Model output discussion 24/01/21

[mulzy]

53 minutes ago, Man Without Beard said:

GEFS mean at T276. That surface Scandi High is growing run by run. I tend to get excited when the mean hits 1030mb.

The cautionary note is that the ECM mean built a large high over the South of Europe by D15. Would suggest we might not get a cut-off Scandi High for long. But it's early days

Yes, heights centred over the Greece locale spreading west into the Central Med is a fly in the ointment in the extended EPS  If we can get rid of these nagging heights then it’s locked in cold.

Edited January 27, 2021 by mulzy

[Anthony Burden]

1 hour ago, johnholmes said:

A genuine question.

What is your reason for saying that, what proof is there of this happening please?

 

Hi I assume you are talking about northern blocking,check out met office 30 day Exeter ie 

Glosea.Nothing sure in life certainly not weather,but a signal is there for sure.

[Battleground Snow]

MJO update,

Still looking good, but it's really dragging its feet to get across the western Pacific,

Perhaps this is why we keep seeing false dawns with high latitude blocking seeming to always be just out of reach in FI?

Does anyone know what could be interfering/slowing down its progression east across the Pacific?

 

[mountain shadow]

7 minutes ago, Battleground Snow said:

MJO update,

Still looking good, but it's really dragging its feet to get across the western Pacific,

Perhaps this is why we keep seeing false dawns with high latitude blocking seeming to always be just out of reach in FI?

Does anyone know what could be interfering/slowing down its progression east across the Pacific?

 

The AAM which is a better measurement of relative angular momentum does show a consensus for some amplification into the start of February, but as you can see, it is by no means a large deviation from the standard anomaly. This would seem to indicate a continuance of what we have now, with wedges as opposed to a proper upper high at Northerly latitudes. Maybe suggestive of a bit more longevity and deeper cold for a while?

 

[Bricriu]

6 hours ago, BLAST FROM THE PAST said:

Maybe the nirvana runs yesterday were the rogues?

 

BFTP

It certainly seems like it.  We get a few juicy runs then it's back to less than promising output. These patterns are very hard to get out, until we see a persistent signal for heights to drop over Iberia I don't see us getting a prolonged cold spell. After having chased a proper cold spell all winter, we'll probably end up with one heading into March.

[jules216]

The pattern in SE Europe is starting to resemble +IOD pattern as per World climate services tweet last week. Good luck trying to get cold weather in to western Europe properly. It might happen through northerly route but not easterly. 

[phil nw.]

The coming few days into early next week look like continuing with this mild/cold/mild setup with the boundary moving north and south.Just the far north looking cold consistently.

Latest fax's at  t24 and t84

shows the northern extent of mild reaching the south of Scotland tomorrow before cold returns by the end of the week. As aside there could well be lot of snowfall around those fronts up there later tonight and through tomorrow,especially over the higher levels and parts of northern Scotland.

Through the next week or so we continue to be on the edge of the cold block to the north and north east with most of the UK getting alternative visits from each as the Atlantic lows keep trying to push against it.

The 06z gefs and 0z eps temp.graphs for Warks sums things up for many in the UK.

Sunday's next move from the Atlantic is really the next point of interest as it heads towards the south of the UK with cold air over much of the country.

Probably best to wait for the short term models to get a handle on detail for this but looking at the 06z gfs run some snow does show up.This on the forwards edge in the south but more likely further north over Scotland as another push of south westerly winds head in across the south.

Following on from the week end the trend is indeed another push through of milder air for most,although this again could well be short lived as another colder trend is shown later next week.

Just an overview as i see it for the next week.Of course some little changes can still show up wrt the boundary of cold/mild but the overall pattern is again the UK in the middle of it somewhere.

[Paul]

I've moved a few recent posts over to the chat thread as they're better suited over there. So if you're wondering where your post has gone, it's here.

 

 

 

[phil nw.]

Just a reminder chaps to post any met.office forecasts /outlooks for discussion in the proper thread.I have just moved one post over there.

Ta

[sebastiaan1973]

22 minutes ago, jules216 said:

The pattern in SE Europe is starting to resemble +IOD pattern as per World climate services tweet last week. Good luck trying to get cold weather in to western Europe properly. It might happen through northerly route but not easterly. 

Not correct from WCS

Climate Driver Update

WWW.BOM.GOV.AU

 

[jules216]

6 minutes ago, sebastiaan1973 said:

Not correct from WCS

Climate Driver Update

WWW.BOM.GOV.AU

 

But doesnt the EPS anomaly agree with their map? Some Atlantic Blocking/UKSpain trough SE Europe high. I thing it sits as good as my bottom on the toilet seat  pardon the language

[southbank]

1 hour ago, Battleground Snow said:

MJO update,

Still looking good, but it's really dragging its feet to get across the western Pacific,

Perhaps this is why we keep seeing false dawns with high latitude blocking seeming to always be just out of reach in FI?

