Model discussion - hunt for cold - Christmas countdown

[camturbo]

4 minutes ago, mountsbaysnow said:

Lets play "Blockbusters"

Or give us a clue

[rwtwm]

2 hours ago, Singularity said:

The trough isn’t locked into particular behaviour right down to the timing of secondary lows swinging etc, the atmosphere is too chaotic for that - but your comment has reminded me that the very negative PDO may be a plausible influence skewing probability toward the unfavourable outcomes.

MJO-wise it’s critical to appreciate that longer duration doesn’t mean more forcing indefinitely. The atmosphere attempts to balance itself sooner than later (AAM dropping, as it will this coming week, meaning we are only just ‘in the game‘ and probably not going to ‘win’), at which point we look to see if the MJO will force AAM back up again before it decays. Current signs are, there’s a good chance of that happening as we head into 2022.

If we’d had a more swiftly (but not rapidly!) moving MJO through 7-8, chances are, it would have aligned well with the AAM climb to produce a more emphatically -NAO spell. On the other hand.

A question if I may.

It's not clear to me how this comment aligns with the use of full month composites when investigating the potential impact of MJO on our weather.

If faster progression brings greater forcing, then shouldn't MJO 7 composites be different to MJO 6->7->8 composites for the same month?

[blizzard81]

37 minutes ago, Blessed Weather said:

 

 

A fascinating topic about which I suspect we have much to learn. Whilst there may be more up-to-date scientific reports around, this 2011 paper Solar forcing of winter climate variability in the Northern Hemisphere (authors including Adam A. Scaife the head of Met Office long range forecasting) shows there is a measurable impact from solar levels on the weather in the northern hemisphere. The study focused on the impact of low solar activity, but it must be assumed the opposite impact for high solar? Some extracts:

The influence of solar irradiance variations on Earth’s surface climate has been repeatedly suggested from correlations between solar variability and
meteorological variables which show weaker westerly winds in the winter when the sun is less active....
We use the SIM observations of solar variability to estimate the change in UV between the maximum and minimum of the 11-year solar cycle and impose this forcing on an ocean-troposphere-stratosphere-mesosphere climate model. Our simulations are for 80 years of solar minimum and 80 years of solar maximum conditions.......
........In winter (December to February) the simulated and observed response at solar minimum shows substantial changes over the whole northern hemisphere. Model sea-level pressure increases at high northern latitudes and decreases at mid-latitudes in both the Pacific and Atlantic basins corresponding to a negative Arctic Oscillation or North Atlantic Oscillation-like pattern.

Full PDF can be downloaded at this link: https://core.ac.uk/download/pdf/76996214.pdf

Many many thanks for that. I think it's something we should all take note of. Plus it might keep our feet on the ground and prevent disappointment when we are forecast cold weather but we also keep an eye on the solar activity at the same time. It will help to keep our expectations in check. 

[mountain shadow]

25 minutes ago, blizzard81 said:

Indeed. The Dec 2012 climbdown was last minute as well. Just like this fiasco this week. I don't believe in coincidences. Ed Stone, I only mention the issue of solar activity on the rare ocassion there is a last minute flip from cold to mild that coincides with a big uptick in solar flares. I truly believe in the connection. Its too much of a coincidence imo. 

Does the opposite not work then? 

We entered Winter with very low solar activity and only received a brief blast of snow from a very, very strong storm. How did we get such a strong storm when solar activity as low.

 

[Catacol]

24 minutes ago, Ed Stone said:

Whatever, the result is always the same: Blankety Blank?

I have no idea what that means, but I do know that the only incident discussed vv solar impacts in recent years has been Dec 2012. We don't get that many failed easterlies because we don't get that many forecast winter easterlies, but 2012 was one and 2021 may prove to be another. Both on the early upwards curve of the next SC.

[Don]

1 hour ago, blizzard81 said:

Its more to do with its affect on the northern arm of the jet over the Atlantic. Studies have shown that ejections (CME's) from the sun increase energy in the northern arm. Of course, this affects the UK but also north west Europe. Some have made the point that some of our severe winters have coincided with solar max but even during solar max, the sun won't be spewing out CME's all the time. Conversely, these CME's can be spewed out during solar minimum or like now, when it is coming out of solar minimum. The studies have shown it is these ejections that ramp up the northern arm in the atlantic and lead to a positive nao. I know Stuart Rampling aka Glacier Point put a lot of credence in this phenomenon. 

