Model Output Discussion - mid Autumn

[Rain All Night]

9 hours ago, RainAllNight said:

Everyone is now showing the "trough to the southwest" solution at day 7, just with varying strengths to the low:

Back to being much messier again at day 10. GEM and JMA have still managed to bring a cold pool across from the east, GFS no longer has - it's let the high sink into the continent. ECM, on the other hand, barely changes between days 7 and 10, and keeps the high over Scandi strong:

The one thing that seems clear about next Friday is that the weather won't be great down south...

[northwestsnow]

EC day 7 and the block is trying to face off the Atlantic

[Kasim Awan]

Just now, northwestsnow said:

EC day 7 and the block is trying to face off the Atlantic

No Atlantic there.

[northwestsnow]

Just now, Kasim Awan said:

No Atlantic there.

Atlantic is always there!!

 

Day 8 

no idea how that chart translates at the surface.

 

[Kasim Awan]

6 minutes ago, northwestsnow said:

Atlantic is always there!!

 

Day 8 

no idea how that chart translates at the surface.

 

4/13C very gloomy windy frost locally in west at night.

Edited October 13, 2023 by Kasim Awan

[northwestsnow]

EC 46 looks to be following UKMET November forecast ...

 

[Kirkcaldy Weather]

On 12/10/2023 at 01:53, Kirkcaldy Weather said:

Let's see the signal for the MJO phases 7 & 8 through October via JMA

• Active West Pacific signals [super typhoon Bolaven]
• Californian >> Mexican cyclonic pattern. Major Hurricane Lidia plus Tropical Storm Max. Also the potential next Rossby Wave via Bolaven into new California Cyclonic conditions 
• Build of pressure through the UK and Scandinavia which transpires as the Rossby Wave within Atlantic continues its progression further East

 

On 12/10/2023 at 01:53, Kirkcaldy Weather said:

be looking particularly toward the patterns getting retrogressive in nature with scope for further blocking which looks to have the opportunities of origin towards Scandinavia"

should we have the elongation of troughing also retrogressive across the UK toward the Atlantic with enough cold air come week one of November I can forsee business in this thread "

JMA with phase 8 

• Retrogression underway via Scandi --- Greenland
• Italian Cyclone
• Troughing through southern US ie GOM
• Deep Russian Troughing

My goodness me that is literal perfection 

Evolution from 2018

 

Output upcoming 

Now we're at the stage where the evolutions via phases 6 through 8 are coming to the forefront paired with the current PNA still being highly positive more info coming below with that.

How does the easterly set up then

On 12/10/2023 at 01:53, Kirkcaldy Weather said:

Build of pressure through the UK and Scandinavia which transpires as the Rossby Wave within Atlantic continues its progression further East

As I discussed prior our Atmospheric river low doesn't fully develop as it is acting as a boost of energy to the deepening cyclone through Scandinavia.

By late Sunday there is an initial cyclone which moves into northern Spain and Portugal 

And our upstream ridge begins to enter UK

 

Come Later Monday through Tues the 1st cyclone centres in Spain and Portugal which nudges and centres the high over the UK

As midweek comes this is the most important part of the Wave Breal

The energy separation acts in 2 significant areas 

1. BOOST INTO THE DEVELOPMENTS AND HIGH PRESSURE FOR SCANDINAVIA 
2. FORCES A NEW CYCLONIC ZONE FOR PORTUGAL AND SPAIN

at similar timing when the heights raise through Scandinavia on the upstream this triggers the new Cyclone probably near Latvia and Lithuania 

This gives us our new Rossby Wave setup as we enter next weekend with the dual cut off lows and increased pressure over Scandi

Some model differences regarding the upstream low however it's probably temporary within that region.

Loving this as we're being directed to the dominating synoptic I believe ️🌨 for Winter 2023 --- 2024

An interesting signal for very end of Oct toward start of November certainly akin to phase 6 with that continually low heights over Maritimes and easy to invisige the troughing on a Northeast SW trajectory through Scandi possibly into UK

 

'Now watch as the MJO begins to traverse into the Pacific. Rainfall anomalies increase which allows a track to begin and orientation curves northeastwards to Alaska with time 

We will see a gradual change from the trough through Alaska into a elongating high which has a great shot of being connected with our Scandi>Greenland High, this has brought interesting potential for an enhanced warming stratospheric zone and early signal to be on lookout with regards to split SPV opportunities into at least  week 1 November possibly extending beyond that.

 

 

[ANYWEATHER]

Probably the best October charts I've seen for many years during this weekend! Fast forward to next week Ecm has the Scandi high demolish the Atlantic...from the uk .?

[WYorksWeather]

And yet again (becoming something of a regular post this), I'm going to have a look at the GFS vs ECM comparison and see what we can glean from it.

As seems to be usual lately, very little difference at T+72, except that ECM has the developing low near Spain fractionally further south.

 

At T+120, GFS allows the low to intrude into the south west of the UK, whilst the ECM still has it trending further south. Both models have a very deep low on the southern tip of Greenland. As yesterday, ECM wants to centre the Scandinavian high a little further east than the GFS.

