257 replies to this topic

[SP1986]

The problem with building blocks is that they are not a guarantee of winter, those building blocks may actually be evident, but all it takes is a train of Atlantic lows to wipe away these building blocks, especially if they exist in the east, and are not sustained by a Greenland block. So as everyone knows, even if there are building blocks emerging, they shouldn't taken as sign for the start of anything grand, or long lasting.

There were numerous times in 2006/2007 when people saw these building blocks, and they did not, for whatever reason, come to fruition.

I do agree building blocks can emerge, but it's fairly obvious they don't always sustain - think for example of this summer just gone.

[bobbydog]

i think the only 'building blocks' are the things that create winter in the first place - the earths tilt on its axis, which causes less daylight, therefore it gets colder.
the 'building blocks' people are talking about are only really in the short term, for a particular scenario. they can only really be seen as they happen, i.e. high pressure over greenland, southerly tracking jet etc. no-one knows for sure if these things will happen in advance but when they do and can be seen to be happening, then maybe they can be called 'building blocks' but only for any given weather scenario and in a relatively short timeframe. even then, we have all seen the ideal scenario evolving perfectly, only for it to come to nothing.
i for one dont think we can write winter off before it has officially even started. even the experts will not say how things will pan out- because they dont know! they give us an idea of what might happen, not what will happen

[CreweCold]

SP1986, on 20 October 2011 - 12:30 , said:

The problem with building blocks is that they are not a guarantee of winter, those building blocks may actually be evident, but all it takes is a train of Atlantic lows to wipe away these building blocks, especially if they exist in the east, and are not sustained by a Greenland block. So as everyone knows, even if there are building blocks emerging, they shouldn't taken as sign for the start of anything grand, or long lasting.

There were numerous times in 2006/2007 when people saw these building blocks, and they did not, for whatever reason, come to fruition.

I do agree building blocks can emerge, but it's fairly obvious they don't always sustain - think for example of this summer just gone.

True, but I associate a hot, dry April-May period with a cooler/wetter summer so to me that would be a building block in the opposite direction.

[bobbydog]

CreweCold, on 20 October 2011 - 12:58 , said:

True, but I associate a hot, dry April-May period with a cooler/wetter summer so to me that would be a building block in the opposite direction.

can you provide any long term statistics to back that up?

[BLAST FROM THE PAST]

I agree that a synoptic chart or two are not building blocks.

[SP1986]

CreweCold, on 20 October 2011 - 12:58 , said:

True, but I associate a hot, dry April-May period with a cooler/wetter summer so to me that would be a building block in the opposite direction.

The fundamental question is, when does a building block become a building block, and when does the building block cease to be a building block and become the actual event. Also how does a potential building block interact with various possibilities? Of course if we knew that...

[johnholmes]

I'm afraid the term 'building block' is yet another example of using a rather clever sounding name which has little to support its use in reality. Sorry to be a killjoy but its a feature of folk on the web I suspect trying to sound rather clever!
Obviously one can use such a phrase but it is overused and seems to lead, reading through this thread, to a touch of impatience with one another in just a few cases?
The term teleconnections is another that has got into use since the web gave us all so much weather information-not a bad term and handy to use rather than the term building blocks as we can actually relate some rough time scales to most of them, AO and NAO, 500mb anomaly charts, MJO, 30mb temperature profile, ENSO; all can be given some kind of time scale in which their effect is most felt.

[Snowmad79]

So the models repeatadly showing height rises to our NW, N and NE along with a southerly tracking jet and WWA up north aided or infact initiated by low pressure which can make a high more robust in terms of becoming more sustainable and evenutally having the effect of a NH block, cannot in the slightest be called a building block for a future weather pattern ?

I suppose it depends on what you personally define as a build blocks really. As I understand things, the NAO and AO are drivers of weather but you dont get a Negative NAO with LP dominating the Iceland/ Greenland area do you ? and High pressure over that area does infact need Warm Air (via advection ?) to become more rebust thus forcing the NAO negative ?

