Severe Siberian icy blast

January 13

So the cold spell hasn't arrived yet but all the talk is about a breakdown fri ?

Could it be the models are overdoing the zonal flow, no wedges or deflections will be sorted yet anyway.

January 12

8 hours ago, MJB said:

Oh dear - not this old chestnut again, its the Model discussion thread, not the pre 120h thread.

It's also a good way of looking for trends. I can't see you commenting against charts that are even further a field. ODD

Then use a BBQ

I wasn't having a go buddy it just baffles me unless its just abit of fun but ppn charts outside t96-120max is just a waste of time because there's zero trends on a miniscule level at that range.

January 12

2 hours ago, MJB said:

Frontal snow ..............................yeah

If that stalls a bit, might get a covering before it goes wet

But are you even taking the time to talk about a chart so far away?!

Surely the focus has to be on the reliable and looking for hints of change or not in the early stages.

Posting a ppn chart 9 days away is as much use as trying to cook without a cooker.

January 12

1 hour ago, IDO said:

The EC op is an outlier for pressure at D8 (London):

So the ridge over the UK is not as strong as the op suggests. That ties in with the mean, closer to GEFS:

There's just no point at all at analysing charts regarding a break down when the models have been finding everything too much with little to know agreement, but the cold is coming.

People obsessing on a breakdown before its began is baffling but each to their own...

Anything removing heights and cold with ease i suggest caution.

We've got some new dater flooding into the models with the fresh influx of spikes in background drivers, further +MT events , favourable wind influx pushing north from the tropics and a high amplified mjo should keep us all interested but its draining in this place every morning people obsessing on every model output even read a few posts saying basically what cold spell, it's all abit pathetic tbh that particularly with the morning blues people making comments based upon a chart thats 192 hours away when we can't even get it right for 4 days away!

A relaxation around the last 5 days of the month or so maybe but can see a snowy breakdown and a temp blip in conditions before renewed bouts of wave breaking keeping the jet amplified but pushing south and another 12 rounds for the mighty vortex that's been knocked from post to post this year already and with the El Nino imprint one of the big drivers a back loaded winter looking very interesting in deed!

January 11

31 minutes ago, Ali1977 said:

Upgrade AGAIN from the icon at T99, block even stronger

The 12z highest pressure point waa 1045

The 18z is 1040

?

January 11

To everyone constantly moaning about lack of snow in the south, we want to keep the cold spell in place, otherwise after 3 days warmer air moving in from the southwest putting the entire thing in jeopardy.

Yes short term loss for longer term gain,

Plus features won't be picked up yet accurately, but enjoy the ride its a marathon not a sprint

January 11

15 minutes ago, ThamesStreamer said:

Surely no point paying too much attention beyond the middle of next week at the moment?

Background signals are all there for severely reduced westerly momentum, and for continued shots at HLB.

Model ensembles beyond middle of next week seemingly struggling with said signals, on top of continued TPV havoc. All seems more volatile than usual.

See how middle of next week shapes up.

I just have a sneaky feeling this year could be some special.

Reading it all in depth is mind boggling to see how the whole planet is stunningly made the intelligence and attention to detail behind our very obsession is unreal.

What was 1947 ? El nino? That was a backloaded winter wasn't it?!

Il get my coat!

January 10

I have to say after just viewing the 18z i haven't read the forum either since 8pm but the gfs run is on a merry road to know where it hasn't got a scubbie mid term to later on.

But there's alot happening at the moment and there's know way the mods have it all figured out, over doing low pressure signals blowing them up is unlikely, a more southerly track will 90% of the time become the form horse, the tropics leading the way in what could be a blue print to use moving forward, its so fascinating I'm late to bed and early to wake up and im blaming you lot

It really can be one of those years

January 10

54 minutes ago, nick sussex said:

That’s funny because the end of 1978 31st December I was flying back from Cyprus with family into Heathrow and there was loads of snow and the North Circular was bedlam .

And I’m flying back next week from Cyprus around the time of the Atlantic low drama .

