Winter Model Discussion 18Z 12/2/13 onwards.

[Jason M]

Very nice ECM, but I’ve seen a few of these on the ECM over the years and not a single one has come close to verifying. I’m far more interested in what the UKMO comes up with over the next couple of days, not ECM beasterlys.

True, but ECM and METO latched onto this together and the key stages occur early on. This mornings run looked a bit 'quick' tbh and this looks a bit more realistic. There is support as SM alluded to earlier within GEFS as well.

Jason

[goosey007]

Yet again though we are talking 8+ days away.

yes but it was 240 or 10 days away on Monday .....so its looking good be positive !!

[Tamara]

This ECM operational does back up that cold cluster grouping on the ECM ensembles this morning - especially the control, which went deep into the Dutch freezer (and us to some degree too). Interesting to see how they sit tonight with the support.

It is slightly delayed though, that is the question, although the delay actually results in the train arriving at Ashford International rather than Paris - sud

Edited February 13, 2013 by Tamara Road

[Pembroke Dangler]

Let the trend be your friend in this situation! I think the detail will change but with heights to the north of the uk showing within the reliable the air will be of the cold variety, just how cold remains to be seen but as the ukmo and ECM are showing the encore of winter could be the best part of an otherwise mediocre show! So here's to the final chapter and let it please have a happy ending.

[Carlrg]

The BOM bringing a big pool of cold uppers in at T168. http://www.meteociel...&mode=1&carte=0

Not a massive amount of Snow but boy it looks cold. http://www.meteociel...&mode=2&carte=0

Edited February 13, 2013 by Carlrg

[BlueHedgehog074]

Should this evening's ECMWF run continue to show favourable blocking to the North/North-East (edit: and as a matter of fact, it recently has on its 12Z run), with UKMO-resque type charts, then I think we can safely dispose the GFS run...

Reasons to bin the GFS run:

1). It's idea of sending some of its Low-Pressure energy North-East over the block to the East seems out of place when compared to the ECMWF, NOGAPS and UKMO:

12Z GFS version:

Marked with a big cross because I agree with others when it feels like it's sending too much over the High Pressure cell with the feeling that it has under-estimated how much energy goes beneath the block.

00Z ECMWF version:

Edit: updated 12Z version:

(just about mananges the undercutting potential even though it looks as though that Low tries to undercut a tad too far North at first. Plus, the later charts in this run are an Easterly dream to behold! ;-))

12Z UKMO version:

12Z NOGAPS version:

With the exception of the old ECMWF 00Z run being posted at 168 hours (just to demonstrate the potential), all 3 of these models essentially show more solidity of the blocking to the North or North-East with most of the energy getting steered Southwards below the Euro/Scandinavian high rather than above it with better undercutting. These 3 get a tick as I do feel their evolution is more realistic when compared with the GFS which seems to do all it can to disallow Lows out West from undercutting the block properly. More models also support the undercutting solution - another reason why I feel quite confident about it.

00Z GEM version:

Probably for the trashcan as well with its questionable progressive Atlantic outlook at 144 hours. Looks like it wants to bring the milder Atlantic back in with more of a zonal(ish) type flow occuring. But it still gets a question mark from me as although it probably is being too eager to knock the block in the East/North-East away, it could be that the other 3 models above may have slightly under-estimated what the energy in the Atlantic will do (although I do still feel it's being a bit too progressive).

2). The ECMWF, on the whole, handles High-Pressure to the East or North-East better. And I think because the GFS may be modelling the heights to our East or North-East incorrectly, this could also be another reason for it sending too much energy North-Eastwards and why it can not handle the Low-Pressure undercutting properly.

3). The ECMWF is still superior to the GFS out at day 6 when it comes to the modelling of the 500 HPA heights in the Northern and Southern hemisphere: http://www.emc.ncep....html/acz6.html -The red line representing the ECMWF has generally been staying higher than most of the other lines that represnt the other models - the ECMWF also has the most points (.831.31 / .843.31) placing it in the top spot. However, throughout the period, the black line (representing the GFS), does occasionly rise higher than the ECMWF's line, but not often.

(Late edit: The link doesn't seem to be working, so have attached the image version of the models' performances):

4. It is not showing what I want.

Reasons we should resist dumping the GFS:

1). It might not be incorrect.

2). A small chance that the other models (except the GEM) may have actually over-estimated blocking to our North/North-East, and it may be possible the ECMWF, NOGAPs and UKMO may be being a little too quick with transferring the heights from the East to our North.

