating in pushing the cold further East & the advection process further South into Europe before it begins to traverse West-

Even one without the other seems enough to make a mockery of our delicate balanced climate-

Ah but what about December 08... Coldest since 1962 thus far I hear you shout-

doesnt count im afraid- I will edit this with the dec 08 Height anomaly for the opening 14 days, what it shows it ONE element of that perfect set of ingredients I mentioned at the start- & thats a mean -VE height anomaly to the East & South East of the UK-

What is missing & has had NO bearing on us so far this winter is any form of +VE height anomly towards the regions like eastern greenland/ Svalbard etc etc-

So whilst we have had an increased frequency of Northerlies for the last 30 days, the ol 'christmas pudding or whatever ghastly name you give it is still in full swing-

Will it change, well this is probaly the biggest talking point amoungst the regulars that ever talk about it- there is no evidence to suggest that in the short term at least the Pac jet & or the stratosphere are going to change so the default forecast for the UK Winter is above average from the increased Westerly vector in the jet, unless we see enough forcing to allow some lower heights to rein to the east/south of the UK- the critical component missing is the heights +VE to the NE

As for Easterlies associated with a very cold upper pool they may have gone for good, or maybe just in our life time-

I HOPE NOT

S

Edited December 15, 2008 by Steve Murr

[SP1986]

A VERY good well thought out post Steve, and I tend to agree, it's the synoptics they have not been there, and your post develops this idea succinctly. I think if I've read what you've said right, it's a change that has resulted in milder solutions for particular synoptics that may have resulted in a different scenario 20 years ago, but I think the point (if Ive read this right) that you suggest about it not necessarily being the form for the future, i.e it could change once again to colder scenarios is a sensible and just point.

I often ask myself would there be as many people posting on these forums if we had a 1963 or even 1981 style winter, I would certainly conclude the marked changes have probably resulted in more interest in cold weather, so in a funny way to keep the masses interested this pattern must essentially continue.

Once again compliments to the post, I think its a well researched, well thought out post, which is not over the top by any means, and describes the happenings of recent times.

[Altostratus]

Interesting research Steve. It certainly seems to fit with what I have noticed from model watching over the past six or so years – everything seems to get forced back to the East! This would certainly suggest an increase in the zonal wind. As a consequence establishing an E’ly flow across the country would be harder than it once was, when the opposing zonal flow was not so strong.

A nice analogy is trying to swim upstream against a strong current. In terms of the cold air reaching Greece, with it being more sheltered, the current is less strong, consequently cold air gets directed into the region with less resistance.

Personally I still believe that it is not impossible to get a deep cold E’ly blast, however, statistically, the chances of getting an E’ly flow may be lower than it once was, due to potentially greater resistance. Feb 2005 is good example that Siberian winds can still reach these shores. IMHO, it was bad luck that year that there wasn’t a significant cold pool that could be advected westwards. Easterly blasts with deep cold air have always been rare though and there is only a handful of examples where the 850hPa -15C isotherm reached the BI, as highlighted in an earlier thread.

The interesting question IMHO is what has caused the increase in zonal flow? A net increase in global temperatures would certainly support the theory.

[trickydicky]

Positives:

*We are 20 years into this cycle, thats a while so hopefully it will change back.

*Volcano's can erupt at any time.

Negative:

*The Little Ice Age lasted between 200-300 years

[WhiteXmas]

IMO there is no such thing. We see 20-30 year cycles of weather patterns. Therefore I personally feel that it isn't feasible to be talking about even larger teapot "curses". We will be pleasantly surprised; whether it is this year I cannot possibly say. However I do know that a Hale winter is not too distant.

Edited December 15, 2008 by WhiteXmas

[ribster]

Dear oh dear, bit like reading Jekyll and Hyde at times, one minute all to look forward to and the next the towel has been thrown in on day 15.

As much as I enjoy coming on here and particularly reading Steve and GPs posts, I think I am going to get a far better picture and much less of a roller coaster ride if I stick with the professional forecasts!

[TEITS]

A rather depressing and yet honest post from Steve which I have to say is difficult to argue against.

Have E,lys disappeared for good?

Well let me put it this way if I thought this was true I would probably stop posting on this forum during the winter months and would probably find a new hobby. Some will probably moan about my attitude but if I was honest every November I look forward to the winter months and all im interested in is seeking the notorious E,ly. Some will think this is OTT but if you live in E Anglia/SE and experienced the winters of the 80's you will know what im on about.

To give you an example of my desire for an E,ly with sub -15C upper temps I shall tell you what I would do if one was showing at +144. After viewing the 18Z I would try and get some sleep although I would struggle to fall asleep as my mind would be on the 0Zs. I would set the alarm for 3.45am, make a cup of coffee and switch my computer on. If the 0Zs continue with the E,ly I would return to bed for a few hrs before the 06Z GFS run come out. I would repeat this pattern right up until the actual arrival of the E,lys. Once those snow showers arrived I would probably be awake all night watching the radar and looking outside at the lamppost. During the day I would spend many hrs watching the forecasts from the BBC and I would especially enjoy reading the teletext forecasts saying "prolonged periods of snow with max temps of -5C".

Im not sure if Steve would be as extreme as me but we both know exactly what an E,ly can bring to our locations hence our disappointment when it goes pearshaped.

Forgot to add that by day 5 I would probably miss all the snow because I would be suffering from exhaustion.

[WhiteXmas]

Have E,lys disappeared for good?

No they certainly haven't and it's obvious that you are of the same belief TEITS. Just remember February 2005 for the closest example.