Is this a sign !

No way as if. Bet you find you're self in a dilemma?! On one hand you want chaos as a snow lover yet on the other hand you have to drive im guessing from the airport lol?!

January 10

53 minutes ago, Met4Cast said:

GWO - Global Wind Oscillation

GLAAM - Global Atmospheric Angular Momentum

AAM - Atmospheric Angular Momentum

Annular mode - Essentially the Arctic Oscillation

Thanks mate i had a few years off the place and im very rusty! Thanks

January 10

2 hours ago, Tamara said:

Bom dia e todos

I make no apologies for yet again re-pasting this sequence originally posted just prior to New Year, because it has become an even more focused roadmap. Not just for the upcoming 10 day period, but indeed confidence increasing as a blue-print for well into the second half of the winter:

....................................................................................................................................................................................

With the Nino attractor phases fully engaged, the amount of westerlies propagated into the atmospheric circulation between tropics & extra tropics do, as you suggest, indicate a higher floor to the angular momentum budget in the 'lull' ahead of the next upswing as the MJO traverses the tropics during January. GWO Phase 4 is a good medium base floor level I would think.

If we were to take a diagnostic template of GWO Phase 4 (and account for a likely return shallow orbit through phases 0,8 & back to 4) during an intermediate 'lull', then that very intermediate lull phase you describe will likely feature the return of a flat upper flow extending towards Europe.

The difference to recently though with the Atlantic forcing will be the jet suppressed further south - and with a cold pool established then attritional forcing of lows against the blocking likely to be a feature. (This accounts for some of the thinking as expressed within my previous posts in respect of the sub tropical jet)

With a cold pool established, any erosion from the south/west into NW Europe is likely to be attritional and not likely to displace cold pooling totally.

Taking into account we are still now in the lag period for the effect of +ve momentum from FT/MT mechanisms c/o the recent tropical>extra tropical cycle, we are seeing the new convective signal come into the Indian Ocean. Sea temp anomalies are supportive of deep thunderstorm convection. This, allied to convection in the western Pacific, will generate further mean zonal west wind anomalies to propagate across the tropics into the sub-tropics. With the westerly wind additions generated in December still in the atmospheric circulation, total and relative angular momentum will increase sending the GWO back into a (potential high amplitude) phase 5 orbit.

This progression & evolution suggests a strong -ve NAO with positive height anomalies shuffling between Greenland > Iceland and Scandinavia. Meantime southern Europe wet & mild under the sub tropical jetstream.

Muito obrigada. Melhores Cumprimentos

......................................................................................

To update the template of this analysis:

A very starkly high octane angular momentum budget is emerging and prolific within the global-wind-flow budgets. This translates to stockpile ammunition supply levels for deeply sustained poleward amplification eddies taking on veritable tanker sized reserves.

Based on how much tropospheric led influence there has been on the NH pattern in recent weeks since the starting pistol was fired to destabilise the polar profile, these further poleward swathes of +ve momentum transport take on especially egregiously gargantuan proportions for future wholesale instability and implosion across the polar field. In this respect it is not hard to comprehend the latest sentiments of Amy Butler and how she sees the synoptic pattern imprinted

The copied post referred to a baseline phase landing place for the Global Wind Oscillation. This baseline, ahead of the strongest wind-additions yet c/o eastward progressing high amplitude MJO wave back to the Pacific has remained higher than intermediate phase 4 (as discussed in the copied post)

The latest GWO phasing, even under present lull stopgap at very low amplitude 5/6, reflects the remaining considerably high levels of +AAM anomalies within the atmospheric circulation as aggregate total AAM. (Phase 4 GWO would be more suggestive of flatter return of the jet and greater attrition from the Atlantic against blocking. (Though even this sharpens somewhat against late Jan/early Feb wavelengths)

This GSDM wind flow budget situation is significant. More on this shortly.

The GWO is a phase plot depiction of aggregate wind-flow within both the tropics (MJO related) and the extra tropics as a measure of how efficiently propagation of wind-flow is proceeding between the tropics & extra tropics. This matters, because it is a barometer for synoptic pattern (poleward) amplification potential and provides a diagnostic towards directional flux of wind-flow eddies.

