Model Output Discussion - Colder but how cold and for how long?

[MATTWOLVES 3]

Blocking regimes gain traction tonight

[sheikhy]

4 minutes ago, Cheshire Freeze said:

There really is no easy way out of this pattern shown on GFS FI

Basically thats as bad as it gets!!!!yeh it will feel cool but theres no way we getting anything meaningful in terms of snow at that precise moment!!its terrible!!!

[nick sussex]

Just catching up with the evening outputs which to be frank are underwhelming after Friday .

Just too much energy spilling east . There were some signs earlier that the energy would split with some heading se .

But the PV blob looks remorseless going by the day ten means .

The UKMO tries to split the energy but still finds an annoying shortwave to the nw .

It’s a bit frustrating in all honesty that the renewed upstream energy decides to turn up after downing a whole lot of steroids !

At least there’s a week of more interesting weather before the crapola hits the fan .

And although disappointing to see the block up sticks at the first sign of trouble some will at least see some snow and likely the odd surprise along the way .

I’d give it till tomorrow to see if we could just squeeze out less energy upstream .

It’s still just that far out in timeframe to hope for some changes .

 

Edited January 12 by nick sussex

[LRD]

Tonight's EC46 pressure anomaly headlines from week 2 onwards:

-Mild week of 22nd - high pressure to the south

-Weeks 29th and 5th - high pressure anomalies over the UK. Probably too close to generate what people on here really want. This can still be represented as blocked (in red) on the ECM regime charts - it's not necessarily indicating a Scandi block

-12th and 19th - pressure anomalies start to rise to our NW and North again

Summary - not exactly spectacular (the signals wouldn't be for Feb this far out anyway) but not bad either

Edited January 12 by LRD

[Mike Poole]

ECM clusters tonight, just one in the really uncertain timescale T120-T168.  Then the computer’s come up with this to T360:

Pick the bones out of that!

I’ve not given up hope that the models have not yet got the early evolution, but will comment on it now by exception if anything interesting happens.

The transition to something milder was always suggested for the last week in January, so no problems with that.  It would be nice to see some proper snow during the cold week to come, but it doesn’t look like it now.

There is interest into February when we will get another crack at it, and there’s a probable SSW in the mix there too, and although it looks a weird one to me, it could certainly help in the period into February when a more amplified trop pattern might well be expected.  With both in mind, I actually think there’s a chance the next chase might be for an easterly, which albeit rarer, has more chance of delivering, we will see…

[LetItSnow!]

2 minutes ago, Cheshire Freeze said:

There really is no easy way out of this pattern shown on GFS FI

Not even worth analysing due to it's timeframe, however, that would probably be decent for Scotland. If we go into a less cold pattern instead of a mild pattern then, with what Tamara says, it's always more likely than not (especially compared to usual) that the pattern will fall back into a pattern conducive to UK cold. Cold zonality is quite a rare beast and a great example of it was seen exactly forty years ago. While I would love a dumping of snow I will always be happy for the Scottish snow lovers to get a dumping. A brief look at the models does suggest some higher pressure to our south around day ten (especially the ECM which looks quite horrid) but I don't think any of the models have a hang on this. I'm not saying that a less cold spell will fail to happen and that we're in for February 1947, but I am particularly cautious at charts showing raging zonality, especially when Tamara highlighted the models are struggling with the current set up, IIRC lack of data with certain telecommunications and an inherent bias to correct the flow westerly when the pattern doesn't know what it's doing. Tamara is very no-nonsense and not a cold ramper so when she highlights a higher probability of cold weather than usual, I take note.

[WYorksWeather]

4 minutes ago, MATTWOLVES 3 said:

Blocking regimes gain traction tonight

Yep, it does look like even though the end of January may well go a bit pear-shaped, there should be more chances in February. Long range models seem to be in agreement.

[Gizzy]

2 minutes ago, WYorksWeather said:

Yep, it does look like even though the end of January may well go a bit pear-shaped, there should be more chances in February. Long range models seem to be in agreement.

Met office already suggesting blocking again in Feb, further hints at Easterly/Northerly.

[aggy]

14 minutes ago, Cheshire Freeze said:

There really is no easy way out of this pattern shown on GFS FI

Can someone explain

what this chart shows and what the issue is 

[Scott Ingham]

1 hour ago, lorenzo said:

At pains of wishing all our lives away and a cold spell right on our doorstep am fascinated right now between 

1 Something like this from 06z GFS - which in isolation - you stopped any of us and said - What kind of winter was this? Would most probably say - Vortex in control Strat-Trop connected, ridging into Europe - the worst of Winters.. etc.

2 Vs - Right now we have an imminent cold spell, granted it has been a long, long , model weary countdown, but the anomalies and progression are probably the *best advertised since 2010 ( Note not same synoptic). And, that we are now into the realms of shorter range modelling tools.

Then, we have the contrast of such a long lead to eventuality, coupled with the last 10 days of Jan being a period where the regimes shift, yet, everything points back to re-load ( seasonals / MJO / AAM / Strat), Nino-expected, QBOe, it really is a winter where everyone on here has been on a roller-coaster.

The point being - it's a new roller coaster, it is not one we have entertained - the Canadian warming perhaps heralded that given it's strength back during Nov, significantly beyond the envelope and very rare in terms of historic dynamics. That's on top of everything else mentioned.

And now, a cold spell and it will be cold - brutally so in some places and noteworthy - is it a stick on for the cold counter part snow - no, and it never would be - this was always the way in any of these winters we herald, there was not wall to wall snow EveryWhere All At Once. And to tonights 12z another variation - EC slamming Scotland with snow has now dipped 300 miles south - we are in a Nowcast scenario.

