Autumn and Winter

[lesta_snow]

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QUOTE(Ross B @ 29 Sep 2006, 12:11 AM) <{POST_SNAPBACK}>

Lesta, can you talk in english and not text language please

The oldies cant understand it

sozzard (sorry)

[wellington boot]

Great to have kept an eye on the threads through the summer and good to be back as Autumn sets in too !

Ah yes we're all coming back now. I've been doing the same through the summer, but i rarely contribute because summer is less interesting. If it's 25 degrees rather than 29 degrees it makes little difference, but -2 makes a big difference to +2. I can already feel the winter tension building....

As for forecasts for the coming winter, I would suggest that any forecast for scandinavian blocking is positive. From my position here in the south east, and moving slightly north west to oxford for large chunks of the coming winter, N'rlys, which we saw plenty of last winter, and even NNE'rlys, give us nothing down here. Easterlies are what we need, and what all the Uk needs if we want to see a real prolonged cold spell. Consistent scandi blocking not only encourages cold pooling to our east, but only needs to push west and south somewhat for us to have a poweful easterly. A consistent scandi high cuts out the problem of always having only one of cold pooling/easterly winds, because it brings both.

As for the slightly positive NAO/El Nino forecast, if we combine that with the Scandi high, it could be good news, because the suggestions that we might have more atlantic weather this year mean we might actually get some ppn alongside the easterly wind, if atlantic lows feed in to lows over northern europe. Like in 1987:

In response to Kold Weather's post,

Intresting chart there Steve, I can't help but keep noticing the trend for LP's to dive SE in the models from 120hrs onwards. Certainly a difference from recent years which had on average a jet stream that was to our north and heading ENE, instead there seems to be a certain split point where Lp's are splitting with the southern cell diving Se. Far too early to tell if this will continue into the winter but it might not be a bad pattern to start getting into, even if at first the temps don't really respond.

Certainly looking at the possible first frost of the year if the feed from behind that Lp at 144hrs is strong enough, though I don't think it'll have enough bite to get a frost past northern England mind you.

which was in response to this image

I would disagree that this is a pattern we want to see. South easterly diving lows are no good, as they will bring us the worst of atlantic wet and mild(ish) weather. Lows heading north to Greenland and then dropping south towards us have been a problem throuhg the last mild ten years. We need blocking up north so that lows track on the south side of the UK.

Good to be back all B)

Edited September 29, 2006 by wellington boot

[kold weather]

Splitting lows can usually a good thing, providing they oc cur in the right area otherwise your right they can lead to mild wet weather, the key is the split being far enough west, if it is then the northern LP will die and will be replaced by a blocking HP cell to our north anyway. We had a great example of this last year:

http://www.wetterzentrale.de/archive/2006/...00120060213.png

Strong Lp to our west, no sgins of any cold on that chart.

Two days later, strong westerly and some of the warmest temps of the winter, but note the elongation of the LP:

http://www.wetterzentrale.de/archive/2006/...00120060215.png

Here we are a few days later again, this time we've got several small secondary depressions circulating around the southern section of the circulation and the LP is starting to undego the splitting processalso note the northern blocking starting to form aa the deep depression starts to weak:

http://www.wetterzentrale.de/archive/2006/...00120060218.png

Lp has split by the 19th and note now the southern Lp is the strongest of the two LP's, it has split and we start to drag in colder air from the east:

http://www.wetterzentrale.de/archive/2006/...00120060219.png

We all know that afterwards we were locked into a colder set-up for a good 20 days as the jet moved southerly and the Greenland high was allowed to really form simply because there were no Lp's to disrupt it, this eventually lead to this:

http://www.wetterzentrale.de/archive/2006/...00220060228.png

It's not always true but i find diving Lp's that are splitting are often a good way to get into this cold set-up, though they certainly are not surefire and can sometimes just lead to toppler ENE shots.

Also on your 1987 chart, that also had a splitting low feature though it wasn't as impressive as the example above (Note the weak cetner south of Iceland marked T.)

http://www.wetterzentrale.de/archive/ra/19...00119870109.gif

http://www.wetterzentrale.de/archive/ra/19...00119870110.gif

http://www.wetterzentrale.de/archive/ra/19...00119870111.gif

It opened the door for that powerful easterly shot.