[trickydicky]

This curse, does the same problem prevent Greenland highs & Polar Lows? Because for us in the North they are as good as Easterlies are for people in the South East.

[andy_leics22]

Excellent post Steve, I hope the weather patterns change for the better again as far as us snow lovers are concerned, only time will tell.

[Solar Cycles]

Well that's that then, December 15th and winter has been and gone. Sorry but I for one think changes are afoot, of course we have had an appalling run of winters of late, but now for the first time in a number of years, we are beginning to see synoptics of yesteryear. Look at October, November, and the first 2 weeks of this month, now tell me when we saw synoptics like those in the last 20 years. I for one, am going for a severe spell of weather, late in the month into next month. even larger teapot your time is up!

[tundra]

Great informative post, cheers.

Steve i heard or read somewhere that the med are expecting and in fact experiencing a much wetter winter. If this varifies then it should at least help the cause.

I read Ed Berry's latest blog and he talks of stronger subtropical westerlies would this lift the midlatitude highs into latitudes we don't want or would this increase more northern type blocking.

He also mentions polar vortex over Baffin Island which if correct would be pretty good i'd have thought.

What say thee?. cheers.

[TEITS]

This curse, does the same problem prevent Greenland highs & Polar Lows? Because for us in the North they are as good as Easterlies are for people in the South East.

I would say so yes.

Apart from E,lys like Jan 87 I would equally welcome a decent N/NE,ly via Greenland HP. The reason being when you have blocking over either Greenland or Scandinavia or both there is always a chance that you will see a prolonged cold spell bringing alternating N/E,lys. The trouble is in recent years we have seen a general lack of blocking to our N with the exception of Feb 05.

Still when I joined this forum Stratos Ferric told me that synoptically speaking E,lys were a thing of the past but Feb 05 proved this isn't the case. Im not sure if you were around during this period but this resulted in many heated debates on here!

[Kentish Man]

Late Feb and Dec 2005 brought a few ice days to Kent from NE'ly airmasses. The classic synoptics were not in place for that long although we had decent snow cover locally on both occasions. As you say sustaining it seems to be the problem these days. Oddly despite this the last 4 winters have been slightly better for snowfall than the period 1997/98- 2003/4. However I do vaguely remember the 1972 - 77 period having not too many classic easterly spells either.

[cheeky_monkey]

However I do vaguely remember the 1972 - 77 period having not too many classic easterly spells either.

yes but thats is only a short period of 5 or 6 years..not 20 years as we are in now..never has there been such a sustained run of mild winters in recorded history

[TEITS]

Speaking of Feb 05 but if you look at the actual synoptics these are far better than some of the E,lys in the 80's.

Only reason why this didn't deliver is because of the time of year and the incredibly mild temps Europe had experienced. If this developed over the next 4 weeks it would be an entirely different story.

So Steve is right in saying 17 years since the UK experienced an E,ly with deep cold upper temps but synoptically its only 3 yrs. This is why I haven't given up hope just yet.

[WhiteXmas]

Very, very good post TEITS. That totally backs up what you and I were saying previously

[Mammatus]

Dear oh dear, bit like reading Jekyll and Hyde at times, one minute all to look forward to and the next the towel has been thrown in on day 15.

As much as I enjoy coming on here and particularly reading Steve and GPs posts, I think I am going to get a far better picture and much less of a roller coaster ride if I stick with the professional forecasts!

Excellent post Steve Murr. I can't compliment that post enough and agree entirely with SP's comments.

TA

[Pennine Ten Foot Drifts]

A truly excellent piece of analysis Steve. I don't think anyone would argue that something had changed in terms of UK winter weather over the past twenty years, and for the first time (at least that I have seen) here is a damned good piece of research which attempts to explain why.

Now it is of course true that anything which changes so apparently abruptly might change back equally abruptly, but that is only true if there were no major underlying reasons for that change other than that 'it's just cyclical'. If however the underlying reason for the change is tied up with increased global temperatures, then would it not be fair to suggest that we won't see a change back to the 'good old days' until global temperatures have subsided to similar levels ? (and I'm not talking about recent apparent temperature fluctuations, which will only have put us back to a point maybe four or five years ago, still well above what was seen twenty years ago).

In fact, perhaps it's a simple as that, we won't see Eighties style winters again until global temperatures are back at Eighties levels ???

Edited December 15, 2008 by Pennine Ten Foot Drifts

[len]

A brilliant post Steve.

The underlying reason for the persistently cooler Stratosphere may well be here:-

"The Stratosphere as a puppeteer of European Winter" a pdf download here......

http://www.europhysicsnews.org/index.php?o...03/epn04302.pdf

Apparently Ozone depletion, exaggerated over the poles, is the likely cause. This won't come right anytime soon.

-------------------------------

Your pictures just tell me what I know I've experienced since I was a boy in the 50's. (And I followed the weather since I was about 10)

There were always mild winters; but there were as many cold ones, when snow stayed for at least a week, even in South Wilts where I was. I remember as well nearly every Saturday hearing the football match cancellations 'oop North due to snow.

I can't find them right now but I've seen graphs that show a step change in 1987. To all intents and purposes the cold winters stopped.

The mild ones just kept on and became virtually uninterrupted mild, which I never remembered before.

And just recently I watched, with a feeling of awful inevitability when the first Atlantic-reassertion charts appeared. The atmosphere seems to be writhing its way back to its current winter default scenario. Hopes dashed.

Thanks Steve

[johnholmes]

a thought provoking post there Steve and this comment from above

The interesting question IMHO is what has caused the increase in zonal flow?

what indeed? Is it the overall temperature rise for the whole globe (average) or something else?

Edited December 15, 2008 by johnholmes