Winter 2023/24 - Discussions & Forecasts

[raz.org.rain]

16 minutes ago, summer blizzard said:

Credit to a member called 40/70 elsewhere. 

 

 

So not totally stellar albeit nothing zonal. 

This seems to be suggesting HP encroaching from the south and Atlantic, would that point towards something milder and wetter?

[Cheshire Freeze]

18 minutes ago, summer blizzard said:

Credit to a member called 40/70 elsewhere. 

 

 

So not totally stellar albeit nothing zonal. 

Strange Meteofrance anomaly for Jan there. Looks half way between a Euro HP and retrogressive signal.

I wonder if there’s a stark dichotomy in the ensembles.

TBF I think this winter will go one of two ways, Euro HP or N blocking galore.

Edited August 15, 2023 by CreweCold

[Don]

Not as good an update as in July then?  Some of those anomalies look a bit like those of winter 2018/19 when we had northern blocking, but also blocking to our south, giving us a mild winter?

METEO France looks poor!

Edited August 15, 2023 by Don

[summer blizzard]

As Crewe alludes to it's possible that the CMC (GEM) and Meteo France are forecasting a transition mid month ect.. but it also looks similar to a month like March 2012 but in winter. On both you can see a Strong Polar Ridge but over Canada and essentially an Azores Low too far west. 

It's also worth remembering winter 2015 especially which while having a weaker Nino, has a similar QBO profile and is one of the few +ONI, -QBO matches. That winter saw the +PNA and blocking somewhere near the UK but never anywhere especially cool.

[sebastiaan1973]

https://easternmassweather.blogspot.com/2023/08/preliminary-analysis-of-extratropical.html?m=1

Review of El Modoki Index (EMI) Analogs for Winter 2023-2024

It was conveyed by Eastern Mass Weather last month that there is currently no strong signal from ENSO either way concerning the ultimate evolution of the ensuing winter.  This was illustrated by referencing the range of seasonal outcomes amongst El Nino Modoki (EMI) Index winter analogs dating back to 1982, which were derived from the EMI forecast issued with the July update from JMA.

 

Summarization and Conclusions

In conclusion, there is no compelling evidence in support of a polar vortex that is stronger than suggested by climatology for the winter 2023-2024 season. The fact that this season will feature the easterly phase of the QBO during the ascent towards the peak of solar cycle 25 in a presumably rather robust basin-wide el nino implies a more disturbed polar domain than last season, if anything. And while there remains a slight chance for residual volcanic enhancement of the PV during the ensuing winter, the primary avenue to an intense PV this season is via the cooling of the western Pacific in conjunction with a continued development into an intense el nino, as was the case in the 1997-1998 winter season. This season also featured the easterly phase of the QBO with an ascending solar cycle, but the ENSO forcing was so intense and displaced to the west that it overwhelmed all other factors.

Edited August 15, 2023 by sebastiaan1973

[Don]

48 minutes ago, sebastiaan1973 said:

https://easternmassweather.blogspot.com/2023/08/preliminary-analysis-of-extratropical.html?m=1

Review of El Modoki Index (EMI) Analogs for Winter 2023-2024

It was conveyed by Eastern Mass Weather last month that there is currently no strong signal from ENSO either way concerning the ultimate evolution of the ensuing winter.  This was illustrated by referencing the range of seasonal outcomes amongst El Nino Modoki (EMI) Index winter analogs dating back to 1982, which were derived from the EMI forecast issued with the July update from JMA.

 

Summarization and Conclusions

In conclusion, there is no compelling evidence in support of a polar vortex that is stronger than suggested by climatology for the winter 2023-2024 season. The fact that this season will feature the easterly phase of the QBO during the ascent towards the peak of solar cycle 25 in a presumably rather robust basin-wide el nino implies a more disturbed polar domain than last season, if anything. And while there remains a slight chance for residual volcanic enhancement of the PV during the ensuing winter, the primary avenue to an intense PV this season is via the cooling of the western Pacific in conjunction with a continued development into an intense el nino, as was the case in the 1997-1998 winter season. This season also featured the easterly phase of the QBO with an ascending solar cycle, but the ENSO forcing was so intense and displaced to the west that it overwhelmed all other factors.

I thought winter 1997/98 was in a westerly QBO?

Edited August 15, 2023 by Don

[Bullseye]

2 hours ago, sebastiaan1973 said:

https://easternmassweather.blogspot.com/2023/08/preliminary-analysis-of-extratropical.html?m=1

Review of El Modoki Index (EMI) Analogs for Winter 2023-2024

It was conveyed by Eastern Mass Weather last month that there is currently no strong signal from ENSO either way concerning the ultimate evolution of the ensuing winter.  This was illustrated by referencing the range of seasonal outcomes amongst El Nino Modoki (EMI) Index winter analogs dating back to 1982, which were derived from the EMI forecast issued with the July update from JMA.

 

Summarization and Conclusions

In conclusion, there is no compelling evidence in support of a polar vortex that is stronger than suggested by climatology for the winter 2023-2024 season. The fact that this season will feature the easterly phase of the QBO during the ascent towards the peak of solar cycle 25 in a presumably rather robust basin-wide el nino implies a more disturbed polar domain than last season, if anything. And while there remains a slight chance for residual volcanic enhancement of the PV during the ensuing winter, the primary avenue to an intense PV this season is via the cooling of the western Pacific in conjunction with a continued development into an intense el nino, as was the case in the 1997-1998 winter season. This season also featured the easterly phase of the QBO with an ascending solar cycle, but the ENSO forcing was so intense and displaced to the west that it overwhelmed all other factors.