Poleward flux has now become quite supercharged

What of the significance of this?

As the intraseasonally driven MJO crosses the Maritimes at high amplitude, then very strong +ve torque mechanisms will be re-engaged to over top a system already awash with +AAM anomalies. The GWO likely to drill upwards into very high amplitude Phase 5/6. Taking into account maximum winter wavelengths, then this teleconnects ever more strongly to entrenched -ve NAO (under chaotic stratospheric diminution to spotweld a deeply -ve Annular Mode).

How can this be visualised?

The upcoming next cascade of westerly wind burst propagation into the extra tropics creates white water rafting within the sub tropical jet from the Equatorial Pacific downstream to the Atlantic -at the same time as the polar profile becomes riven with -ve mean zonal -ve wind anomalies. Defining solid roadblocks for southward directive of a deeply unstable thermal boundary.

How can this in turn be visualised?

With deeper upper cold air ensconced north of the polar boundary, this leads to feedbacks of entrenched surface cold with time to feed an ever starker thermal boundary, This encourages and emboldens larger progressions of numbers of kayaks slipstreaming below it. This translates to trains of low pressure undercuts - and it is not difficult to envisage the potential for high impact weather events to unfold in such a scenario.

The kayak posse delivers an "atmospheric river" of saturated sub tropical air and a large jump of temperature into the upper teens for my part of the world well below the thermal boundary at the same time as in contrast...

.... that is better left to the mercurial imaginations of any members who might be looking in from NW Europe.

Putting all this diagnostic analysis together, it is hard to see anything other than a tanked -ve Annular Mode relationship dominating much of the rest of the winter. However, and as ever, further analysis is wholly prudent to document how proceedings unfold.

Muito obrigada. Feliz quarta-feira

Well a difficult read particularly when im learning alot again now and understanding things so much better but with that comes an obsession to read carefully every word because its part of my learning process but when i haven't got loads of time it really come up at wrong time for me but everything has been put on hold!!!

I need to understand the abbreviations used, gwo, glam, aam, annular mode. I understand the geography and science behind it but i need a better understanding on it all if im taking my journey seriously.

Any references greatly appreciated

Cheers

Shaun

January 9

2 minutes ago, markw2680 said:

That will be such a waste, just ignore the baby wetting in here, it gets to me too but you and the other knowledgeable folks in here is what makes it the best weather chat on the net

I've heard its going to be very wet around Birmingham and quite unusually snowy around Warwickshire so yes you will be getting wet and il be building snowmen with you're nephew and niece!!!

*Don't remove it's humour between my brother and me!*

January 9

3 minutes ago, bluearmy said:

Icon has been around for donkeys - was DWD back in the day

I think it’s a reasonable model - I’d rate it at gfs levels.

Yep I'd prob say the same re ratings but the gfs is wild always has been, good at picking up new trends but really over reacts to others but at least we're in the game this year its keeping me interested at least!

January 9

8 minutes ago, seabreeze86 said:

UKMO is rock solid again fantastic model viewing , I really can see it being wrong over the GFS at day 5

The UKMO 12, has to be top 5 easy nicest set of charts iv watched come out, absolute belters.

Whats the verification stats for icon in comparison to the gfs anybody know? And how long have we all been into it because its only been big in hear for the last 2 years max i think?!

But icon i have to admit im enjoying the flirt you saucy mare just keep showing us the goods please!

January 9

5 minutes ago, Ice Day said:

So day 7.5 on the 6z vs the 0z

That's quite some inconsistency at that range. The models are clearly struggling with some significant chaos in the background signals, which is a positive I guess!

The removal of heights over greenland and obsession on bringing everything from the azores low and then higher heights from Spain goes against teleconnections with so much phasing up north losing the northern hemisphere profile with 36 hours or so just wont happen.

The low pressure will be shunted south with each run id be surprised to see it touch the south coast.

