Model Output Discussion - 18z 31/10/15 onwards

[Cheshire Freeze]

ECM delivers an early Christmas cracker for cold lovers but we have been here before with it over recent winters so I can understand the suspicion that this will be another let down.

 

At this point I'd back its view at least in terms of the phasing/timing upstream over the central USA. This does have good support from the other models bar the GFS.

 

For the GFS to be right then the ECM/UKMO/GEM/JMA would all have to be wrong at T144hrs, indeed even at T120hrs the others are already beginning to phase the north/southern jet streams and the GFS isn't interested.

 

The changeover to cold is not as simple as it could be because of the long train of low heights which runs sw/ne, you'll note that as the upstream flow amplifies one parcel of energy gets separated and runs sw. You're not dealing with a simple flow amplifies upstream ridge builds into Greenland clean northerly scenario, these parcels of low heights like the UKMO has at T144hrs over sw Greenland are still complications.

 

Its for this reason that I'd urge some caution in viewing the ECM's later output, the JMA solution shows how things could get more complicated. If things turn out more like the JMA then you can still get to cold as long as you get trough disruption from that Atlantic low this then can sever the connection between the Euro high and the high over Greenland.

 

So I think we need a few more runs and agreement upstream and a better idea of how the models will handle those complications before getting too excited about tonights ECM.

 

Wise words Nick and I agree. However I'm more interested in the initial hurdle at day 5/6- get this out of the way and you can sit back a lot easier than if the GFS turns out to be correct. A waiting game with the JMA- a road to grimsville with the GFS.

[phil nw.]

Not wanting to dampen the building excitement on here but i couldnt help noticing the big fat HP centred over Iberia shown in those charts posted by Phil.

That could be a foe for the South, in coming weeks if it does not shift v much.

Again it's down to the degree of ridging towards Greenland early on BR.

The ECM solution would force a better downstream trough bringing that colder air further south flattening that Euro high.

[Methuselah]

I'll go one further- the ECM run is the best opening to winter charts we've seen since 2010. Locked in wintry pattern shown post 168 hours. As Steve M has said that's a 'boom' if it could get to day 5.

Or, as the past 13 years' history has taught us - it all goes 'phut'!

[carinthian]

Well, the ECMWFs next viewing will reveal something interesting for next weekend regarding snow potential for the North.

 C

ECMWF delivers classic winter charts for next weekend . If this turns out, snow will be the theme for the North, especially, Northern half of Scotland. Here there will be a strong gradient in potential temps at 850pha level that will be associated with an Arctic Front. Will the cold snowy weather push south ? Still a lot  to resolve at the moment. We have to have UKMO on board, but I am sure things will get interesting as trough disruption looks the form horse to take over Scandinavia and the Baltics in 6/7 days time. This time the Siberian Block may soon call the tune.

 

C

[nick sussex]

Wise words Nick and I agree. However I'm more interested in the initial hurdle at day 5/6- get this out of the way and you can sit back a lot easier than if the GFS turns out to be correct. A waiting game with the JMA- a road to grimsville with the GFS.

I'm pretty sure the GFS is wrong at T120 and T144hrs, however that's only half the battle!

 

The Duty Forecaster at NCEP looking at his version of our fax charts has ditched the GFS, you can see here the comparison:

 

NCEP T144hrs

 

 

GFS T144hrs

 

 

You can see the GFS no phasing, more progressive with the PV lobe. In the NCEP fax phased more amplified. The US fax looks like a blend of the other models, thankfully no modification towards the GFS.

[ANYWEATHER]

So....Are we being led up the Garden path...? Ecm at the totally unreliable time frame At T+240 hrs  shows "snowmegeddon " which shows unusual November weather  the gfs shows a no mans land...   Extremely interesting charts ! It looks as though the second half of November could be quite opposite to the first half....So the options on the table tonight is for the Uk to cool down dramatically during later next week, and beyond... By My Thoughts....

1/ a stormy cold period in the next two weeks

2/ An extremely cold  spell from the North [iE Ecm]  or

3/  The usual default pattern from the Atlantic...

