Model Output Discussion - 16th Jan 12z onwards - Smile While You Post!

[steveinsussex]

Please explain your point..

This isn't showing anything progressive in my eyes, am I missing something?

 

sorry, the excitement got the better of me

[cornish snow]

Please explain your point..

This isn't showing anything progressive in my eyes, am I missing something?

I think the main thrust of his point was,the only way is up.

[winterof79]

The 18z a good illustration of the differences in the extended gefs and ECM ens. The ECM would likely have sent that system se, disrupting across the uk whereas the ncep fi trend is to extend the Azores ridge further east and the systems will disrupt well to our east.

Touch and go on the GEFS

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240

[A.J]

Good lord, there's some off topic stuff in this thread......please keep to the model discussions everyone.......Posts about the met office and/or met office TV personalities really need to go in the 'weather in the media' threads otherwise this thread rapidly goes off on tangents

 

Many thanks 

[Timmytour]

Touch and go on the GEFS

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240

Come on in....

[Nick F]

18z GFS still has back-edge snow signal along the front moving SE on Friday, though what normally transpires is that the air cold enough/dry enough at the surface for snow to fall normally lags too far behind unless it's a potent northerly (anyone still remember 28th Jan 2004?).It's rare that you see a UK wide back-edge snow event from the NW as GFS portrays. It's come up with this idea a few times this month.

Interesting what's driving this persistent deep troughing over Europe as advertised by medium range guidance. + PNA pattern upstream (ridge over western N America and trough over eastern NA) looks to become locked in for a while and this teleconnects to Azores high displaced north a little and the Euro trough. So a slow-moving wave/trough pattern looks to lock in for the rest of Jan, with a strong signal for cold northwesterly flow to persist most days with the odd milder day thrown in.

GFS has toyed with the idea of a cold northerly shot too further down the line, so be interesting to if these pop up again over the next few days.

Prospects for early Feb certainly look encouraging, the strat PV is forecast to be displaced toward Siberia and this displaced vortex would make it more favourable for wave upwelling, further weakening the already weakened vortex and help slow down the jet stream to perhaps generate some high latitude blocking, though we are some way off that perhaps manifesting in the output for now.

[winterof79]

18z GFS still has back-edge snow signal along the front moving SE on Friday, though what normally transpires is that the air cold enough/dry enough at the surface for snow to fall normally lags too far behind unless it's a potent northerly (anyone still remember 28th Jan 2004?).It's rare that you see a UK wide back-edge snow event from the NW as GFS portrays. It's come up with this idea a few times this month.

Interesting what's driving this persistent deep troughing over Europe as advertised by medium range guidance. + PNA pattern upstream (ridge over western N America and trough over eastern NA) looks to become locked in for a while and this teleconnects to Azores high displaced north a little and the Euro trough. So a slow-moving wave/trough pattern looks to lock in for the rest of Jan, with a strong signal for cold northwesterly flow to persist most days with the odd milder day thrown in.

GFS has toyed with the idea of a cold northerly shot too further down the line, so be interesting to if these pop up again over the next few days.

Prospects for early Feb certainly look encouraging, the strat PV is forecast to be displaced toward Siberia and this displaced vortex would make it more favourable for wave upwelling, further weakening the already weakened vortex and help slow down the jet stream to perhaps generate some high latitude blocking, though we are some way off that perhaps manifesting in the output for now.

Yes,was that the Thundersnow event.Quite extraordinary early one afternoon up here I believe.

[Woollymummy]

I remember that Thundersnow, rain, hail, snow falling on wet, hail-covered ground created an instant winter wonderland .

[Dean E]

Yes,was that the Thundersnow event.Quite extraordinary early one afternoon up here I believe.

 

Also remember this well, got a hour of drizzle followed by downpour of snow one evening (not sure if it was the same system). My first experience of Thunder snow. If I remember correctly, quite a few areas experienced this?

 

Another note (sorry mods again) for the first time, its been a pleasure to once again read this discussion. Some very good posts this evening.

 

Back to the models,

 

That Azores High just won't budge will it? 

 

 

However, could aid later in the future, but no sign as of yet.

[bluearmy]

models firming up on the replenishing euro trough by the back end of next week.

Need to see the American ext ens models lose their appetite for the Azores ridging east week 2.

