Model Output Discussion - New Year and Beyond

[Man With Beard]

58 minutes ago, Allseasons-si said:

Anyone noticed the eyewall in the channel?

Quite something! If it snows, it could be blizzard like, winds are going to be strong around that core.

[Allseasons-Si]

2 minutes ago, Man With Beard said:

Quite something! If it snows, it could be blizzard like, winds are going to be strong around that core.

You can see it nicely on this link.

Meteociel.fr - Radar de précipitations pluie et neige - Royaume-Uni/Irlande

WWW.METEOCIEL.FR

---

La météo en temps réel et prévisions météo pour la France, Observations météo, modèles numériques et logiciels météo (GFS, ECMWF, UKMO, GEM, AROME, ARPEGE, JMA)

 

[Man With Beard]

40 minutes ago, RainAllNight said:

The Met's first go at drawing the breakdown on Friday:

For interest, here are their first two attempts at drawing Thursday noon (24 hours apart), the differences between them show you what a difficult job they have even within 5 days...

It's screaming "delayed breakdown" to me as lows keep slipping to the south?

[Battleground Snow]

Control going for it again.

 

[swfc]

9 minutes ago, Man With Beard said:

It's screaming "delayed breakdown" to me as lows keep slipping to the south?

On 13/01/2023 at 19:36, Quicksilver1989 said:

Well if you want an 1050mb high over Iceland and -10C uppers for days on end you aren't going to be impressed very often. Prolonged cold and snowy spells are more difficult to achieve in this day and age. Yes it is a polar maritime airmass which isn't too unusual but if we get a pivoting band of snow then it will be unusual in the context of recent winters.

Of course it may not produce anything notable but it wouldn't be wise to rule it out at this point.

Wow has the bar been lowered that much looks dry moving into febuary but ssw etc really? Barring December it's been a bust tbh. Its another straw but the dry weather will be welcome.

[Allseasons-Si]

On the conversation of a Bartlett high,...i did a little reseach

a mid latitude high is between 50-60 degrees north where as a bartlett high is at a lower latitude than 50 degrees north.

[swfc]

Just now, Allseasons-si said:

On the conversation of a Bartlett high,...i did a little reseach

a mid latitude high is between 50-60 degrees north where as a bartlett high is at a lower latitude than 50 degrees north.

That's how bad the mo is. Good Post tho,

[Allseasons-Si]

The 850's are getting colder dragging the mean down

18z vs 00z.

Edited January 15, 2023 by Allseasons-si

[Derecho]

52 minutes ago, swfc said:

Wow has the bar been lowered that much looks dry moving into febuary but ssw etc really? Barring December it's been a bust tbh. Its another straw but the dry weather will be welcome.

Well look at the archives from times when the UK winter was much colder, the Decembers and Januaries of the 1870s and 1880s for example. A lot of those cold spells didn't have the exceptional synoptics we chase here every winter (January 1881 and February 1895 being obvious exceptions). They were notable for their persistence, an initial cold shot followed by surface cold lingering. Look at December 1874, 1879 or 1890 on the wetterzentrale archives. 

In fact I can imagine if the model output discussion thread existed in January 1880 a lot of people would have been fed up of the boring weather that winter despite it being severely cold.

The colder uppers and cleaner synoptics often occur later in the winter when the Arctic is at its coldest and SSTs are also at their coolest (less risk of shortwaves). However that is countered by the increasing solar radiation at this stage.

We won't get -15C 850 easterlies very often at all these days unless something fundamentally changes with atmospheric circulation patterns in our part of the world. That's the way it is so people perhaps need to drop their expectations a bit. People are simply chasing cold and snow potential.

Edited January 16, 2023 by Quicksilver1989

[feb1991blizzard]

number 1 the best 18z GEFS member, not many others resembnling the same patter unfortunately.

Thats what you call a blizzard.

 

Edited January 16, 2023 by feb1991blizzard

[Allseasons-Si]

4 minutes ago, feb1991blizzard said:

number 1 the best 18z GEFS member, not many others resembnling the same patter unfortunately.

Thats what you call a blizzard.

 

Trend setter that is

and if that comes off,...the i will remind myself and this post that i was not joking ha ha.

Edited January 16, 2023 by Allseasons-si

[Eagle Eye]

I feel so lucky to be a weather forecaster, the girl that broke up with me and the girl that rejected me keep asking me for forecasts .

Going to quote myself here from a couple of my recent posts;

January 8th (ignore the fact that I literally forgot where the Aleutian region is):

"-VE EAMT event towards next week retracting the pacific jet but the intimal state of the PNA and the MJO Tropical forcing, suggests a movement towards a North Pacific trough connecting up with the Aleutian low. This may mean that we see the +VE Ural Block/BK development but also some sort of ridge/blocking over the US to mid Atlantic region and its important where that forms for our Troposphere pattern for late January/early February. Given the forecasting range, its fairly unlikely to be forecasted well yet. Its good that the signal for the Ural Block + Aleutian Low remains.

So Tropical forcing and the development around the Scandi-Ural region will be extremely important going going February but some PM air in the shorter-term is gaining some decent backing.

Clear signs of that strong atlantic +VE heights development and the resultant flow that'll likely bring cold to the UK though how strong is yet to be decided."

January 11th;

"Therefore, the progression of Wave-1 would suggest movement of the +VE anomalous thermal line to be more West allowing for the strong thermal energy Tropopause transport across the Atlantic signalling for extratropical thermal increasing of Wave-2 formation for the mid-Atlantic progression towards the Scandi-Ural-BK area.

...