If the busted cold spell is down to the ramp up in solar activity and CME's, how annoying is that as it was fairly quiet up until recent weeks?!  Winter comes along and the sun wakes up!  Feels like us coldies do not have a chance!

[Catacol]

2 minutes ago, mountain shadow said:

Does the opposite not work then? 

We entered Winter with very low solar activity and only received a brief blast of snow from a very, very strong storm. How did we get such a strong storm when solar activity as low.

 

The opposite would be moving from a period of high activity to an instantaneous period of near zero activity. That clearly wasn't the case in late November because solar at the moment is relatively low. The only shift from the norm at the moment can be up and not down....

Edited December 23, 2021 by Catacol

[Don]

30 minutes ago, blizzard81 said:

Indeed. The Dec 2012 climbdown was last minute as well. Just like this fiasco this week. I don't believe in coincidences. Ed Stone, I only mention the issue of solar activity on the rare ocassion there is a last minute flip from cold to mild that coincides with a big uptick in solar flares. I truly believe in the connection. Its too much of a coincidence imo. 

Yes blizzard81, I remember there was speculation about the big uptick in solar flares during December 2012 effectively scuppering the cold spell.  However, the sun soon calmed down and the rest of winter was decent.  Hopefully the sun will do the same this time......

[Catacol]

8 minutes ago, Don said:

If the busted cold spell is down to the ramp up in solar activity and CME's, how annoying is that as it was fairly quiet up until recent weeks?!  Winter comes along and the sun wakes up!  Feels like us coldies do not have a chance!

We probably need to move away from discussing sunspots and solar flares before it annoys those who think it poppycock - but for those who see a link the timing is surely laced in irony. We have indeed gone a long time since we had a big uptick in solar activity, and right when we get a rising GWO orbit via decent MJO activity and an eQBO the sun decides to spit.

I'm not sure of the link - but Malcolm's paper highlighted higher up I have seen before. The whole 11 year solar cycle theory rests on the idea that an active sun peps up the jet stream and a quiet sun allows the jet stream to wobble. Note the jet is now forecast to move off its NW/SE previous trajectory and onto a flat westerly. It could be coincidence or it could be causal. At some point I'm sure peer reviewed research will delve more deeply into the theory. Right now all we have is a correlation based on 2 incidents in the last 10 years, the second of which (2021) hasn't actually happened yet!!

 

Edited December 23, 2021 by Catacol

[Downburst]

46 minutes ago, Ed Stone said:

Thanks, Malcolm, it is indeed a fascinating theory, and one I have no problem in accepting. But what I do find annoying is that some folks reflexively quote it whenever a projected cold spell fails to materialise, or a run of favourable model-runs goes pear-shaped. Good grief, there can't be that many coronal mass ejections!

 

Exactly and I have read that paper several years ago and glad you quoted it as there are not many follow up studies I have found, although I am not in the filed. In Science one paper doesn't prove a theory.  think the general publics view of "energy" from the sun may be different to what actually happens to deviation in net "energy" arriving at this speck of a planet with or without Sun Spots. There was a few folk here ranting we were into a new Maunder Minimum mini ice age anytime this cycle a few years back. 

One other thing I saw reading this thread over the last week or so was references to the ECM 46 day weekly anomaly. the charts showed a higher pressure from climate norm over a week to our north, not a day, a week in total, 7 days and even at that a slight one. It could easily have been mean low pressure and not any high at all.  It was just showing higher than the normal low pressure, a higher low. Yet folks discounting the chart post the event as they said it was showing "high Pressure".  Some of these folks have been posting for years here and it is very disheartening to see no progress in basic chart analysis. It would help if some effort....  

[RCT]

After what we have all witnessed over the last few days I think we can all agree that even though it's currently forecasted get rather mild into the new year we can all say with confidence that it could flip back within in a short period of time... so think we just need to take what we see with a pinch of salt at the moment  

[Methuselah]

9 minutes ago, Don said:

If the busted cold spell is down to the ramp up in solar activity and CME's, how annoying is that as it was fairly quiet up until recent weeks?!  Winter comes along and the sun wakes up!  Feels like us coldies do not have a chance!

"2018-19 was one long 'busted cold spell' that ended with 21C in February. Even the Met were predicting an onset of cold, snowy weather?

