The hunt for cold - Model discussion (late November)

[Mike Poole]

3 minutes ago, sorepaw1 said:

It's got an evil face and white eyes.

lol Yes but there's 3 of them.

Edited December 1, 2018 by Mike Poole

[sorepaw1]

3 minutes ago, Mike Poole said:

lol Yes but 3 of them?

There's no mistake that's the Beast ok lol

[BLAST FROM THE PAST]

Models have gone from horrendous zonal as some took as gospel.....and in sane breath yoi can’t take as gospel what we have now.  BUT, the propensity for cold to dominate is back in play after a few days of it being off the table according to the Ops. Let it develop....because it IS developing.....

don’t be shocked if there is snow to fall in further south places over next 7 - 10 days than being forecast currently....even if transient in nature

 

BFTP

Edited December 1, 2018 by BLAST FROM THE PAST

[Duane S.]

And so... the final run of the Autumn signs off with this outrageous offering...

I’ve been around the block enough times to know this. When we are genuinely staring down the zonal barrel, the charts simply do not show this. Not even in FI.  And certainly not to the extent that, albeit still only a minority, these charts are cropping up.

We are not looking at a flat jet 3 - 4 week zonal onslaught. There are times when, yes, that is the case in UK winters, but this is not one of those times. Of course - we could end up with just that, a mild zonal December. But there is clearly  a blocking signal later in the month. Granted, not a strong signal by any means, but it’s there.

The MJO will likely be passing through the wrong phase at that time but it doesn’t control our weather, it only influences it. To my mind, Wave 1 displacement could be the big player here, keeping the vortex on the NW side but more NW than default. This will encourage heights to build NE and very robust ones too. Think Feb 1991. 

Which is why I don’t get those who have already written off the month. Bizarre. Note, I am not predicting one outcome or the other (just yet), just pointing out that at this juncture it is completely wrong and misleading to rule anything out from mid month to the end of the month.

 

[tight isobar]

12 minutes ago, s4lancia said:

And so... the final run of the Autumn signs off with this outrageous offering...

I’ve been around the block enough times to know this. When we are genuinely staring down the zonal barrel, the charts simply do not show this. Not even in FI.  And certainly not to the extent that, albeit still only a minority, these charts are cropping up.

We are not looking at a flat jet 3 - 4 week zonal onslaught. There are times when, yes, that is the case in UK winters, but this is not one of those times. Of course - we could end up with just that, a mild zonal December. But there is clearly  a blocking signal later in the month. Granted, not a strong signal by any means, but it’s there.

The MJO will likely be passing through the wrong phase at that time but it doesn’t control our weather, it only influences it. To my mind, Wave 1 displacement could be the big player here, keeping the vortex on the NW side but more NW than default. This will encourage heights to build NE and very robust ones too. Think Feb 1991. 

Which is why I don’t get those who have already written off the month. Bizarre. Note, I am not predicting one outcome or the other (just yet), just pointing out that at this juncture it is completely wrong and misleading to rule anything out from mid month to the end of the month.

 

Good post.

And notes the mother lobe limpit-situ..

But wave destruct in 'perfect' measure.

As responces play kiss chase...

And in the middle is the boy with all the girls!!!.

Honestly..there is serious miss diagnosis here...

And the vig-vortex is a little light years away here...as the data is still not prog-of the melting in the alaskan/canadian needle..pin in balloon strike...

Which as we gain through raws...and indeed/supports..will jump out with notable insight!!..

The pressing of trop-teasing..has took the dinner money @the strat..'overall'.

And i reiterate...some twisting and munip-..will be the order....as 4 mid/latter prognosis!!!!

As the rapid connects, gain.

Again the pv-as a whole is a scared wolf..driven from the pack...

Look 4 dramatic ens shake...and indeed..some reevaluation-of dec-formats/forecasts!!!

 

Edited December 1, 2018 by tight isobar

[JeffC]

6 hours ago, sorepaw1 said:

It's got an evil face and white eyes.

Quite witch-like, maybe the three meet again in thunder, lightening or snow! (With apologies to Billy Shakespeare)" where the place?" Er, UK wide will do nicely thanks!

[ICE COLD]

No comment on the ECM ? Why ? It’s bloody brilliant . Oh yes sir . 

Edited December 1, 2018 by ICE COLD

[ICE COLD]

Where is everyone? The charts are looking good this morning. Surprised there’s not more excitement. The runs where terrible 36 hours ago , they have now flipped and are looking excellent.

