Model Output Discussions 06z 04/11/16

[andymusic]

yep - high pressure right over the UK - in total control of our weather - settled conditions, cold at nights - but also at times drawing up slightly warmer weather from the south too - at least right now everyone can get there xmas shopping done in decent conditions - seems we are gonna have to wait for the snowy winter onslaught further into December now - as was said a week or so ago - lots of blocking forecast - but where was the block was gonna sit - was it gonna be favourable for the UK? - well right now not quite - but settled and fine ain't such a bad set up - we'll get the chance of colder and more severe set ups end of December and through Jan first part of Feb - so let's hope the ideal set ups really get there act together then to deliver the seasonal goods - and of course end of Feb through March - as the seasons have tended to meander forwards we have to remember some of our coldest snowiest conditions will turn up then - Andy over and out

[knocker]

I forgot to add this to my original post but still looking at some renewed amplification down the line. I still don't think worrying about the detail of this current HP is very important in the long run if the MET and ec46 are on track

Edited November 30, 2016 by knocker

[Ali1977]

ECM firing WAA into Greenland at day 6, this could be an interesting run.

[Great Plum]

First post of the season in here for me. Currently a balmy -6.4c in Charlwood down the road!

Good to see that the 0z ensembles looking for a change mid month... is that a COBRA run I spy as well in the ensembles?

Still all to play for - keeping dry as well!

 

[knocker]

The ecm treats the perturbation that breaks north from the trough to the SW slightly differently than the GFS. It runs it north into Ireland and then east to bring outbreaks of rain to the UK by T162. Just a blip

[Seasonality]

Different solution again from ECM this morning. More n/s orientation of high pressure cell with vortex now touching central Europe.

[Seasonality]

Cold pushing west. 

[bluearmy]

ECM very different re the n Pacific ridge and this makes any quick route to deep cold for nw Europe very difficult to imagine. Of course fi is fi on any op run and the 12z will probably deal with the Pacific ridge differently. I note the whole GFS suite handling the upper strat differently so perhaps could be a message there.

Howver, the road still leads to where Exeter expects re the GEFS fi so it may just be a case of chilling out for a week until fi GFS begins to get a handle on how it intends to drain away those euro heights and more intriguing runs appear in the distance. I wouldn't worry about our surface high - will be history by then. It's the upper ridge we need to head west. 

Edited November 30, 2016 by bluearmy

[IDO]

1 hour ago, Mucka said:

That's not what the stats say and where did anyone say UKMO day 6 should be taken as gospel?

On the second statement, which is it, clear potential or hard to see cold/snow prospects? .

Hi

I was talking about UKMO propensity to appear to undercut in these situations. Steve Murr refers to them many times as a precursor to retrogression. Yet they rarely move closer than D6. 

As for "potential" it's the watch word from the experts so I am not going to argue with that. Mid term you may see cold and snow but I don't. Just my opinion from what I am seeing. In fact the current output is the least appetising for snow and cold for a while and November has a CET of -0.2c below average so just average stuff at the moment. 

 

 

[SMU]

1 hour ago, IDO said:

Come on guys, the UK D6 charts are woeful when it comes to HP -v- LP, they are akin to D10 ECM charts. I rarely pay any attention to them as clearly they have issues.

My thoughts are that we remain in a holding pattern where the PV remains subdued but there is no forcing to create a more prolonged amplified pattern. It shows that even with a weak PV you need the right synoptics to get long term cold. 

We have gone from the Russian/Siberian High & Azores mid-latitude quasi block setup to an Azores & Pacific HP combo.But again both haven't the heart to be anything but topplers if they do venture into semi-higher latitudes, so effectively still a rather mobile NH pattern within those confines.

Of course as time passes the PV gains a bit more energy just to make any meridional pattern a little bit tougher.

It looks pretty clear we have a sinking high around D8-D10 and its direction of fall will define the upper flow over the UK, with GEM bringing us a warming (average T850s >8c above normal) whilst the GFS a mild flow (T850s +4c above average). As that sinks the cycle starts again, and the next wave from the Azores pushes towards the UK. I am sure the FI GEFS will have some producing  stellar runs, but that has been the modus operandi for weeks and it may be better to assume the status quo until one of these elusive background signals change the pattern. However that has low confidence as the second pulse from the Azores after D10 and the sinking high could be difficult to model at this range. 

Being honest it is hard to see any cold/snowy pattern developing by mid-December but the potential remains clear and hopefully its just a matter of time.

Morning All

IDO - you posted more or less the same post Saturday (4 days ago ) showing the GFS ENS mean & the GEM around 192 + saying the high was a sinker & quote - I expect the temps to be North of +10c by day 10 possibly 14c- yet todays day 6 Mean T2M temp max ( which is your day 10 ) are just 4c

It shows that using the GFS ENS as the benchmark can be wildly wrong. Especially when taking the mean 500 & trying to extrapolate the surface temp-

The models arent brilliant this morning however I will be reviewing them post the 12s which I think will be better- 

[mhielte]

There was me thinking we were in a cool/cold pattern already?

850s 4 or 8c above average won't push the temperatures up much lets be honest (worth mentioning that it'll doubtless evolve differently anyway).

[london-snow]

22 minutes ago, Steve Murr said:

The models arent brilliant this morning however I will be reviewing them post the 12s which I think will be better- 

A common theme which is becoming ever more popular i note that the overnighters seem to downgrade the previous evenings 12s only to upgrade in the following afternoons 12s.

Of course it's only a upgrade if you're a cold weather fan!

