Model discussion highlights

[Ali1977]

As a mean that is quite convincing for some snow chances!! We aren’t talking FI here

[EML Network]

well well well.

Both GFS and GEM trying to sniff out an Easterly in FI

We might just be on the cusp of chasing down yet another cold and snowy spell after next weeks breakdown.

What an epic month this is turning into.

[minus10]

3 hours ago, RainAllNight said:

Here's that pattern starting to come into view. The TPV moves away and heights rise behind it, lows start tracking south of us, we start to dry out especially further north, Spring stays out of sight for now.

Yes this is evidenced with a signal in one form or another for a rise.in heights in many of the models..

Gfs, Icon, Gem , Ukmo..12z

...interesting to see how this plays out given the mjo highly amplified foray into level 8 recently and the continued effects from the ssw..

 

 

[Anthony Burden]

Evening all,Signs of northern blocking appearing on GFS / GEM could be a cold March through out except for a few. milder blips,possibly the best March for cold lovers for a very long time.

[Captain Shortwave]

Certainly evidence to suggest that we could develop an area of heights to our north at the end of week 1.

   
 

Either way I suspect that pattern will become sluggish as the Arctic maritime north westerly early next week clears away.

[Rain All Night]

1 hour ago, Skullzrulerz said:

What does the UKMO/ECM say?

Here are the UKMO precip types for the next week if you were interested.

[Summer8906]

1 hour ago, Anthony Burden said:

Evening all,Signs of northern blocking appearing on GFS / GEM could be a cold March through out except for a few. milder blips,possibly the best March for cold lovers for a very long time.

The GFS 12Z is indeed much more encouraging than some of the dire recent runs. Each attempt of the Atlantic to bring in SW-ly gloom only lasts a couple of days, with the SW-lies being pushed back by easterlies on a couple of occasions, one in around a week's time and then another around the 22nd.

Also, in far FI, has this chart for the start of BST, which looks ideal for enjoying the longer lighter evenings:

Wetterzentrale - Top Karten - GFS Europe 12Z

WWW.WETTERZENTRALE.DE

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Wetterkarten GFS Europe 12Z

 

Edited March 10, 2023 by Summer8906

[Summer8906]

1 hour ago, Ali1977 said:

As a mean that is quite convincing for some snow chances!! We aren’t talking FI here

That prediction, of course, shows just how bad southern England is for snow within western Europe as a whole, including both more northern parts of the UK, and seemingly, all but the NW and SE of France. Even supposedly very mild Bordeaux seems to have a better chance..

Edited March 10, 2023 by Summer8906

[stodge]

Evening all

More signs this evening of the traditional late winter/early spring northern blocking heaving into view.

As the LP next week, as it slows and disrupts in mid-Atlantic, heights can build from the north (or possibly the south, as JMA suggests). As the HP moves into Scandinavia, the Baltic trough heads south west and the NE flow re-establishes over the British Isles (even though its; the second half of March, plenty of -12 850 air embedded).

Tonight's GEM 12Z OP is a gem (sorry) for cold fans with the Scandinavian heights and LP heading ESE crating a nice battleground through central Britain.

The battle between colder and warmer airmasses is what spring is all about - we know the warmer air mass will win out at some point. The margins are very fine - it doesn't take much to shift the pattern between cold and warm at this time of year so we often see quite wild fluctuations in synoptics and in surface conditions so it can be 5c one day and 15c and a couple of days later and then back to 5c again.

[Rain All Night]

Back in mid-December when everyone was lamenting the untimely return of the Euro high, these charts would have been therapy...

The GFS ensemble wind roses have been very keen to bring north-easterly winds to me on the south coast for the last few runs.

The ECM ensemble is less willing to commit, but it's there on the table.

(18th-24th March shown above)

[Nick F]

Doesn't appear to be a great deal of consistency in the medium to extended range from operational model outputs at the moment. And the EC clusters don't really clear the waters.

Wave lengths beginning to change now with the season but also we have lag of MJO at high amplitude, almost off the RMM plot, through 8 and I - which the composites show higher heights around Greenland and Iceland and lower heights to the south. 

March phase 8 and 1 high amplitude

March phase 8 and I in neutral ENSO

EC and GEFS ens mean suggesting day 10 a similar albeit not carbon copy of the patterns above:

Potential for brief easterly or northeasterly there in the medium range, if next week's trough moving in from the Atlantic following the northerly clears east onto the near continent, but EC does appear to want to hang this trough back to the SW. But with the blocking signal around Greenland and Iceland - the jet should be supressed and thus potential for further reloads of cold lurking close to the north after the northerly reload on Tuesday. Don't think winter is done with us after the cold shot early next week.

Edited March 11, 2023 by Nick F

[Cambrian]

A real struggle remains for the Atlantic to impose itself on Northwest Europe, as the season tries but fails to turn, the demarcation between mild and cold merely oscillating north and south, being determined by the location of the slow-moving low pressure systems nearby. 

The 0z GFS ensemble means show a cold northerly flow at day 4, part of the same long-haul flow along the trough from the Siberian Arctic via Scandinavia that has brought the recent cold spell. 

  

An important change by day 8 as the Scandinavian trough eases. Low heights over the Norwegian Sea are pushed away as a surface ridge extends south from Svalbard, the heights to our north steering mid-Atlantic efforts southeast into France and Spain, the troughing then to our southwest bringing us in to a southeasterly flow off the continent. A period ripe for further trough disruption, perhaps slightly further south than during the last few days.