The EC control has twice built a ridge from the Atlantic over the day ten trough sinking so although looking unlikely at the moment, I wouldn't discount it.

EDIT: and then day 10 ECM appeared! Hemispherically, that NH profile could easily evolve into the coldest feb ever. It won't though!

Edited January 21, 2015 by bluearmy

[Ali1977]

ECM day 10 has potential to create some Northern blocking, still looking good for another blast of winter later next week.

[winterof79]

models firming up on the replenishing euro trough by the back end of next week.

Need to see the American ext ens models lose their appetite for the Azores ridging east week 2.

The EC control has twice built a ridge from the Atlantic over the day ten trough sinking so although looking unlikely at the moment, I wouldn't discount it.

EDIT: and then day 10 ECM appeared! Hemispherically, that NH profile could easily evolve into the coldest feb ever. It won't though!

But could it evolve into something even near?That would suffice.The ridging from the other side of the pole is becoming a recurring theme on the output.X polar flow a possibility. Edited January 21, 2015 by winterof79

[Duane S.]

Oh you little tease ECM! A quick scan through GEFS and there is support for a similar idea with quite an amplified flow progged at that range.

I think after a week or so of alternating average / cool for most of us, heading into Feb is starting to look very interesting indeed

[West is Best]

models firming up on the replenishing euro trough by the back end of next week.

 

 

'The back end of next week' is T200+ so isn't it a bit tautologous to describe the model outputs as 'firming up' at that range? UKMO doesn't even go out beyond T144, probably very wisely. Given recent events, where some of the models were inaccurate at T48, might it be wise to be take a big pinch of gritting salt, of which there's currently plenty left over, to that long range?

 

I can't see signals for anything in these outputs other than a mobile flow with occasional PFJ kinks to allow us to experience some polar maritime incursions. That's brilliant for the Scottish ski resorts, and may, occasionally, see some more wintry mix further south. That's about it.

Edited January 21, 2015 by West is Best

[Polar Maritime]

Yes a fantastic last frame from the ECMWF, Very promising signals remain for the turn of the Month from both ECM & GFS. With Hight's pushing up into Greenland bringing a cold N/N/E flow.

 

Edited January 21, 2015 by Polar Maritime

[West is Best]

'The back end of next week' is T200+ so isn't it a bit tautologous to describe the model outputs as 'firming up' at that range? UKMO doesn't even go out beyond T144, probably very wisely. Given recent events, where some of the models were inaccurate at T48, might it be wise to be take a big pinch of gritting salt, of which there's currently plenty left over, to that long range?

 

I can't see signals for anything in these outputs other than a mobile flow with occasional PFJ kinks to allow us to experience some polar maritime incursions. That's brilliant for the Scottish ski resorts, and may, occasionally, see some more wintry mix further south. That's about it.

And by the way, if we're not careful we see what we want to see. Look at the 0z GFS ensembles and there's 1. massive scatter and 2. a lot of milder members:

 

https://forum.netweather.tv/gallery/image/20709-/

 

There's nothing 'firmed up' or in good support in that mess. Could be mild. Could be cold. Could be in-between. Not being tricky, I just don't want to see people let down (again).

Edited January 21, 2015 by West is Best

[bluearmy]

'The back end of next week' is T200+ so isn't it a bit tautologous to describe the model outputs as 'firming up' at that range? UKMO doesn't even go out beyond T144, probably very wisely. Given recent events, where some of the models were inaccurate at T48, might it be wise to be take a big pinch of gritting salt, of which there's currently plenty left over, to that long range?

 

I can't see signals for anything in these outputs other than a mobile flow with occasional PFJ kinks to allow us to experience some polar maritime incursions. That's brilliant for the Scottish ski resorts, and may, occasionally, see some more wintry mix further south. That's about it.

Richard - the ens and anomolys are in agreement. They will not be spot on at ten days but this broad run has repeated on ECM and gefs. Granted that the pendulum could swing to a flatter trough but at the moment if anything, it's headed the other way. The ops are purely for window dressing at this range but given that they also agree with the ens, that's good enough for me to call it 'firming up'at this range.

[winterof79]

'The back end of next week' is T200+ so isn't it a bit tautologous to describe the model outputs as 'firming up' at that range? UKMO doesn't even go out beyond T144, probably very wisely. Given recent events, where some of the models were inaccurate at T48, might it be wise to be take a big pinch of gritting salt, of which there's currently plenty left over, to that long range?