Additional thoughts: Because these outlooks the models show are in an FI sort of time-frame with some disagreement here and there, future updates from various models will needed to see how the blocking potential to our North or North-East develops. Decreasing support and some incorrect modelling of the Atlantic and/or blocking to our East could mean the cold Easterly blocking idea could be taken away from us as fast as a bolt of lightning.

One other thing to note is that according to these GFS and ECMWF 8 to 10 day pressure anomaly charts, higher than averge heights dominate the North of the UK on the ECMWF version (to the left) - these of which stretch from Scandinavia and extend all the way pass Greenland into the Northern America area with average, or lower than average, heights to the South. This would perhaps suggest solid blocking to our North in general with Low Pressure systems tracking to our South with cold, Easterly or North-Easterly winds likely. The GFS version (to the right), however, has higher than average heights over us with some of it extending to our very North with lower than average heights to our West and some lower than average heights into the far South-East Europe area. Although this would probably indicate High-Pressure being over, or close, to us, I do think some adjustments and upgrades made to the GFS version of the anomaly charts could mean it may end up being more like ECMWF's version... although even then, ECM's version could end up being more like the GFS version. But due to more models support ECMWF's blocking ideas, probably not. Both of these charts do at least hint at some sort of (possible) blocked outlook for the future with the Atlantic unlikely to make much of an impact at all.

Overall, thanks to some model support, possible underdoing of undercutting Lows (GFS 12Z run), and with the anomaly charts showing a blocking-like pattern, I do get a feeling a colder more blocked pattern is where we could be heading, although depending where High-Pressure sets up will likely to have an affect on whether we get a snowy unsettled outlook, or a cold, dry one.

Edited February 13, 2013 by DiagonalRedLine

[Grimsby Snow Lover]

The BOM bringing a big pool of cold uppers in at T168. http://www.meteociel...&mode=1&carte=0

Not a massive amount of Snow but boy it looks cold. http://www.meteociel...&mode=2&carte=0

If anything like that does verify then the cold uppers could help generate convection showers. When looking for snow though its best off waiting until the actual day its due as there are so many different variables that need to be correct for snow too fall. T168 is way to far out to worry about where and when it will snow. Good charts though non the less.

Edited February 13, 2013 by Grimsby Snow Lover

[Isabellesnanny]

Forgive my ignorance as I am pretty poor (well very poor in fact) at translating the maps. Can you tell me when temperatures will start to get colder - looking at forecasts for the week through to next Weds/Thurs temperatures are showing double figures - is this not going to be the case and if not when will we see temperatures start to fall again after mild blip we are now due to get?

Thanks

[Cheshire Freeze]

Ooooooft that ECM run :o

Just wait a minute whilst I prise my jaw off the floor

[Frosty.]

The Ecm 12z gives all us cold/snow lovers plenty to smile about, the really cold air is knocking on the door in 7 days and then it just accelarates us into the freezer with plenty of snow potential and with severe frosts, pretty much perfection from where i'm sitting, looking forward to more good news from De Bilt ensembles and NOAA discussions and then the freshly drawn fax charts tonight.

EPIC T+240 chart

[Blake]

Forgive my ignorance as I am pretty poor (well very poor in fact) at translating the maps. Can you tell me when temperatures will start to get colder - looking at forecasts for the week through to next Weds/Thurs temperatures are showing double figures - is this not going to be the case and if not when will we see temperatures start to fall again after mild blip we are now due to get?

Thanks

I would imagine from this time next week. Tuesday would be the last "mild" day of this less cold period.

[Cheshire Freeze]

I know I keep banging this drum but to get the cold easterly followed by retrogression and the PV dropping south across Scandi really is the holy grail of synoptics, especially at this time of year when cold from the NE is a lot more productive.

[BLAST FROM THE PAST]

This is a chart that IMO is utter perfection....oh dear. This though shows what CC has been chasing, even late on in season daytime maxima sub zero.

UKMO absolute beauty again...

This set up is prolonged too....if it verifies then I salute RJS....c'mon.

Just to be a tad cheeky as Pete has already 'liked' my post....BOOM!

BFTP

Edited February 13, 2013 by BLAST FROM THE PAST

[Gibby]

Good evening. Here is the report on the 12z output from GFS, UKMO and ECM for today Wednesday February 13th 2013.

