Model Output Discussion - Into 2024

[Ali1977]

The snow that falls day 8/9 lasts till day 12 when the easterly kicks in - I’d take that

[GokouD]

These GFS runs seem to be pushing an insane amount of cold down into the US, I bet they're cheering for it over there. It seems a bit OTT to be true though...

[LRD]

35 minutes ago, bluearmy said:

The good news is that we can all go to bed! 

You went to bed too early

[Scott Ingham]

Just now, Allseasons-Si said:

Just had an hickup,....really?

i love this chase ha ha.

This feels like it’s picked up on the next stage of travel into Scandi and has rushed through the outcomes forgetting we’ve got a large blocking high in Greenland! 

[ICE COLD]

Here comes the real deal of cold  

[Uncertainty]

2 minutes ago, Scott Ingham said:

Yep! And the reason why I normally use the regional thread. I have a lot of knowledge that I try to share on here but it’s like a school ground in here! It’s pathetic!

You seeing the same Scandi heights we spoke about? Yeah potential there mate!

Great to see a model play with it as an option. Last nights pub run had a look at scandi too.

 

Even earlier on in the run it moved towards the ecm solution; it’s not as simple as a bit of the ridge collapses to Europe and the spell is over. If remnant heights remain to the N and the jet stays well to the south then someone’s going to get pasted. This run is showing us how that could then translate to a much longer spell, even though the ens haven’t really been keen on the idea. 
 

Brilliant to have your input on here Scott. It’s an open forum so people are gonna have their own views but don’t let it stop you sharing your knowledge and putting your time and rep on the idea to actually make a forecast. The more high quality posts we get on here, especially ones which offer direction on the future based on evidence  - the better the experience is for everyone. 

[cold snap]

Blocking reforming. Atlantic stopping.

Deep mid winter has arrived at 300 hrs 

[Woldsedge]

I know the GFS looks an absolute pigs ear tonight, in fact an utter mess. However it does look on the cold side. This chart from Dec 81 also looks an absolute disaster area but it was absolutely perishing believe me, once cold becomes embedded at the surface, it can take a hell of a lot to shift it it certain circumstances 

[tight isobar]

Just now, Scott Ingham said:

This feels like it’s picked up on the next stage of travel into Scandi and has rushed through the outcomes forgetting we’ve got a large blocking high in Greenland! 

Bang on.. the evolutionary trait of the gfs after 108/168.. is somehow disturbing!!.. it deviates in a Bipolaric slant…. Then by way of narssasism, goes from zero to hero…. 

[LRD]

3 minutes ago, Ice Day said:

This place 

Anyway, onto the models, and it's unlikely the Control is going to provide any succour for the coldies, going the way of the Op at 138

The mean is a pretty good representation at the same time of the control and op

The GFS is an absolute dog with a bone on this one. Are we about to witness one of its finest moments or a classic GFS backtrack? As @tight isobar says, given the timescales concerned, we're not going to have to wait long to find out.  

Yep, what a win for GFS this would be. I don't think it will be but...

[kold weather]

Despite a rough start the 18z run goes onto to become a bit of a classic.

Goes to show what better upper synoptic can do in the long run if we luck out.

[bluearmy]

3 minutes ago, LRD said:

You went to bed too early

Been doing this way too long to make a schoolboy mistake like that !

whilst gfs is likely wrong in the medium term, it may have strayed upon a new longer term option.  There have been clusters sniffing around a scandi ridge in the extended period 

[tight isobar]

Just now, kold weather said:

Despite a rough start the 18z run goes onto to become a bit of a classic.

Goes to show what better upper synoptic can do in the long run if we luck out.

A rough start??. You wouldn’t have the GFS atm as a babysitter!!! 

[Scott Ingham]

1 minute ago, Uncertainty said:

Great to see a model play with it as an option. Last nights pub run had a look at scandi too.

 

Even earlier on in the run it moved towards the ecm solution; it’s not as simple as a bit of the ridge collapses to Europe and the spell is over. If remnant heights remain to the N and the jet stays well to the south then someone’s going to get pasted. This run is showing us how that could then translate to a much longer spell, even though the ens haven’t really been keen on the idea. 
 

Brilliant to have your input on here Scott. It’s an open forum so people are gonna have their own views but don’t let it stop you sharing your knowledge and putting your time and rep on the idea to actually make a forecast. The more high quality posts we get on here, especially ones which offer direction on the future based on evidence  - the better the experience is for everyone. 

