Model Output Discussion 01/09/17

[booferking]

7 minutes ago, MR EXTREMES said:

I really think I'm going to throw the towel in.

Very disappointed indeed it's not going to happen the heights to the south are really stubborn maybe Nina forcing is the thorn in the coldies sides.

Once again close no cigar but hey mild and stormy in the later runs.

Although it's only November so maybe we might get another shot.

Lets wait until ECM then we can throw the towel in together.

[Team Jo]

Can I just pop in and say that we had very similar ‘winter’s over’ commentary not two days ago, then a staggering pub run with everyone on the cusp of bulk buying salt and now we are back to despair, all in the space of 48 hours. As tempting as it is to get emotionally invested into these outputs, given next week is still all rather interchangeable depending on the model, I’d suggest not hanging on every frame of every run.... as the wise have probably said, the models don’t set the weather. The weather (and some mind boggling statistical data) sets the models. It’s going to be a very very long and frustrating winter otherwise! Of course if you need to vent your frustrations there is the Moans and Ramps thread just a couple of clicks away...

[The PIT]

Well the GFS was the first one to spot a change in lala land with a switch from a cold dominated outlook to steadly milder one. ECM and ukmo following slowly.

[northwestsnow]

1 minute ago, The PIT said:

Well the GFS was the first one to spot a change in lala land with a switch from a cold dominated outlook to steadly milder one. ECM and ukmo following slowly.

not sure i agree with that PIT, gfs has been churning out some cold runs over the last day or two while the euros said no.

Anyway, im off to the moan thread, i have a feeling i might be posting there for quite a while.

[Nick B]

I think it's been mentioned before but key to almost all lasting cold setups for the UK as a whole is generally going to involve a lowering of heights over the continent.  As soon as the deeper blues on the 500mB charts are modelled as appearing for a reasonable length of time, centred somewhere around N. Italy, S. Germany, Austria, Czech and S.E France, then the UK is in with a much better shout for a lasting cold spell.  This will generally hold true whether it's via a Greenland or a Scandinavian high.  Situated here in middle-ish Germany, that happens to be what I am looking out for too - UK and Germany will both win when that occurs.  As long as the yellow concave shape is showing in any way over Europe, we're on dodgy ground.

The recent depth of cold in the ENSO state, somewhat unexpected only a few weeks ago (-0.5 to -1.0 was on the cards, now looking like a solid -1.5, albeit largely on the Eastern side), may throw a spanner in the works but can be overridden if other factors are strong enough (the MJO is not looking like helping us out, AAM will be low).  Several factors were working against a cold North Western Europe in the heart of winter last year and right now, we are still in Autumn.  I have a feeling we may have to grit our teeth through an extended period of zonal weather, however that does not mean it's necessarily going to be mild all the way.  I'd like to continue to see some WAA putting a bit more stress on the PV as well as getting the cold a bit closer to this part of the world.  That, for a more substantial return later, rather than a watered-down attempt now (if you'll excuse the pun).

[Geordiesnow]

Although the Euro heights are probably not helping, I think the main reason why the models are struggling to bring the cold down from the North is down to the west based NAO and history tells us that it will be mild for us when that happens so those Euro heights are not going to go away. As I said a few days ago I think its meteologically (almost) impossible for the UK to get cold weather with a west based NAO. Some GFS runs hinted at the return of the PV in the Labrador Sea which perhaps helped to form a proper Greenland high and the Northerly as a result but very few runs have been showing this so its no real surprise it has eventually changed again.

Whilst you can't rule out a return to cold weather after this weekend chilly snap, I just think the overwhelming evidence suggests it will be mild next week, how long it will take for the Atlantic to fully come in is a bit more uncertain at this stage though. If this what happens its most certainly will be a missed opportunity when you got ridges and an Arctic high over the poles at the moment

[phil nw.]

Some interest in the gefs height.anomalies suggesting we may not go mild zonal for too long.The main strength of the growing pv over the Siberian side with +ve anomalies still to our north west.

Probably no immediate signal for a notable cold pattern but further polar maritime shots quite possible with further Atlantic ridging.

[blizzard81]

We should be used to this by now. I think this is the third or fourth year on the trot that the models have forecast a very cold last third of November only for this to implode nearer the time. I will be shocked if ecm shows coldie eye candy tonight. 

[The PIT]

27 minutes ago, northwestsnow said:

not sure i agree with that PIT, gfs has been churning out some cold runs over the last day or two while the euros said no.

Anyway, im off to the moan thread, i have a feeling i might be posting there for quite a while.

Remember I'm looking mostly at one 12oz.

[Geordiesnow]

8 minutes ago, blizzard81 said:

We should be used to this by now. I think this is the third or fourth year on the trot that the models have forecast a very cold last third of November only for this to implode nearer the time. I will be shocked if ecm shows coldie eye candy tonight. 

Last November was a cold one though, at least around this time last year it was according to the achieve charts. I do think its unfortunate on a UK's perspective that days ago, the models picked up on the west based NAO signal and as soon as that happens, mild weather becomes a heavy favorite

The only hope for coldies is that the models perhaps pick up the signal the NAO won't become too far west based and we get a better ridge into Greenland like a few GFS runs and a couple of ensemble runs have shown. It just shows the fine margins really.