At this point everything becomes complicated and affected by every other thing as without a developing Atlantic-Europe Wave, the Vortex doesn't lose it's polar-night jet signal much, instead it's displaced to over us (e.g. not what we want) but if we can get a warming Wave over the pre-mentioned area; then that should stretch the Polar Vortex and at least slow down the mean to average to below average I would suspect. Beyond that, we need the signal around the Scandi-Urals area to repeat and that would likely cause at least an attempt at a split. "

January 13th;

"The shifting of the jet might be persistent with cyclonic wave breaking linked with the eventual move towards +VE mid-high lat North American heights and so consistent with Trop-Strat coupling for a quasi-stationary link between the +VE Alaskan Block and the forcing on the Strat pattern for the Wave-1 warming. More importantly, it helps with the shifting of the warming Wave poleward and shifting the Vortex but it needs to be a much stronger secondary Wave pushing towards the Scandi-Ural region then it would be a split. Though at this range, the forecast is likely to be well off, in this situation I wouldn't expect that much of a split though as the Wave-2 in Europe doesn't look that strong but if we can get a Tropopause Eddy Heat Flux re-driving towards the Scandi-Ural region then in the forecasted situation; that's the best option."

January 14th;

"the signal for the -VE EAMT would usually suggest an extension of the Atlantic jet but given the base state of the Pacific, it may enhance retrograde WAA into the East of North America whilst extending the Equatorial Atlantic Jet and backing the Eurasian feedback to affect the high pressure cell expansion into SE Europe. Theoretically, that creates the backing for a Scandi based Scandi-Ural Blocking signal"

... 

Forecast (ish) now;

That retrograde signal for that continues to show with poleward heat transfer and abnormal mass transport. This should lead to vertical heat transport though where and when depends on the speed of Rossby thermal transport and the energy released/held in planetery waves via thermal Eddy transport and the ability of the Tropopause to vertically transport the Eddy heat flux.

The reaction in the Troposphere seems a little too quick for my liking. Not necessarily because it's timing is off but because it means that it'll be another wasted Ural Block as the transition of the Pacific Wave is just a little too slow for it to be Wave-2 but it will continue to strengthen Wave-1 significantly to really put pressure on the Strat (ignore that it's the 12z run for Eddy heat flux, 18z hasn't loaded for me yet). 

What's important to me is that we keep up that signal for some sort of Scandi-BK Blocking up fairly well. Given a good transition of Wave-1 towards North America by early February then that Trop signal will really give the Strat a good Wave-2 to deal with but right now the Wave-1 seems contempt with staying over Eurasia-Pacific. So looking at the bigger picture and it's the development of the Aleutian low that'll be important of the transitioning of Wave-1 towards the Pacific-North American area. If we can get that sorted out properly then we really could be in business. A Scandi-BK high and Aleutian low combination is one of the best drivers of abnormal Stratospheric circulation and if I remember correctly can often lead to splits. Importantly though, that signal is looking fairly borderline for now so we'll have to wait and see how this truly does evolve...

Edited January 16, 2023 by Eagle Eye

[Weather-history]

UKMO has  more of a high pressure influence 

 

 

[Rain All Night]

58 minutes ago, Weather-history said:

UKMO has  more of a high pressure influence 

 

 

Nice

[carinthian]

23 hours ago, carinthian said:

Morning all.Latest GFS  still shows colder air hanging in there over the SE of England this time next week. The run does indicate some resistance of the colder block close by to the Atlantic encroachment. Less support from UKMO/ECM for this but some squeeze on the milder air possible to take place as pressure rises behind any shortwaves that develop to the west. I think this is not yet a done deal to a full on flip to milder conditions again. 

C

Morning all, just a follow on from yesterdays post , where I mentioned that pressure rise behind any shortwaves would be the best bet to prolong any colder spell this coming week. Looks like UKMO is on board with this development with cold staying in situ across much Europe , including the British Isles. Unfortunately, not much support from the other main models but I still remain up beat about a squeeze to take place on the Atlantic push. Not a done deal to full frontal mild push yet .

C

[That ECM]

T168 all 3.  Gfs in the middle? Cool/cold 4 days and  we watch to see where we go. High over us looks favourite to me at the moment but enough in fi to keep the interest.

[northwestsnow]

EC day 10

potential..

[northwestsnow]

GEM day 10

[KTtom]

1 hour ago, Weather-history said:

UKMO has  more of a high pressure influence 

 

 

The bane of a British winter sticks out like a sore thumb on those charts and its up to its tricks again....before anyone asks what im talking about...its purple!

[nick sussex]

The UKMO has the better shorter term solution keeping the cold longer than any other model .

The ECM is the quickest to remove the cold air but has the better potential past day 7.  The GEM also has potential, a word that I’m sure begins to grate with coldies ! 

I’d be surprised if the UKMO is correct here as it rarely wins out when it’s the colder outcome .

[That ECM]

3 minutes ago, northwestsnow said:

GEM day 10

 All fi when looking at nhp.

[northwestsnow]

I suspect Exeter will shift emphasis to a more settled outlook today.. 

Coldies need a bit of luck but if the cards fall right.....

[joggs]

29 minutes ago, That ECM said:

T168 all 3.  Gfs in the middle? Cool/cold 4 days and  we watch to see where we go. High over us looks favourite to me at the moment but enough in fi to keep the interest.

Well,imo if it's dry then there is interest but if it's cold longer-term, as long as you've got a big purple blob over Greenland and Azores high,it's not good news.

[That ECM]

I’ve found the non fi output though.

[Rain All Night]

The EPS clusters depict the high really wanting to go north in one way or another...

Mean at day 10 pointing slightly towards Greenland

Edited January 16, 2023 by RainAllNight