Model Output Discussion - Deeper into Autumn

[blizzard81]

18 minutes ago, Uncertainy said:

Barely any model discussion on here tonight . Loads of climate discourse and very few charts. This thread is where you analyse and discuss the latest model output, not ruminate on the loss of another potential cold U.K. winter over a month before it’s even started.

If I were wanting a real cold spell, not a weak chilly November Atlantic ridge that flatters to deceive but allows the SPV to ultimately dominate (Ala last year), I’d be looking for a Scandi (high) Greenland (low) dipole to disturb the strat and kick off the blocking that the seasonals have long suggested.

A but like this then, late on the Gem ens…

 

2/3rds of eps members have a similar picture, but look more unsettled generally

In the meantime (e.g the next 10-14 days) it will continue wet in the W and quite possibly nationwide should the low move closer.

Should this pattern persist, sooner or later the SW winds will align and a very wet atmospheric river episode could occur, we have avoided one so far with the southerly nature to the flow.

Longer term, it may be a 2009 redux, it may not. But don’t forget the purpose of this thread before you post. 

Dont know who in particular you are aiming your post at but seem as though I was the one who mentioned November 2009, all I will say is the point of my post was to stress that I liked the idea of trough disruption in early November, caused in part by blocking over western Russia/eastern Scandi. This is what happened in Nov 2009 and we are seeing something very similar develop on the models presently. It bodes well for the coming winter imo and I also posted a chart . 

[Downburst]

Well this evening’s ecm at least shows the presence of my hoped for high pressure sitting out west at the very end of the run. November 5th and some promise, that’s if I haven’t drowned by then. All going to plan this is heading this way, but I’m not betting on it.

the 46 day charts are suggesting high pressure hanging on for at least 10 days from maybe around the 10th, so perhaps a frost or two at least. 

14 - 21 Nov 500 chart. Who knows, might be end of good weather for ducks and bring in excellent weather for duck shooting, which would be a terrible turn of events for the ducks in all fairness.

[Uncertainty]

16 minutes ago, blizzard81 said:

Dont know who in particular you are aiming your post at but seem as though I was the one who mentioned November 2009, all I will say is the point of my post was to stress that I liked the idea of trough disruption in early November, caused in part by blocking over western Russia/eastern Scandi. This is what happened in Nov 2009 and we are seeing something very similar develop on the models presently. It bodes well for the coming winter imo and I also posted a chart . 

You did indeed pal it was certainly not aimed at you. 

[LRD]

Ridiculous warmth today but the ECM ensembles at 850 show something more normal as we go into the new month

Really small beer but it's very, VERY early and time for something more substantial to develop

Don't go for pattern matching though so not sure about the 2009 comparisons

[LRD]

GFS ensembles similar to ECM

Maybe something, at least, a bit eventful even in the tropical SE (although Thursday and Sunday just gone were fun IMBY) as we go into November. But we'll see

[blizzard81]

2 hours ago, blizzard81 said:

This is what I like to see as we enter November. Trough disruption in our vicinity. Very reminiscent of early November 2009.

With regards to trough disruption and block to our east in early November, nevermind 2009.......

[Cheshire Freeze]

After a bland couple of runs, the GFS resumes its interesting latter FI scenarios

[Cheshire Freeze]

Epic control FI coming? If nothing else it carries on the theme of pattern change second week of Nov onwards-

Huge ridge exiting the ESB there

[Rain All Night]

I had been noticing that the takeaway message from the farthest reaches of the 15-day ensembles seemed to be that the ridging to our east is strong and will fight back robustly against any incursions... you might have to watch an animation to see what I mean, I have linked one below (the GEFS 18z).

https://www.tropicaltidbits.com/analysis/models/?model=gfs-ens&region=nhem&pkg=z500a&runtime=2022102618&fh=354

But then in the GFS 18z operational, it gets torn through like it's paper! 

Edited October 27, 2022 by RainAllNight

[PiscesStar]

Hey Guys! The latest gfs run shows a watering down or a much more mobile pattern emerging to previous runs. At the latter part of the run signs of a cooler influence are shown. Promising if seasonal is your "thing"! Not so good if we need to keep the heating off like I do. 

Edited October 27, 2022 by PiscesStar

[Scott Ingham]

13 hours ago, Weather Enthusiast91 said:

These charts aren't looking very promising as there still isn't much sign of a return to seasonal temperatures. Any signs just keep getting pushed back, which has been a common occurence during 2022.

If this is the future for our autumns, then I may have to (finances permitting) consider emigrating. 

I disagree. Im with Crewe on this.

Very november 2009. Perfect to give the strat an early kicking.

Also high amplitude phase 7/8 of the mjo with a lag effect to the first 2 weeks of december are perking my interest (a little bit for now)

[Scott Ingham]

8 hours ago, blizzard81 said:

This is what I like to see as we enter November. Trough disruption in our vicinity. Very reminiscent of early November 2009.

Agreed im VERY encouraged. 2009 is a year ive had in my head tbh as well since the end of August. First or second week in december for a first cold shot

[Uncertainty]

The clusters in the extended are favouring a major Urals high

 

The op goes for it sooner, but it’s an outlier and I don’t trust it yet (3 consecutive runs and my eyebrow will be raised…)

The GEFS also remain keen

 

The gfs op looks a lot like the 3rd eps cluster

This is all early days and there’s a good chance this unsettled spell goes on for 300+ hours but surely all this momentum will force some blocking sooner or later. The favoured position, at present, is Scandanavia esp given the Nino-like state of the atmosphere at present.

