Model Output Discussion - Into Winter

[January Snowstorm]

The ecm at 240 (Christmas Eve)

Plenty fuel in the Atlantic to keep a very zonal, perhaps stormy Christmas period

Any cold looks transient

Edited December 14, 2023 by January Snowstorm

[TSNWK]

1 minute ago, January Snowstorm said:

The ecm at 240 (Christmas Eve)

Yep… ecm is sobering….. 

[mountain shadow]

1 minute ago, nick sussex said:

 

Its hardly covered itself in glory over the last few weeks .

 

That was exactly my thinking too. 

The ECM Op has consistently underplayed the ridge.

[Vikos]

Synoptics are likely more autumn‘ish than winter‘ish… like all the years before. Prolonged autumn going into spring, winter is culture cancelled, thanks to climate change with new record high temperatures…

[joggs]

Poor ECM tbh. I'm not really feeling this cold snap. Crumb of comfort is that it could be under doing the high in the Atlantic and we know how progressive the GFS can be.

Think we'll have to wait for the 2 Nd week of January onwards for anything prolonged(cold).

Waiting game for the strat and trop to finally play ball.

[TSNWK]

3 minutes ago, joggs said:

Poor ECM tbh. I'm not really feeling this cold snap. Crumb of comfort is that it could be under doing the high in the Atlantic and we know how progressive the GFS can be.

Think we'll have to wait for the 2 Nd week of January onwards for anything prolonged(cold).

Waiting game for the strat and trop to finally play ball.

I’m with you.. just not feeling it at all.. gfs is stormy cold cyclonic 3 dayer before heights ridge in from the Atlantic into Europe for Christmas week… ecm does not provide the rough and tumble of gfs..

[BLAST FROM THE PAST]

41 minutes ago, Vikos said:

Synoptics are likely more autumn‘ish than winter‘ish… like all the years before. Prolonged autumn going into spring, winter is culture cancelled, thanks to climate change with new record high temperatures…

Wonder what the equivalent thread is like with the Aussies….bonkers anomalies everywhere.

BFTP

 

 

I’ve plucked this one from the GEM as an example 

that little depression SW tip of Greenland.  That develops into the storm force nw’lies /n’lies.  Wasn’t this what Matt Hugo mentioned to watch out for yesterday?

here’s the feature on GFS

 

I’ve been in the potential storm or 2 camp for Xmas for a while.  
Wonder if the story of storminess over the festivities will be the main story .
 

BFTP

Edited December 14, 2023 by BLAST FROM THE PAST

[cyclonic happiness]

That is one vicious storm on the 22nd!!

[Vikos]

9 minutes ago, BLAST FROM THE PAST said:

Wonder what the equivalent thread is like with the Aussies

BFTP

 

 

I’ve plucked this one from the GEM as an example

Well, figuratively and metaphorically speaking, this is the other side of the coin…

[Penguin16]

Underwhelming ECM. The odd chillier day that’s about it.

Edited December 14, 2023 by Penguin16

[LRD]

Looks like any cold weather is being squeezed in terms of longevity and diluted in terms of severity unless you believe the GFS

ECM is awful if it's cold you want but let's see what the ensembles and clusters say. As Vikos said, it's more autumnal than wintry albeit the chilly and, potentially, turbulent side of autumn. GFS at least offers 3 interesting days, especially for the North and NW. But, at this point in time, it just looks like a classic 90s toppler to me

Edited December 14, 2023 by LRD

[Vikos]

Just now, LRD said:

But, at this point in time, it just looks like a classic 90s toppler to me

[Nick F]

12 minutes ago, Penguin16 said:

Underwhelming ECM. The odd chillier day that’s about it.

It highlights the danger of relying on a very strong and flat jet stream over the N Atlantic to shift south to bring us cold for long enough, the flow needs to be more amplified upstream to give anything more than brief shots of marginally cold air.

GFS buckles the jet stream upstream to the south of Greenland weekend of 23/24, so delays lows moving in from the west enough to get a brief cold blast just before Christmas, before it flattens the jet Christmas onwards, EC just too flat.

We are seeing the typical watering down of cold and flattening out of any amplification when we get nearer when we get these strong upper flows from the NW.

Edited December 14, 2023 by Nick F

[Ali1977]

Let’s see what the EC ENS say, I’d think the Op will be on the warm side between 22-26th!! 

[Big Gally]

The ecm has brought the cold forward. Last night it had it around the 23rd. Today looks more around the 20th/21st. I still think there’s time for upgrades. Enjoy the show! ️️

[BartyHater]

A definite step in the wrong direction for cold from the overnight runs and as others have said, ECM is very sobering.

Interestingly the GFS charts for Xmas period at 276hrs are not a million miles away from where they were at 384hrs 4 or 5 days ago, proving the model unfortunately handles these Atlantic setups extremely well in general.

As was said last weekend, 3-4 days can be FI in certain situations, but in others it can literally be 13-14 days when talking about the general pattern.

The 00 GFS ENS at least provides a crumb of comfort in so much as the Op is a mild outlier post Xmas, but in truth there’s very little genuine cold in prospect pre or post the big day away from Scotland, where hopefully they will see some meteorological Xmas cheer.