 

I can't see signals for anything in these outputs other than a mobile flow with occasional PFJ kinks to allow us to experience some polar maritime incursions. That's brilliant for the Scottish ski resorts, and may, occasionally, see some more wintry mix further south. That's about it.

It is not your average west to east mobility though Richard.I have picked one out but there are quite a few more consistantly progging this hence the firming up.

The GEFS

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=240

[Nick F]

GFS has toyed with the idea of a cold northerly shot too further down the line, so be interesting to if these pop up again over the next few days.

 

 

GEM and ECMWF having a northerly party at day 10:

 

http://www.wetterzentrale.de/pics/Rgem2401.gif

http://www.wetterzentrale.de/pics/Recm2401.gif

 

GFS a little earlier but a toppler:

 

http://www.wetterzentrale.de/pics/Rtavn2348.gif

 

00z H500 comparison over the NH shows an increasingly convoluted flow developing, +PNA ridge western N America, eastern N America trough, teleconnecting through to Azores high ridging north and Euro trough. Quite of lot of warming/trop waves over Bering Sea, Alaska/Yukon again working poleward, which is a good thing to build heights over the pole.

 

Edited January 21, 2015 by Nick F

[bluearmy]

And by the way, if we're not careful we see what we want to see. Look at the 0z GFS ensembles and there's 1. massive scatter and 2. a lot of milder members:

 

 

There's nothing 'firmed up' or in good support in that mess. Could be mild. Could be cold. Could be in-between. Not being tricky, I just don't want to see people let down (again).

Also, i was speaking about a euro trough. What have the uppers for little Hampton got to do with a euro trough?

[Ali1977]

Be interesting to know what the latest ec32 is predicting, there is a lot of scatter amongst the ensembles, but the mojority show the PV breaking up next week in some shape or form.

Edited January 21, 2015 by Ali1977

[West is Best]

Also, i was speaking about a euro trough. What have the uppers for little Hampton got to do with a euro trough?

 

A butterfly flaps its wings in ...

 

Fair enough. It's just that, as we know, wherever we look, whether that's upstream or downstream '10 days' and 'firming up' are phrases that should be kept apart. In my humble opinion.

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2015012100/ECH1-240.GIF?21-12

 

So then we arive back on the model rollercoaster after a few days that overall have over promised & under delivered, all be it with the exception of the zone of heavy snow last night.

ECM gains interest at day 8 & by 10 is nice across the NH, as ever though we need some consistency to day 5 & 6.

 

I think im going to have a couple of days off-

S

[IDO]

Over 50% of the GEFS send a trough through the UK into Europe, not dissimilar to the ECM. However all but two of them remain in a mobile pattern and push that trough east. by D12:

 

 

 

However the ones that are not showing this trough at D10 do try later in FI. Beyond that everything but the kitchen sink, with small clusters of various solutions. It would be hard to say a pattern was emerging from the GEFS in FI, so it does look like anything is possible after in this fluid setup. No doubt we will have a better idea in a few days.

 

I am not sure this trough is a signal for a flip to a cold synoptic. IMO it is from the Azores getting pumped up from a wedge of heights exiting from the US D2-3:

 

 

It builds to 1040mb and becomes the main driver for the Atlantic after D5. That robust block diverts the lower heights over the top into Europe:

 

 

After D10 on the GEFS we have another wedge of heights over the US pushing into the Azores block and they shift the pattern east. Maybe that is systematic of the GFS Atlantic mobility bias showing and in time it may change to something akin to the ECM who absorbs that second HP system into the Azores and builds an Atlantic ridge (though possible ECM bias)?

 

This synoptic does look like having good verification as all models have these bursts of higher pressure moving into the Atlantic so something favourable may develop from that especially as it is during a period where the PV is mobile. GEM at D10:

 

Edited January 21, 2015 by i'm dreaming of...

[bluearmy]

Be interesting to know what the latest ec32 is predicting, there is a lot of scatter amongst the ensembles, but the mojority show the PV breaking up next week in some shape or form.

That was yesterday morning Ali.

Generally a mean nw flow though euro low anomolys become high days 22 onwards before dropping back again at the end. id say generally cool for uk and occasionally cold and by the same token some milder spells likely.