Edited September 29, 2006 by kold weather

[Big Bear]

In the 367 years of the hadley series, BB, there has never been anything like the last 15 years. The closest was a run of 15 years in the late 1930s to 1940s, where 5 years were above 10C and 5 years above 9C, but the average temp is, really, nothing like as high as the last 15.

Does that help your judgement?

Paul

Thanks Paul

Yes that helps, but can you also answer this...

When was the last significant run of mild winters?

BB

[Dawlish]

Thanks Paul

Yes that helps, but can you also answer this...

When was the last significant run of mild winters?

BB

Well, they are certainly interesting questions, BB. The answer is again, there has never been a series of mild winters that approaches the winters of the last 14 years, as far as I can see and certainly not the last 19 years since 1986, the last winter in which we had a negative CET month (February, god it was cold. We came back from living in the tropics at the end of January and I was teaching in a classroom where the heating didn't come on until school started and the morning temp in my tutor room was 4C! All the teenage hard cases were sat there, shivering, in coats at registration - me too!)

I haven't got the full winter averages, maybe Kevin can help here, but I took the baseline as winters which did not have a monthly CET below 2.0C, because that would have left a sense of cold afterwards (maybe not the best measure, but the easiest to scan!) . The last 14 winters haven't. Feb 1991 was the last time with a CET of 1.5C.

The closest matches are 1902-1914 and 1744-1756, though I don't think either come close to the 1992-2005 average and neither sequence lasted as long.

If you wish to do the actual calculations, I've included the Hadley series table below. It is really interesting to scan through it, but I just can't be *rsed to add all the 346 winters up and divide by 3!!

Regards, Paul

Edited September 29, 2006 by Dawlish

[snowmadchrisuk]

I can see it being a cold october this year, There is a chill in the air across the midlands at nights at the moment, unyet this time last year we were still wiping the sweat off our heads. It's also a good sign that the met office has done a complete turn around to there initial winter forecast. I think the easterlys will come in febuary.In the mean time we will have a few northerly blasts and transisitonal snow fall as weather fronts try to come in from the west and take over from the northerlys. Could be our year cause although we missed out last year the rest of europe didnt and last year could have been the start of a trend of majour cold pooling to our east.

chris

Edited September 29, 2006 by snowmadchrisuk

[Weather-history]

The longest interval between sub 3C winters is 22 years between 1894-95 and 1916-17.

We are now currently in the longest interval between sub 2C winters, 27 years and counting.

The longest interval between sub 2C months, 15 years and 7 months and still counting.

Despite the recent run of mild winters, we have yet to have equalled the record of 4 consecutive winters with a CET of 5 and greater (1911-14). 6 Novembers of the 1910s were colder than the following December.

Edited September 29, 2006 by Mr_Data

[Dawlish]

The longest interval between sub 3C winters is 22 years between 1894-95 and 1916-17.

We are now currently in the longest interval between sub 2C winters, 27 years and counting.

The longest interval between sub 2C months, 15 years and 7 months and still counting.

Despite the recent run of mild winters, we have yet to have equalled the record of 4 consecutive winters with a CET of 5 and greater (1911-14). 6 Novembers of the 1910s were colder than the following December.

Thanks Kevin! A data dog you are!

Paul

[Thundery wintry showers]

I cannot agree that we had a lot of northerlies last winter. There was a 36-hour event in mid December, and another one in early February, and that was it.

As for easterlies being what we need, as far as I remember we had plenty of them last winter- one around 27-29 December, one around 5-9 January, a brief easterly around 24-26 January, and a long easterly spell in late February. Only the easterly of 27-29 December produced anything widespread, and away from favoured areas (Sussex, NE England, E Scotland) accumulations were not generally significant.

The problem was generally that the Scandinavian blocking high was too far east, pulling in easterlies with a relatively southerly source, or keeping the continental air too far east, courtesy of the northerly tracking jet with low pressure over Iceland and Greenland. On the other hand I remember a good frontal battleground around 12 March 2006, delivered by a strong blocking high over Scandinavia, with severe snowfalls in places, but crucially, the Scandinavian High was far west enough to bring the continental air to Britain.

You can argue that by "easterlies" it means scenarios where the Scandinavian High extends westwards and directs the coldest air west to Britain, but it illustrates the fact that, as with northerlies, we need the "right" synoptic setup in order for a cold snap with an easterly source to bring widespread snow. Northerlies generally don't deliver much away from favoured areas without extensive blocking to the NW and a southerly tracking jet; the same is true for easterlies without extensive blocking to the N/NE and a southerly tracking jet.

