Model Output Discussion - Colder spell ending, what's to follow?

[Nick F]

Trying to find some crumbs of comfort for coldies, but they're rather thin on the ground.

00z EC for London does show the EPS T2m mean dropping over Xmas period, which follows yesterday's 12z run doing the same thing, so could be a sign that we see amplification in the upper flow appear after 10 days that allows deep cold gathering to the north to be released our way. 

Today's 00z

Yesterday's 12z 

But, a long way off and can change if the EPS picks up less favourable signal. So for now, it's hard to swallow after all the optimism for remaining blocked at the start of the month, but it's the norm for December, several days of wind and rain ahead.  100-150mm accumulated totals showing on GFS in the west over coming days, up to 100mm in the south. Just hope we can avoid serious flooding issues in the run up to Christmas.

Look out for trends of amplification upstream in model runs, as this will be the escape route from what's on the menu for the next 7 days.

[STRiZZY]

8 minutes ago, Valleyboy said:

I would forget pinning hopes on any snow this Christmas.  The Atlantic looks to take hold for the foreseeable.

I hear you, but there are still 14 days until Christmas and two weeks out is certainly not a reliable time period for any model. Granted it does not look great for snow/cold lovers for the next week but there is still time for a turn around for the week after. 

[Tim Bland]

12 minutes ago, Valleyboy said:

I would forget pinning hopes on any snow this Christmas.  The Atlantic looks to take hold for the foreseeable.

Looking at the 00z GFs and the 06z ensembles there is Still a chance of ridge making lows track far enough south for some snow on their norther edge. Almost zero chance of the ‘beast / blast from the east’ some are forecasting though.

[warrenb]

Let's be honest, the pattern is stuck (as it has been for months and months) with slow movement of the Rosby waves West to East, and at present we are in the trough. Depending on how quickly the patterns move will determine if we get a cold spell or a love spring as we had last year.

Edited December 11, 2020 by warrenb

[IDO]

Looking at the latest GloSEA update and it backs up that this is likely to be a front loaded winter and those expecting a cold Jan-Feb look away:

Ensemble-mean maps

WWW.METOFFICE.GOV.UK

---

Ensemble-mean fields up to six months ahead. Updated monthly,

So the models are not on our side, milder and wet with a classic UK winter setup is what the algorithms are saying. Some may pin their hope on a SSW but that was too little and too late last winter so maybe wary of that rescuing us? Hopefully mixed in with the general theme we can get a few cold spells and that we get a bit more luck than the recent one!

[mb018538]

 

[warrenb]

4 minutes ago, mb018538 said:

 

Looks like we could  be in for a repeat of last winter, which down here didn't include a single flake of snow. Looking a the charts, we are just as I said earlier in the wrong part of the globe for the pattern that is setting up.

[BarometerCat]

2 minutes ago, snowblizzard said:

Ensemble-mean maps

WWW.METOFFICE.GOV.UK

---

Ensemble-mean fields up to six months ahead. Updated monthly,

Unfortunately, I think the UK winter (as we used to know it) is dead in the water!

Perpetual Spring in terms of temperatures virtually every year!

With a massive risk of flooding in many prone area's

As a severe cold and snow lover, it's really quite depressing!

Help me out here,  I am not seeing spring like temperatures coming up?    Not in models or forecasts, where are these showing?   All I can see is this same pattern more or less repeating in the near term. Not really interested past +144 at the moment. 

[Eagle Eye]

Certainly some big lows around the 25th

 

[SqueakheartLW]

Still some milder options in the GFS 06z output but less of them at least ... good. However a lot more colder options have returned, none are beasterlies unfortunately but some look like they are going to evolve into something much better just after Christmas Day

I will get the doom and gloom out of the way first with the milder options that showed up, that is all 7 of them, 2 fewer than the 00z

GFS 06z Member 1

Long fetch SW winds from the Azores, not what I ordered for Christmas Day weather wise

GFS 06z Member 3

Generally mild for all except for northern Scotland that sticks out into that Arctic air. A nice white Christmas if you live up there, otherwise a green Christmas for the rest of us. This chart also features that big Greenland high and when I ran the run to the very end it looked like that was going to win in the end as the low pushed east and cold air started to dig in behind it

