Model Output Discussion - 15th March onwards

[Cambrian]

I like the ECM control for often being useful in sniffing out longer term trends, indicating the general direction of travel, especially when it keeps tight with the operational run up to its end at day 10. 

Yesterday’s 12z and today’s 0z are a case in point. And look where the control is headed from around day 9 on the ensembles. 

 

It’s a fair point that the ensemble means are staying close to average, but if you take the T850 of -5 degrees for Birmingham as a cut-off and compare the two runs, there is quite a tight cluster below -5 forming after day 9 or 10 on the 0z that wasn’t there yesterday. 

The control itself has a very reasonable evolution too, shown here through to day 15, the steady west-east movement of the Atlantic trough, stalling over Europe as heights building through central Russia, combining with those Greenland heights we’ve been watching, serve to lock the trough in place and keep us in the polar air and a cold, cyclonic setup.

 

The movement of the trough to the east of the UK and Ireland and then stalling over Europe and the push of heights into Greenland are both supported by the 0z ensemble mean, so there is broad synoptic support for the control. 

As usual, I have no great preference either way, it does what it does, but there are some reasonable indications here that a decidedly cold week for Northwest Europe at the end of March is very feasible. 

Edited March 16, 2023 by Cambrian

[richie3846]

2 hours ago, Cambrian said:

I like the ECM control for often being useful in sniffing out longer term trends, indicating the general direction of travel, especially when it keeps tight with the operational run up to its end at day 10. 

Yesterday’s 12z and today’s 0z are a case in point. And look where the control is headed from around day 9 on the ensembles. 

 

It’s a fair point that the ensemble means are staying close to average, but if you take the T850 of -5 degrees for Birmingham as a cut-off and compare the two runs, there is quite a tight cluster below -5 forming after day 9 or 10 on the 0z that wasn’t there yesterday. 

The control itself has a very reasonable evolution too, shown here through to day 15, the steady west-east movement of the Atlantic trough, stalling over Europe as heights building through central Russia, combining with those Greenland heights we’ve been watching, serve to lock the trough in place and keep us in the polar air and a cold, cyclonic setup.

 

The movement of the trough to the east of the UK and Ireland and then stalling over Europe and the push of heights into Greenland are both supported by the 0z ensemble mean, so there is broad synoptic support for the control. 

As usual, I have no great preference either way, it does what it does, but there are some reasonable indications here that a decidedly cold week for Northwest Europe at the end of March is very feasible. 

As is often the case as the sun grows in strength, cold potential may be tempered with sunshine, at least during the day. Other cold spells of recent weeks have lacked sunshine for most, if not all of the country. 

Cambrian, do you see any signs that this potential cold air will follow suit and be a greyfest, or are the indicators that it could be more of a sunny cold, which would be more typical for late March and early April?

[Chesil View]

3 hours ago, Cambrian said:

I like the ECM control for often being useful in sniffing out longer term trends, indicating the general direction of travel, especially when it keeps tight with the operational run up to its end at day 10. 

Yesterday’s 12z and today’s 0z are a case in point. And look where the control is headed from around day 9 on the ensembles. 

 

It’s a fair point that the ensemble means are staying close to average, but if you take the T850 of -5 degrees for Birmingham as a cut-off and compare the two runs, there is quite a tight cluster below -5 forming after day 9 or 10 on the 0z that wasn’t there yesterday. 

The control itself has a very reasonable evolution too, shown here through to day 15, the steady west-east movement of the Atlantic trough, stalling over Europe as heights building through central Russia, combining with those Greenland heights we’ve been watching, serve to lock the trough in place and keep us in the polar air and a cold, cyclonic setup.

 

The movement of the trough to the east of the UK and Ireland and then stalling over Europe and the push of heights into Greenland are both supported by the 0z ensemble mean, so there is broad synoptic support for the control. 

As usual, I have no great preference either way, it does what it does, but there are some reasonable indications here that a decidedly cold week for Northwest Europe at the end of March is very feasible. 

Jff but I'd happily take that ecm control run Cambrian.

[Big Dave]

18 hours ago, carinthian said:

Evening. Well I am rather gob smacked looking at the 850mb temp chart from ECM  at day 10. Just look at those positive values over much of Central and Eastern Europe. Strange to see readings  so high under a extended European trough at the end of March . Surely something wrong in this out put ? Donavon's old hit record ," Mellow Yellow " comes to mind. Looks like UK tapping into some Arctic Air mass going by this chart but with snow melt advancing in the Alps ?

C

Goodness I hope you're wrong about snow melt advancing in the Alps!   Looking forward to some Easter skiing! 

 

[Cambrian]

1 hour ago, richie3846 said:

As is often the case as the sun grows in strength, cold potential may be tempered with sunshine, at least during the day. Other cold spells of recent weeks have lacked sunshine for most, if not all of the country. 