  

Out to day 12, the low heights are pushed around to our south as we stay in the cold air, uppers falling away again over the UK and Ireland, the surface flow by then more than hinting at an easterly with low pressure setting up over the Mediterranean, to the south of an extensive Eurasian ridge holding a large pool of cold air in place, including the spoils of the ongoing cold-mild battle over the UK and Ireland.

  

The burst of NAO+ signal is shortlived and is replaced by a blocking signal on Thursday’s ECM extended weather regimes forecast that is probably due to the Eurasian ridge. Looking further forward to week 2 and beyond, this is fortified by a modest Atlantic ridge signal, which might be read as an attempt to account for the northern blocking being applicable to both the Atlantic and European sectors as the Scandinavian trough fades and the NAO+ signal is further diminished, as shown in the change in the mean pressure anomalies between weeks 1 and 2.

  

An Atlantic incursion over the next few days, low pressure soon getting to our east to deliver a northerly, then into a further spell of attritional battling of air masses, with the cold air generally having the upper hand.

Plenty of scope for further cold and wintry weather for the UK and Ireland through the main part of March. 

[Met4Cast]

The outlook is rather messy at the moment but lets try to make some sense of it. I'm at the edge of my knowledge here so bare with me. 

The MJO is currently pushing through phase 8. The recent westerly trade winds in the Pacific however look to weaken and turn easterly again and I suspect this will destructively interfere with the MJO probably preventing it from cycling into stage 1 & instead will rapidly weaken it into the COD.

 

The sustained AAM that we've seen recently will likely begin to fall as a result, probably as we head towards the end of the month factoring in the lag but timing is not strong suit. 

With this in mind, I suspect re-newed blocking attempts are possible through the second half of March albeit with changing seasonal wavelengths we'll be battling with an increasingly northerly jet stream. I'm not confident on any re-newed strong bounts of cold/snow impacts but the potential does appear to be there, at least for a while. 

As the AAM begins to fall we'll probably see high pressure increasingly prone to sticking closer to the UK and into April this could (depending on it's placement) lead to some much awaited spring warmth. 

In the shorter term, the rest of March could potentially be quite wet in places with lows pushing across the UK, we need to watch for any potential re-newed HLB as this combination of lows + cold could lead to further disruptive snowfall.

[Rain All Night]

You can see our Atlantic episode stalling after the 16th on these 850hPa temp graphs...

You can see the jet stream changing around that date on this ICON run...

Edited March 11, 2023 by RainAllNight

[Rain All Night]

7 hours ago, Nick F said:

Wave lengths beginning to change now with the season

Could I ask what this means?

Edited March 11, 2023 by RainAllNight

[alexisj9]

41 minutes ago, RainAllNight said:

Could I ask what this means?

Jet stream naturally heads north, and thing start warming up.

[geordiekev]

1 hour ago, RainAllNight said:

Could I ask what this means?

Wavelength increases, thus less amplification [2] & return to flat upstream pattern, ergo zonality, although a few periods of interest before then [3]

[JR319]

I’ve noticed on Monday, there will be gusts of between 50-60mph quite widely across England and parts of Wales. 
 

Is this worth discussion and/or any weather warnings or is this standard weather for this time of the year? 

[SilverWolf]

1 minute ago, JR319 said:

I’ve noticed on Monday, there will be gusts of between 50-60mph quite widely across England and parts of Wales. 
 

Is this worth discussion and/or any weather warnings or is this standard weather for this time of the year? 

I would say def worth discussion - especially given the lack of named storms this winter! But I can’t do the technical stuff, so over to others for that… 

[alexisj9]

3 hours ago, JR319 said:

I’ve noticed on Monday, there will be gusts of between 50-60mph quite widely across England and parts of Wales. 
 

Is this worth discussion and/or any weather warnings or is this standard weather for this time of the year? 

Yes it's worth discussing, of course. Not had many wind storms this year down south. A few over in Scotland, including Otto.

[Rain All Night]

I made these ensemble mean jet profile GIFs thinking I would have something to say about them, turns out that I don't, other than that I assume the big void over Europe from about day 9 onwards means large spread/uncertainty...

[geordiekev]

2 hours ago, RainAllNight said:

I made these ensemble mean jet profile GIFs thinking I would have something to say about them, turns out that I don't, other than that I assume the big void over Europe from about day 9 onwards means large spread/uncertainty...

The spiral effect seems to be an almost constant feature I've noticed this Winter, with jet stream far South in Africa & all around the globe until it reaches Atlantic. I'm taking a stab in the dark this is normal & linked to AAM etc & to be non technical the plughole effect

[Anthony Burden]

Morning all,once again GFS /GEM keen on northern blocking to establish in eight to ten days still a way off but looking highly possible that March will go down as as one of the coldest in many years possibly breaking a few records.

[Guest]

4 minutes ago, Anthony Burden said:

Morning all,once again GFS /GEM keen on northern blocking to establish in eight to ten days still a way off but looking highly possible that March will go down as as one of the coldest in many years possibly breaking a few records.

Not seeing anything to support that wild claim in the model output! Double figures for many today and a mild night tonight with fluctuations in the coming days but nothing to support record breaking cold. Let's have some realism please.

[keithlucky]

21 minutes ago, Tidal Wave said:

Not seeing anything to support that wild claim in the model output! Double figures for many today and a mild night tonight with fluctuations in the coming days but nothing to support record breaking cold. Let's have some realism please.

Met Office seem to picking up a cold continental feed possible with HP to the north dragging a cold continental feed ,in7days time.