Yeah it is! It’s something we discussed I think a week ago with input also from Tamara Catacol and Met4cast. I won’t let anyone drive me away mate. My input is all about 2 or 3 weeks down the line and I’m being called arrogant because of a running joke about Scott Ingham day on the 15th I’ve made more bad calls than good just like everyone else that is amateur and I may seem excited about things playing out but what some people don’t understand is when for 3 years you’ve been learning and perfecting a science and just one run follows a script that you had in your head after hours of learning it’s rewarding! Anyway I post for newbies myself and for my own learnings and passion for the weather! I genuinely think some just don’t like to see other people get better at something! 

[Cheshire Freeze]

3 minutes ago, bluearmy said:

Been doing this way too long to make a schoolboy mistake like that !

whilst gfs is likely wrong in the medium term, it may have strayed upon a new longer term option.  There have been clusters sniffing around a scandi ridge in the extended period 

It does make sense as the strat (and ultimately trop) vortex shifts back west.

It could be the case that there is some overreaction in some NWP products to this occurring (firing up a very +ve AO and NAO).

Edited January 9 by Cheshire Freeze

[Allseasons-Si]

There is my arctic rabbit sitting proud,i remember a cold spell showing the same synoptic charts(cannot remember the year) that produced.

i really must go now,...hold the fort and be nice

[Scott Ingham]

4 minutes ago, tight isobar said:

Bang on.. the evolutionary trait of the gfs after 108/168.. is somehow disturbing!!.. it deviates in a Bipolaric slant…. Then by way of narssasism, goes from zero to hero…. 

Yeah how often do we see model chaos once a new signal is picked up and rushed through? It happens a lot!

[LRD]

Just now, bluearmy said:

Been doing this way too long to make a schoolboy mistake like that !

whilst gfs is likely wrong in the medium term, it may have strayed upon a new longer term option.  There have been clusters sniffing around a scandi ridge in the extended period 

Ha ha!

Yes to be fair Scott and a couple of others did call the potential for a scandi ridge last week. I think you might have mentioned something too. It's only one run of course and longer term models like EC46 haven't picked up on that yet. Probably a phantom in the GFS machine again but let's see if it's somehow latched on to something

[Geordiesnow]

3 minutes ago, Ice Day said:

This place 

Anyway, onto the models, and it's unlikely the Control is going to provide any succour for the coldies, going the way of the Op at 138

The mean is a pretty good representation at the same time of the control and op

The GFS is an absolute dog with a bone on this one. Are we about to witness one of its finest moments or a classic GFS backtrack? As @tight isobar says, given the timescales concerned, we're not going to have to wait long to find out.  

If the PV enters Greenland from the Arctic, then the GFS will be more accurate, if it's wrong on that, we could see more something like the ECM. 

Despite me saying the UKMO is not like that, on second thoughts it's not far off and arguably occurs around a day later hence the 168 hour chart although there might just be enough height rises/forcing to get more cold air mixed in again.

This is real knife edge stuff unfortunately albeit as I said earlier the northerly will occur in some form, it's just how long it lasts and can we stay in the cold air when it does collapse(which it will as that is what is being modelled).

[Scott Ingham]

Just now, Cheshire Freeze said:

It does make sense as the strat (and ultimately trop) vortex shifts back west.

Makes sense from a tropical perspective mate as well. An AAM surge and quick move towards phase 6 of the MJO would make sure of this but tbh it looks and feels 10 days too early for me and so it’s messing up with the current pattern

[nick sussex]

A disaster would be a mild sw flow.

The GFS 18 hrs run hasn’t thankfully delivered that.

So onto tomorrow. 

This saga is going to have its own box set soon ! 

[Richard Fisher]

34 minutes ago, MattStoke said:

Oh but it does for many.

Why is the border between snow and rain always the M4? Is this by chance or is there a geographical explanation why this happens a lot?

[Purga]

12 hours ago, Purga said:

GFS 06z not an entirely satisfactory run although somewhat better than the dreadful 00z & at least hinting at a Scandi High

 

The Scandi High theme being developed on the 18z run. Let's hope it is a ever stronger feature going forwards.

 

Edited January 9 by Purga

[Phil Blake]

1 minute ago, Scott Ingham said:

Makes sense from a tropical perspective mate as well. An AAM surge and quick move towards phase 6 of the MJO would make sure of this but tbh it looks and feels 10 days too early for me and so it’s messing up with the current pattern

Could be one of these times the gfs finds a signal. Looses it and brings it back closer to range. 

I didn't really get the @Scott Ingham day thing as you had mentioned a few times the cold could land couple of days either side as you can't pin down the lag exactly. Anyway keep it up. 

[Johnp]

Just now, Richard Fisher said:

Why is the border between snow and rain always the M4? Is this by chance or is there a geographical explanation why this happens a lot?

I think it’s partly a case of when there’s an on shore drift from the wind, the distance to the M4 is sufficient to mix out any milder air keep it all as snow.