Cambrian, do you see any signs that this potential cold air will follow suit and be a greyfest, or are the indicators that it could be more of a sunny cold, which would be more typical for late March and early April?

If it verifies as modelled by the 0z ECM control (a big if, of course, at this range!), from the look of things it would be cold and cyclonic, for a good few days, (which is what captured my attention, particularly as we haven’t seen an extended cold, cyclonic spell for a good while), and would probably bring us organised bands of precipitation with brighter, showery spells in between. Frosty nights for many too. 

Here is the precipitation graphic for that control run from day 10 to 15. And look at those temperatures - “brisk” might be a good word! 

 

Though a long way off, and only one of many potential outcomes, it’s always fascinating to see how a northerly, if it taps a proper Arctic source and aligns right, can still pack it for cold all the way through to early April. 

[Rain All Night]

1 hour ago, Cambrian said:

If it verifies as modelled by the 0z ECM control (a big if, of course, at this range!), from the look of things it would be cold and cyclonic, for a good few days, (which is what captured my attention, particularly as we haven’t seen an extended cold, cyclonic spell for a good while), and would probably bring us organised bands of precipitation with brighter, showery spells in between. Frosty nights for many too. 

Here is the precipitation graphic for that control run from day 10 to 15. And look at those temperatures - “brisk” might be a good word! 

 

Though a long way off, and only one of many potential outcomes, it’s always fascinating to see how a northerly, if it taps a proper Arctic source and aligns right, can still pack it for cold all the way through to early April. 

Not the same setup, but that reminds me of 7th April 2021, that was raw, even in the 'mild' part where I was...

As an aside, I've been waiting for Meteociel to update its vault of ECM reanalysis charts beyond June 2022, and at some point recently that has happened, so we can now relive some of our favourite weather moments from the second half of last year:

https://www.meteociel.fr/modeles/archives/archives.php?day=12&month=7&hour=12&year=2022&map=5&region=uk&mode=2&type=era

Edited March 16, 2023 by RainAllNight

[carinthian]

4 hours ago, Big Dave said:

Goodness I hope you're wrong about snow melt advancing in the Alps!   Looking forward to some Easter skiing! 

 

Hi Big Dave, where you going ski-ing.? 21c in the forecast for the next 5 days in the valleys over here. Spring has sprung early ! Bet your bottom dollar it with snow for Easter thiough !

C

[minus10]

Well the gfs 12z op, mean and long term mean all kinda singing from the same song sheet later in the run which is saying.....

......average fayre for late March........

Edited March 16, 2023 by minus10

[jamesthemonkeh]

Some rather extreme warmth for Eastern Europe keeps cropping up on GFS for the end of the month.

[Stuie]

16 minutes ago, minus10 said:

Well the gfs 12z op, mean and long term mean all kinda singing from the same song sheet later in the run which is saying.....

......average fayre for late March........

Yep as much as the scatter may raise eyebrows, the 2M temps for London put things in perspective.

[Stuie]

Awaiting the ECM 12z ensembles but can we have a huge round of applause for it`s tightest run in ages, the 0z. See rebooting does work.

 

EDIT: 12z back to the wobbles with a near outlier.

Edited March 16, 2023 by Stuie

[Rain All Night]

[damianslaw]

GFS with a pattern that has a brick wall in the N Sea, the atlantic trough just sits in situ for an age to our west, low pressure not able to break east, eventually we see heights build to the NW and pull down a long fetch NE flow.

ECM conversely has no problem shift the trough east and looks to be trending cold and cyclonic.

Either way, nothing settled on the horizon anytime soon, take your pick mild/wet - staying mild/wet or trending cold/wet.. 

[Guest]

Nothing particularly interesting on the horizon but one thing for sure is that the record March cold touted by some is well and truly off the table.  I wonder what went wrong? I guess we won't ever know as it seems some magical vanishing acts have taken place!

In fact, if we carry on at this rate it could end up milder than normal for the month as a whole which would be a turn up for the books after the cold start.

. 

[Don]

22 minutes ago, Tidal Wave said:

Nothing particularly interesting on the horizon but one thing for sure is that the record March cold touted by some is well and truly off the table.  I wonder what went wrong? I guess we won't ever know as it seems some magical vanishing acts have taken place!

In fact, if we carry on at this rate it could end up milder than normal for the month as a whole which would be a turn up for the books after the cold start.

It's happened plenty of times in the past where colder looking months have ended up milder than average, February 2021 an example?

[KTtom]

This should help the areas in the south west still in drought...mild southwesterlies to dominate, at least through next week. As Tidal Wave mentions above, not what we were led to believe was going to be the likely outcome post SSW.