 

By T+168 (the equivalent of yesterday's mild spell on the ECM at T+192), the situation is fairly messy. GFS has a deep low spinning out in the mid-Atlantic, and ECM wants to intensify the trough to our south west. ECM is still a bit milder from days 5-7 than GFS, but both models have moved towards each other.

 

 

Rounding it all off, at T+240, the pattern is incredibly messy. A series of small lows over the UK and out to our west, the Scandinavian high sinking further south and east on both charts.

 

Bonus chart - well into FI and beyond the ECMs range, but the GFS eventually powers up the jet stream and sends a pretty major storm flying in our direction...

   

[WYorksWeather]

Should also finally mention that these charts are reasonably trustworthy representations of the ensembles, neither chart is really going crazy into FI.

GFS ensembles for London, Sheffield, Newcastle and Inverness:

   

ECM:

   

Of course, as others have correctly noted, surface temperatures are less well-correlated with airmass temperatures at this time of year.

[Don]

1 hour ago, northwestsnow said:

EC 46 looks to be following UKMET November forecast ...

Today's 16-30 day forecast from the Metoffice has changed from slightly below average temperatures to above average with the chance of colder spells.

[northwestsnow]

20 minutes ago, Don said:

Today's 16-30 day forecast from the Metoffice has changed from slightly below average temperatures to above average with the chance of colder spells.

Faulty.

Easterlies in Nov..

[sheikhy]

20 minutes ago, northwestsnow said:

Faulty.

Easterlies in Nov..

Any pics buddy?!!

[northwestsnow]

6 minutes ago, sheikhy said:

Any pics buddy?!!

 

 

 

Edited October 13, 2023 by northwestsnow

[sheikhy]

1 minute ago, northwestsnow said:

 

 

 

Nice one!!Also stronger scandi high and further west at 168 hours on gfs 18z!!!

[Don]

30 minutes ago, northwestsnow said:

Faulty.

Easterlies in Nov..

Will their forecast change again?! 

[Allseasons-Si]

The tpv looks kind of marmalised on the gfs 18z run and even a hint of the pv stretched at 10hpa with a slight warming right at the end...

keep it that way as we go into winter propper,...BOOM

[Allseasons-Si]

Quite a decent geo pot mean there from the gefs 18z even out to fl with lower hieight's from Iberia to med and +ve heights Scandi to greenland and across the pole to Alaska and eastern Siberia

at face value,...that is as good as a winter chart that you could hope for but can this manifest further as we go into the winter months,...one to watch

i am here again for the long slog of the winter months (the best time of the year IMO) of when there is so much to talk about and learn and i have learn't so much in here thanks to a great close nit community,you all have been a credit to this forum

gear up guys,...winter is coming

well i hope so

good night.

 

[Cheshire Freeze]

2 hours ago, Allseasons-si said:

The tpv looks kind of marmalised on the gfs 18z run and even a hint of the pv stretched at 10hpa with a slight warming right at the end...

keep it that way as we go into winter propper,...BOOM

If we keep the pressure on the developing vortex I'd be flabbergasted if we're not in with a sniff of a rare November warming.

[sheikhy]

Horrible wet runs from gfs and ecm!!ecm esepecially rain just becomes slow moving across the uk!!!i either want the scandi high to influence our weather fully or just bugger off!!!hoping for a change on the 12zs!!

[Premiere Neige]

5 hours ago, Cheshire Freeze said:

If we keep the pressure on the developing vortex I'd be flabbergasted if we're not in with a sniff of a rare November warming.

Does anyone know when we last had a November warming? I know there was one in 1962...

[Mike Poole]

12 minutes ago, Premier Neige said:

Does anyone know when we last had a November warming? I know there was one in 1962...

1958 and 1968 are the only two official November SSWs according to the NOAA compendium:

NOAA CSL: Chemistry & Climate Processes: SSWC

CSL.NOAA.GOV

---

NOAA CSL: Advancing scientific understanding of the chemical and physical processes that affect Earth's atmospheric composition and climate.

These are defined as a reversal of zonal winds at 10hPa 60N.  

There is some suggestion that 1962 had a ‘Canadian Warming’ (not a full reversal, and I’m struggling to find an exact definition of precisely what a Canadian Warming actually is, but it can happen in early winter but not necessarily an official SSW).  Anyone able to shed any light?

Both 1958 and 1968 were El Niño and easterly QBO years, interestingly.  And an early SSW has shown up as an outside possibility on 2 seasonal models in the October updates (GloSea6 and DWD, the German model).

Edited October 14, 2023 by Mike Poole

[Anthony Burden]

Morning all,ECM this morning maintaining a mildish October theme after a short cold spell.

[Tommytomtom]

7 hours ago, Cheshire Freeze said:

If we keep the pressure on the developing vortex I'd be flabbergasted if we're not in with a sniff of a rare November warming.

May i ask what a November warming is?  Ive googled it and nothing came up

Edited October 14, 2023 by Tommytomtom

[northwestsnow]

I do hope we don't spend the next 10 days with a sagging block to the NE and Atlantic lows getting stuck near the UK..

No thanks weather God's..