Upcoming winter speculation and chat - October edition

[sebastiaan1973]

https://www.weatherbell.com/preliminary-2019-2020-winter-forecast

The Weatherbell forecast for the US. They see similarities with winter of 2014 en 2015. E.g. sea surface temperatures for the coast of Alaska.

[coldwinter]

People keep saying the GLOSEA was completely wrong last winter and it just isnt true. Here was the Nov update

A *weak* blocking signal to the north and troughing into eastern europe. Here is what actually happened

A *weak* area of blocking to the north and troughing in eastern europe, it did miss the strong azores high coming through spain into the UK, but to say it was completely wrong isnt true. The anomalies for this year are VERY strong for what looks like a strong PV, looking at current modelling our high pressure over Taymyr and northern siberia is being replaced by low pressure, if that hold for the rest of this month that would favour a +ve AO, which could be what the model is reacting too.

So, through this month into the all important November, we look for all of the usual stratospheric disturbances that will cause the vortex to weaken and promote blocking as we go into winter. It is simply too early to say what is going to happen in the next month and a half which lays the blocks for early winter at least. In our current QBO state any  SSW is more likely to be later than earlier in the winter. 

So strap in and enjoy the ride

Ryan.

 

[Methuselah]

Another thing that must confound LRFs is that, as the AGW-based forcings strengthen, so the others must weaken...Those putting all their eggs in the Solar-minimum basket (in anticipation of a new Little Ice-Age) for instance, may be sorely disappointed?

On the other hand, they might not?!

[Chesil View]

58 minutes ago, coldwinter said:

People keep saying the GLOSEA was completely wrong last winter and it just isnt true. Here was the Nov update

A *weak* blocking signal to the north and troughing into eastern europe. Here is what actually happened

A *weak* area of blocking to the north and troughing in eastern europe, it did miss the strong azores high coming through spain into the UK, but to say it was completely wrong isnt true. The anomalies for this year are VERY strong for what looks like a strong PV, looking at current modelling our high pressure over Taymyr and northern siberia is being replaced by low pressure, if that hold for the rest of this month that would favour a +ve AO, which could be what the model is reacting too.

So, through this month into the all important November, we look for all of the usual stratospheric disturbances that will cause the vortex to weaken and promote blocking as we go into winter. It is simply too early to say what is going to happen in the next month and a half which lays the blocks for early winter at least. In our current QBO state any  SSW is more likely to be later than earlier in the winter. 

So strap in and enjoy the ride

Ryan.

 

I have to respectfully disagree with you there Ryan. Although it picked up weak blocking to the north. By not picking up on the continual Azores high interference. It missed out on the strongest element affecting our weather in that period. If it can't pick out the strongest element affecting the weather in any given winter period then it has essentially failed to pick up the strongest signal and as such by signalling weak blocking to the north rather than strong Azores high facors it didn't forecast the period correctly even at a broad rush level

Edited October 12, 2019 by Broadmayne blizzard

[Don]

1 hour ago, Ed Stone said:

Another thing that must confound LRFs is that, as the AGW-based forcings strengthen, so the others must weaken...Those putting all their eggs in the Solar-minimum basket (in anticipation of a new Little Ice-Age) for instance, may be sorely disappointed?

On the other hand, they might not?!

Well, this is the thing and I wondered if that was part of the reason why last winter went Pete Tong?  The more AGW strengthens, then obviously less room for manoeuvre when it comes to getting cold synoptics.

[E17boy]

Good afternoon peeps

How is everyone? Hope you all are doing well. I have not been on here for ages but now my winter chase for snow has started and I have boarded the winter train.

its a very wet start here in East London Walthamstow today pouring with rain and I think that's the way the rest of the day is shaping up, autumn has certainly started. 

By looking at the current modelling and the comments from the more knowledgable, looks as if we have got this pattern for some time, with some signs of the Azores high making a presence at the later stages. I mention the Azores High every summertime fans dream but every cold chasers nightmare in winter depending on where it sits. 

As many of you, i do hope that we see some sort of pattern movement come November that may set us coldies up well for winter. I must admit I do feel a bit cautious due to the latest long term model predictions I do hope it's not a winter that comes and goes without any show. 