[Weather-history]

Mentioning about January 1981 in another thread, it is often overlooked. It wasn't a bad month for snow lovers at least for northern parts especially for the first two-thirds. Mild interludes interspersed with cold ones with snow and snow at the transitions. 20cm at Glasgow airport on the 16th

http://www.wetterzentrale.de/archive/ra/19...00119810115.gif

http://www.wetterzentrale.de/archive/ra/19...00119810117.gif

Days with falling sleet/snow

Heathrow: 8

Elmdon: 8

Ringway: 13

Glasgow: 14

Aberdeen: 16

Belfast: 10

Edited September 29, 2006 by Mr_Data

[Big Bear]

Thanks Kevin and Paul for coming back with all that data.

So it appears almost a centry ago the UK was in a mild run (12 years) of winters. I bet they were not ramping on and scare-mongering about global warming then

If it was so mild for so many winter seasons 100 years ago then whos to say the repeat we're suffering of 13 years now won't end this winter, or next winter.. or soon after that.

The fact is by the law of averages (and the law is the law) that we will see a below average winter or at least 1 winter month soon, snowless or not.

As for all this talk about 'the wrong' easterlies, in my books if its 6 degrees with a gentle SE breeze and light-grey murky skies, it ain't an easterly!!

[Guest Mike W]

With regards to what Big bear said about the run of mild winters that they had in the early part of the 20th Century and that they didn't talk of GLobal warming, is that they didn't finish yar in year out with a annual 10.** CET and thery didn't finish year in year out with only getting 1 or 2 average to below monthly CET's, basically their years balanced out, thanks perhaps largerly due to the sulphate pollution they had back then acting as a counterweight to the CO2 and other warming emmisions, which don't do anymore.

[Dawlish]

This is in hopefully a more appropriate place now..

Your reply unfortunately but perhaps not surprisingly does not represent the sentiments and logic of my own post at all. I have not, and as clearly stated by me in that post, tried to refute GW at all but have instead given a feasible account of what may happen in forthcoming British winters - irrespective of GW, irrespective of what you may wrongly think I think, and in my own opinion, not wistfully through frozen spectacles.

Beyond saying this there is nothing else gained to be said, other than down a predictable slippery slope in the light of the ever prevailing attitude.

Tamara

This is a very good account of last winter

It also demonstrates well the corner stone that needs to be placed (and that can be placed with timing) for the sort of deeper cold that was in evidence to our east last winter. Higher Greenland pressure in the earlier part of the winter when the cold block was so intense would have pulled the Scandinavian block that bit further west and advected the coldest air over us and probably provided a sub 2C CET month.

Tamara

Ah! Hope on, Snowp! With your optimism, you take soooo many Internet tipples off me! I had the distinct feeling my reply might be "unfortunate" for you. Have you ever wondered why the "ever prevailing attitude" is so?. Perhaps because the overwhelming torrent of evidence backs it up, whereas your own view is mainly based on one single winter (the coldest in the last 9) and an awful lot of hope?

Paul

[Big Bear]

With regards to what Big bear said about the run of mild winters that they had in the early part of the 20th Century and that they didn't talk of GLobal warming, is that they didn't finish yar in year out with a annual 10.** CET and thery didn't finish year in year out with only getting 1 or 2 average to below monthly CET's, basically their years balanced out, thanks perhaps largerly due to the sulphate pollution they had back then acting as a counterweight to the CO2 and other warming emmisions, which don't do anymore.

My point was basically that people will always blame GW for above average winters, until the next proper cold spell. Even then, the cold spell will probably be 'all because of GW as well'.. .along with above average rainfall, below average rainfall and above average temperatures. Goes back to what I was saying about scaremongering - no matter what the type of weather we're having.

[Dawlish]

My point was basically that people will always blame GW for above average winters, until the next proper cold spell. Even then, the cold spell will probably be 'all because of GW as well'.. .along with above average rainfall, below average rainfall and above average temperatures. Goes back to what I was saying about scaremongering - no matter what the type of weather we're having.

