Model Output Discussion - Spring Has Sprung

[winterof79]

  @Mike Poole can you let NW know before he becomes a statistic.

[Dennis]

  @bluearmy

well alot above us - i mean strato/tropo) has effect on positions 

its just some fun to study on it

 

GFS6z

 

 

Edited January 29 by Dennis

[Anthony Burden]

 Morning all,GFS showing cold incursion at 192hrs what happens from then is very much up for debate lots of ways this could go but I still believe the met office extended forecast that has a northerly with wintery period has a lot of credibility,of course the proof is in the pudding.

[Eagle Eye]

MJO phase 8 and built-up momentum response likely late February or into March. There appears to be a good chance of a phase 8 w/the w'ly moving w'ly burst as the slow Nino-neutral/Nina transition occurs and the phase 7-8 is also typical of that transitioning time. However because of the w'ly burst, perhaps the response would be more neutral/Nina esque. The MJO low pass appears to suggest neutral with slightly more amplification with the momentum. As we get into March we really need more amplification though. Given the potential before this in mid-Feb isn't looking as good as it was before though there's some decent colder solutions in the spread. 

Edited January 29 by Eagle Eye

[MisfitDog3]

 

The Low forecast to pass north of Scotland, well up near the Faeroes, mid week looks to be a real beast. The Met Office have this at 949mb and then 944mb as it passes over the Norwegian Coast. The squeeze on the southern flank is something to behold. One to watch. 

[Downburst]

  @MisfitDog3 @Methuselah

It is extremely low. The lines of longitude and latitude on the map due to the spherical map are condensed the further north and hence the pressure lines appear to be too.  So it can appear more condensed in my opinion, but open to argument, which is a given on here  

[Paul]

56 minutes ago, MisfitDog3 said:

The Low forecast to pass north of Scotland, well up near the Faeroes, mid week looks to be a real beast.

It is a biggie. GFS has it deepest currently (no shocks there!). (GFS, ECM, Meto and Arpege shown here). 

 

 

[MAF]

You wouldn't want to be out on a fishing boat in that! 940   

[AO-]

For those who thought number 13 was an unfortunate number, think again. Just had to show this one 

Still a way to go to get it within the reliable though. 

 

[Ice Day]

There is undoubtedly an emerging signal for something colder showing up on the GEFS, starting around day 11.

It's a such range though it's no more than a watching brief at the moment.  However, given the rubbish being churned out of late, any glimmer of light is worth pursuing (assuming cold is your thing).

[Cambrian]

One of those times when it’s of particular benefit to have modest expectations of the models in the nearer ranges, not be swayed too much by individual operational runs and focus on the core evolution of what is actually being shown. 

6z GEFS staying true to form with the modelling of recent days.

Stage 1 : day 1, getting some fresher air in behind the cold front passing through tonight. Might see the sun tomorrow! Note the low to the east of Greenland. 

 

Stage 2 : day 3-5, the low moves through the Norwegian Sea to northern Scandinavia. This is the first (unsuccessful) attempt at setting up a Scandinavian trough. A strong build in heights to our west over the Atlantic is squeezed flat by day 5 as the next low exits Greenland. However, this one’s the boy for Scandinavia.

 

Stage 3 : day 7-9, the low pressure sets up over Scandinavia, while there is another northwestward build of heights up through the mid Atlantic, an important phase as it pushes more directly north through Iceland, ridging north to Greenland. This build in heights keeps a substantial separation between the Scandinavian / NW Russia and eastern seaboard troughs, and pulls the flow through northwest Europe around more to the north.

 

Stage 4 : day 10-12, the trough extends back west through Western Europe, clearing the heights out of Iberia, a decent cold signal developing by then, and at this range, not to be sniffed at.

  

It’s a very well repeated core evolution of the models of the last few days. I’m looking forward to seeing if and how exactly something like it might transpire!

Edited January 29 by Cambrian

[Dennis]

MJO 29-1

[Jacob]

@DennisWhere can I learn to read these MJO charts and where can I find them?

 

 

[Paul]

28 minutes ago, Jacob said:

Where can I learn to read these MJO charts and where can I find them?

This is a good place to start

https://community.netweather.tv/learning/teleconnections/

And here for more research and learning

https://community.netweather.tv/learning/research/madden-julian-oscillation-mjo-r36/

[TEITS]

Amazed nobody has mentioned how closely the GEFS control follows the GFS.