I will be looking closely at the movement of the Azores Hight as this has been the destroyer of many of our winters. Let's hope some HLB sets up and changes the pattern we don't want to be stuck in.

figers crossed 

THE SEARCH FOR MY WINTER WONDERLAND HAS BEGUN

wishig you all all a great day

regards

 

[Jordan S]

4 minutes ago, E17boy said:

Good afternoon peeps

How is everyone? Hope you all are doing well. I have not been on here for ages but now my winter chase for snow has started and I have boarded the winter train.

its a very wet start here in East London Walthamstow today pouring with rain and I think that's the way the rest of the day is shaping up, autumn has certainly started. 

By looking at the current modelling and the comments from the more knowledgable, looks as if we have got this pattern for some time, with some signs of the Azores high making a presence at the later stages. I mention the Azores High every summertime fans dream but every cold chasers nightmare in winter depending on where it sits. 

As many of you, i do hope that we see some sort of pattern movement come November that may set us coldies up well for winter. I must admit I do feel a bit cautious due to the latest long term model predictions I do hope it's not a winter that comes and goes without any show. 

I will be looking closely at the movement of the Azores Hight as this has been the destroyer of many of our winters. Let's hope some HLB sets up and changes the pattern we don't want to be stuck in.

figers crossed 

THE SEARCH FOR MY WINTER WONDERLAND HAS BEGUN

wishig you all all a great day

regards

 

Morning!  Wet here too looks to stay that way until atleast tomorrow afternoon! Ducks are loving it. 30-40mm is being shown over this weekend so a soggy one!.. Anyway hope you get your snow this winter! 

[Summer Sun]

 

[Snowy Hibbo]

30 minutes ago, Summer Sun said:

 

You beat me to it! Thanks @Summer Sun

1. Snow & Ice conditions good for Eastern US, Japan and Europe/UK.
2. MJO largely good for European and UK snowfall, perhaps less so later in winter. Similar for Eastern US and Japan.
3. Oceanic ENSO good for Japan, Southwest US and Eastern US.
4. -AAM good for Europe, Eastern US and Japan, less strong later in winter.
5. Stratospheric conditions favourable for Eastern US, Japan and Europe/UK.
6. Solar minimum favourable for more snowfall for Eastern US, Japan and Europe/UK.
7. Atlantic favourable for a snowy UK winter and colder Europe.
8. QBO favourable for Eastern US, UK and Europe.
9. North Pacific favourable for Eastern US, less so for PNW.

All this is good for a snowy winter IMO, contrary to the models (yes I know, bold, but I have the reasoning to back it up :) ).

[NeilN]

I hope that comes off we get a snowy winter. Screw the long-range models!!

Another thing, doesn't a wet autumn often mean a cold winter? 2009 had a wet autumn and we all know what followed that, plus I am sure 1984 had a wet autumn and a cold winter. Even 2012 was a wet autumn, and the winter turned out OK. 

 

 

[Met4Cast]

7 hours ago, frederiksen90 said:

Because seasonal forecasts do not predict an SSW, this does not mean that a significant SSW cannot occur. 

This is a valid point. There is some thought that last winters SSW was caused by a well timed weather pattern event, if this was the case then long range models couldn't possibly predict that type of SSW. 

SSW's are good however downwelling as we saw last year can be slow/even fail to happen, so an SSW occurring is only half the battle. SST's in the Atlantic are much more favourable this year and favour a more -NAO, something we've seen fairly consistently since April

Seasonal models are nice to look at but shouldn't be taken with more than a pinch of salt, especially at this lead time.

[Beanz]

4 hours ago, Snowy Hibbo said:

You beat me to it! Thanks @Summer Sun

1. Snow & Ice conditions good for Eastern US, Japan and Europe/UK.
2. MJO largely good for European and UK snowfall, perhaps less so later in winter. Similar for Eastern US and Japan.
3. Oceanic ENSO good for Japan, Southwest US and Eastern US.
4. -AAM good for Europe, Eastern US and Japan, less strong later in winter.
5. Stratospheric conditions favourable for Eastern US, Japan and Europe/UK.
6. Solar minimum favourable for more snowfall for Eastern US, Japan and Europe/UK.
7. Atlantic favourable for a snowy UK winter and colder Europe.
8. QBO favourable for Eastern US, UK and Europe.
9. North Pacific favourable for Eastern US, less so for PNW.

All this is good for a snowy winter IMO, contrary to the models (yes I know, bold, but I have the reasoning to back it up ).

Genuine query.  I was under the impression (more than likely the wrong one!) that the Atlantic was warm and not favourable for cold in the UK.  What’s your thinking here? 