We need cut off highs and cut off lows to keep things clean with as little phasing as possible id say give it a few days and we will look less messy and calm nurvs lol

January 8

4 minutes ago, Tom Quintavalle said:

That stuff forecast to cross from Holland into the Southern North Sea looks interesting, especially for Kent.

Rain radar & weather forecast | Meteoradar

WWW.METEORADAR.CO.UK

View the current rain and weather forecast on the rain radar at Meteoradar.

Buienradar.nl - Buienradar.nl - Weer - Actuele neerslag, weerbericht, weersverwachting, sneeuwradar en satellietbeelden

WWW.BUIENRADAR.NL

Actuele buienradar en actueel weer voor Nederland en Europa, actuele satellietbeelden, actuele temperaturen, neerslag, en veel meer!

Regards,

Tom Q.

I have just posted in the model thread about this, tbh i have a sneaky feeling a swathe of England are going to get caught out later, the ppn is Belgium crossing the channel looks organized and long, get the sea into the mix and should start to move in land later but im anticipating alot more than currently modeled.

Im pretty sure that's tied up in the colder uppers

January 8

6 minutes ago, MattStoke said:

ICON upgrade on snow shower risk for today/tonight. This model tends to struggle with shower development beyond very short range.

What i can say is there's alot of ppn towards France and Belgium now crossing the channel i think tonights going to be alot more active than people think

January 7

1 hour ago, Mark wheeler said:

Is that the one that started as rain for a few minutes then boom, snowmaggedon ?

Yes lol but apparently that wasn't one according to rather a blunt response but i remember the bbc1 weather talking about this polar low coming down Northern England very intense only about 2 hours worth of heavy snow but thunder the lot it was class it changed from rain to snow in a big gust of wind it was unreal

January 7

1 minute ago, sheikhy said:

THE greatest rain to to thundersnow event ever to this day for me!!if that is the one you are on about!!!!was like a wall of snow coming towards me that afternoon after ot started as rain!!!!got close to 10 cms in couple of hours!!!!!

Me in redditch at the time had about 2 inches that froze immediately after and we had mint sledging the next day i was about 21 so 19 years ago

January 7

29 minutes ago, bluearmy said:

I agree

That system forms out of a shortwave s of Iceland - barely has its origins in the Arctic. Can’t recall the last proper polar low we’ve actually seen

Do you remember the one in 2002/3 one Jan afternoon it swept south bought mayhem to midlands south rushour

January 7

1 minute ago, Froze were the Days said:

Closer to slider territory I would think...getting colder.

They have no low pressure southeast to slide into its high pressure with low pressure to our north for the same time frame 240,

January 7

1 minute ago, That ECM said:

T168 all 4.

Its struggling to bring everything south because of the stubborn mid lat heights.

January 6

26 minutes ago, Daniel* said:

that’s true but there’s a major difference in outcomes between fleeting northerly cold winds and something more sustained. I just feel it is important to stress and express the uncertainty, recent runs from EPS have deteriorated and it’s not just the OP. Confidence is low.

Jan 16th… Jan 20th

The second one just spells battle ground to me, greenland still warm and Europe still cold. Its 14 days away lol

January 6

1 minute ago, Daniel* said:

It a significant decline from recent days both forecast for Jan 17th the newest on left and right from 12z of 4th. The blocking signal to NW has weakened it’s not a good trend and see stormy area across pond which further tries to erode. We see this a lot with Greenland blocking sadly as we get closer… I’m not saying it’s over with, but these are not giving me encouragement at all.

In complete honesty if you're taking things literally at t300 then you're setting yourself up for a bumpy ride, the computer models pick up on a trend and tend to over react to a signal then level out somewhat and its a process of two or three times it goes back and forth but the signal is strong. Northerly blocking and cold air moving south.

Leave the detail out for now

January 5

From years of experience the models pick up new trends, forcings on a blocked pattern and tend to over react to something new, normally takes a few days to level out sometimes it disappears but they normally find a middle ground once they get to grasp with the scenario

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