Or have I missunderstood ?

My post this morning is amatuer but thats all I am and they definately werent isolated charts. The models have shown height rises to our NW, N and NE, which I believe is important for a potent cold spell to develop (not just for a -Nao).. down the line.

I think in reality we are using this thread becuase if you post about charts in FI and try to discuss what pattern could emerge from them (even if it doesn't turn out that way in the end) and they are related to colder weather, you get shot down by the mild weather fans.

[Robbie Garrett]

Comparing the Actual chart 6th Nov last year to this years 6th GFS forecast. Clearly showing high pressure that we need for a Northernly block is forming to our south west, so why's everyone going for Above Average/Average? Nice cold airmass to our east too But at the end of the day, maybe it's a good thing that we are having all these LPs running through a bit now instead of at a later date.


But I have to agree, last year's November end spell would be remarkable to be repeated this year. If anything's going to be coldest, it's probably going to be December. I'd give it two weeks to calm down a bit, and see where we are at.

Edited by Robbie Garrett, 21 October 2011 - 18:37 .

[ITSY]

The danger is what happes in late FI in the 12Z GFS. A huge Blast from the East heads our way only for building blocks to allow troughs and atlantic dominated weather to 'bail us out' and leave E.Europe in the freezer (-4c by day) and us in a comparitvely balmy 14C. In other words, don't use the emergence of blocks at this stage as the holy grail to clues of a cold winter - it could simply lead us the other way. One thing is for sure though, model watching of the next 2-3weeks will start to become more and more interesting as the possibility that one of these highs could deliver cold increases with the onset of winter.

[chionomaniac]

The problem with the current output Robbie, is that we should be careful not to look for things that just aren't there.

Ha! Beaten to it!

Edited by chionomaniac, 21 October 2011 - 18:44 .

[nick sussex]

In terms of the much debated building blocks I think they're a load of twaddle!

The atmosphere is not static and hence the best looking output can go downhill very quickly, to suppose an end result to the building block this would suggest that a+b+c= cold spell or conversely mild spell.

However for example negative AO, amplified jet and blocking over Greenland could be seen as a building block to a cold spell, however unfortunately the neg NAO was too west based and the UK ended up on the warm side of the trough, so basically these building blocks ended up delivering zero for cold lovers.

The background neg AO may help later in the winter if it remained constantly however its not static so there are no guarantees, as with all positives for cold in the UK you need alot of things working together to deliver .

My often used clutching defeat from the jaws of victory phrase I think sums things up, one loose brick and the building comes crashing down!

So no matter how many alleged cold building blocks there are theres always that previously unforeseen variable that can pop up to derail any cold spell.

[bobbydog]

nick sussex, on 21 October 2011 - 19:30 , said:

In terms of the much debated building blocks I think they're a load of twaddle!

The atmosphere is not static and hence the best looking output can go downhill very quickly, to suppose an end result to the building block this would suggest that a+b+c= cold spell or conversely mild spell.

However for example negative AO, amplified jet and blocking over Greenland could be seen as a building block to a cold spell, however unfortunately the neg NAO was too west based and the UK ended up on the warm side of the trough, so basically these building blocks ended up delivering zero for cold lovers.

The background neg AO may help later in the winter if it remained constantly however its not static so there are no guarantees, as with all positives for cold in the UK you need alot of things working together to deliver .

My often used clutching defeat from the jaws of victory phrase I think sums things up, one loose brick and the building comes crashing down!

So no matter how many alleged cold building blocks there are theres always that previously unforeseen variable that can pop up to derail any cold spell.

totally agree nick. (see my post #42). i dont think we can look at the models and see any pattern forming for the winter, as things can change so rapidly anyway. looking from both sides of the fence, some people are seeing 'building blocks' whilst others are writing winter off before it has started. can anyone honestly say, at this stage before the last two winters, that there were any 'building blocks' in place to decide the outcome either way? i'll bet not!