 The Rollercoaster ride is sure on its way....

 

[fergieweather]

Note clear polarisation of CTRL versus DET; the latter following a slightly more distinct (colder) cluster. I've yet to go through the stamps.

[Cheshire Freeze]

Day 8 ECM ensemble mean says YES

 

[Frosty.]

Well I almost missed the BEST run of the season so far but I finally made it and it's such a pleasure to post these sensational charts too after months of very mild mush. It's been a long warm autumn but let's hope it has one hell of a wintry sting in it's tail. These are stunning charts from the Ecm 12z with 522 dam thicknesses pushing quite a way south and this run has built on the wintry potential of the ecm 00z and it really couldn't be better. The ukmo & gem 12z are both cracking runs and this is the icing on the cake...      BOOM!!  ..  

[BLAST FROM THE PAST]

Got to say a few things here, may go down badly, well indifferently.

 

Firstly there is upgrade galore going on and yes the pattern is 78esque with Lps tracking ever further south and even becoming sausage like....potent indeed.

 

I've had faith in this change for some time, considerable time BUT before we go off on one....this is looking more cold potent than I thought..no doubt....I thought stormy, colder, wetter, pretty wintry for some at times......not pretty wintry all round. 

 

Big Steve Murr said no one forecast this.....unfortunately Madden has...and to the correct timing too...now that has put the spanner in the works....

 

BFTP

 

 

Sausage like LP

 

 

 

 

 

Edited November 13, 2015 by BLAST FROM THE PAST

[bobbydog]

Got to say a few things here, may go down badly, well indifferently.

 

Firstly there is upgrade galore going on and yes the pattern is 78esque with Lps tracking ever further south and even becoming sausage like....potent indeed.

 

I've had faith in this change for some time, considerable time BUT before we go off on one....this is looking more cold potent than I thought..no doubt....I thought stormy, colder, wetter, pretty wintry for some at times......not pretty wintry all round. 

 

Big Steve Murr said no one forecast this.....unfortunately Madden has...and to the correct timing too...now that has put the spanner in the works....

 

BFTP

he's been forecasting snow every week since the beginning of october. same as the last 4 years. he will be right eventually. anyway, it hasn't happened yet....

[Spah1]

ECM ensembles will be very very interesting tonight- solid support at day 6 and it's over to the GFS. I'd love to see a flip from the GFS on the 18z to support the likes of the GEM and ECM but that's probably hoping for too

much. Still, any move towards those models by the GFS would see feedback mechanisms take over anyway I suspect- the upshot of this being it'd probably get there eventually but maybe not as quick as the ECM tonight. We await with interest...

What time are they out?

Why isn't their time pinned with the other model output times?

Edited November 13, 2015 by Spah1

[Cheshire Freeze]

What time are they out?

Why isn't their time pinned with the other model output times?

 

Can be found here....updated about 15 mins ago

 

http://www.meteociel.fr/modeles/ecmwf.php?ech=72&mode=1&map=1&type=1&archive=0

Edited November 13, 2015 by CreweCold

[BLAST FROM THE PAST]

he's been forecasting snow every week since the beginning of october. same as the last 4 years. he will be right eventually. anyway, it hasn't happened yet....

Agree with last 4 words Bobby....

 

BFTP

[bobbydog]

maybe no-one forecast snow- professional forecasts go with the most likely scenario. no-one said it couldn't happen....

lovely ecm charts-

madden aside, the worry was, we would be stuck with an immovable euro high for weeks on end. we now know thats unlikely. never any guarantees where the weather is concerned but now the future is looking a little whiter...

[bluearmy]

the onset of this possible coldish spell caught my eye on the ecm because of the support that the op had way up to 10hpa.  if anything the op is solidifying the scandi trough high up in the strat with nw europe having the extension of the pv in a way usually reserved for arctic canada or greenland. 

 

this strat support was evident earlier on in the year when we saw a persistent scandi trough deliver the coldest week of the winter. despite looking like a toppler at first, the trough kept replenishing itself. on this occasion, i was again confident of its sustainability via good upper strat support.

