Model output discussion - January cold spell ending, what next?

[sundog]

12 minutes ago, slater said:

We will tap into this cold air in March and April , we all know it will happen 

Personally I think there will be a delay.  But I reckon February will be the month of interest.........

[dragan]

Although there is a lot of divergence in the models, it seems however, around the 18/19th there is more and more agreement for us to be in a north easterly flow, with high pressure to varying degress to the northwest , and a low over scandanavia somewhere.

Although this is far out, the similarities are quite stark, i mean, how close are we to saying, there is a ‘more than likely chance this is happening’

 

Edited January 9, 2021 by Paul

[carinthian]

23 hours ago, carinthian said:

Afternoon all.  Just have received a snow forecast up date and the latest model indication has put us over here in high class category alert for substantial snowfall in resort for Wed/ Thurs next week with 50cm or more fresh snowfall. You might also be interested that in the parameters, risk of snowfall has been flagged for the spine of the UK ( same time ) I would view that as the Pennines. Have not seen the models this morning but would assume possible transition or boundary snowfall at height. Will have a more in depth update tomorrow from our portal service with view to you guys going forward. Now I ask is the present UK cold spell on the wane or not.?

C

Ok folks a bit of an update from the team over here. Looks like mid -week some severe cold to develop over Central Europe and especially to the NE in Scandi land. The feeling is that with-in the time span 96h-144t will now be  crucial as to where the British Isles is heading ( snow and freezing temps or mild and damp ). As early as Wednesday a leading snow edge front will try and move through but its progress likely to be slow. The snow computer has halted this close to Eastern Britain. So overall, a strong backing of the ECM run from this morning which has the intensifying cold to the NE winning out, maybe sooner rather than later during this coming week. The high pressure to the SW of The British Isles obviously being a big potential spoiler to this scenario but the view from over here is that the eastward Atlantic energy remains rather weak over the coming days. The models likely to continue to throw up more conundrums as rapid changes are now taking place high up in the turbulent atmosphere so they advise.

C

Edited January 9, 2021 by Polar Maritime
Snipped blank.

[Mike Poole]

3 minutes ago, dragan said:

Although there is a lot of divergence in the models, it seems however, around the 18/19th there is more and more agreement for us to be in a north easterly flow, with high pressure to varying degress to the northwest , and a low over scandanavia somewhere.

Although this is far out, the similarities are quite stark, i mean, how close are we to saying, there is a ‘more than likely chance this is happening’

 

At the moment I’d say about 60% chance.  

[sheikhy]

15 minutes ago, XtremeUKWeather said:

Is it possible for you to share this

weather model ecmwf model - united kingdom - surface pressure [base + 24] [base= 09-01-2021 06 utc]| weatheronline

WWW.WEATHERONLINE.CO.UK

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[mulzy]

17 minutes ago, sheikhy said:

Ecmwf 06z not backing down judging from the pressure chart at 72 hours!!!

It is slightly more progressive than the 00z run. Uppers of -3 over London at Wed 13th 00z as opposed to -5 from the 00z run.

Edited January 9, 2021 by mulzy

[northwestsnow]

1 minute ago, Mike Poole said:

At the moment I’d say about 60% chance.  

Like it Mike!

I'll raise you to 75% ...

Just get that ridge into Greeny and watch that bitter Arctic air flood south west..

[Rocheydub]

1 hour ago, Jason H said:

I agree with this post, but it's a slightly condecending way of putting it. 5 days is the maximum at the moment and probably most of the time. But it had to be said, each run seems to end cold. 

It’s spelled condescending 

Sorry, couldn’t resist!!!

[Djdazzle]

10 minutes ago, Bartlett High said:

What are the uppers like?

Marginal!

Back to the models, @carinthian’s post was very.good, but I worry that there seems to be a pivotal point for the UK between cold and mild. Sadly, in those situations, mild is nearly always the outcome.

[Vikos]

EC Scenarios of 00z run, rock soild!

+168h

+240h

+300h

+348h

[lawrenk]

19 minutes ago, Djdazzle said:

 It’s also high pressure dominated!

How about we start a “Nept Weather” thread?

[NewEra21]

With all the flip flopping amongst the current output, even within a relatively short timeframe likely being caused by the SSW. I wouldn't be surprised to suddenly see freezing charts covering us in a shorter timeframe than some are currently predicting. 

The cold is clearly going to be dropping into Scandi and Europe, and once that happens it doesn't take much of a backing west of the pattern before we join them.

Could all go wrong of course, but that's just my hunch as of now. I feel we could have cold on our doorstep sooner than we might think!