[I remember Atlantic 252]

2 minutes ago, ICE COLD said:

Where is everyone? The charts are looking good this morning. Surprised there’s not more excitement. The runs where terrible 36 hours ago , they have now flipped and are looking excellent.

in their pits, but thought EC would liven forum up

[ArHu3]

2 minutes ago, ICE COLD said:

Where is everyone? The charts are looking good this morning. Surprised there’s not more excitement. The runs where terrible 36 hours ago , they have now flipped and are looking excellent.

I'm waiting until the ensemble comes out, gfs and parallel not really on board yet 

[ICE COLD]

1 minute ago, ArHu3 said:

I'm waiting until the ensemble comes out, gfs and parallel not really on board yet 

Morning, I’m just loving the fact all models have moved away from zonal. The gfs is still good has high pressure building north it’s just not as good as the ECM .

[Chesil View]

A nice run from the ECM this morning pushing the trough into south Scandinavia and Denmark and allowing hieght rises in the vicinity of Iceland which try very hard to join up with the the Russian high to our North east. Certainly ties in with last night's De Bolt ensembles going cold later in that run.

Edited December 1, 2018 by Broadmayne blizzard

[seabreeze86]

Momentum definitely on our side again but lots to resolve. Height rises over Scandinavia looking probable but still on a knife edge in my opinion. 144 hrs the key time frame we need the upstream pattern to play ball still it does on the ECM and we  see the rewards 

[bluearmy]

7 minutes ago, ArHu3 said:

I'm waiting until the ensemble comes out, gfs and parallel not really on board yet 

Thinking back to yesterday, the gfs runs were very mobile in week 2 but because they got enough amplification in the crucial phase, the ridge gained latitude and the Atlantic undercut. The 00z op is trying but the pattern is too far to the east and it get overrun ....the para just doesn’t  quite get it right in fi but it isn’t far away from a good back end to week 2. both runs have a different polar profile to gem and ec whereby the Canadian vortex begins to exchange low heights to Asia on our side of the pole - remember my posts early last week on this - unless you have a strong upper ridge already in place forcing split flow then that exchange over our side of the polar field is curtains for us to go cold in this phase. incidentally, my fence sitting staying 50/50 after yesterday’s output is predicated on the extended clusters over the past couple days really not running with a solidly wintry offering more than 15%.  Whilst there are five on offer, only one of the five shows that persistence in the pattern ...... I’m waiting to see this increase - the eps are running to day 15 at a similar resolution to the gfs op to day 10. they are capable of deciphering a difficult solution. Once I see these clusters gaining momentum on a sustained scandi ridge with some split flow to keep it in place then i’ll be content to jump off that fence. 

[Seasonality]

Cheeky little day 10. 

[Nick F]

On ‎26‎/‎11‎/‎2018 at 08:10, Nick F said:

Given the expected upstream changes triggered by MJO over WPO/EPO region along with wave no. 2 forcing, I'd say justified confidence in pattern change back to blocking through week 2 of December after a week or so mobile/ unsettled/ mild Atlantic weather, though the models are to-ing and fro-ing over where to build the block. No guarantees of course.

 

18 hours ago, Nick F said:

I'm not so enthusiastic as I was a week ago that we'll see proper blocking anytime soon, i.e. next few weeks, as there just looks like too much El Nino westerly momentum and a trop PV too close to the NW to allow blocking to form near enough to the UK or position ideally for any deep cold to spread across the UK.

Looks like the models are picking up some transient eddies in the generally fast zonal westerly jet stream ploughing across the N Atlantic into western Europe, which may form some transient ridges that could pull down some cold arctic air to bring a brief 1-2 day cold snap, with snow for northern UK a real posibility.

But I do feel that there is not going to be enough amplification in what is an enhanced jet stream over the N Atlantic - fuelled by cold over NE USA/E Canada over the next week or two and strong westerly momentum over the Pacific.

However, the state of the stratospheric polar vortex remains intriguing as we head through December, with forecast pulses of poleward wave activity hitting the PV over the next few weeks according to 10hPa wind/height forecasts, so be interesting to see how this impacts the sPV, i.e. displacement later in Dec or SSW in the New Year perhaps.

My reverse psychology by issuing downbeat expectations for blocking yesterday has worked this morning looking at the models! Maybe should have stuck with my post back on Monday (above), perhaps the models are finally picking up on the lag response of a more amplified MJO through 7-8-1 now. 