Not really, BB. I think you miss the point. The main fact I got from my research for you, using the Hadley series, is that there has been nothing, really, in the past, to compare to the last 14 years of warmer winters, in either length, nor average temperature and no sequence even remotely as warm, or as long as the warmth of the last 15 summers. A long dataset is bound to throw up some runs of colder and warmer than average summers, purely by chance. It would if you tossed a penny 347 times, you'd get runs of either heads, or tails, but I doubt whether any of the previous runs would prove statistically significant ie there was a cause more important than chance, but the warming we are in is statistically significant. That's the overwhelming difference.

We are warming more than at any time in the last 347 years and it is not a sequence that is down to chance, so therefore it is much more likely to continue, than to end.

Paul

Edited September 29, 2006 by Dawlish

[Big Bear]

Well Paul, if you flipped that coin a thousand times, you would have to expect a run like we're currently in at some point wouldn't you. Just because its the here and now doesn't necessarily mean its a never ending upward trend.

Edited September 29, 2006 by Big Bear

[VillagePlank]

My point was basically that people will always blame GW for above average winters, until the next proper cold spell. Even then, the cold spell will probably be 'all because of GW as well'.. .along with above average rainfall, below average rainfall and above average temperatures. Goes back to what I was saying about scaremongering - no matter what the type of weather we're having.

I think that this is valid point. What weather are we expecting with a predicted temperature increase that is less than a normal diurnal range in the UK?

[The Eagle]

The weather works in phases. Were just in a slightly mild phase IMO which hopefully we are coming out of.

Edited September 29, 2006 by Icicles

[wellington boot]

I cannot agree that we had a lot of northerlies last winter. There was a 36-hour event in mid December, and another one in early February, and that was it.

As for easterlies being what we need, as far as I remember we had plenty of them last winter- one around 27-29 December, one around 5-9 January, a brief easterly around 24-26 January, and a long easterly spell in late February. Only the easterly of 27-29 December produced anything widespread, and away from favoured areas (Sussex, NE England, E Scotland) accumulations were not generally significant.

The problem was generally that the Scandinavian blocking high was too far east, pulling in easterlies with a relatively southerly source, or keeping the continental air too far east, courtesy of the northerly tracking jet with low pressure over Iceland and Greenland. On the other hand I remember a good frontal battleground around 12 March 2006, delivered by a strong blocking high over Scandinavia, with severe snowfalls in places, but crucially, the Scandinavian High was far west enough to bring the continental air to Britain.

You can argue that by "easterlies" it means scenarios where the Scandinavian High extends westwards and directs the coldest air west to Britain, but it illustrates the fact that, as with northerlies, we need the "right" synoptic setup in order for a cold snap with an easterly source to bring widespread snow. Northerlies generally don't deliver much away from favoured areas without extensive blocking to the NW and a southerly tracking jet; the same is true for easterlies without extensive blocking to the N/NE and a southerly tracking jet.

Well perhaps there weren't many real potent northerlies last winter, but on this forum we were certainly talking about the prospects of northerlies most of the time, and while they may not have come off to full effect every time, there was an almost ever present greeland high, and lows frequently dipped down and affected northern areas somewhat, even if not further south. Furthermore, you neglect to mention the major snowfalls up north of last march, when aberdeen and co got pounded with feet off snow. That was from a very potent and set in northerly set up.

As for what you say about easterlies, I would repeat what Big bear wrote:

As for all this talk about 'the wrong' easterlies, in my books if its 6 degrees with a gentle SE breeze and light-grey murky skies, it ain't an easterly!!

Any incidents last winter when we experienced winds from the east, I would not call 'Easterlies'. There was no long draw from a cold pool to our east. There was no significant low pressure action near us to bring any snow, and most of the time, as you say, the scandi high was away to the east so we didnt really get a full blast. A few half hearted attempts.

As you say at the end, both an easterly and a notherly depend on the right synoptic set up, and i do realise this. The reason i was being positive about the prospect of a more prominent scandi high, is that we never had a consistent, strong scandi high last winter. If we were to get that this winter, the chances of it extending west at least on one occasion and certain other factors cooperating would be reasonable.

[Snowly does it]

Well perhaps there weren't many real potent northerlies last winter, but on this forum we were certainly talking about the prospects of northerlies most of the time, and while they may not have come off to full effect every time, there was an almost ever present greeland high, and lows frequently dipped down and affected northern areas somewhat, even if not further south. Furthermore, you neglect to mention the major snowfalls up north of last march, when aberdeen and co got pounded with feet off snow. That was from a very potent and set in northerly set up.

