Alternate Model Discussion - into 2022

[Kasim Awan]

2 minutes ago, knocker said:

I was about to post same

The purpose of this thread is to encourage a few other people who are overwhelmed by the main thread (including myself), to an alternative, slower paced environment. @knocker, your input will be invaluable here.

[Hullsnow87]

7 minutes ago, Kasim Awan said:

Boxing day onwards looking pretty high confidence for cold and wintry now

Xmas day more 55/45 for cold into England

Do you think prolonged or a cold snap? What is you take on the blocking I get a feeling very rare Sypnotics for the time of year.

[winterof79]

UKMO 168Z I know it overcooks 850s but what is not to like

Edited December 19, 2021 by winterof79

[Kasim Awan]

18 minutes ago, Georgina said:

Well I for one am very confused by the other thread 

You will feel more at ease here. We're creating a slower paced, more relaxed and tolerable environment ☺ A few others will be posting their analysis in here too.

[Mike Poole]

11 minutes ago, Kasim Awan said:

The purpose of this thread is to encourage a few other people who are overwhelmed by the main thread (including myself), to an alternative, slower paced environment. @knocker, your input will be invaluable here.

The problem is that this never works.  I wish it did.  But at the end of the day there is just one conversation about the hunt for snow, and whichever threads are available it will find the one it finds and that will become the go to thread for many posters.  I totally understand the reason for this thread, but if the likes of yourself - and you’ve been pretty much on the ball with this one - only post here, then others will follow.  

[Kasim Awan]

4 minutes ago, Mike Poole said:

The problem is that this never works.  I wish it did.  But at the end of the day there is just one conversation about the hunt for snow, and whichever threads are available it will find the one it finds and that will become the go to thread for many posters.  I totally understand the reason for this thread, but if the likes of yourself - and you’ve been pretty much on the ball with this one - only post here, then others will follow.  

You have a go mate I always have a yes we can approach to everything I do in life. Once this thread creates it's own vibe it will go off in a completely different direction from the main model thread and be highly useful breathe of fresh air to people. This is a slower paced thread.

Would be great to see more of your level headed input in this thread Mike.

ECM will start rolling out soon.

Edited December 19, 2021 by Kasim Awan

[Mike Poole]

13 minutes ago, Kasim Awan said:

You have a go mate I always have a yes we can approach to everything I do in life. Once this thread creates it's own vibe it will go off in a completely different direction from the main model thread and be highly useful breathe of fresh air to people. This is a slower paced thread.

Would be great to see more of your level headed input in this thread Mike.

ECM will start rolling out soon.

We’ll see - I think the mods changing this thread to slow paced rather than short range might help.

I’m not that phased by the 12z runs so far - I think they show that the envelope of uncertainty is enormous, even at fairly early times, even T72-T96.  At that range you’d back the UKMO over the others for this neck of the woods for sure.  I think the uncertainty might be due to the weakness of the block, which in turn is ‘perhaps’ related to the NH being primed for a meridional jet for ages now.  

And if the ops are struggling at short range, then with their lower resolution, the ensembles are no help either.

On to the ECM.

Edited December 19, 2021 by Mike Poole

[Hullsnow87]

5 minutes ago, Mike Poole said:

We’ll see - I think the mods changing this thread to slow paced rather than short range might help.

I’m not that phased by the 12z runs so far - I think they show that the envelope of uncertainty is enormous, even at firstly early times, even T72-T96.  At that range you’d back the UKMO over the others for this neck of the woods for sure.  I think the uncertainty might be due to the weakness of the block, which in turn is ‘perhaps’ related to the NH being primed for a meridional jet for ages now.  

And if the ops are struggling at short range, then with their lower resolution, the ensembles are no help either.

On to the ECM.

Hi Mike what does that meridional jet mean please thanks.

[Mike Poole]

1 minute ago, Hullsnow87 said:

Hi Mike what does that meridional jet mean please thanks.

Wavy north to south.  As opposed to zonal, direct west to east - which for the UK brings the prevailing westerlies from the Atlantic.  This has been largely absent, apart from for very brief periods,  for about 1 year now.  Some appear worried that this might suddenly change on Christmas Day of all days!   

The NH pattern has been unusual this year, right through the summer months too. 

[Hullsnow87]

11 minutes ago, Mike Poole said:

Wavy north to south.  As opposed to zonal, direct west to east - which for the UK brings the prevailing westerlies from the Atlantic.  This has been largely absent, apart from for very brief periods,  for about 1 year now.  Some appear worried that this might suddenly change on Christmas Day of all days!   

The NH pattern has been unusual this year, right through the summer months too. 

Thanks for that been long time lurker so still learning much appreciated thanks.

[Kasim Awan]

ECM is a carbon copy of the UKMO at 120h. Let's see where it goes.

[Summerstorm]

Maybe time to start looking at the period after Christmas? As long blocking stays strong there is the potential of a NE/Nly flow after the LP system runs through the UK will be looking for a similar evolution to the GEM. 

Edited December 19, 2021 by Summerstorm

[Kasim Awan]

Ecm op not great - chin up guys. Still time for a wobble back until we get Xmas day within 96h. That's 6 ecm runs for it to revert cold again.

[Kasim Awan]

7 minutes ago, Summerstorm said:

Maybe time to start looking at the period after Christmas? As long blocking stays strong there is the potential of a NE/Nly flow after LP systems runs through the UK will be looking for a similar evolution to the GEM. 