[SMU]

@Snowy Hibbo

Interesting to put a forecast out so early - however in order for that to land your going to need some support from the stratosphere In Nov ( or Early Dec ) - All the blocked AO / NAO winters that startes in Dec ( which you indicate ) all had early warmings - Similar to 1981/ 2009 for example-

If that were me I would have released that forecast in 6 / 7 weeks time when the stratospheric profiles & coupling have become more apparent.

As highlighted earlier in this thread at least the persistence of the -NAO may lend some support to the forecast over & above the norm- Its that AO block - that cannot sustain without the strat...

Good luck anyway.

[Newberryone]

8 hours ago, E17boy said:

Good afternoon peeps

How is everyone? Hope you all are doing well. I have not been on here for ages but now my winter chase for snow has started and I have boarded the winter train.

its a very wet start here in East London Walthamstow today pouring with rain and I think that's the way the rest of the day is shaping up, autumn has certainly started. 

By looking at the current modelling and the comments from the more knowledgable, looks as if we have got this pattern for some time, with some signs of the Azores high making a presence at the later stages. I mention the Azores High every summertime fans dream but every cold chasers nightmare in winter depending on where it sits. 

As many of you, i do hope that we see some sort of pattern movement come November that may set us coldies up well for winter. I must admit I do feel a bit cautious due to the latest long term model predictions I do hope it's not a winter that comes and goes without any show. 

I will be looking closely at the movement of the Azores High as this has been the destroyer of many of our winters. Let's hope some HLB sets up and changes the pattern we don't want to be stuck in.

figers crossed 

THE SEARCH FOR MY WINTER WONDERLAND HAS BEGUN

wishig you all all a great day

regards

 

With the likelihood of far less changeable and unsettled weather taking hold shortly after mid month I find the above post very sobering indeed as it highlights the many pitfalls that come with pressure rises from the south as we enter one of the most highly anticipated seasons of the year. While getting a break from all the rain is perfectly understandable I fail to grasp all this enthusiasm that there seems to be for the possibility of an Indian summer. All very well if it laid the foundation for something far more palatable come Dec, Jan, Feb, but how often has that been the case.  

[MATTWOLVES 3]

Alot has been spoken about the long range models being poor for cold this year..... But, and its a big but.... Let's take a look at the big freeze of 1987....basically an average winter which Contained one of the most brutal frrezes of the century!! It spanned almost 11 days, with some parts of the UK being buried in up to 6Metre drifts of snow, temps going below - 20C at one point!!! Why do I harp on about this, and just what as it got to do with the coming winter? Even a mild winter can bring a big freeze with big snowfalls, the models at the time of this freeze really had no idea that it was about to hit so hard, most of Europe was mild, and so was the UK leading up to it! Intense cold coming out of Western Russia, with high pressure moving out of Siberia and planting itself over Scandinavia...... And boom.... Look what followed!! If I recall at the time some climate experts said that the freeze was partially down to Global Warming, and to expext many more events like this in the future!!! Well my friends, perhaps we are getting close to another extreme event of this magnitude.. Even in a mild Westerly dominated winter, we can still be hit for 6 with this kind of set up!!! For me huge amounts of Arctic ice melt will only serve to increase the chances, however short there duration maybe..... So let's all salute 1987....and pray for a repeat..... Hopefully this year!!!! Enjoy the rest of your weekends good folk. 

 

[Snowy Hibbo]

6 hours ago, Beanz said:

Genuine query.  I was under the impression (more than likely the wrong one!) that the Atlantic was warm and not favourable for cold in the UK.  What’s your thinking here? 

As @Met4Cast uses in the chart above, there is a significant cold anomaly right in the middle of the Atlantic. So that could help spur the -NAO and a colder winter for the UK.

4 hours ago, Steve Murr said:

@Snowy Hibbo

Interesting to put a forecast out so early - however in order for that to land your going to need some support from the stratosphere In Nov ( or Early Dec ) - All the blocked AO / NAO winters that startes in Dec ( which you indicate ) all had early warmings - Similar to 1981/ 2009 for example-

If that were me I would have released that forecast in 6 / 7 weeks time when the stratospheric profiles & coupling have become more apparent.

As highlighted earlier in this thread at least the persistence of the -NAO may lend some support to the forecast over & above the norm- Its that AO block - that cannot sustain without the strat...

Good luck anyway.

