Model Output Discussion - Cold spell ending - what next?

[Lukesluckybunch]

3 minutes ago, AO- said:

The problem with EC tonight is the WAA being too far east and tilted the wrong way. It is more progressive with the WAA. Small differences are needed upstream to get where the GFS is heading. To start with the high pressure near the coast of the US. Small details will make a big difference, but I suspect the EPS to be more supportive of the GFS scenario. 

3 minutes ago, AO- said:

The problem with EC tonight is the WAA being too far east and tilted the wrong way. It is more progressive with the WAA. Small differences are needed upstream to get where the GFS is heading. To start with the high pressure near the coast of the US. Small details will make a big difference, but I suspect the EPS to be more supportive of the GFS scenario. 

Day 10 AO.looks starting to show some promise..you would think it will at least turn cold and dry thereafter,looking at the day 10 chart

[Stuie]

2 minutes ago, Mike Poole said:

OK, so it’s a day late with the amplification, ECM T240:

Same page in my book.

How does that work with a positive NAO Mike?

[AWD]

3 minutes ago, Stuie said:

Looking at the wind issue again for Sunday night/Monday morning. Using the Arpege, western and southern coasts around 50-60 mph gust with Northern Scotland taking the brunt with upto 90 mph gusts.

Not sure what the UKMO values look like but probably the stormiest of all the models.

Here is the 12z Arpege wind gusts forecast for Sunday night mate, much easier read here;

[That ECM]

Firstly it beats wind and rain in my book. 
 

secondly, I’d like to get close to this and see what evolves.

[Stuie]

Just now, AWD said:

Here is the 12z Arpege wind gusts forecast for Sunday night mate, much easier read here;

Cheers mate, was converting km/h to mph in my head. Looks similiar.

[nick sussex]

The overall pattern has good agreement after the weekends wet and windy weather .

So the upstream troughing will dig south and there will be several attempts to cut shortwave energy se to the east or ne.

Pressure rises to the ne but the question is can that troughing sharpen up enough and will we see a westwards correction. 

We certainly need the MJO to move out of phase 5 and into 6 as quickly as possible and preferably into 7 but the models seem less interested in the latter happening . There’s also a question mark over the amplitude of the signal.

 

[AO-]

4 minutes ago, Stuie said:

How does that work with a positive NAO Mike?

Positive NAO is roughly Low pressure over Iceland and high pressure to the South. Which still is the case in the current calculation. There is a strong gradiënt over Iceland in the GFS. But with a blocked continent this should not be a problem. It can eventually turn into a negative NAO when the Scandiblock retrogresses by support of the MJO 8 towards Grreenland. 

[Bricriu]

9 minutes ago, Stuie said:

How does that work with a positive NAO Mike?

I believe It worked in 1991 

[Bricriu]

5 minutes ago, nick sussex said:

The overall pattern has good agreement after the weekends wet and windy weather .

So the upstream troughing will dig south and there will be several attempts to cut shortwave energy se to the east or ne.

Pressure rises to the ne but the question is can that troughing sharpen up enough and will we see a westwards correction. 

We certainly need the MJO to move out of phase 5 and into 6 as quickly as possible and preferably into 7 but the models seem less interested in the latter happening . There’s also a question mark over the amplitude of the signal.

 

I hope the MJO isn't going to cod us again.  It's unlikely  the Scandi High will come off in that case. 

[Bricriu]

12 minutes ago, AWD said:

Here is the 12z Arpege wind gusts forecast for Sunday night mate, much easier read here;

Thats a major storm  for us if it comes off, but I have a feeling the French model is overdoing it 

[stodge]

Evening all

So ECM, GEM, GFS OP and GFS Control in the 12Z suite all derail the Atlantic train next weekend. Far too early to be anything more than eye candy but perhaps a well-signalled sign of how we break out of the pattern coming in over the weekend.

The big question as always is or will be the strength of the northern arm of the jet - it may well be it'll take two or three attempts before a Scandinavian block can fully assert but it's encouraging for fans of dry in particular and cold to an extent to see the trend.

I'm not keen on another Siberian warming emerging in early February as it rarely ends well unless it can do something significant.

Baby steps for now - many will welcome the dry trend to the weather especially in the south and east after the December deluges.

[northwestsnow]

9 minutes ago, Bricriu said:

I hope the MJO isn't going to cod us again.  It's unlikely  the Scandi High will come off in that case. 

MJO  might be really important, no COD please..