Potentially attention needs to shift towards Boxing day onwards.

[MJB]

The long rangers show strong heights to the NW , yet looking at the GFS the heights virtually vanish ...........any ideas?

[Paul]

So, putting some ground rules/guidelines in place for this thread:

• Please don't post one liners about a model run/partial model run
• Please post post charts (or data from them) to back up your point of view
• Please remember this isn't a hunt for cold thread so the focus may solely be on the model output rather than on whether there's cold weather expected
• Posts can cover the longer or shorter range on the models - but please make it clear what time frame and locations you're referring to

These are in addition to the usual guidelines on the forum, which can be summarised as:

Be kind -- Stay on topic -- Share your knowledge -- Be polite -- Be honest -- Be tolerant -- Be family friendly

 

[Kasim Awan]

MOGREPS data is released and it is showing roughly 65% of it's 18 ensembles support the theme of colder air moving south west across the UK on Christmas day. 35% support the ECM / GFS theme.

MOGREPS-G chart

WWW.THEWEATHEROUTLOOK.COM

---

MOGREPS-G numerical weather prediction model

 

Edited December 19, 2021 by Kasim Awan

[knocker]

No significant changes with the medium term anomalies this evening. The salient points remain; upstream amplification; Russian ridge linking to the Greenland block; And a westerly upper flow across the Atlantic linking the tpv lobe in the NW Atlantic to another isolated over northern Europe with the UK sitting in a sort of no mans land betwixt the two energy flows. Tricky detail at this range with temps below average but likely with a marked N/S bias

[BlueHedgehog074]

23 hours ago, DiagonalRedLine said:

Have edited my original post in this thread to reflect that of the name change. You’re certainly welcome to continue to use this thread for short range model discussion if you wish, though

(Rarely quote my posts but…) Edited original post again to reflect another new name change to this thread  

Please though do keep it friendly in here. Thanks all

[Ravelin]

Looking at the GFS 12Z 850 ensembles for my location, which will be much more favourable than most is interesting... 

There is slightly less scatter than there was on the earlier GFS runs but still a lot more than yesterday, and starting at a relatively early point. What I often find more useful though is the box plot version... 

The first obvious observation is that the OP is an outlier, in the true sense rather than how 'outlier' is often used on the other thread, from around the 30th onwards. Secondly, look closely at the lower 10-50% quantiles and out to the end of the 31st they are much more tightly grouped than the upper 10-50% quantile. That's indicative that there's much more grouping going on in the colder ensembles than for the warmer ones. Hopefully that means a greater chance of the cold options winning, but then again the 'outlier' OP could be the winner, such are the vagaries of the weather. 

[snefnug]

Question from a lurker here.  Given the model  modelling difficulties last week re uk/Europe weather and impact downstream from tropical storms or tornadoes (?) what impact would the recent Typhoon Rai have on the models.  Apologies if I am getting the turbulence names mixed up.  

[Frostbite1980]

15 minutes ago, snefnug said:

Question from a lurker here.  Given the model  modelling difficulties last week re uk/Europe weather and impact downstream from tropical storms or tornadoes (?) what impact would the recent Typhoon Rai have on the models.  Apologies if I am getting the turbulence names mixed up.  

Hi mate i believe the typhoon has caused confusion with regards to the MJO progression as we want it to move through phase 7 and 8 as soon as possible to aid northern blocking however the typhoon has caused a little confusion as to how quick that happens if at all. The MJO will have an effect on what all the main models ie GFS, UKMO and ECM churn out.

[abruzzi spartan]

Hello on here, just a tiny post from me to say that this thread is great as it's balanced and kind with lots of knowledge being shared.  I'm as far from technically knowledgeable as it's possible to be but I love writing about weather almost as much as I love living it and it's lovely to find this rather slower paced and thoughtful thread.  Thanks.

[Summerstorm]

Well the war over how far south or north the Xmas low pressure will go continues to rage on 

Looking at longer term developments below there is a few things to look out for. 

Way out in FI and unlikely to come of but GFS exploring the Scandi route eventually, wonder if this is a trend we should look out for during into the first half of January.

 

In the meantime as mentioned in the other discussion stratospheric developments may also be something to keep an eye on as we go through the rest of winter. A displacement would seem within the realms of possibility and depending on where the vortex is displaced could have big consequences be it bad or good depending on your weather preference. 

 

Edited December 19, 2021 by Summerstorm

[Georgina]

4 hours ago, Ravelin said:

Looking at the GFS 12Z 850 ensembles for my location, which will be much more favourable than most is interesting... 

There is slightly less scatter than there was on the earlier GFS runs but still a lot more than yesterday, and starting at a relatively early point. What I often find more useful though is the box plot version... 

The first obvious observation is that the OP is an outlier, in the true sense rather than how 'outlier' is often used on the other thread, from around the 30th onwards. Secondly, look closely at the lower 10-50% quantiles and out to the end of the 31st they are much more tightly grouped than the upper 10-50% quantile. That's indicative that there's much more grouping going on in the colder ensembles than for the warmer ones. Hopefully that means a greater chance of the cold options winning, but then again the 'outlier' OP could be the winner, such are the vagaries of the weather. 

This may be a stupid question but how can you tell if the op is an outlier and what does that exactly mean does it mean that it’s not worth looking at ? Thanks and sorry for the daft question xx