Edited March 17, 2023 by KTtom

[ANYWEATHER]

Atlantic ,yes that's on the cards for the forseable, plenty of rain to come and potential stormy periods as well. It looks like Easter will be mild wet and windy overall, but perhaps can catch some Spring sunshine at times between the incessant Atlantic gloom.....

[lassie23]

GFS keeps suggesting cold scenarios at the end of March, they keep vanishing and reappearing.

Edited March 17, 2023 by lassie23

[minus10]

Well mild it may be for a while but EPS showing trend to cool down again for late March ..

12z Thursday

0z

..quite a cluster below the mean...

...anomaly supports this cooler trend for late March...also fairly unsettled...however we will see no doubt...this of course set against a strengthening sun..could be good growing weather if we can avoid the late frosts..

 

[Cambrian]

Yes indeed @minus10, the 0z ECM 15 day ensemble is a game of two halves. 

The 0z ECM T850 ensemble shows above average temperatures for the next week, in fact decidedly mild at the beginning of the week, but a much colder week 2 in the offing. It looks like yet another example of the post-day 10 ECM control detecting the trend (12z Wednesday) then forming a cluster around it (Thursday), then beginning to drag down the mean (today).

  

So it’s a gathering trend appearing in today’s 0z ensemble - the mean, op and control all dropping to -4 degrees for Birmingham by day 10. The control carries on it with its descent to around -7 degrees by the end of the month. 

As early as day 10, the 0z mean shows a surface northerly over the UK and Ireland, with lowering uppers, to the west of the returned Scandinavian trough. 

  

At day 12 on the 0z ECM control, it’s cold and getting colder, a flow from the Arctic maintained and the jet stream heading into Iberia.

   
From the ECM at least, a clear trend to markedly colder weather over the next fortnight and a very chilly end to March. 

[mushymanrob]

Hmm... the latest EPS run suggests a pretty normal , average Westerly/unsettled pattern... culminating in this very average looking chart for April 1.

[IDO]

The models mostly show average fare; no signs of sustained northern blocking or high amplitude long waves, just run-of-the-mill March variations. The GEFS mean has been consistent run-on-run, and the tPV remains in the Asia/Siberia region, so there is a low expectancy of anything other than transient cold. The ECM highlights this:

A brief northerly (D10) as the trough moves east, with westerly Atlantic lows lined up for the UK following that. Looking at the GFS op, that has now ditched even that brief northerly around D10 and is very westerly based. The wedges to our north keep the jet more south than average, but with the tPV placement an adverse driver for sustained shots of UK cold, we are stuck in a changeable regime.

GEFS mean D8-16: 

 

[Atmogenic]

15 hours ago, jamesthemonkeh said:

Some rather extreme warmth for Eastern Europe keeps cropping up on GFS for the end of the month.

let's hope that pushes its way towards us to get out of this dreaded cold 

[Cambrian]

Yes, it’s interesting alright. 

Even at day 10, we have to reconcile a largely westerly pattern on the 0z ECM 500mb normalised anomaly, with more of a northwesterly on the EPS 500mb anomaly, with the Scandinavian trough / North Sea low on the ECM mean anomaly and the surface northerly indicated on the mean chart itself. 

   

It looks like they’re all saying something similar but not quite the same! Might be a bit of “you pays your money and you takes your choice” for a while, but with a trend towards certain signals emerging. ECM mean at one end of the spectrum here, GFS only slowly coming on board (perhaps) with the 6z op,

though 0z GEM was broadly supportive of the potential for a colder spell too - mean, anom, op with T850s.

  
 

Edited March 17, 2023 by Cambrian

[minus10]

1 hour ago, Cambrian said:

Yes, it’s interesting alright. 

Even at day 10, we have to reconcile a largely westerly pattern on the 0z ECM 500mb normalised anomaly, with more of a northwesterly on the EPS 500mb anomaly, with the Scandinavian trough / North Sea low on the ECM mean anomaly and the surface northerly indicated on the mean chart itself. 

   

It looks like they’re all saying something similar but not quite the same! Might be a bit of “you pays your money and you takes your choice” for a while, but with a trend towards certain signals emerging. ECM mean at one end of the spectrum here, GFS only slowly coming on board (perhaps) with the 6z op,

though 0z GEM was broadly supportive of the potential for a colder spell too - mean, anom, op with T850s.

  
 

Yes perhaps gfes slowly inching towards something cooler for a brief period towards end of March..

Oz

6z

...with a drop in the mean of approx 2 deg on 27th...big deal many will say...just run to run variation...perhaps...and all within the scope of 'average' March fayre...however will be interesting to see if the ecm ens / mean trend to this cooler 3 or 4 days continues and whether gfes continue to edge towards it...or will it fizzle...perhaps a case of average or cool average towards end of March...could make a difference if any nightly clear skies occur as frosts could be potentially more damaging to gardens now...watching brief i think...

 

Edited March 17, 2023 by minus10