This isn’t the final forecast, this is just the last one I do for the entire globe, hence the global charts. I do a specific final UK/Europe forecast, where hopefully I have a bit more stratospheric guidance. But yes I am banking on a SSW at some point. I do see perhaps a good chance for some strat warming in November/December though. And there’s plenty of factors supporting the potential for a SSW anyways.

 

[Weather-history]

Solar activity and the 6 severe winters of the 20th century (sub 2C for CET)

1916-17 (just before maximum)

1928-29 (just after maximum)

1939-40

1946-47 (just before maximum)

1962-63

1978-79 (approaching maximum)

4 of them occurred within a year either side of solar maximum.

None of the other 2 occurred within a year of solar minimum.

Edited October 13, 2019 by Weather-history

[Downburst]

44 minutes ago, Weather-history said:

Solar activity and the 6 severe winters of the 20th century (sub 2C for CET)

1916-17 (just before maximum)

1928-29 (just after maximum)

1939-40

1946-47 (just before maximum)

1962-63

1978-79 (approaching maximum)

4 of them occurred within a year either side of solar maximum.

None of the other 2 occurred within a year of solar minimum.

It would be better if the cycle was always referred to a Solar Sunspot Maxima or Minima, or some way to emphasize the sun spot. I’ve always worried about the general public thinking, oh a weak sun etc. Not saying it doesn’t contribute to weather, but the certainty in some people’s mind even given the facts such as you’ve shown. Better off praying for global impacting volcanoes as they seem to have more real frequent correlation to cooling on a global scale. Still the Thames was frozen......

[coldwinter]

23 hours ago, Broadmayne blizzard said:

I have to respectfully disagree with you there Ryan. Although it picked up weak blocking to the north. By not picking up on the continual Azores high interference. It missed out on the strongest element affecting our weather in that period. If it can't pick out the strongest element affecting the weather in any given winter period then it has essentially failed to pick up the strongest signal and as such by signalling weak blocking to the north rather than strong Azores high facors it didn't forecast the period correctly even at a broad rush level

The issue is people take them too literally, banking on a cold winter based off weak blocking to the north isnt wise, anyway as Steve says, still far too early to issue proper outlooks, another 3 weeks at least before we can start  wondering what early winter may bring, let's hope we arent staring down the barrel of a rampant PV.....

[Methuselah]

The reason that I do not make LRFs is a simple one: Shannon entropy:

For each detailed LRF (the really silly ones that include dates and such) there is one, and only one, combination of circumstances/events that'll create the desired 'hit'; the number of 'misses', on the other hand, is astronomical...?

Multiply that (already infinitesimal quantity) by the number of individual forecasts made annually, and a reasonable number of years (20?)...and the chance of consistent success is...not very great? 

 

So, that's why I cannae be bothered. But, carry on you guys -- and ignore this curmudgeonly old fart!

Good luck, All!!!

[MATTWOLVES 3]

2 hours ago, Downburst said:

It would be better if the cycle was always referred to a Solar Sunspot Maxima or Minima, or some way to emphasize the sun spot. I’ve always worried about the general public thinking, oh a weak sun etc. Not saying it doesn’t contribute to weather, but the certainty in some people’s mind even given the facts such as you’ve shown. Better off praying for global impacting volcanoes as they seem to have more real frequent correlation to cooling on a global scale. Still the Thames was frozen......

Praying for global impacting volcanoes would be like praying for a lot of lost lives! So I'm not sure that would be a good thing in our search for meaningful cold. Low solar minimum should have an effect on the strength and position of the jet stream.... Would that be enough though!! Obviously it could be overridden by other global factors.... Alot of water to pass under the bridge these coming weeks, should be at least interesting. 

[SMU]

The next 4 weeks in terms of polar heights feel like they are going to be very important in the grand scheme of things in terms of seeing how the predisposed troposphere which thus far has been primed towards a -NAO comes up again a record cold stratosphere trying to down-well to the surface-

Its at this point you would expect based on history for the models to trend towards significant positivity on the AO & NAO & repeatedly the modelling does reflect that in the day 11-16 arena however as we move into the day 8-11 timeline the trends are opposite for the polar field & look more blocky.

If we take todays ECM day 7 & below put the day 10 chart from 3 days ago you can see how the +AO has been overestimated with the vortex now modelled to be pushed out of the pole again-

We can also see a wedge of higher heights over the pole in the mix now-

So what was modelled to become a positive AO is now likely to be neutral at best.