The Greenland high wasn't evident at all until February was it?

[wellington boot]

I shouldn't have to spend time continually amending your incorrect assumptions and misrepresentations of what I post.

Suffice to say, it might not have occured to you Dawlish, but I am trying to post (like everyone else) to a forum beyond just yourself and, frankly, don't want the same GW rhetoric being stuffed down my throat everytime I try and participate on here. Not because I can't face it, or wish to refute its obvious existence, nor because I have to go upstairs to get a pillow to cover my head away from the 'truth' but because you say the same thing at every possible opportunity and I feel I cannot post without you popping up everywhere with the same thing.

I do not profess to have great in depth knowledge and certainly don't expect everyone to agree with me, but, strangely enough to you, I can wake up every morning aware of your alleged grave consequences for the British winter - and as much as I love snow and it will be indeed very disappointing to me if your predictions come true I won't need counselling if it doesn't, because it won't pay my bills or keep a roof over my head.

Hope the irony in all of that is not lost.

Furthermore, I do not expect you to accept my opinion, (nor care a jot whether you do actually), but would ask as nicely as possible that you desist from discrediting my posts, and others, with very tiresome pie in the sky hopecasting jibes. That is where the 'prevailing atittiude' lies.

Thank you

Tamara

A very nice post snowprincess. Beautifully written! And I would agree with you that Global Warming theory advocates (not very elegantly put...) tend to shout about it indiscriminately, often without knowing anything about it (not to suggest that you know nothing about it Dawlish). Global warming is certainly happening, but it is an extremely gradual process and neither has nor will cause such a sudden increase in temperature that snowy winters here will never be seen again. Remember also that the UK is not the entire planet. Many places exist around the globe which will have experiences opposite to ours, where their recent winters have been colder and snowier than usual.

With the right synoptics, the UK will get cold, snowy weather during winter.

[Dawlish]

The reason i was being positive about the prospect of a more prominent scandi high, is that we never had a consistent, strong scandi high last winter. If we were to get that this winter, the chances of it extending west at least on one occasion and certain other factors cooperating would be reasonable.

Absolutely right, wellington, the logic and meteororology are fine; the key word, is...."If".

Paul

Edited September 29, 2006 by Dawlish

[wellington boot]

The Greenland high wasn't evident at all until February was it?

Ah I'm getting careless. I think you're probably right. Though it certainly had a good run when it arrived. I only started posting in feb i think though, after watching previously, which i had forgotten, and from when i began posting regularly I seem to remember a greenland high in place most of the time! Thank you for the correction.

Absolutely right, wellington, the logic and meteororology are fine; the key word, is...."If".

Paul

As always my friend I only brought it up because predictions for this winter seem to suggest that we might see some consistent scandinavian blocking. So I feel cautiously optimistic about the chances.

[Snowly does it]

Ah I'm getting careless. I think you're probably right. Though it certainly had a good run when it arrived. I only started posting in feb i think though, after watching previously, which i had forgotten, and from when i began posting regularly I seem to remember a greenland high in place most of the time! Thank you for the correction.

Oh I am just going from memory, I can remember sitting up to wtach the first proper retrogression on the models come into reliable timeframe sometime in Feb. (woooo life is fun!)

We got stuck in January under the anticyclone., December was unremarkable until the Boxing Day fun and games till New Year. Actually the inrider and outrider November and march hit the jackpots northerly wise.

If the GH is more prominent in December/Jan this year we may well find a white mist a comin from the North at a better time for sticking around!

[wellington boot]

Oh I am just going from memory, I can remember sitting up to wtach the first proper retrogression on the models come into reliable timeframe sometime in Feb. (woooo life is fun!)

We got stuck in January under the anticyclone., December was unremarkable until the Boxing Day fun and games till New Year. Actually the inrider and outrider November and march hit the jackpots northerly wise.

If the GH is more prominent in December/Jan this year we may well find a white mist a comin from the North at a better time for sticking around!

I'd rather it didn't. I feel rather disillusioned with Northerlies these days! Down here in Sussex/Oxford, Northerlies aren't much use. Too many mountains in the way. And those annoying lows which don't want to come closer than denmark...grrr.

Let's hope the GH slips on all the ice and ends up over scandi, bringing both of us metres of snow and ice and burst pipes...