Model Output Discussion - The final stretch to Christmas

[Mucka]

you may regret that in the morning mate.....

 

And anyone unfortunate enough to be in that part of Scarborough when the time comes   . 

[Neilsouth]

Over on NW they are getting out the Champaign which is ridiculous from one run, a UK High is a good bet for new year and the best we can hope for but a proper Scandy high is unlikely IMO.

 

Andy

 

 

You've got to laugh at some of the comments on TWO, nobody knows what is going to happen, it could go either way. So Andy's prediction is even a push

[london-snow]

I refuse to get remotely excited about an easterly shown on one run from the GFS. It has my attention don't get me wrong, but it's flipped completely in the space of 6 hours! A pub run classic for now, to be continued, just don't expect to wake up at 6am to those same charts, because if they are still there I'll drive to Scarborough and skinny dip myself.

Honestly you seem to have such a up & down day it's a lot like the output we have been seeing the past few days.

Those who read my past few posts (A few days ago) as i stated a good chance of seeing a easterly set up call it a gut feeling...

However viewing the latest output and the hints if not trend to a cold easterly especially from the gfs which shows a big backtrack should we take that as gospel?

IMO I don't think so i feel that a half way house will play out I.E a settled period with frost and fog on offer. After that it's anyone's guess/prediction.

I'd love to be proved wrong but after sticking to my previous thoughts and posts i now can see a sinking LP after christmas followed by a prolonged period of stubborn HP its where we go from that point i feel our winter will be won or lost.

Merry Christmas to all on here and I hope im way off the mark..

I doubt I'd get a lot of likes for this post such as sm & tiets however i like the rest of you are hoping for that big undercut into a cold easterly which is my favourite. Let's all hope the trend from the gfs continues and grows stronger. As we have seen before the gfs handles easterlys BAD and as we all know regarding past e/ene in winter comes the big two words with the gfs WESTWARD CORRECTION..

Edited December 24, 2014 by london-snow

[meathead]

Even if we do get an easterly will it actually be any good? Europe isn't very cold right now.....

[Bonjangle]

Been some great chart's tonight and all getting very exiting ' but Curiosity killed the cat .. wait until UKMO is certain as i only follow them and there Fax Charts , do not ever trust Computer Model's they are very Bullish at time's and they get your hope's up , then Bang .... Downgrades again ... Listen and learn .. i seen it all before many of time's in here ... Have a great Christmas Aqua Star Mist .

[snowangel32]

Looking at the mods cant see much to get excited about yet all i can see is an outside chance of snow for the far se and proberbly scotland and maybe higher ground but no widespread snow forecast yet and the scandanavian high is in fi territory and we have all seen this week not to take any model as gospel so hope for further upgrade tomoz. Merry Christmas evreone and hope we all get a snowy new year.

[Trom]

.

It really was quite something else last year I wonder what your friends in wi would of made of it all.

As for the models I think they make there calculations on what the see at that time and due to outside influences (ie solar activity)the 12h chart on the 00z run is never the same as following 00h chart on the 12z.

Sorry I meant to imply that, what was it from the initial variables caused the switch and how quickly in the model the flip occurred.  So I want to see the next control and ensembles from the ECM to see how confident it is relative short run, as we have a run of 1 for GFS (even if it is in the direction most posters want).

 

Best mate is from Seattle (so knows our weather), has lived in Texas and now lives with the polar opposite in WI.  He's in his 12th year and hates it - but they're paying him enough to live with it!

Edited December 24, 2014 by Trom

[Timmytour]

Just to add a note of potential caution, where of course so many other notes are worthy of mention

But would i be right in saying a SSW could actually work against us? In that what seems to be the perfect set up for us could get disrupted to such an extent that an excellent winter outlook is shifted to a pretty mild one?

Great GFS eye candy, but I wonder if it's reached this potential solution without yet getting a hold on the disruption caused by an episode of SSW?

[Mucka]

Decent output this morning so far out to mid term with the possibility of an Easterly setting up somewhat enhanced rather than diminished IMO and even if raging Easterlies are not modelled there is generally East flow setting up across the output and no sign of zonal so far.

 

GME looking good

 

[Eugene]

GFS 00Z FI showing the classic atlantic low/scandy high undercut you want for heavy snow in the midlands, and showing that even when the atlantic gets through its still cold with temps really struggling, great run with bags of potential, love when GFS is onboard.

[Mucka]

GFS ensembles getting on board.

 

 

   

[weather_it_will]

The tracking of the low at 72HRS is far from nailed.The GEFS ensembles showing it centred anywhere from Scotland to Bristol.

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=72&code=3&mode=0&carte=

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=72&code=14&mode=0&carte=

[Duane S.]