[booferking]

9 minutes ago, Downburst said:

Exactly and I have read that paper several years ago and glad you quoted it as there are not many follow up studies I have found, although I am not in the filed. In Science one paper doesn't prove a theory.  think the general publics view of "energy" from the sun may be different to what actually happens to deviation in net "energy" arriving at this speck of a planet with or without Sun Spots. There was a few folk here ranting we were into a new Maunder Minimum mini ice age anytime this cycle a few years back. 

One other thing I saw reading this thread over the last week or so was references to the ECM 46 day weekly anomaly. the charts showed a higher pressure from climate norm over a week to our north, not a day, a week in total, 7 days and even at that a slight one. It could easily have been mean low pressure and not any high at all.  It was just showing higher than the normal low pressure, a higher low. Yet folks discounting the chart post the event as they said it was showing "high Pressure".  Some of these folks have been posting for years here and it is very disheartening to see no progress in basic chart analysis. It would help if some effort....  

Hence the reason why we should never look any further than the daily NWS for the short range output we were done up like a kipper.

Reference #ECM 46

Edited December 23, 2021 by booferking

[alexisj9]

1 hour ago, mountain shadow said:

A "return to colder conditions"? 

Did I miss something? We haven't had colder conditions to return too.

Considering down here we've been stuck on temps at around 4-6 degrees or colder, since the high went a bit higher up, I disagree, it's been cold, just not the snowy type.

 

[Cold Winter Night]

When there is a fine margin between cold and mild, snow and rain (or dry), with the boundary line close by, you know that some will be on the 'wrong' side of that line, whatever their preference is.

Now it looks like most of us will have to accept that we will not see an exceptional event during Christmas. Some might still see snow flakes, with still a minor chance higher up in the UK and a minor chance for me in Holland. I won't count on it, but it's not completely gone. Here in Holland, Christmas Day itself looks at least cold, which did not look likely just a few days ago.
The past two days have been pretty wintry here as well. Frost nights, almost an ice day (one tenth of a degree short in De Bilt!) and beautiful white frosted landscapes under a calm atmosphere. I enjoyed it. It shurely has not been like that in the week before Christmas for a number of years.

I don't really get why some pretend that Greenland blocking has not come/failed and that therefore the MJO-based expectations were wrong. The MJO composite is an average, and not all the years going into that composite look exactly alike, quite the opposite. Some will look really different.
But still, we expected Greenland height rises with that MJO-7, and look at the present state: A Greenland High is right there, and it has been cold, here at least.

Now, the EPS regime chart shows a move to its circle of death. With the fading of the Greenland High, the NAO- signature dimishes, and as heights begin to rise in Europe, the move to BLO+ begins towards 192h.

Where will that end? We don't know yet. It might be Scandinavia. The next chase is on.
In the mean time, we will have probably have to endure a mild end of the year, but don't count on the present ensemble to have final answers on the early days of January yet.

[Don]

4 minutes ago, Ed Stone said:

"2018-19 was one long 'busted cold spell' that ended with 21C in February. Even the Met were predicting an onset of cold, snowy weather?

Yes, wasn't it just! 

I think Catacol is correct and we should move away from discussing that yellow disc in the sky for now! 

[Lukesluckybunch]

so what the hell we going to do now on here...haha

[Tamara]

On 23/12/2021 at 12:04, rwtwm said:

A question if I may.

It's not clear to me how this comment aligns with the use of full month composites when investigating the potential impact of MJO on our weather.

If faster progression brings greater forcing, then shouldn't MJO 7 composites be different to MJO 6->7->8 composites for the same month?

@Singularityanswered this question very well a few pages back *and very much a similar message I repeat many times). The MJO is one component of the global wind-flow budget (a very important one) - but the extra - tropical circulation also has to be considered to get a fuller picture of the overall tropospheric circulation and how in turn this affects the relationship within the stratosphere

As far as I am concerned the tropical MJO and extratropical GWO (Global Wind Oscillation) have produced a' harmonious' wind-flow signal based on amplified rossby wave propagation from the tropics to extra tropics and created a profile for deceleration of zonal winds between 50N and 60N. Hence the presence of the wedged heights circa Iceland to Greenland, following on from the mid latitude block close to the UK. However, the impression among the disappointed within this forum that the diagnostics 'doesn't work'is not just down to the need to fit the diagnostic to one favoured outcome and which obscures that the synoptic response has actually been a close match in terms of height anomalies and placements (notwithstanding the failure for strong enough and sustained enough cold air advection to deliver the weather that UK members want to see). Its also to do with the following:

1) Insufficient cold air close by to the UK to tap straight into and create a stronger dense profile of cold air - hence harder to get enough negative tilt on low pressure areas to disrupt for the greater part of what is a small geographical area (the UK) within a large Northern Hemisphere, let alone island within a large continental landmass one side and a vast ocean the other. Precise geographical alignment is required at the outset to direct this to a small island, notwithstanding 2) which is most relevant of all

2) However another take-away, and really the more important one that looks set to facilitate the lifting out of cold air trying to advect southwards across the UK without too much resistance is the solar uptick/ -ve  (easterly) QBO interface helping to weaken the burgeoning heights over the Arctic and hence the blocking structures towards Iceland retrograding towards Greenland have been made weaker than they otherwise might have been.

At the same as the polar cell is weakened, a boost to the Hadley cell occurs and subsequent expansion of sub tropical riding. The interest, which I have repeated looking ahead, is whether the adjustments occurring within the Pacific to alter the rossby wavelength feedbacks and hence keep an unstable GSDM profile (which adds further amplification into the atmospheric circulation) can override the ongoing dampening down of blocking structures trying to establish further poleward as further momentum transport occurs, or whether the countervailing equatorward processes prove stronger than this and instead sustain strong sub tropical ridges amidst the backdrop of the lowering of pressure in the middle and upper layers.

Its very much one set of forcing coming up against an opposite set of forcing and really quite fine margins between a strong Hadley cell and weaker polar cell or vice versa,  weakened sub tropical forcing and increased propensity for momentum transport to migrate anticyclonic wave-breaking to higher latitudes. In this respect a floor to angular momentum is required additionally through active tropical convection sustaining deeper into the winter- as collapsing AAM entails greater polar jet strength which would add further weight and attritional forcing to the solar uptick/-ve QBO forcing lowering pressure at higher latitudes.

Its not straightforward one way or the other. Equally, the -ve QBO, on the basis that the solar uptick is not sustained could on the other hand dovetail with buoyant tropical convection and lead to the opposite regime and evidence of other winters with similar parallels to now has seen January and into February have quite different blocking structures to the ones advertised for the end of 2021 and into 2022. I am happy with the current evolution and some further balmy warmth down here in Portugal, but from a weather pattern point of view and suspending personal preference, it is also very interesting to see how these conflicting tropospheric/stratospheric factors play out and which gains an upper hand over the extended period.

Edited December 23, 2021 by Tamara

[alexisj9]

7 minutes ago, Lukesluckybunch said:

so what the hell we going to do now on here...haha

Wait for the 12z and have another moan I guess. Although there's still some interest if the 6z was correct, it's just not all that good now.

[mountain shadow]

If it really is scientific fact that a sudden brief increase in solar output can override expected weather patterns and that sudden increase in solar activity is largely unpredictable, then what is the point of spending billions on medium to long term forecasting?

Might as well stick to t+74. 

[Lukesluckybunch]

7 minutes ago, alexisj9 said:

Wait for the 12z and have another moan I guess. Although there's still some interest if the 6z was correct, it's just not all that good now.

lol yea sounds about right..and interest for which period?

[alexisj9]

6 minutes ago, Lukesluckybunch said:

lol yea sounds about right..and interest for which period?

North on Christmas day, Midlands boxing day. But looks disappointing anyway.

[Alexis]

1 hour ago, Catacol said:

I have no idea what that means, but I do know that the only incident discussed vv solar impacts in recent years has been Dec 2012. We don't get that many failed easterlies because we don't get that many forecast winter easterlies, but 2012 was one and 2021 may prove to be another. Both on the early upwards curve of the next SC.

Bear in mind this easterly was really only a stonker on one ECM run 7 days ago. It was immediately watered down and ever since any predicted easterly has been a weak and transitory affair.

[Connor Bailey Degnan]

I hate to ask, but has the UK ever had a colder than Average Jan and Feb when the Dec CET is above 6? Can't think of one. Unfortunately this winter looks like it's going down the gutter.

[Don]

2 minutes ago, Connor Bailey Degnan said:

I hate to ask, but has the UK ever had a colder than Average Jan and Feb when the Dec CET is above 6? Can't think of one. Unfortunately this winter looks like it's going down the gutter.

Winters 1985/86 and 1986/87 were cold and the Decembers were 6.3C and 6.2C.  Albeit, that was a long time ago!

 

Edited December 23, 2021 by Don