[booferking]

Dare i say it but ECM looking best out of the 3.

Edited November 16, 2017 by booferking

[weirpig]

2 minutes ago, booferking said:

Dare i say it but ECM looking best out of the 3.

Bet me to it  better heights on the ecm looks a stronger block 

[ZK099]

1 minute ago, weirpig said:

Bet me to it  better heights on the ecm looks a stronger block 

Best block since the 18z last night. Maybe, just maybe... ?

[weirpig]

Ecm what are you doing? 

[bluearmy]

Interesting ...........

[snowray]

This is getting silly now.

[nick sussex]

Shortwave chaos!

All big 3 disagree with these and this looks like its got a bit more mileage to go. No resolution tonight regardless of what the ECM does in its later output.

[Derecho]

6 minutes ago, Optimus Prime said:

Just give up. It ain't gonna happen.

The latest ECM disagrees



Not sure why you are writing off the rest of November, when the pattern for next week still isn't settled. Yes the milder option has the greatest chance of prevailing but a lot is yet to be resolved.

[ZK099]

2 minutes ago, weirpig said:

Ecm what are you doing? 

Fantastic blocking. Best since last night. Where are the 'ECM is king' guys now?? ?

[weirpig]

3 minutes ago, nick sussex said:

Shortwave chaos!

All big 3 disagree with these and this looks like its got a bit more mileage to go. No resolution tonight regardless of what the ECM does in its later output.

Yep enough for me  still lots to be resolved  

[Nick B]

Found the following site for charts recently, might have been flagged elsewhere but it's an excellent resource for charts.  If you don't mind using a translator, you'll find almost every parameter you could hope for (though the key is knowing what to use when...

e.g. for general outlook up to maybe 120-212, dependent on dear old Shannon E., standard 500 geopotential: https://kachelmannwetter.com/de/modellkarten/euro/europa/geopotential-500hpa/20171119-1800z.html

for the next day, determine whether you might see white stuff, there's a whole host of parameters to choose from, such as 925 temperature: https://kachelmannwetter.com/de/modellkarten/euro/europa/temperatur-925hpa/20171117-0900z.html,

probability of heavier precipitation: https://kachelmannwetter.com/de/modellkarten/euro/europa/niederschlag-ueber-10mm/20171117-0000z.html , dew point: https://kachelmannwetter.com/de/modellkarten/euro/europa/taupunkt/20171117-0000z.html etc.etc.

Enjoy

[joggs]

Can't they just all agree and put it to bed:0

[bluearmy]

that run was pretty close to avoiding phasing the atlantic and arctic low heights. pretty confident that the 00z will reveal if it will actually be possible to do this or if they can phase in a position favourable to bring cold to nw Europe. still the most unlikely call.

[Catacol]

23 minutes ago, Nick B said:

 I have a feeling we may have to grit our teeth through an extended period of zonal weather, however that does not mean it's necessarily going to be mild all the way.

Accurate I think. Modelling of the jet over the Pacific has been all over the place too recently, and this has helped create huge model uncertainty, but what we can see clearly is low AAM, no MJO influence yet (probably 4 more weeks away), a Nina pattern taking hold (uncertainty on how long it will take to couple effectively to the atmosphere) and the vortex predictably gaining strength. The decoupled state of ocean, atmosphere and vortex at present will allow variations from a Nw and Sw direction with a jet that will look anything but flat for a bit longer yet, but without proper Pacific forcing the chance of a substantial block to our north setting up shop is slight. We may get temporary topplers, and I suspect a good start to the Scottish ski season my be in the offing with plenty of NW shots - but lowland snow via sustained cold in the south just doesn’t look likely to me.

From here the odds are in favour of a move to a more zonal December. This may be delayed by a week if the trop pattern can stay disconnected a while longer - Ant Masiello has suggested this is possible - but westerlies by mid December are probable.

Patience is required. The chance of a change to something much more interesting sits with the next MJO cycle (possibly aided by a resistance to Nina anomalies in the central Pacific) and hopefully a Nina that doesn’t bottom out too low and perhaps begins to wane in January. This could create interest via vortex disruption and renewed pulses of energy into northern latitudes that could possibly aid in creating a blocking pattern.

This is a January conversation. Right now I’m happy with a few frosts and a fairly benign pattern with westerlies slow to take hold. But I think it is only a matter of time until they do.

Anyone heard from GP recently?

[Geordiesnow]

Still a west based NAO on the ECM though, despite the details changing for the UK from each run which as you expect, this is the common theme so whilst the cold air tries to filter in, the milder air soon fights back, nevertheless it shows not everything is a foregone conclusion and the uncertainty still surrounds just how quickly any milder air gets in over the whole of the UK.

Its one of those where what the GFS showed earlier is not as far away as some might think just like when the charts were showing cold weather, the milder SW'lies were not too far away either, its kind of knife edge stuff if albeit the mild air is still the form horse.