All models have the change to much milder conditions well under way now with a warm front currently crossing Central and Eastern areas with a cold front sliding SE across the UK overnight and at first tomorrow. The snow, turning to rain soon will clear Eastern areas with a thaw setting in widely later in the night. In the West the already milder conditions will bring a band of rain through from the NW overnight followed by clearer and drier conditions before morning. This will extend to all areas soon after dawn with tomorrow showing NW winds, sunny spells and scattered showers in the North and West but much more importantly a lot milder than of late. Friday too sees a fine and bright day for many as a ridge crosses the UK through the day. Over the weekend it still looks like a more cloudy spell over Saturday will bring a little rain while Sunday becomes dry and bright again for many and maybe not quite as mild.

Through next week GFS shows High pressure well established to the East of the UK with a gentle South or SE flow blowing over the UK for most of the week. The weather would be fine for most with some sunny spells but also some cloudier spells but little of any rainfall anywhere. After a mildish start to the week temperatures will slowly fall off later to just below normal with some frost opportunities at night anywhere where skies clear. In FI tonight the Atlantic ratchets up a few gears with a gradual decline to more unsettled conditions with rain and eventually strong winds too. With an Atlantic influence and winds turning to the SW the temperatures would be on the rise again towards the seasonal normal.

The GFS Ensembles show a warmer spell of weather on the way. Only a few members show anything significantly cold over the coming two weeks though the operational described above was a mild outlier for much of the mid and end part of the run. With near to average uppers and relatively dry conditions for a time it will feel much better than of late. Rainfall amounts do increase though later.

The Jet Stream shows the flow collapsing around the UK in the coming days before increasing again on a more Southerly latitude as we move into next week and beyond.

UKMO shows a High pressure area developing over Northern Scandinavia with Low pressure over Eastern Germany. The resultant East or NE flow suggest that increasingly cold air will move West over particularly Southern Britain with scattered wintry showers likely in the SE later.

ECM shows a build of pressure too over the early days of next week with Low pressure off to the West and SW. With a return to rather colder conditions quite early in the week as winds settle SE or East the chance of wintry precipitation increases again with time as pressure falls and deeper cold spreads West on an increasing Easterly flow with sleet and snow becoming quite widespread in shower form at least in the latter half of next week.

In Summary it's GFS against the Euro's again tonight with the American model showing a dry and mildish spell replaced by equally mild and increasingly unsettled conditions as we move deeper into the output period with wind and rain for all by then. The Euro's on the other hand indicate an increasingly quick return back to rather cold conditions next week with the Jet Stream pushed South and pressure becoming High to the North and NE over Scandinavia bringing the risk of snow showers or maybe even something rather more prolonged snowfall in places if the Euro's solutions verify.

[Mair Snaw]

well some truly stunning charts in FI from ECM, Said earlier that i would look forward to a steve murr boom post and it didnt take long, maybe just once this winter we can get a chart like t216/240 to verify at say t72. great posts in here again today and many thanks to the members that make this a fantastic place to learn.

Off to the pub to by a stiff drink for the GFS and roll on the pub run and a few more backtracks towards the mighty ECM cheeeerrss.

[phil nw.]

The ECM places that block further NW in later frames which improves our chances of a better cold spell from the NE with some snow.

This was my concern with the 00z output that showed the block would end up too close to the UK sending the deeper cold into the continent.

The encouraging thing is the earlier ridging further north which is also favoured on the UKMO

http://www.meteociel...20-21.GIF?13-18

http://www.meteociel...H1-144.GIF?13-0

The American models still push the ridging further east at this stage

http://modeles.meteo...nh-0-144.png?12

http://modeles.meteo...nh-0-144.png?12

so still the differing views of how much energy goes across the north still there.

With the height anomaly ens outlooks placing those +ve heights further north between Scandinavia and S.Greenland then you would have to think the Euro models are handling the pattern closer to those forecasts.

Whether we get the Wintry setup of the ECM Op remains a possibility but a colder easterly of sorts looks more likely later next week as those heights build north.

Edited February 13, 2013 by phil nw.

[Duane S.]

Best combined UKMO / ECM run of the season. GFS continues floundering like a fish (flounder?) out of water. BUT wait, what's this? The GEFS ens are starting to wake up and smell the coffee! The Op will follow, kicking and screaming no doubt, but it will have to follow in the next 48 hours (you would imagine).