 

my eye is also taken by the gulf of alaska high anomoly by day 10. quite marked. i thought we should be seeing a sustained low there in a  nino winter ..........

[Paul_1978]

Big Steve Murr said no one forecast this.....unfortunately Madden has...and to the correct timing too...now that has put the spanner in the works....

 

BFTP

 

 

Sausage like LP

And we know how much Steve likes his pressure patterns shaped like sausages.

On another note, is there such a thing as getting these charts too early? After all is only 13th Nov today.

[I remember Atlantic 252]

And we know how much Steve likes his pressure patterns shaped like sausages.

On another note, is there such a thing as getting these charts too early? After all is only 13th Nov today.

 

Not for your location, could be an issue for me at low level south, Northern members especially above 200m, have the right to be getting excited

[Duane S.]

Blimey, not half bad chart output tonight! From the ECM especially. We've been almost entire winters before without seeing such good runs. Trouble is of course we've been here before and I suspect that is the main reason this forum isn't going into total meltdown right now (because the ECM run and its further potential warrants it) is that we've all been burnt with teasing ECM over-amplification charts many times before.

BUT there is a different non-standard 'look' about the NH profile this lead up to winter, I too spot a 1978 esque look with that tasty D10 chart from the ECM. Upstream, the jet direction/angle over the states would seem to be favourable for an eventual window of opportunity to pump warm air off the eastern seaboard into towards Greenland, so I think it has every chance of occurring. To what degree and just how many hurdles to be cleared, yet to be determined!

Interesting to see the Strat taking a back seat with this tropospheric led cold spell on the cards (potentially at least). It has seemingly popped up with very little warning. I posted a chart a couple of days back from one of the GEFS Ens that showed this evolution but it was way further into FI and I must admit that I didn't see anything happening as quickly as the the ECM would have us believing but maybe this time ECM... ?

Edited November 13, 2015 by s4lancia

[bobbydog]

And we know how much Steve likes his pressure patterns shaped like sausages.

On another note, is there such a thing as getting these charts too early? After all is only 13th Nov today.

lol no. they are 10 days away, taking us to the 23rd. it happened in 2010. theres nothing to say we couldn't get a blend of 2010/11 with a 2009/10. now that would be a winter to remember...

[BLAST FROM THE PAST]

the onset of this possible coldish spell caught my eye on the ecm because of the support that the op had way up to 10hpa.  if anything the op is solidifying the scandi trough high up in the strat with nw europe having the extension of the pv in a way usually reserved for arctic canada or greenland. 

 

this strat support was evident earlier on in the year when we saw a persistent scandi trough deliver the coldest week of the winter. despite looking like a toppler at first, the trough kept replenishing itself. on this occasion, i was again confident of its sustainability via good upper strat support.

 

my eye is also taken by the gulf of alaska high anomoly by day 10. quite marked. i thought we should be seeing a sustained low there in a  nino winter ..........

BA

I suppose this shows why over 100 years of analysis done by members on here as revealed 'no bias to UK winter under nino conditions' ie we have had mixture of mild, average and cold evened out over the century ?  It may have a base state but other factors certainly modulate it

 

BFTP

[Cleeve Hill]

Having just read the last few pages, it's great to see the contributions from netweather best. Just need glacier point to make an appearance. Lorenzos comments last night summed it up perfectly. What I do like is the "Gung Ho" style of people here. The met office and pro forecasters are so cautious whereas someone on here will stick their neck out. Well done lads and lass.

[BLAST FROM THE PAST]

 

 

 

Now have a look at T240 ECM

 

 

 

 

The Queen is alive....long live the Queen

 

 

Just got a 'sign'....if I donate some more to CIN this will happen.....I'm off to make a call

 

 

 

BFTP

Edited November 13, 2015 by BLAST FROM THE PAST

[bluearmy]

extended ecm maintains an upper ridge of sorts around greenland and a scandi trough. the atlantic running into the base of this troughing in our locale. expect a cooler set of london ens later.  interesting.

[Frosty.]

Looking back to the classic late November 2010 freeze, there are similarities with the current Ecm 12z...fingers crossed