[knocker]

If it's of any interest a quick revisit to the subject of 850mb temps that Nick touched on previously

Last night's Camborne sounding had a 850mb temp of +4.5C, in fact the 700mb is only -3.3C. The surface at 1023mb is +2.4C quickly rising to +5.0C at 1009mb as the radiation inversion kicks in under clear skies and light winds. In areas of the country where this surface cooling will be far greater than this the radiation inversion will far more impressive.

Edited November 30, 2016 by knocker

[Troubleatmill]

Postage stamps the GEFS 00z are starting to look promising to me from mid month, a fair number now showing some decent blocking to the Northwest of the UK. Looking to see if we can get more members on board on future runs.

[blizzard81]

Poor ecm op this morning for our neck of the woods. Don't want this repeated on the 12z tonight. Again the ridging benefits the US, they get the frigid cold again.

[Seasonality]

8 minutes ago, london-snow said:

A common theme which is becoming ever more popular i note that the overnighters seem to downgrade the previous evenings 12s only to upgrade in the following afternoons 12s.

Of course it's only a upgrade if you're a cold weather fan!

I've noticed this too. Which makes the schadenfreude laden doom monger types who emerge from their burrows each morning look even more ridiculous imo. Still varying outcomes being shown, run to run and inter model differences. And not quite December yet, so to use an old cliche, more runs needed.

[pdiddy]

Regarding upgrades/downgrades, always worth looking at the runs independently, i.e. 12z to 12z and 0z to 0z to see how the synoptics evolve.

[musician]

2 hours ago, IDO said:

Come on guys, the UK D6 charts are woeful when it comes to HP -v- LP, they are akin to D10 ECM charts. I rarely pay any attention to them as clearly they have issues.

My thoughts are that we remain in a holding pattern where the PV remains subdued but there is no forcing to create a more prolonged amplified pattern. It shows that even with a weak PV you need the right synoptics to get long term cold. 

We have gone from the Russian/Siberian High & Azores mid-latitude quasi block setup to an Azores & Pacific HP combo.But again both haven't the heart to be anything but topplers if they do venture into semi-higher latitudes, so effectively still a rather mobile NH pattern within those confines.

Of course as time passes the PV gains a bit more energy just to make any meridional pattern a little bit tougher.

It looks pretty clear we have a sinking high around D8-D10 and its direction of fall will define the upper flow over the UK, with GEM bringing us a warming (average T850s >8c above normal) whilst the GFS a mild flow (T850s +4c above average). As that sinks the cycle starts again, and the next wave from the Azores pushes towards the UK. I am sure the FI GEFS will have some producing  stellar runs, but that has been the modus operandi for weeks and it may be better to assume the status quo until one of these elusive background signals change the pattern. However that has low confidence as the second pulse from the Azores after D10 and the sinking high could be difficult to model at this range. 

Being honest it is hard to see any cold/snowy pattern developing by mid-December but the potential remains clear and hopefully its just a matter of time.

At last! someone who can spell STELLAR correctly!

[mountain shadow]

1 hour ago, Seasonality said:

A

[mountain shadow]

Not sure how that happened above.

Anyhow, I personally feel the models have handled the UK high quite well. They have shown it to pretty much persist into mid month and thats what is happening. Looking for snow in the first couple of weeks is not on the cards.

What we are looking for is sign of Greenland heights from mid December onwards and the GEFS are better today for this. 

 

[Seasonality]

14 minutes ago, musician said:

At last! someone who can spell STELLAR correctly!

Yes, but I believe it became a bit of an in joke to call it a Stella run. The amusing misspelling was then turned into a riff on the 'pub run' as in Stella Artois

[Geordiesnow]

Clearly less energy is going under the high inititally on the UKMO and then we see its start to show similar to what most models are thinking that might happen and perhaps you got to say the most likely outcome at the moment which is when rather than IF the high sinks.

Could change though and the modelling of the pacific ridge will no doubt vary. The only dissapointment from me really is there was no follow on development from yesterday's UKMO run in particular but apart from that, its how you were regarding the output.

[nick sussex]

Rather than try to spin things I'll be blunt the ops today are utter crxp for real cold! By real I mean cold uppers rather than inversion cold.

The ECM  departs from the last few days by taking much of the PV west rather than keeping this towards Siberia. This is not good news and lets hope its a one off because that could seriously throw a spanner in the works of those longer ranges forecasts.

The Euros starts to go pearshaped quite early because of the SOD (shortwave of death), this heads nw and phases with the upstream trough which then helps to force a lot of energy ne'wards.

The biggest disappointment isn't so much missing out on a possible easterly but even second prize seems to have bitten the dust of an early retrogression of the high.

The UKMO suffers the biggest climb down and goes from best output yesterday to worst today which will probably mean it verifies! In the world of models you're only one run away,  going from lauded Oscar winning actor to daytime soap has been!

 

[Catacol]

1 hour ago, IDO said:

In fact the current output is the least appetising for snow and cold for a while

Every now and again a comment is posted that requires a response - and in this case a single word will do. Rubbish. There is never any guarantee of snow, but with high pressure flirting with a move to higher latitude by mid month, and a great deal of cold air gathering to our east the output is actually as good for snow and cold as we have had in years.

 

[blizzard81]

The ops are indeed terrible this morning. That by the way is not doom mongering. It is reading the models and saying how it is. What worries me most is the lack of cross polar flow in our direction on all the ops. You would think the ops would be the first to pick this up in the extended. Well, they were the first to pick it up - until this morning! What has changed? Can any of the experts on here give any clues?