Does anyone know what could be interfering/slowing down its progression east across the Pacific?

 

would NINA have effect - colder water dome how snuffs out the wave ? im sure we had this a few years back promising signal that came to an abrupt end in the pacific basin?

[Battleground Snow]

8 minutes ago, jules216 said:

But doesnt the EPS anomaly agree with their map? Some Atlantic Blocking/UKSpain trough SE Europe high. I thing it sits as good as my bottom on the toilet seat  pardon the language

Interesting the Feb - April period shows 2018.. I remember a couple of chilly episodes in the months of that particular year

[Battleground Snow]

7 minutes ago, southbank said:

would NINA have effect - colder water dome how snuffs out the wave ? im sure we had this a few years back promising signal that came to an abrupt end in the pacific basin?

Possible, although it's just about to fall back into the weak category. Its not so much losing amplitude, it's not making progress eastward

[johnholmes]

1 hour ago, Anthony Burden said:

Hi I assume you are talking about northern blocking,check out met office 30 day Exeter ie 

Glosea.Nothing sure in life certainly not weather,but a signal is there for sure.

Thanks for the answer Anthony, agreed re Met but not sure we have any model we can see that consistently suggests this

[johnholmes]

8 minutes ago, Battleground Snow said:

Interesting the Feb - April period shows 2018.. I remember a couple of chilly episodes in the months of that particular year

It would be very unusual not to get 'chilly episodes' in that period.

[Cold Winter Night]

2 hours ago, Man Without Beard said:

GEFS mean at T276. That surface Scandi High is growing run by run. I tend to get excited when the mean hits 1030mb.

The cautionary note is that the ECM mean built a large high over the South of Europe by D15. Would suggest we might not get a cut-off Scandi High for long. But it's early days

 

1 hour ago, sebastiaan1973 said:

Yes it does. But is it a real 'cold delivery service'? In the ENS I don't see powerful Scandihighs as a result of heat advection from south to north. As e.g. in February 1991.

That high ECM mean over Europe at day 15 is the result of Cluster 1 and 3 combined.

Separate they look different. It's not a classic Euro High, that High anomaly.

And, as Sebastiaan's 1991 chart shows, you initially don't even need super low heights over Europe to still get a serious cold flow going from a Scandi High. (Note: I am not saying here that we will see a 1991 scenario).

[Battleground Snow]

8 minutes ago, johnholmes said:

It would be very unusual not to get 'chilly episodes' in that period.

I was being  facetious John, and referring to the severe weather we had end of Feb / March in 2018, which along with 2013, was quite extreme for the UK, they were both also Nina years

Edited January 27, 2021 by Battleground Snow

[Cold Winter Night]

33 minutes ago, sebastiaan1973 said:

24 minutes ago, jules216 said:

But doesnt the EPS anomaly agree with their map? Some Atlantic Blocking/UKSpain trough SE Europe high. I thing it sits as good as my bottom on the toilet seat  pardon the language

If the IOD doesn't really go positive until March, or even April, how can it be the cause of an anomaly on February 11?

Even if an anomaly is similar to the anomaly that is associated with some index (no matter which one), said anomaly is not necessarily caused by whatever that index indicates.

[Battleground Snow]

The low is sliding on the icon.

The Saturday snow event is still there too, however it's very marginal.

 

[Tim Bland]

Icon still looks good for some snow on Sat. Could be a bit marginal but there is plenty of precip if we can get the DP low enough? 

Edited January 27, 2021 by Tim Bland

[weirpig]

Saturady on the Arperge  not without interest  Wales  and central southernEngland

 

 

[Tim Bland]

4 minutes ago, weirpig said:

Saturady on the Arperge  not without interest  Wales  and central southernEngland

 

 

Arpege looks a fair bit south of icon which pushes it right up to the north midlands then it stalls and dies out around the M4. Will be interesting to see the next few runs of the ECM as it did quite well ahead of last Sunday . Usually I’d say it will trend south but it has been a trend north in the last 24hrs...

[weirpig]

8 minutes ago, Tim Bland said:

Arpege looks a fair bit south of icon which pushes it right up to the north midlands then it stalls and dies out around the M4. Will be interesting to see the next few runs of the ECM as it did quite well ahead of last Sunday . Usually I’d say it will trend south but it has been a trend north in the last 24hrs...

Yep  it also slides the low on Sunday  and misses  the Uk  scrapping the tip of Cornwall 

[Mike Poole]

ICON 12z at T132 and T180

I’m finding this quite educational, it didn’t look like the low would slide to start with, but such a weak ridge seems to be sufficient, hence T180 chart.  The early evolution of this is so important and i wonder if the 12z suite today sorts this out in favour of the weak block.

T850s far too warm, but it is about the start of an evolution to cold.

Edited January 27, 2021 by Mike Poole