However, a way to go yet, blocking signal increasing for 2nd week of December for now as TPV to the NW retreats, jet buckles over UK and the Euro trough, but will it position favourably?

At least the 00z EPS and GEFS mean singing from the same hymn sheet at day 10.

Edited December 1, 2018 by Nick F

[JBMWeatherForever]

The ECM starting to look very interesting for the second week in December onwards.  Hopefully the GFS will start getting into a Christmassy mood shortly,I think it might. Then we may well be staring down the barrel of a mid December direct hit from the "Beast from the East" !   Its December so, put up the tree - check, make my first mince pies - check, write to Santa - check.  Dear Santa, please can we have some Narnia scenes delivered to the UK before Christmas !   

[Stuie]

Well hello ECM, this is much more like it.

 

[Johnp]

2 minutes ago, JBMWeatherForever said:

The ECM starting to look very interesting for the second week in December onwards.  Hopefully the GFS will start getting into a Christmassy mood shortly,I think it might. Then we may well be staring down the barrel of a mid December direct hit from the "Beast from the East" !   Its December so, put up the tree - check, make my first mince pies - check, write to Santa - check.  Dear Santa, please can we have some Narnia scenes delivered to the UK before Christmas !   

Agreed - I'd settle for a mild January and February if it meant a week of snow either side of Christmas.

[johnholmes]

Most of you will like what the 500 mb EC-GFS shows this morning, especially the EC. Both have increased the +ve heights and ridging towards Greenland with a flow N of W into the UK  and on into the marked trough/cut off low each shows over Europe. It remians to be seen if NOAA this evening also goes along similar lines which it showed last evening.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

[BlueHedgehog074]

1 hour ago, I remember Atlantic 252 said:

in their pits, but thought EC would liven forum up

Looks like this morning’s 00Z GEM run may just do the same thing too.

Swiftly develops amplification in the Atlantic towards the end of the run with the Western UK High getting sucked up North. Colder air draining down from the North and North-East with the Atlantic terminated. Looks like the amplified High Pressure system may poke its way towards Scandinavia if the run was to go out any further.

Still may be worth keeping the sledge locked away in the shed (or wherever it’s kept) for now until confidence increase further regarding this sort of set up. Not bad anyway. 

[Stuie]

GEFS seems to be on the same page around week 2 too. An exciting pattern evolving.

 

Edited December 1, 2018 by Stuie W

[Methuselah]

Blimey peeps! What a turnaround, since this time yesterday!

[carinthian]

15 hours ago, carinthian said:

Another run and the developing Scandinavian Block comes back on the scene again. Each time it brings it a little nearer to a more liable time frame. Maybe it will be dropped again in consequent runs but it is a reappearing theme. You may have noticed in the above post , the forecast of the  important 300mb jet has been all over the place in the period 10- 15 days, varying from full on Atlantic zonal  to being split to pieces as shown on this latest run. No wonder models are all over the place at the moment but something must be stirring to keep showing these charts to flip -AO in a instant. All very interesting. In the short term the wave track still not settled for early next week, UKMO moves its a little further north but could easily take a route into the continent. Our outer perimeter snow model does have some snow on its northern edge for a while, especially over high ground , maybe from the borders to the North Midlands but this will change on a hourly basis. Have a good weekend ,out on the slopes tomorrow!

C

Morning all, a visit to the refreshment hutte along the Advent Path. Hot Gluewein and the sweet smell of oranges and cinnamon. You just know Christmas time has arrived. First day of our new ski -season today, so excited about that. Regarding the models another step in the right direction with some kind of agreement with ECM and GFS for blocking to develop. The GEFS control model below out at 192t brings this develop a little bit closer with each run. You would expect the trough out east to sharpen into a long wave pattern out to period 240t with a switch to a NEly flow into the British Isles. We will have to wait for further consistency and the support from other models including the UKMO  before  we can confidently predict a more sustained cold spell to develop, but a big step in the right direction this morning. Our own singular model has consistently shown this development for some time now  in the Medium to long range forecast. I will get an update from them on Monday morning to see if they still hold to this line of thought but in the meantime going to get my skis out and see if my body is still in sync with them !

[Summer Sun]

The ECM mean and op are all over the place after Tuesday. The general trend is down after the 7th it's just how low the means peaks at -3 on the 850's whereas the op is peaking around -7c