As we head out to day 10 on tonights ECM the heights point to a slightly negative AO

 

This isn't really consistent with the coupling of the Trop > Strat & should these charts come to verify with a -NAO & -AO then this should give us more confidence as we head to winter that the seasonal models could be wrong.

Also just a footnote on them- the enhanced azores high could be modelled correctly in terms of additional depth over winter however its location could be more vertical in lattitude with the icelandic low be positioned more Eastward - This would bring a whole different weather pattern to the UK away from mild & wet....

S

PS its also worth noting that on October 13th the sea ice extent dropped back below the record low 'recovering' 2012 by 30k -

The last 30 or so days have seen the deficit of about 600KM2 slowly reduce with a combination of low increases interspersed with occasional loss days so the growth curve has been very weak leading to the crossover day yesterday. Its unlikely ( based on current rate of growth & the +SSTA ) to catch back up in the very near future.....

Edited October 14, 2019 by Steve Murr

[Roger J Smith]

Here's my contribution to the discussion:

The following is a preliminary long-range forecast for winter 2019-20, If it seems necessary, I will amend or update this forecast in mid-November. 

This appears likely to be a season where high energy weather events will be grappling with a fairly robust supply of colder air at high latitudes.

Britain and Ireland can expect a very unsettled winter with frequent low pressure systems steered by a strong jet stream running a little south of its average position.

This favours a split north-south outcome where the south is often on the milder side of the storm track getting strong southwest winds and rain, while the north is more open to snow, ice and easterly winds. 

The north-south divide may be enhanced by the likely appearance of strong blocking highs over eastern Scandinavia and western Russia. I don't think these are going to dominate the circulation but they will come into conflict with the zonal regime at times, forcing it to dive southeast around 5-10W and into France and the western Mediterranean. This may be another winter of heavy Alpine snowfalls and frequent severe cold spells in Germany and possibly Belgium and Netherlands into northeast France. 

Battleground conditions seem likely at times across southeast England into Wales and central to northern Ireland. Frequent snow events may occur in northern and even central England, and southern Scotland, also Northern Ireland and some adjacent parts of the Republic of Ireland. 

Some heavy precipitation is likely in this scenario, heavy rain in most cases in southern England, especially the southwest, and the southern third of Ireland (Munster and south Leinster).

A set-up like this may not remain steady-state, but could fluctuate north-south bringing the milder conditions further north at times, while setting the battleground further south at other times. However, the tendency will be for temperatures to average closer to normal or above in the southwest, and below normal in Scotland.

This pattern could evolve into a colder February or even March if the strong jet stream loses energy, then the blocking may be able to assert more control. 

North America can expect a rather harsh winter in general, with severe cold waves at times, colliding with an active storm track from Texas northeast towards Virginia and southeastern New England. There could therefore be heavier than average snowfalls in the Ohio Valley, Midwest, and inland Mid-Atlantic to northeastern states. A pattern like this would not rule out one or two coastal blizzards in the mix. The west will be dominated by persistent cold high pressure trapped in valleys, and coastal areas will have a fairly average winter with a lot of rain, low cloud and moderate southeast winds. Snow on western mountains will be generally a bit above average but might be twice normal in the southern Rockies and northern Arizona around Flagstaff. Drought will break during the winter for California. 

This may also be one of those winters where extreme cold moves south from Siberia into China, Korea and Japan. 

 

[carinthian]

My daughter who lives in Stockholm reports some excitement by the media regarding the early on set of winter in the Northern and even parts of Central Sweden with snow cover quite widely reported to be holding and persistent low temps over the past 2 weeks. Thing look like warming up further south but the north continues locked into the cold block. Maybe a sign of things to come ?

C

[staplehurst]

On 13/10/2019 at 08:15, Downburst said:

It would be better if the cycle was always referred to a Solar Sunspot Maxima or Minima, or some way to emphasize the sun spot. I’ve always worried about the general public thinking, oh a weak sun etc. Not saying it doesn’t contribute to weather, but the certainty in some people’s mind even given the facts such as you’ve shown. Better off praying for global impacting volcanoes as they seem to have more real frequent correlation to cooling on a global scale. Still the Thames was frozen......

Here's how UK winters (DJF) compare to the sunspot cycle historically. Of course events such as the Beast from the East were only 1 week long, so have less impact on a 3-month average etc