[Drifter]

23 minutes ago, Stuie said:

How does that work with a positive NAO Mike?

Many scandi highs of the past occurred during +ve NAO phase. 

[northwestsnow]

Well im going to have a look at EC 46 regardless..

The model was seeing HP in our locale now we need to see if it can nudge the high north...

[Mike Poole]

24 minutes ago, Stuie said:

How does that work with a positive NAO Mike?

It is part of the process that will (hopefully) turn it negative - but not in 10 days time, nailed on positive until then as the GEFS based output you show indicates.

[Daydream Boy]

3 hours ago, Bats32 said:

Ouch, could we be looking at another 1987 here?

Hardly! Those gusts are in kph not mph. 1987 storm had much higher gusts. 

[DaveF]

UKV has really increased the Monday 00Z wind gusts in the 15Z run (first image) compared to the 03Z run (second image). Looks like his is going to be a major storm, especially where I am in NW Wales. It's suggesting gusts of 80-90mph even in the Midlands.

[Stuie]

11 minutes ago, Mike Poole said:

It is part of the process that will (hopefully) turn it negative - but not in 10 days time, nailed on positive until then as the GEFS based output you show indicates.

Cheers, Mike. Let`s see.

[Anthony Burden]

Evening all,The Atlantic surge might well be short lived charts beginning to firm up on high pressure within a week or so time frame in regards to positioning all fingers crossed for a east/northeast feed eventually.The important fact cutting of the Atlantic train gives hope in getting a cold feed to establish over the UK.

[bluearmy]

Eps control is close to the op at day 10 and evolves in a way that many are expecting with scandi ridge of sorts and a slow move nw thereafter 

[Mike Poole]

Big changes on the ECM clusters tonight - you may not be surprised by this if you’ve followed the earlier output this evening.

T120-T168:

The changes beginning to show at T168 with a trough in the Atlantic and ridge through the UK towards Scandi, in all clusters, most pronounced on clusters 1 and 3.  

T192-T240:

The signal gets magnified on cluster 1 in this timeframe building the Scandi high (33 members).  More muted on cluster 2.  

We await the extended clusters (not out yet).

Edited January 18, 2024 by Mike Poole

[TillyS]

6 minutes ago, Anthony Burden said:

Evening all,The Atlantic surge might well be short lived charts beginning to firm up on high pressure within a week or so time frame in regards to positioning all fingers crossed for a east/northeast feed eventually.The important fact cutting of the Atlantic train gives hope in getting a cold feed to establish over the UK.

They are not 'firming up' on this.

There is very little in the ECM to support it as the Atlantic is not in abeyance and any high pressure at T240 is just as likely to get flattened by the Atlantic. There isn’t any support from the UKMO out to T168. Even the GFS operational is out on a limb with the idea, which anyway was out at T300 or so:

That doesn’t mean that the Atlantic won’t blow out. It might. And eventually it will. But please let’s not gild the lily. We have at least a week (could be a fortnight or more) of wild and mild according to the latest runs. By the time this hits at the end of this weekend, we’ll certainly know we’re back under the influence of Atlantic storms. It looks pretty serious:

 

17 minutes ago, DaveF said:

UKV has really increased the Monday 00Z wind gusts in the 15Z run (first image) compared to the 03Z run (second image). Looks like his is going to be a major storm, especially where I am in NW Wales. It's suggesting gusts of 80-90mph even in the Midlands.

It does indeed look serious and ought really to be taking more of our attention.

[AO-]

Great improvement tonight by EC. dont need to say more. A lot more support for the GFS scenario. 

[TillyS]

40 minutes ago, stodge said:

Evening all

So ECM,

Not the ECM.

Without any northern blocking and those powerful SW winds up over the top, and warming Scandinavia, this is a recipe for a flattening of the high - kicking it out across northern Germany. If you watch it from T198, to T216, into T240 this is the process. Which is about the worst possible outcome for UK cold.

Edited January 18, 2024 by TillyS

[damianslaw]

Mmm interesting developments, more in the sense GFS and ECM are showing quite similiar synoptics as we end January...heights building to the south quite strongly with a signal for these to edge north and eventually NE, setting up a potential much colder continental flow from the east, I say potential only at this stage and we are probably talking at least 2 weeks away.

In the short term, after a cold blocked 2 weeks, notably more so in the north, we have at least a week of very mild and at times very wet and windy weather commencing Saturday.

Winter 2023-24 could turn into a very topsy turvy rollercoaster ride.. 

Edited January 18, 2024 by damianslaw