Just to add a note of potential caution, where of course so many other notes are worthy of mention

But would i be right in saying a SSW could actually work against us? In that what seems to be the perfect set up for us could get disrupted to such an extent that an excellent winter outlook is shifted to a pretty mild one?

Great GFS eye candy, but I wonder if it's reached this potential solution without yet getting a hold on the disruption caused by an episode of SSW?

 

Of course it could but it is not as though a technical SSW is some sort of finite tipping point. The sort of charts starting to show up in FI are as a result of a Northern Hemispheric shakeup predominately caused by stratospheric warmimngs and wave activity, these may or may not lead to an SSW down the line. Only in hindsight are we likely to know if an SSW has been detrimental to our cold chances and whilst there have been occasions when it has been attributed to that, there have been a heck of a lot more occasions when it has produced the goods.

 

Great charts coming out this morning following on from yesterday. The overall trend is starting to become clearer, I think... EPO ridge with Wave1 forcing the vortex to our NW, Wave2 response and an Atlantic ridge will want to form but will be unable to because of the low heights of Greenland, this is likely to lead to a short term MLB around us before ridging to Scandi and the setup of a much more robust block to our NE, then look to the NW as vortex energy starts to undercut the high and the block retrogresses back west. That's the theory and if it plays out expect everything from unsettled with frequent periods of cold rain to a dry settled period to a full blown snowy Easterly as we head into 2015. Great times to be a model watcher!

[joggs]

I just wish the latest mo update would back the last couple of runs up.Amazing turnaround though,but is it another false dawn for coldies?.

[That ECM]

I just wish the latest mo update would back the last couple of runs up.Amazing turnaround though,but is it another false dawn for coldies?.

Certainly going to be some happy people this morning. ECM is looking interesting out T192. Met will want to see some more runs and consistency before changing outlook but they will be taking note for sure. Maybe they are going to change it tomorrow as a present to the coldies!!

[SnOwFeSt]

Great looking potential on the charts this morning. Snow potential in the reliable timeframe with some very exciting possibilities beyond. Nice to see a much weaker vortex than of late, an undercutting jet, and heights building over Scandinavia.

[Severe Siberian icy blast]

Whether we get a full blown easterly or a cold high with a slight easterly element or a high sat directly over us remains to be seen , at the moment the coldest air goes southeast into Europe , it looks dry cold and frosty rather than snowy but still very interesting all the same .

Just keep our feet on the ground as nothing is done and dusted and we no how volatile the models are , but it does look a good bet with a Scandi high been odds on in some from way or another .

We really need the jet to stay South , we do not want the northern arm firing up and going over the top of the ridge , like it does on the ECM , we have low pressure systems moving Northeast over the block which will sink it eventually . So we want a clean split jet , with the majorly going under . If we can get that , then a snowy set up will inevetibly follow with lows going under meeting the cold air and having a good battle .

In the mean time the ens look cold

And another major warming all the way through increasing in latter stages with a nicer split

The vortex looking very battered as we go into jan , I'm now thinking its only a matter of time untill we face our first major cold spell in 2 years .

Edited December 24, 2014 by Severe Siberian icy blast

[Severe Siberian icy blast]

Whether we get a full blown easterly or a cold high with a slight easterly element or a high sat directly over us remains to be seen , at the moment the coldest air goes southeast into Europe , it looks dry cold and frosty rather than snowy but still very interesting all the same .

Just keep our feet on the ground as nothing is done and dusted and we no how volatile the models are , but it does look a good bet with a Scandi high been odds on in some from way or another .

We really need the jet to stay South , we do not want the northern arm firing up and going over the top of the ridge , like it does on the ECM , we have low pressure systems moving Northeast over the block which will sink it eventually . So we want a clean split jet , with the majorly going under . If we can get that , then a snowy set up will inevetibly follow with lows going under meeting the cold air and having a good battle .

In the mean time the ens look cold

image.jpg

And another major warming all the way through increasing in latter stages with a nicer split

image.jpg

The vortex looking very battered as we go into jan , I'm now thinking its only a matter of time untill we face our first major cold spell in 2 years .

We can see what I mean hear ,

Jet riding over the top of the ridge , , which means no undercuts , and no favourable easterly fetch .

However further on Into fi the GFS sends the jet South , which in turn sends the low pressure systems diving South undercutting the block which in turn would likely lead to a snowy spell , given its low res , it becomes rather messy but you can the point .

[IDO]

Looking like some snow potential for Sat-Sun as the lower exits the UK. About 40% in  the S/SE and 60% further north with hills probably the most likely. Lots of rain before the back edge snow.