So there are evident similarities between the two respectable models, the only real difference is that one is about a day sooner in its evolution of the cold. But what I like so much is at D10 on the ECM is it looks like the real event is yet to hit with the vortex shifting around way to our NE readying itself for a SW plunge towards us?

Back down to earth... and we all know it won't verify exactly like the Euros are showing but the theme has been showing fairly consistently on those two for a while now and with the Western vortex continuing to drain it all looks very plausable to me that we are indeed heading for a cool - cold spell in a bout a week's time. The real question is are we then heading for a very cold / severe spell thereafter??

One last comment on the GFS, I hope the NOAA didn't spend much money on that upgrade a while back, if they did they might want to think about asking for a refund...

[Captain Shortwave]

Excellent output again, if you look at the steps towards the big prize, in reality if we making it to T120 unharmed then we are in with a real chance of some severe winter weather. Get that first area of heights building to our north and surely the rest will follow.

Edited February 13, 2013 by Paul

[Froze were the Days]

Great great Euro's but we've all been here before - taking more interest at what the UKMO will show within the 144z window over ECM now but obviously hope the 2 are in tandem.

[london-snow]

Funny that,t192 always 8 days away!!!!!!

I was commenting on the ECM run only. Contrary to what the likes of chino thinks. I am as big as a snow and cold ramper as the next. However unlike some on here i fail to get happy over charts that are out in fi ( Especially after the winter we have had thus far ).

- If we look at the past two cold spells that has happened these are the steps it has took.

1 - Great fi runs & the forum goes into meltdown.

2 - As we get closer & closer it gets watered down.

3 - Right down to it now & we are facing a brief colder snap with marginal temps & dp's.

So whats my point?

= I dont buy it ( Especially the way this winter has panned out ) until reliable no matter if every single model showed consistency.

Edited February 13, 2013 by Rybris Ponce
depersonalized.

[nick sussex]

Looking across all the outputs its really the GFS/GEM against the rest of the guidance. The UKMO looks the least fraught way forward as that's already built a strong foundation because it clears the energy east into Scandi allowing a nice gap to appear between Iceland and Scandi.

A lot of cold synoptics do rely on timing, tonights ECM manages to clear most of the PV eastwards just in time taking the pressure away from the high.

So in effect we want to see the PV relocate over Scandi but at the same time doing so in a way to allow the high to retrogress at a sufficiently north latitude.

If things go well then you can stay in the cold as that happens and then wait for the next reload from the n/ne. It's happened before in Dec 2010 so we shouldn't always assume that it has to go wrong!

However we have to bear in mind that the real interest from the ECM happens post 168hrs and we have to factor in margin for error at least for the initial cold pool advecting westwards.

In terms of the overall evolution if you're looking for the best late winter synoptics then the ECM although slower than the UKMO certainly delivers a very good set up in terms of locking in the cold.

But in terms of a more solid foundation getting that gap between Iceland and Scandi at just 96hrs shown on the UKMO would certainly add a layer of insurance going forward.

[london-snow]

Belting run this is turning into.

http://www.meteociel...M1-216.GIF?13-0

Surprised at some of the 8 day comments. The trend is very similar between the UKMO/ECM the only difference is the UKMO is 24hrs ahead.

How many times has a 8 day cold & snowy chart come to fruition without any hiccups or without it being toned down even when like you say the big two are singing from the same sheet..

[Zenarcher]

The ECM and UKMO are both great runs for cold weather the GFS may not be as good but if you look at some of it's previous runs in the last 24 hours we do see it slowly improving one thing that has changed is the GFS yesterday was showing a big deep Atlantic low not many on here were convinced that it was right on it and today the GFS has dumped the idea of the very deep low and made it a whole lot weaker this is a good early sign. Thanks to the weaker low better heights develop to our North near Greenland compared to yesterdays 12z run where we didn't have any build up there at all.

[Dave Kightley]

Great runs from the Ukmo and ECM firming up on this signal for a little while now... Timing and the exact location of where the high ends ups yet to be decided bit you would favour the South/ East of a colder spell end of next week at least.. getting interesting again and the best part of it all.. Proper height rises this time around.

CFS picked up on this signal quite nicely and if its got the right idea then may continue into March.. Anyone who says it rubbish is not always the case and then ECM is not better if wrong.

Edited February 13, 2013 by Dave Kightley

[DEYS(Kent)]

51 members and a few like the Op it seems.