 

Edited December 14, 2023 by BartyHater

[carinthian]

23 hours ago, carinthian said:

Morning all, some interesting charts this morning. The incoming cold coming shown at various rates with the GEM the most progessive and ECM slowly heading there. I draw your attention to the chart below (GEM op at 168T) . As also shown on the UKMO extended and ECM  ,there is a formation of what we used to call a "curveball low " that forms along the top  of the Huge Mid - Atlantic High between Southern Greenland and Labrador. It develops where the thermal gradient and pressure gradient is greatest and its this formation that can be rapid as highlighted in the post yesterday by @Nick F. So just another feature to watch with interest over the coming days but from a coldies point of view encouragingly improved charts from all the models this morning. However, for real cold I would like that Scandinavian trough to eventually dig south prior to Christmas   and that would up the snow stakes for many in UK/ Euroland.

C

Morning boys and girls, the extended chart from UKMO is of interest .. Yesterday , as highlighted  in the above post was the possible formation of a "curve low ". This chart shows its formation and  likely to deepen as it heads towards  southern Scandinavia . These lows usually have a narrow warm sector on the southern flank and in the boundary zone where the colder rushes in there is a potential for very powerful winds to develop. Think this is definitely one to watch and could be an eventful Thurs into Friday next week.

c

Edited December 14, 2023 by carinthian

[TillyS]

Morning. 

At the moment I’d suggest to keep expectations of this northerly within sensible bounds. Not because GFS nearly always downgrades these closer to the event but because support for something genuinely substantial is limited outwith its model from UKMO and ECM, and even more significantly from within its own model. Here are the GFS ensembles showing limited support for its northerly:

 

The models might pep this up but it’s probably better than evens that it will go the other way and become a grazing low pressure. Potent for Scottish mountains and perhaps high ground in the north of England but generally likely to be fairly modest in performance.

Still, it will be a nice seasonal feel to the air for two or three days immediately prior to Christmas.

[Nick F]

24 minutes ago, Vikos said:

Overall, the route is rather mild‘ish than cold in terms of winter weather conditions… 

next stop of hope would be a ssw somewhere in January, but we all know how long it takes to deliver any goods (if at all)…

we have to face it, December isn’t a winter month any more, last one was 13 years ago and was peaking out in a series of mild winters…

Think many on here will disagree with regards to the UK, many saw snow last week, while around 11th/12th Dec 2022 it snowed a lot in places, and Dec 2022 was below average. For Germany in your location, there's been cold and snow this December, e.g, Munich 40cm of snow.

Back to the models, going through the GEFS postage stamps on Xmas Day, hardly any members going for amplification over the Atlantic on Xmas Day, most looking flat, fair few are mild SWly, a few cold zonal or cold NWly. 

Edited December 14, 2023 by Nick F

[E17boy]

This was exactly the point I made in my post yesterday. These kind of setups rarely get us into a prolonged cold set up all the jigsaw has to be in place. I could not make out what all the fuss was yesterday for a PM airflow. 
 

does look as if we will have to be patient and wait for the right set up to deliver our goods. Once we are playing with Iberian heights to go in the right direction then a lot of times the writing is on the walls.

take care all 

[Day 10]

2 hours ago, northwestsnow said:

MEAN XMAS EVE 18Z GEFS

MEAN XMAS EVE 00Z GEFS

I'm going to assume more members are further south with the pattern which is obviously positive for cold lovers...

Nice trend, keep dropping lower please.

[BLAST FROM THE PAST]

 

the 00z GFS in deep FI gives the ‘feel’ of a SW/NE tilt. But looking at each perturbation and the ens, it’s on the high end mild.  So something to watch but not a done deal.  

 

BFTP

 

 

Edited December 14, 2023 by BLAST FROM THE PAST

[TillyS]

42 minutes ago, Nick F said:

It highlights the danger of relying on a very strong and flat jet stream over the N Atlantic to shift south to bring us cold for long enough, the flow needs to be more amplified upstream to give anything more than brief shots of marginally cold air.

GFS buckles the jet stream upstream to the south of Greenland weekend of 23/24, so delays lows moving in from the west enough to get a brief cold blast just before Christmas, before it flattens the jet Christmas onwards, EC just too flat.

We are seeing the typical watering down of cold and flattening out of any amplification when we get nearer when we get these strong upper flows from the NW.

This is a great post. We’d all do well to hold onto this in the weeks ahead.

It’s better amplification and northerly blocking we really need to see for something sustainably cold.

[AO-]

Good Morning,

 

Seems like there is less uncertainty with regards to 21st-24. Much colder than before (at least for my location), which is a start. Afterwards many options are open but it would be nice to see a block appearing somewhere soon. For that matter I dont like the evolution of the Atlantic through near Labrador. Wel, thats just details. Hopefully a precursor to a very cold January.

Edited December 14, 2023 by AO-

[BartyHater]

31 minutes ago, carinthian said:

Morning boys and girls, the extended chart from UKMO is of interest .. Yesterday , as highlighted  in the above post was the possible formation of a "curve low ". This chart shows its formation and  likely to deepen as it heads towards  southern Scandinavia . These lows usually have a narrow warm sector on the southern flank and in the boundary zone where the colder rushes in there is a potential for very powerful winds to develop. Think this is definitely one to watch and could be an eventful Thurs into Friday next week.

c

Whilst not a perfect match the differences between ECM and UKMO are relatively small at 168hrs, so unfortunately I can see no good reason for the latter to go in a different direction to the former….if it extended to 240hrs of course.