[chionomaniac]

The thing is with building blocks is that there are so many. At this point in autumn we can only look at foundations but that is hardly likely to provide a house we can live in! We need the bricks, mortar, roof, windows, insulation, wiring, plumbing, etc.... and we won't know whether they can be provided until far later! We only need one of these factors not to be in place and our house remains inhabitable.

Patience needed here, and lets see how many bricks we have in place come the end of November!

[peterf]

has this thread turned into an episode of Grand Designs?
christ almighty lets keep things in plain English.

woops sorry i see it's a building block thread.as off to the more normal winter thread.

[Grimsby Snow Lover]

I don't know about everyone else but I for one believe the chances of winter starting like last year are very slim indeed. Don't get me wrong, there is nothing more I would like than a foot of snow on December the 1st. What we have to remember is that we also have January and Februaury to look forward to as well. After all these months were quite uneventful last year so if different building block develop this year then who knows what might occur. We were spoilt rotten last December and I personally think this has raised everyones expectations (mine included) As for building blocks, I will be concentrating my eye on any blocking to the north and the positioning of the jet. When it begins to migrate towards Spain I will begin to get excited.

[Snowmad79]

IIRC, GP was hinting at certain teleconnection indices this time last year, and into the beggining of Nov 2010 that were said to favour Northern Lattitude blocking downline which turned out to be the case and he did also mention as did others including myself that La Nina favours Dry Cold winters which most of us went for.

When did the models first start to latch onto those things last year ?, If you read the archived winter thread part 3 (model threads dont seem to be archived at all) last year you will see lots of hype based on model output starting in late October 2010 before models really started ramping up the wild start to winter in the early part of November 2010.

So to say we should be waiting until December for clues for the upcoming winter, thats just ludicrous.

[bobbydog]

ask anyone to remember a large scale snow event, i'll bet february '91 comes up. i distinctly remember that the december before it was mild and wet. a very memorable winter, yet (at least for my location) it only lasted about a week and a half!

[Snowmad79]

bobbydog, on 21 October 2011 - 20:29 , said:

ask anyone to remember a large scale snow event, i'll bet february '91 comes up. i distinctly remember that the december before it was mild and wet. a very memorable winter, yet (at least for my location) it only lasted about a week and a half!

I do remeber the early 90s where the best of weather came in latter half of winter. Mainly becuase our School was regularly shut due to 3ft -10ft drifts in oldham area. Similar story for 96/97 where I was snowed in at work all day. We started at 6 or 7 in the morning and snow fell all day that day and they kept us there for health and safety reason until the roads were cleared, but that never happend so I snook out and went home. Little did I expect to be seeing trucks burried fully under snow.

But yeah the starts of those winters must have been milder and or wet because I dont remember. Co-incidentally, the winters we both just mentioned were nuetral enso.

[bobbydog]

Snowmad79, on 21 October 2011 - 21:09 , said:

I do remeber the early 90s where the best of weather came in latter half of winter. Mainly becuase our School was regularly shut due to 3ft -10ft drifts in oldham area. Similar story for 96/97 where I was snowed in at work all day. We started at 6 or 7 in the morning and snow fell all day that day and they kept us there for health and safety reason until the roads were cleared, but that never happend so I snook out and went home. Little did I expect to be seeing trucks burried fully under snow.

But yeah the starts of those winters must have been milder and or wet because I dont remember. Co-incidentally, the winters we both just mentioned were nuetral enso.

actually, i dont remember any decent winters in the south east between '91 and the last couple of years. i moved down here in december '89 from the newcastle area (i am originally a geordie!) where we seemed to have proper winters most years. funnily enough, i only ever remember once having a day off school because of snow. maybe because back then we all walked to school, through all weathers, instead of being chauffered as kids are nowadays