GFS 06z Member 6

A transitional poorly timed mild spell that looks to be clearing out as the day progresses with a cold front pushing from W to E

GFS 06z Member 8

Another long fetch SW wind run here but less mild than the first example

GFS 06z Member 16

Another long fetch SW wind example but from further south. Has the potential to go very mild if the pattern sticks

GFS 06z Member 28

A mild affair in the south of the UK but closer to average in the north. Could go either way after Christmas

GFS 06z Member 29

A December 2015 type chart. Has the potential to go very mild and could be the mildest of all of the featured runs

At least I have got that doom and gloom out of the way nice and early. Now for the cold fans here is the better part of this update. I have put the least cold option first and the coldest one last

GFS 06z Member 19

This looks like a transitional snow event for some, especially the further N and E you go. Not the classic white Christmas you would want where the snow sticks around but more a temporary covering before the milder air arrives later on

GFS 06z Member 12

Similar to the above only that the air is colder overall and the switch to milder looks to be more temporary and most likely in the south only. The north could see snow for most of the day here

GFS 06z Member 5

A cold and anticyclonic option here. Frost and fog the order of the day but the uppers would suggest just a little too warm for snow

GFS 06z Member 18

Very much like the above run other than the high is centred over the UK instead. A tiny bit colder than the last option and similar weather too

GFS 06z Member 9

Now here's a potential snow maker event. A slack area of low pressure within marginal uppers. Could either be cold rain, sleet or snow with this setup depending on exact parameters at the time

GFS 06z Member 30

Another cold anticyclonic setup with similar conditions to the first 2. Probably the coldest one of the 3 so far

GFS 06z Member 17

A bit of cold air caught up with these 2 low pressure areas. Very likely marginal snow makers in both of them, especially the further north you go. A white Christmas possible here.

GFS 06z Control Run

A decent control run for Christmas Day if frost and fog are your thing. Coldest in eastern areas with the best of the sunshine. Probably cloudier and less cold in the W and some of the N as well

GFS 06z Member 27

A perfectly setup battlefield here with the low to the south vs the high to the north. The UK itself is under quite cold uppers and not far from the low either so potential here for some wintry showers. Even heading to the end of this run didn't show a clear winner between the low and the high.

GFS 06z Member 20

A very slack flow here in no mans land between systems and quite cold uppers caught up in the mix. Most likely dry, cold and frosty but with no particular high pressure to be seen then wintry showers cannot be ruled out here that could fall as snow too

GFS 06z Member 11

The coldest of the options with an Arctic northerly for Christmas Day. Snow showers likely in the N and E in particular

Summary

Overall an improvement on the 00z GFS but still no where near as good as yesterday's earlier runs or ones from the day before. Lets hope that the 12z gets us back on track again before hope of a seasonable or white Christmas fade completely for yet another year. To have 11 runs that are colder this time compared with just 3 in the previous run is a good improvement.

The counts for 06z are as follows:

Mild = 7

Cold or V Cold = 11

Less cold or Average = 14

[Jeremy Shockey]

 GFS 06 pert 12  ( just for fun )

You never know ...........there are some cold options too for 23rd / 24th and it is still nearly 2 weeks away.

It wouldn't take much for us to get some very cold air from the North West direction just before Christmas ...........keep some faith ( if you can )

[Blessed Weather]

If your post has gone missing it's probably been moved over to the Moans, Ramps & Chat thread. Please stay on topic in here: Model Output Discussion. Thanks.

 

[snowspotter]

28 minutes ago, Barometer Cat said:

Help me out here,  I am not seeing spring like temperatures coming up?    Not in models or forecasts, where are these showing?   All I can see is this same pattern more or less repeating in the near term. Not really interested past +144 at the moment. 