Do we have tentative beginnings of Scandi things ahead... January and now may be the appetiser - the real deal may be Feb.

Great post! I’m fascinated to see if Scandi heights do come to pass as another test of long range forecasting tools. I’m with you as well. February has the potential to be the main course of this winter 

[Paul]

Just now, aggy said:

Can someone explain

what this chart shows and what the issue is 

It shows unsettled, mild weather. But it is also the gfs @ 12 days away, so not necessarily anything to hang your hat on!

[Duane S.]

The models are struggling, everything is very much still on the table. 

ECs making much less of the ‘mild blip’ for the far south and keeping things very cool indeed in the UK tropics. GEFS? Hasn’t got a scooby…

[121]

1 hour ago, Harveyslugger said:

Monday is the Pembrokeshire dangler?you can see it on ukv

Hanging our hats on solely ukv is a dangerous game. We might get the odd shower that’ll crop up last minute but, based on the outputs available tonight as a whole, I think S.coast of England is the best chance of anything tangible.

(This is bordering if not regional material) Experience tells me that southward corrections are likely whilst northward less so. And that’s what we would need for us to really see anything tangible imo.
 

…but never say never.

Nos Da!

[Duane S.]

Well, there it is (very nearly at least). The mean has been edging that way for a few days now. Just into official SSW territory, could be the shortest one in history though

Edited January 12 by Duane S.

[Eagle Eye]

Despite a potential major warming and split (sort of) , the increasing barotropic wave disconnects between wave heat and the wave itself pushing it polewards. This is usual, however...

1) The reversal is unlikely to be strong

2) We are relying on wavebreaking

3) This rules out a reflection unless it occurs before the SSW. This does not rule out future reflections though. 

Further on point 2

Longevity of wavebreaking appears to be short and overriden by other factors. Nor does it push equatorward, so it's just a downwelling of - VE zonal mean anomalies for a few days, a failed major SSW proper response if it happens. 2nd in the last 2 major SSW's (pretty sure that one that was in I think 2021 didn't connect with the troposphere). It's possible wavebreaking could still make it down but it appears unlikely. 

Edited January 12 by Eagle Eye

[stodge]

Evening all

Plenty of depsondency on here this evening though to be honest the notion of the cold being maintained past next weekend was always marginal at best. I love NAVGEM 12Z as it at least keeps us cold to Saturday.

My view is the prolonged Wave 1 warming has sent the remnants of the PV over to Canada/Greenland dispersing the warmer uppers from Greenland and encouraging explosive cyclogenesis off Newfoundland as warmer and colder airmasses collide. 

We could very well have a 14 day milder spell or interlude but the PV remains distressed at best and the chance of a cold outbreak in February remains very much on the table.

As for snow this week, don't know - certainly in northern Scotland and on higher ground - as for prolonged disruptive snow to lower ground it doesn't look like that type of breakdown.  More of a whimper than a bang as the cold flow dies away, we have a col and a short lived final ridge (could be very frosty next Friday and Saturday for example) before the Atlantic systems arrive and we return to more typical winter conditions with rain and wind and it could be quitre stormy to end January.

[Ali1977]

Pub runs can be full of surprises, let’s see what happens next week for some snow chances - even if they are gone by the 00z!!

[sheikhy]

Just now, Ali1977 said:

Pub runs can be full of surprises, let’s see what happens next week for some snow chances - even if they are gone by the 00z!!

Waiting for your icon 18z updates mate!!!!

[MATTWOLVES 3]

Hope mods don't mind but would just like to share this with you from another knowledgeable guy..Good signs moving forward.

[MAF]

There is a lot of 'hanging hats' in posts above. Is that because people are looking too far ahead?

in the coming days we have a full on northerly, a channel low which might be more north than south, ppn likely to be snow in the north and possibly the south depending on the low, sub zero windchill or 'feel like' temps and wintry conditions for the next 3-5 days. 

Hey! it's winter in the UK lets be happy that at least it 'feels' like winter and not autumn regardless of what a computer model tells us

[Weegaz]

Hopefully the last two conditions are not met next week but it looks like a week of nowcasting in the regionals.

The last week of posts have been enthralling and informative, thank you.

Hopefully the 18z output throws another spanner in the works to keep us all glued

[Stuie]

4 minutes ago, MAF said:

There is a lot of 'hanging hats' in posts above. Is that because people are looking too far ahead?

in the coming days we have a full on northerly, a channel low which might be more north than south, ppn likely to be snow in the north and possibly the south depending on the low, sub zero windchill or 'feel like' temps and wintry conditions for the next 3-5 days. 

Hey! it's winter in the UK lets be happy that at least it 'feels' like winter and not autumn regardless of what a computer model tells us

Nothing strange here, it's just the annual Netweather mood swings.

Situation should be pretty clear of this potential 'spell' by Sunday night.

[stodge]

If you want a laugh, go and look at the CFS 12Z for the month. Lots of cold starting as early as January 31st.

Mild spell? More like blink and you'll miss it.

[MOF]

Did anyone read Tamara's post...doesn't look like it with all the doom and gloom on here. There's always the chance the models are wrong and will swing back

[Eagle Eye]

Is there a term coined for "model depression" because there should be. 

Why do we all suddenly trust the models now that they aren't showing exactly what we want a week away? 

For most of you this is a hobby, you're supposed to enjoy hobbies. I know it's hard because of let downs but there's also the occasional time where you haven't been let down. Every snowflake counts.