Model Output Discussion - Into Winter

[Harveyslugger]

5 minutes ago, MattStoke said:

ICON 6z keeping Monday’s front further south. 

Do you think it's more likely to be south of this?

[MattStoke]

1 minute ago, Harveyslugger said:

Do you think it's more likely to be south of this?

Possible but most models actually take it further north at the moment.

[bluearmy]

4 minutes ago, BartyHater said:

Yeah I get that and I'm not without hope....I still can't see any way to avoid the change, but I was careful to say 'milder' rather than mild or very mild, I'm far from convinced will see either of those devils.

It does look more than unlikely that we avoid a return to average temps and possibly the odd mild day. but how long that lasts for is , as you say, the question. as a preference, I wouldn’t be against a very mild couple of days if it’s connected to a strong burst of WAA.   Context . 

[Derecho]

29 minutes ago, BartyHater said:

Yeah I get that and I'm not without hope....I still can't see any way to avoid the change, but I was careful to say 'milder' rather than mild or very mild, I'm far from convinced will see either of those devils.

Yup and aside from the ICON 00z, the cold is being shifted away from Scandi in all the operationals now. I think that low between Greenland and Norway was the big spoiler. That Svalbard high of interest is now sinking into central Russia as mild air makes inroads further eastwards at our latitude.

The EC at T240 could risk locking in some mild weather for a while if the high builds into central Europe. Would be a long way back to cold from that... it is at least at T240. GFS 00z really wasn't good either, UKMO 00z is of a little more interest but pretty poor this morning again.

Edited December 2, 2023 by Derecho

[nick sussex]

There’s perhaps one opportunity to eject some shortwave energy east se and this would need to happen to extend the cold further and cause a domino effect on the future evolution .

You can see the ICON similar to the others . They try to eject some shortwave energy off the main complex low upstream .

The mechanics essentially the two lows will essentially spin anti clockwise as this happens because of some forcing from the ne some energy tries to head east se .

You can see that shortwave . We don’t manage to eject that cleanly to run into France . This would further promote heights to the north .

Its a longshot but realistically I don’t see any other opportunity within the day 5 timeframe .

[blizzard81]

Good summaries this morning. Probably the most sobering set of runs in quite a while. I was hoping for more trough disruption. Unfortunately, it looks like those atlantic lows are forming into the 'bowling ball' variety. Let's just wait to see how long it takes for the atlantic to run out of puff. Sounds like all the drivers etc point to it being a temporary affair. Then back to something much more exciting. 

Edited December 2, 2023 by blizzard81

[snowsummer]

10 hours ago, Allseasons-Si said:

Erm!!!,...WOW!!!

I remember  seeing a chart like this 10 years ago when i first joined. I asked what the "big black bit" meant. Strangly, nobody replied lol. I understand now of course, but something else i remember from that winter,   there was no cold, snow or anything of significance.  Lets hope this year is different.

[Dignity]

Well, that's a light dusting of snow here that definitely wasn't modelled this morning! (Dundee, 139m ASL)

[Lincs Observation]

Looks like everyone can take a break and relax for the next week as me move into the transition, might do some of us some good to look away from the models before we go again in the lead up to the Christmas holidays.

time to concentrate on Christmas shopping and pre Christmas work parties.

This last period has been very interesting indeed and I suspect that the fun is far from over as we turn into the new year.

back in a week to see what’s going on 

 

[blizzard81]

I've been looking at the ecm run again because something struck me the first time I viewed it. Does anyone else think that the transition from the 144 chart to the 168 looks odd? Like, it doesn't look like a natural 24 hour progression that you would expect to see? Or it could just be me. 

[Polar Maritime]

Please posts any snow reports/nowcasting into the regional threads, it's going to be a busy evening

Edited December 2, 2023 by Polar Maritime

[Frigid]

3 minutes ago, blizzard81 said:

I've been looking at the ecm run again because something struck me the first time I viewed it. Does anyone else think that the transition from the 144 chart to the 168 looks odd? Like, it doesn't look like a natural 24 hour progression that you would expect to see? Or it could just be me. 

Very odd, that 970mb low pretty much fizzles out. A good sign imo.

[Mike Poole]

20 minutes ago, blizzard81 said:

I've been looking at the ecm run again because something struck me the first time I viewed it. Does anyone else think that the transition from the 144 chart to the 168 looks odd? Like, it doesn't look like a natural 24 hour progression that you would expect to see? Or it could just be me. 

In between frames might help!!

Longer term, I think it is clear now that the sliding lows scenario to preserve the current cold went out of the window yesterday, the bowling ball lows it is, but they cannot move east much past the UK, so we will get warmer as the WAA ahead hopefully pumps up a high that will be of benefit later.  