It’s on the Met Office link as a huge area of positive temperature anomalies for the entire winter period shown in red especially Northern Europe and Siberia 

[syed2878]

1 hour ago, STRiZZY said:

I hear you, but there are still 14 days until Christmas and two weeks out is certainly not a reliable time period for any model. Granted it does not look great for snow/cold lovers for the next week but there is still time for a turn around for the week after. 

 I would say two weeks is quite reliable when Atlantic is forecasting for our little island as this is our default button sadly unless the Gulf stream changes suddenly after all the promise charts over the last week or so this does not look too inviting what we are watching now personally I think it is January we will see signs of cold on the NWP. as Cold-Eeze in the UK I think we just going to have to take it on the chin this time round just like last few winters. 

[sebastiaan1973]

1 hour ago, IDO said:

Looking at the latest GloSEA update and it backs up that this is likely to be a front loaded winter and those expecting a cold Jan-Feb look away:

 

So the models are not on our side, milder and wet with a classic UK winter setup is what the algorithms are saying. Some may pin their hope on a SSW but that was too little and too late last winter so maybe wary of that rescuing us? Hopefully mixed in with the general theme we can get a few cold spells and that we get a bit more luck than the recent one!

Combined with the news of a non-active MJO, we can presume this winter won't deliver the 'goods'. So another winter with a positive NAO. Since 2013, every month had a positive NAO. Amazing and frustrating.

[STRiZZY]

1 minute ago, syed2878 said:

 I would say two weeks is quite reliable when Atlantic is forecasting for our little island as this is our default button sadly unless the Gulf stream changes suddenly after all the promise charts over the last week or so this does not look too inviting what we are watching now personally I think it is January we will see signs of cold on the NWP. as Cold-Eeze in the UK I think we just going to have to take it on the chin this time round just like last few winters. 

Yeah I have to disagree. No model has a verification rate at 14days that could be seen as reliable. However I do concede that the likely hood of a cold Christmas is not looking great.  

[Weathizard]

Why are people posting the GLOSEA 3 monthly charts like they are absolute certainties? 
 

Negativity is understandable at the minute we are stuck in a frustrating rut despite unusual charts on a hemispheric level with a beleaguered vortex and strong arctic heights but long range models are notoriously useless, the weather can’t be predicted next week - let alone 2 months away. 

Remember how many winters we’ve had good background signals and ended up with zilch before you write off winter because of a 3 monthly GLOSEA

 

Its December the 11th!! Winter is yet young.

 

 

Edited December 11, 2020 by Weathizard

[syed2878]

1 hour ago, IDO said:

Looking at the latest GloSEA update and it backs up that this is likely to be a front loaded winter and those expecting a cold Jan-Feb look away:

Ensemble-mean maps

WWW.METOFFICE.GOV.UK

---

Ensemble-mean fields up to six months ahead. Updated monthly,

So the models are not on our side, milder and wet with a classic UK winter setup is what the algorithms are saying. Some may pin their hope on a SSW but that was too little and too late last winter so maybe wary of that rescuing us? Hopefully mixed in with the general theme we can get a few cold spells and that we get a bit more luck than the recent one!

 I must say that is disappointing news I was hoping this model would be on our side this winter sadly not how ever even in most dire winter surprises could come here and there if that was going to be a SSW later on in winter surely the UK net office model would have picked it up.

[Kentspur]

How are we looking with some of the background signals today?

Zonal winds still showing a strong signal for weakening over and around the Christmas period, Arctic Oscillation looks looks even more negative, however the NAO is looking less negative and nearer neutral now going towards January.

Meanwhile the MJO is stalling nearer the COD and further away from phase 6.

Both positive and negative updates here, I'm not convinced of anything significant until we see clearer evidence for a decent cold spell lining up from the pros on here.

Edited December 11, 2020 by Kentspur

[mountain shadow]

4 minutes ago, Weathizard said:

Why are people posting the GLOSEA 3 monthly charts like they are absolute certainties? 
 

Negativity is understandable at the minute we are stuck in a frustrating rut despite unusual charts on a hemispheric level with a beleaguered vortex and strong arctic heights but long range models are notoriously useless, the weather can’t be predicted next week - let alone 2 months away. 