But such highs are notorious for evaporating from output in winter so let’s keep a close eye.

 

[northwestsnow]

Subtle hints the models are picking up on a change as we head through the 2nd week of November this morning..

EC168

EC 192

slower on GFS but a similar evolution.

 

[johnholmes]

Tend to agree with the above post.

Most model outputs, for example GFS 00and ECMWF 00z both suggest this. Also the 500 mb anomaly charts change the 500 flow from south of west into the UK to a more westerly flow with lowering heights. This would support the synoptic models for a change to more normal temperatures.

This EC output illustrates this idea

http://www2.wetter3.de/Fax/00_ECMWF_ENS_p0_500hPa+144_240.gif

 

[Kirkcaldy Weather]

The building blocks (little play on words there ) are starting to come into the modelling with good frequency, for any newer model watchers don't worry on the exact location at this point, might be a block to the east with retrogression to Greenland or might develop more readily toward Greenland first...currently I'd think the natural progression would move it in that direction anyway. Here's the original charts 

 And besides the block setting up I highlighted another significant thing to watch for 

Might be the tropospheric PV moves to a pretty highly favourable position for an easier path to get into the proper snow producing upper temperatures than if it was sat closer to the Canadian / U.S side.

Currently I look at it a bit like we are choosing a puzzle we'd most like to build its no rush let the pattern develop, the next stage will be figuring out exactly which pieces go where

[damianslaw]

ECM showing interest at the 9 day timeframe, low pressure disrupting and heights building in over the top ridge into scandi. Interesting.

Edited October 27, 2022 by damianslaw

[Kirkcaldy Weather]

2 hours ago, Kirkcaldy Weather said:

The building blocks (little play on words there ) are starting to come into the modelling with good frequency, for any newer model watchers don't worry on the exact location at this point, might be a block to the east with retrogression to Greenland or might develop more readily toward Greenland first...currently I'd think the natural progression would move it in that direction anyway. Here's the original charts 

 And besides the block setting up I highlighted another significant thing to watch for 

Might be the tropospheric PV moves to a pretty highly favourable position for an easier path to get into the proper snow producing upper temperatures than if it was sat closer to the Canadian / U.S side.

Currently I look at it a bit like we are choosing a puzzle we'd most like to build its no rush let the pattern develop, the next stage will be figuring out exactly which pieces go where

Just want to add this onto my post as it's pretty much in line with it 

Let's see what the 12zs go for

[LRD]

Size does matter. Look at the size of that High pressure system to our South on the UKMO 168 chart

It covers virtually the whole of the continent south of the Channel and also a significant part of North Africa and over the East Atlantic. Incredible and hopefully NOT a sign of things to come for the next 4 months but that looks robust. Surely, it's being overdone?

[phil nw.]

Yes it looks like we move into a more westerly pattern as go into November after this exceptional warm southerly type setup.

We see the Euro high finally overcome with the ridging pushed further east as the Atlantic lows approach from the west.

Something more typical for late Autumn with temperatures closer to average.

 

[Cambrian]

The first few days of November are looking like they’re going to be a good deal more lively in terms of North Atlantic weather than we have seen for a good while. 

The 12z GFS mean shows the North Atlantic low deepening 10mb between day 7 and day 8 - a marked drop for the mean at that range. 

 

The mean jet stream chart at day 8 shows a continuous tract from the Baja California to Belgium. In recent months, it’s more normally a runty looking monochromatic blue slug by that point, which apparently, on googling, is perfectly feasible.

 

The energy driving through the Atlantic trough also succeeds in eventually dragging some colder air south by day 10. 

   

The end of the first week in November looking rather cold and changeable in chilly westerly winds, the rain and temperature drop together perhaps enough to turn your slugs blue. 

[johncam]

To be honest it's all a bit meh , nothing in the charts to suggest anything but mild and wet at times 

[Newberryone]

Well today's 12z Ecm certainly ends on a bit of meh note for those seeking something more seasonal as hinted at by the 00z run. Chalk and cheese springs to mind when comparing the 2 outcomes. In fact higher pressure from the south as early as next Thursday 3rd Nov pushes the jet stream further north unlike the previous run which overall looked far more unsettled throughout the outlook period.

[damianslaw]

24 minutes ago, Newberryone said:

Well today's 12z Ecm certainly ends on a bit of meh note for those seeking something more seasonal as hinted at by the 00z run. Chalk and cheese springs to mind when comparing the 2 outcomes. In fact higher pressure from the south as early as next Thursday 3rd Nov pushes the jet stream further north unlike the previous run which overall looked far more unsettled throughout the outlook period.

Models quite volatile just beyond reliable, chopping and changing, suggests pattern change on the cards, and they need more time to latch onto the likely trend. 

Edited October 27, 2022 by damianslaw

[Uncertainty]

Jam tomorrow perhaps, but the EPS have really come on board with the +SCAND pattern idea, so much so that we almost have a mean easterly flow by the end of the run. A rare beast at that range I can tell you and often indicative of a genuine signal rather that anomaly ‘noise’.

 

Compare this to the GEM ensembles, which are reasonably similar

Which translate to this anomaly chart

 

With the JMA weeklies giving the same picture, and the mjo forecast to stay between phases 5 and 7 for the foreseeable, I’d say the SPV is already getting a tad nervous…

 

The chances of a drier, more seasonal period in mid to late November are higher than normal.

 

The regimes show a clear bias towards blocking patterns.

More speculatively, the foundations for a colder early winter period are also starting to fit into place.