Edited December 2, 2023 by Mike Poole

[sebastiaan1973]

And while a technical SSW is difficult to forecast with precision at extended leads, the expectation based on the composite analogs remains that one will indeed take place between approximately Christmas and January 8, along with a major winter storm in the vicinity of the holiday week. This impending disruption of the polar vortex is not only significant due to the sensible implications for later December and into January, but also the balance of the winter season given the unexpected prevalence of the negative NAO through the early portion of December. Having the NAO average negative prior to the vortex even weakening makes it extremely likely that December will end up featuring a negative NAO in the monthly mean. This represents a significant deviation from warm ENSO climatology and offers invaluable as to how the rest of the season may evolve. Research conducted by meteorologist Eric Webber confirmed that El Niño events that feature a greater incidence of negative NAO in December are more likely to exhibit additional episodes of high latitude blocking, leading to a colder and snowier outcome for January through March over the Eastern US.

 A nice read -> https://easternmassweather.blogspot.com/2023/11/december-preseason-impressions-appear.html

 

And the Tweet where he writes about:

https://twitter.com/webberweather/status/1728115422648562170?s=20

[blizzard81]

5 minutes ago, Mike Poole said:

In between frames might help!!

Longer term, I think it is clear now that the sliding lows scenario to preserve the current cold went out of the window yesterday, the bowling ball lows it is, but they cannot move east much past the UK, so we will get warmer as the WAA ahead hopefully pumps up a high that will be of benefit later.  

Thanks Mike. Looks less odd now but still a little. I didn't realise you could see these shorter interval time steps on the ecm run so thank you. 

[nick sussex]

The GFS 06 hrs run tries but we don’t manage a clean ejection of the shortwave .

We need a complete separation from the upstream mothership ! No hang back of energy .

This is important . It will then promote heights circled yellow . This then adds forcing on the bottom low .

This will alter the track into the UK .

Edited December 2, 2023 by nick sussex

[MATTWOLVES 3]

14 minutes ago, Lincs Observation said:

Looks like everyone can take a break and relax for the next week as me move into the transition, might do some of us some good to look away from the models before we go again in the lead up to the Christmas holidays.

time to concentrate on Christmas shopping and pre Christmas work parties.

This last period has been very interesting indeed and I suspect that the fun is far from over as we turn into the new year.

back in a week to see what’s going on 

 

Don't be telling the Netweather owners that..ie take a break and turn this place into a graveyard! Let's keep the place buzzing right through the December period!

Don't be focusing to much on parties as your judgement will become seriously clouded from intoxication my friend

For several days back to back we have seen very negative 0z data being churned out,only for the 12s to upgrade yet again!

A difference in the data? No probably not but a problem with the data handling the sypnotics! Perhaps swinging from overplayed Atlantic incursion and downplayed cold blocking,to this scenario being switched around again.

So I would say hold fire and wait for the 12s and the 18s to run and see if this current trend continues,or its yet again nwp struggling to get too grips with the evolutions.

The longer term situation still looks exciting anyway,and I can guarantee the next cold wave will yet again cause havoc with the models.

So enjoy your Weekend and get some shopping done and let's keep the atmosphere in this place buzzing...as by and large its been electric the last couple of weeks.

[Mike Poole]

8 minutes ago, blizzard81 said:

Thanks Mike. Looks less odd now but still a little. I didn't realise you could see these shorter interval time steps on the ecm run so thank you. 

Yes, they are here:

WWW.METEOCIEL.FR

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Meteociel propose le modèle deterministe de ECMWF CEP en Open-Data avec une résolution de 0.4°

They also include more charts such as precipitation, jet stream etc.  But they aren’t available until slightly later than the run comes out.

[bluearmy]

Deleted 

Edited December 2, 2023 by bluearmy

[Battleground Snow]

30 minutes ago, nick sussex said:

The GFS 06 hrs run tries but we don’t manage a clean ejection of the shortwave .

We need a complete separation from the upstream mothership ! No hang back of energy .

This is important . It will then promote heights circled yellow . This then adds forcing on the bottom low .

This will alter the track into the UK .

Arpege cuts off just before we can see if this would happen.

Very disappointing 00z runs on the whole though, which seems to be a constant thing at the moment 

[blizzard81]

Cmon own up...... Which one of you invited Uncle Barty for Christmas?

[Purga]

06z now wants to go uebermild.

May not end up as bad as it looks at first glance. WAA & all that jazz.

[MattStoke]

2 hours ago, MattStoke said:

ICON 6z keeping Monday’s front further south. 

UKV 6z similar.

[Jacob]

Is there a way to access MetDesk charts for free?
 

[Summer Sun]

Just now, Jacob said:

Is there a way to access MetDesk charts for free?
 

https://www.wxcharts.com/?panel=default&model=ecmwf,ecmwf,ecmwf,ecmwf&region=uk&chart=overview,850temp,wind10mkph,snowdepth&run=00&step=027&plottype=10&lat=54.524&lon=-1.556&skewtstep=0