Thanks very much for sharing this. That sounds very promising if one is after a cold winter. Will need to bookmark that website for coming months. Thanks again

[Cheshire Freeze]

6 hours ago, summer blizzard said:

As Crewe alludes to it's possible that the CMC (GEM) and Meteo France are forecasting a transition mid month ect.. but it also looks similar to a month like March 2012 but in winter. On both you can see a Strong Polar Ridge but over Canada and essentially an Azores Low too far west. 

It's also worth remembering winter 2015 especially which while having a weaker Nino, has a similar QBO profile and is one of the few +ONI, -QBO matches. That winter saw the +PNA and blocking somewhere near the UK but never anywhere especially cool.

CFS certainly backs up the dichotomy theory.

After days of churning out nothing but zonal, the CFS throws out a run for December that is blocked from start to finish, including a decent Christmas Day

Edited August 16, 2023 by CreweCold

[Weather-history]

On 12/08/2023 at 14:53, SqueakheartLW said:

 

As for the CFS I'd say this is

C omplete

F abricated

S ***

 

 

How well did CFS do for predicting the July just gone? 

Indeed how did any of these long range models did for July 2023?

A good test for the performance of these long range models. 

 

[WeatherArc]

Im seeing quite a few vids/tweets suggesting the US Northeast will have a better chance of snow and wintery weather this year, I wonder if this will have any effects on our own winter? 

[cheeky_monkey]

20 hours ago, summer blizzard said:

Credit to a member called 40/70 elsewhere. 

 

 

So not totally stellar albeit nothing zonal. 

looks dry and relatively mild for my location 

[BruenSryan]

18 hours ago, Don said:

I thought winter 1997/98 was in a westerly QBO?

It was westerly in the lower stratosphere (50hPa) but slowly transitioned to easterly reaching 30hPa by February. It was a transitioning winter rather than a particular phase of dominance unless you go lower down.

9 hours ago, Weather-history said:

How well did CFS do for predicting the July just gone? 

Indeed how did any of these long range models did for July 2023?

A good test for the performance of these long range models. 

 

Forecasts through various points in June. Started off with an anticyclonic signal to the east which would be a very warm/hot month. It began to raise heights over Greenland coming to the end of June and our anticyclone disappearing. It eventually caught onto the low pressure in July itself. IE CFSv2 didn't forecast July well, at all.

[Rain All Night]

10 hours ago, Weather-history said:

Indeed how did any of these long range models did for July 2023?

I wondered this myself, so I did, er, this. Turns out the answer is, "not well" (beyond 1 month in advance)...

Edited August 16, 2023 by RainAllNight

[Rain All Night]

Thought I'd throw this in for good measure. December 2022, our most recent interesting winter month.

Much thanks to Meteociel for making this possible, of course. 

The models are, from top to bottom:
ECMWF – SEAS5
UKMO – GloSea6
ECCC – CanSIPSv2.1
JMA – CPS3
NCEP – CFSv2
DWD – GCFS2.1
Météo-France – System 8
CMCC – SPS3.5 
C3S – Multi-system

Edited August 16, 2023 by RainAllNight

[Addicks Fan 1981]

Think July was initially forecasted to be anticyclonic, but the weather behaved in a niña like way in spite of niño developing.  MattH did a fantastic post about it in the model thread and about the GSDM budget which I will research over more.   

Not the fact anybody got it wrong necessarily but to me the collapse of the AAM and lack of any wave activity meant that July didn't go according to plan.   

The easterly zonal winds were responsible for giving us the July it gave in tandem with the AO/NAO both being negative.

There doesn't seem like there's a downwelling wave forecast although the positive IOD could throw a potential curveball into the mix for this winter coming up.   

Edited August 16, 2023 by Addicks Fan 1981

[Thunder Snow]

Love it when thoughts turn to winter, best time of the year. Although we are still in summer and to be fair I've quite enjoyed this summer. Yes there has been some wet days, but there has also been some warm sunny periods to. Once more nothing to hot. So roll on winter 

[Cheshire Freeze]

Just the slight windchill

Gets even colder too

A few frozen pipes on this run!

Edited August 17, 2023 by CreweCold

[SqueakheartLW]

1 minute ago, CreweCold said:

Just the slight windchill

Gets even colder too

BANK

I'll take that one

[Don]

1 minute ago, CreweCold said:

Just the slight windchill

Gets even colder too

Just a light jacket required!  Looks like that low was a slider!

[Cheshire Freeze]

Just now, Don said:

Just a light jacket required!  Looks like that low was a slider!

It was indeed

 

The NH plot is a peach

[Liam Burge]

5 minutes ago, CreweCold said:

Just the slight windchill

Gets even colder too

A few frozen pipes on this run!

Lets hope we see this at T0 sometime this winter!!!

[Don]

3 minutes ago, CreweCold said:

It was indeed

 

The NH plot is a peach

Perfect! 

[Chesil View]

15 hours ago, CreweCold said:

Just the slight windchill

Gets even colder too

A few frozen pipes on this run!

Very Feb78esque there Crewe.

I'd take that any day of the week.

[northwestsnow]

Nino now almost certain to be in the strong possibly super strong category.

Saying that I'm sure Glosea for example will have factored a strong Nino in its August Winter  update...

 

 

[Don]

2 hours ago, northwestsnow said:

Nino now almost certain to be in the strong possibly super strong category.

Saying that I'm sure Glosea for example will have factored a strong Nino in its August Winter  update...

Well I hope so, otherwise it's likely the long range models are leading us up the garden path!! 

Edited August 18, 2023 by Don