When this happens you take note in my experience. I expect the GEFS mean on the 6th Feb to start dropping from 0C towards -5C for my location.

I feel some excitement is going to return back to this thread very soon.

[Dennis]

newest AO 29-1

[Kirkcaldy Weather]

 

Warnings issued

 

Starting to get a cleaner idea of the likely direction / evolutions through February and heading into March, firstly I'd like to show whats been happening with the below average temperatures zone I mentioned which is running across the southern regions of the Northern Hemisphere 

Azerbaijan & Iran

 

 

 

The colder temperatures at surface and upper levels will gradually continue eastward and move across Asia by one of the timeframes I'll talk about in a sec.

 

'As the positive PNA feedback progresses eastward pairing with the MJO patterns I've covered in depth, a +PNA does have a tendency of being supportive for Atlantic ridging / blocking which moves in the direction of Greenland and in connection to a trough further east ie Scandinavia, Baltic regions which gives a doorway for something cooler > colder from the north'

"Though I'm not putting a massive amount of emphasis into exact timeframes from my POV ATM it's looking favoured for this by approx February 4th / 5th and starting to see a possible redux around 1 week later ie 11th / 12th February."

Looking like a decent set of estimates and further excellent representation of exactly what I'd expect from the MJO feedback.

Low pressures crossing the UK in particular the northern portions which feed into the Scandinavian trough developments, Troughing and aforementioned colder conditions into Asia > East Asia, High pressure / block across the East > Northeast of America and the Maritimes with further above average temperatures no surprises from my POV on that. Continuing trough and noteable cold across Alaska too.

 

Looking to the 2nd and latter half of February with the MJO currently being in a phase 7 for the last days of January This gives the following feedback 

I'm really liking the CFS for this period already matching really great.

January phase 7 does give a window for colder conditions from the Northeast perhaps Easterly at times.

Moving forward a February phase 7 sees feedback bringing high pressure development to our East Northeast and extending across the UK

Both of these setups can be seen in the below

With the supportive precursors and MJO the stratospheric warming did indeed begin in small amounts during week 4 of January and as the MJO influence within the Pacific takes place the warming increases during the first half of February 

Prime time showcase of El Ninò in February 

We might have a brief re entry of phase 6 during week 1 of February though there is no complete agreement for this, however it's relatively similar to the setups currently materialising should it occur.

We'll continue seeing patterns which link to El Ninò throughout March and I'd favour potentially the first few weeks or so of April, following that time it's a gradual move into ENSO Neutral with some themes continuing of heading into La Ninà by late spring and particularly Summer 2024.

As 2012>2013 is among my top analogues it wouldn't be shocking for relatively similar setups to occur should MJO progression be conducive and potential feedback of stratospheric events.

[josh-weather]

  @TEITS An outlier compared to the ensemble members though - I thought the point of the control was to see if resolution was having an effect. If the op and control are the same then resolution isn't affecting the ensemble outcomes, which I'd take as reinforcing the outcome of the ensembles overall - which are mostly mild for that date. In other words the fact op and control match is an indication that the ensemble as a whole might be decently reliable. Please somebody explain where I'm getting this wrong, everything I learnt I learnt from this place

[Dennis]

NAM 29-1

[CoventryWeather]

ICON looks v good at 180. GFS looks poor at 144 but let's see if it improves.

[Dennis]

GFS 3-5 febr ideas

[northwestsnow]

  @CoventryWeather UKMO looks very similar 

[CoventryWeather]

UKMO Vs GFS Vs ICON at 144. 

Some differences over the arctic and how strong the Azores ridge is. 

GFS is sort of a middle ground solution at this range, but closer to the UKMO. 

Edited January 29 by CoventryWeather

[TEITS]

So despite the 06Z being much colder than the ensemble mean. The 12Z follows the 06Z with regards to temps.

Not surprising and I expect the 12Z GEFS mean will lower from 0C for the 6th Feb

  @CoventryWeather UKMO would produce a decent N,ly at +192. How far S the cold air would push is difficult to say.

[northwestsnow]

  @TEITS Ukmo 168

i honestly dont see a northerly 24 hours later from 168..