[bluearmy]

9 minutes ago, mulzy said:

It is slightly more progressive than the 00z run. Uppers of -3 over London at Wed 13th 00z as opposed to -5 from the 00z run.

By T90 the precip is about 50 miles further east of the 00z ans uppers and Dp’s approx 1c higher across e England. Obviously not the trend we want if it continues but within a margin of error, run to run at this range. 

[Vikos]

15 minutes ago, northwestsnow said:

Like it Mike!

I'll raise you to 75% ...

Just get that ridge into Greeny and watch that bitter Arctic air flood south west..

After EC and GFSp are nearly on the same tracks, I would even raise this to a 85% outcome probabilty

[CSC]

I think some may be exceptionally surprised with the days ahead. There have been moments, albeit rare, where the GFS is entirely wrong even just 48h+ out. So expect surprises. 

My bold prediction is that within 7 days, we are going to see a cold N’Ely. This period of time just feels different, and I really just don’t think the U.K. will go considerably mild again for quite some time. A mild rest on Monday - Thurs and then back to cold and snow potential from then onwards is my view. Hang on in there. The ride has just begun.

 

 

[Djdazzle]

1 minute ago, Vikos said:

After EC and GFSp are nearly on the same tracks, I would even raise this to a 85% outcome probabilty

You are very optimistic. Been burnt too many times to go for anything beyond 50:50.

[Methuselah]

I thought it might be time to post the GEFS 06Z ens... And there are plenty of nippy, potentially snowy runs among them -- not least, the Operational and Control:

    

    

And the NH profiles seem to be headed in the 'right' direction, too:

    

    

[DavidS]

24 minutes ago, Djdazzle said:

Marginal!

Back to the models, @carinthian’s post was very.good, but I worry that there seems to be a pivotal point for the UK between cold and mild. Sadly, in those situations, mild is nearly always the outcome.

Yes, the chances of reverting to something more akin to climatology is always there. However this isn’t your typical winter, so our chances for colder are higher than would typically be the case.

[sheikhy]

29 minutes ago, bluearmy said:

By T90 the precip is about 50 miles further east of the 00z ans uppers and Dp’s approx 1c higher across e England. Obviously not the trend we want if it continues but within a margin of error, run to run at this range. 

Ye i did say earlier the ecm might have gone off on one with the generous snow amounts for midweek aswell!!!

[Vikos]

18 minutes ago, Djdazzle said:

You are very optimistic. Been burnt too many times to go for anything beyond 50:50.

You're right.

I have to mention, that I live on the continent, so I have a slightly better chance of prolonged (hard) cold here.

Sorry, sometimes I just forget that this is a Brit's forum...

[Snipper]

53 minutes ago, slater said:

Same here since last Monday temps for My area been showing 9c for the coming week, now 5c and 6c, no one going to know what’s to happen, look at Madrid today, no one really expected all that snow 

If you have Windy app it is quite good looking at the webcams in Spain. The app will show new snow cover. Most show a stream over a 24 hour period. Lot of places start with no snow and then a lot. Very envious. 

[Tim Bland]

1 hour ago, Mike Poole said:

It is actually pretty cold on Neptune too.

As others have mentioned, the GFS // has been quite consistent compared to the current GFS, and is beginning to pull away in the verification stats:

Interesting that during normal times it verified pretty similar, but as the main upgrade is massively increased vertical resolution, you could say it is made for the aftermath of an SSW.

GEM (CMC) is also outperforming both GFS GFSp and UKMO! It still doesn’t get much airtime on here though

[Mike Poole]

1 minute ago, Tim Bland said:

GEM (CMC) is also outperforming both GFS GFSp and UKMO! It still doesn’t get much airtime on here though

GEM has been very good since it had an upgrade sometime in 2019.  It is usually 3rd above GFS.

[Tim Bland]

3 minutes ago, Mike Poole said:

GEM has been very good since it had an upgrade sometime in 2019.  It is usually 3rd above GFS.

I’ve always championed it, as you say it verifies very well and often above GFS. We also get to see all the data , eg precip charts so I’ve always wondered why it gets ignored in favour of GFS and often just get laughed at when posted.  

[londonblizzard]

33 minutes ago, General Cluster said:

I thought it might be time to post the GEFS 06Z ens... And there are plenty of nippy, potentially snowy runs among them -- not least, the Operational and Control:

    

    

And the NH profiles seem to be headed in the 'right' direction, too:

    

    

Looking good. Netweather has the most visually readable GEFS ensembles graph, but when are they going to start showing the full 30-set not just 20?