 

London graph: 

 

The low on the GEFS cuts SE in line with ECM and the cold pool sets up in Europe. The ECM op is more in line with its mean of last night where the high slowly sinks and we lose the cold uppers:

 

D8:  

 

Similar to the GEFS mean:  

 

So compared to this time yesterday the GFS mean has the Atlantic slower so the MLB lasts longer and the ECM mean has the Atlantic faster and the MLB lasts shorter. Pretty much inline with normal expectancies. GEM goes with a ML high by D10 after a brief easterly:

 

 

 

The GEFS after D10 are pretty hum drum for the UK but from Sat-Tue there are some low 850s so feeling seasonal. The GFS P keeps the cold going a bit longer but has little support. Its whether the models have again picked up a signal after D6 over done it (as usual) and will continue to downplay the possible easterly, more in line with the consistent mean (sinking high). Of more interest is the strat possibly in its last rites so early January things could change quickly.

Edited December 24, 2014 by i'm dreaming of...

[Frosty.]

Let's be positive, last Xmas the models were diabolical with no end in sight to the technically mild, very wet and windy filth but now we have growing support for a much colder and increasingly blocked outlook with undercut potential. I'm going to enjoy Christmas even more now.

[Nick F]

Now the high res of GFS, UKMO and ECM roughly agree on the Fri/Sat low's track - heading east into mainland UK then heading SE into the near continent (albeit exact track still to be refined), the next hurdle is how the high/MLB evolves once the low exits the scene Sunday onwards.

 

00z ECMWF det shows more energy going beneath the block across SW Europe than GFS, with lows moving east into Iberia t+192-216. The EPS mean clearly more amplified than GEFS mean at t+192, but we have to weigh up the fact that ECMWF can have the tendency to over amplify at times while the GFS has a tendency to quickly supress any ridging:

 

ECM vs GFS t+192

 

EPS mean vs GEFS mean t+192:

 

But, the Euros appear to be leading the way thus far with developments across N Atlantic and Europe, so have more faith in their handling of any blocking that develops over northern Europe over coming days.

Edited December 24, 2014 by Nick F

[Captain Shortwave]

A lot to play for and really not much to say beyond what I said last night, ultimately where the high centres itself will be crucial to how cold it gets and whether there will be any snow for anyone.

Day 5 charts

UKMO

UK high, it sticks there at day 6

 

ECM

The high is a little further north west compared to the UKMO, we get a slack continental flow throughout the rest of the run with perhaps some scattered wintry showers down the east coast for a time.

 

GFS

High building through the UK which slowly drifts east until it hits the deep cold pool over central/southern Europe. Dry and chilly for most.

 

Parallel

UK high, but it displaces much better over that cold pool and allows an easterly to set up, southern England becomes very cold from day 6 onwards as that cold pool manages to get into that area of the UK.

 

GEM

Quite strong north east winds, more significant than the other models. This model offers the best initial chance for wintry potential with showers for eastern coasts, a poor upstream pattern later sinks the high into a more Euro based one but still cold at the surface.

 

So the pattern we end up with will be determines by two factors, firstly the initial amplification in the Atlantic which will give our starting point for the high, the second is the movement of the deep cold pool which will move into central Europe. As seen you can have a poor initial position for the high, but you can still get the cold in later if the cold pooling moves west enough for the high to drift towards Scandinavia. I must stress either way we should see some proper seasonal weather develop with frosty nights and temperatures below average for the time of year.

Edited December 24, 2014 by Captain shortwave

[Lincstim]

Let's be positive, last Xmas the models were diabolical with no end in sight to the technically mild, very wet and windy filth but now we have growing support for a much colder and increasingly blocked outlook with undercut potential. I'm going to enjoy Christmas even more now.

Frosty , I absolutely love your positivity and hope !

I'm just finding IT difficult to follow on here because for every 4 comment favouring the cold there is then 1 or 2 comments taking it away!

Appreciate that nobody knows and there is still a massive chunk of winter to come.

Edited December 24, 2014 by Lincstim

[snowice]

Frosty , I absolutely love your positivity and hope !

I'm just finding IT difficult to follow on here because for every 4 comment favouring the cold there is then 1 or 2 comments taking it away!

Appreciate that nobody knows and there is still a massive chunk of winter to come.

That's the mildies vs coldies anyway it looks like there is a good chance of an easterly developing on the models this am ecm has the high in a more favorable position to get some cold uppers comming from the east.There is a note of caution as we do not no were the jet will go and this will effect how cold any easterly will be,so positive out look over all good reasons to be happy but more runs needed to see what position the high takes.Ecm for me is the best with a north east flow! Edited December 24, 2014 by snowice

[karlos1983]

sifting through the GEFS Purbs, looks like the signal is still very much there for Height's to the East/North East. Some looking pretty tasty.

 

 

That's the last one from me today, I'm off to Scarborough