Remember how many winters we’ve had good background signals and ended up with zilch before you write off winter because of a 3 monthly GLOSEA

 

Its December the 11th!! Winter is yet young.

 

 

They are posting it, because it is a forecasting tool using model output. It also one of the best in the world.

The 'cold' spell we have just had, does indeed look like our front loaded Winter has come and gone and barring the occasional toppler, it does indeed look like that is it.

Certainly, virtually zero chance of proper cold spell greater the 5 days.

[Frosty.]

Call me crazy, actually call me insane...actually I am clinically insane...go figure ( all these mild winters )...., BUT I am seeing some wintry potential longer term between crimbo and new year in the GEFS 6z...anyone feel free to contradict me but there is currently potential for something of a wintry nature during the festive period....I’ve been seeing signs of the jet (PFJ) digging further south as time goes on..don’t laugh, I’m being sincere...now I’m going back to the insane asylum...catch you guys later..down the road..unless the 12z runs show narnia!!  

PS..such a looooong page ( longest page in netweather history..hmmm? )... and such a hot topic ..well, not currently but when the 12z begins....... at least despite my insanity my sense of humour is still intact..or is it..?!..I admire all the enthusiasm on here..we have such crap winters don’t we...compared to Canada, Finland..Russia ?...anyway...have a great winter..I mean Friday..

 

PS..where’s TEITS?...really miss some of the greats from the past..well, from the golden era of 2005!

Edited December 11, 2020 by Jon Snow

[hurricane-anna]

Seriously, can't we just have model discussion in here?? All of u writing off winter on the 11th dec make me laugh.. yes we want snow, yes we want cold and yes we want a white xmas but were a tiny island mostly influenced by the Atlantic.. most years we struggle to get a dusting of the elusive white stuff, if it happens it happens, most of the time these things 'pop up' within a very small timeframe and even the best forecasters get taken aback by how fast they show up and then become reality.. personally I love watching possibilities out in fl but seriously how often do they come true.. I'd rather be here to learn, observe and see if it happens, but slashing wrists over 1 run, calling off winter in the 2nd week of december??? I think some of u need a long lay down with a few bevvys and some off screen time... 

Sorry for being a mardy fart...

Please get back to the models... sorry for being off topic

[BlueHedgehog074]

7 hours ago, swfc said:

Morning. Yes I'd agree with your post. Nothing unusual with the outlook it's December after all. I think people may be wise to stick to reliable time frames"whatever model you consider best" and stave off any kind of let down they may feel is Warented. 

Yep, would say it feels, at the moment, like standard December fair. Perhaps with the exception of the Vortex being disorganised, although nothing too extraordinary. Sticking to the more reliable time frames is safer emotionally lol, even when we know some of the charts in FI are prone to wild swings. It can be fun looking at the longer range charts in the distance, or to see if there are any possible trends. And it’s always interesting to see some of the people on here giving in-depth analysis of what the weather patterns may do in the future. But the more reliable time frame is the best to avoid the risk of ginormous teddies being thrown out of the pram Helps to keep expectations down. 

Could end up finding that when becoming too drawn in by charts outside of the reliable time frame, that you miss out on some fun weather in the shorter term. Such as heavy snow coming down from the North on radar to conquer your area. 

In fact, that brings me to another point. When a cold and snowy spell is currently in process in the UK, some of us then may be worried or eager about constantly looking at the models to see when it may break down. Which is kinda a shame, as you could end up forgetting what’s happening right now. Not really enjoying the experience, or being in the moment, with what the weather is providing outside. 

[alexisj9]

1 hour ago, snowspotter said:

It’s on the Met Office link as a huge area of positive temperature anomalies for the entire winter period shown in red especially Northern Europe and Siberia 

Just to point out, this is a three month long anomaly so there will most definitely be variations, some of which could be cold spells with snow.

[TSNWK]

Just now, alexisj9 said:

Just to point out, this is a three month long anomaly so there will most definitely be variations, some of which could be cold spells with snow.

Agreed.. give me a one week like Jan 87 or Feb 91 in the height of winter and I will happily scuttle off to the summer storm chase thread..