Focussed Model Discussion

[Singularity]

I’m not going to lie; there’s some weird things going on with the models at the mo. Tropical signals apparently improve yet wave pattern trends go the other way - go figure!

It’d be quite something, regardless, for disturbances across the US to interact in the most problematic way twice in the pace of a fortnight... so we’ll see on that. It’s the apparently nonsensical broader scale patterns that bug me more at the mo. What’s missing, and is it in the teleconnection science or the NWP modelling?

[WhiteFox]

1 hour ago, IDO said:

A lot of the experts viz background signals are suggesting from late Jan the MJO will help with a Pacific wave. The mean above is, in fact, contrary, with a Pacific Trough. The GEFS have been picking this up for a day or so and bringing it forward and more defined. We wait to see if other models change their MJO signal.

It's all a bit muddy right?

The trade winds burst has eased through and it looks like forecasts for MJO progress further through phase 6 and on towards phase 7 than was the case a few days ago. Possibly leading to more of an EN rather than LN imprint over the Pacific and PNA? 

Increase in Frictional and Mountain Torque also may help to shift pattern somewhat. Been trying to get to grips with this with Tamara's assistance, so hopefully starting to get a bit more idea on what on earth it all means!

In which case, suggestive of blocking possible to NE at some stage, especially if MJO can continue at a decent amplitude to phase 7. Of course, a lot depends on how the PV lobe over Canada behaves and further impacts of SSW...

A waiting game, but hopefully it won't take until the tail end of February!

[kold weather]

12 minutes ago, Singularity said:

I’m not going to lie; there’s some weird things going on with the models at the mo. Tropical signals apparently improve yet wave pattern trends go the other way - go figure!

It’d be quite something, regardless, for disturbances across the US to interact in the most problematic way twice in the pace of a fortnight... so we’ll see on that. It’s the apparently nonsensical broader scale patterns that bug me more at the mo. What’s missing, and is it in the teleconnection science or the NWP modelling?

I know, we would be mad crazy unlucky for it to go wrong again, and yet the models are all lining up in a row now and I'd say its odds on now, despite what the tropical forcing suggests.

I know one of the mets on an American forum says that ones of the most stubborn and potent PV lobes he has ever seen, its even too strong for them and suppressing everything too far away for them! I wonder if its just a little well entrenched and with the ENSO signal basically flatling there isn't really anything post SSW to shift the pattern that becomes established, especially as the troposphere response has thus far been pretty piddly.

Just can't shif the pattern and that vortex is locked in place more or less.

Also, the Arctic forecast has gone right down the pan as well recently, the upper high not making any near as much inroads.

Edited January 23, 2019 by kold weather

[WhiteFox]

3 minutes ago, kold weather said:

 

Also, the Arctic forecast has gone right down the pan as well recently, the upper high not making any near as much inroads.

Yes, that really stands out. The models keep showing a negative AO on the cards, yet it keeps failing. All lessons for future events I guess!

[chris55]

I guess it’s sensible to take output in the mid term (120+) with an open minded approach. 

Many options on the table (as is normal) but with the current synoptic pattern ,well away from our normal prevailing westerly/zonal flow,  and with the SSW influence ,the models will not necessarily pick out the correct solution as we head into each individual model run.

Lots of options available, nothing set in stone.

should prove for some excellent discussion in the coming weeks.  

 

[Stu_London]

Been a similar theme for much of this month.

Just too much energy blowing up at short notice - so whilst the 7-10 day charts have been amazing - they have largely collapsed when entering into the reliable 72-96 period. Add to that that actual heights in the arctic have rarely delivered even at quite short notice and it becomes easy to see why the whole process has been so frustrating for cold/snow hunters.

Not that surprising when you consider that January's have been quite zonal in most recent years. 

I think we will get a decent cold spell on the back of the SSW but for my money it will be probably early to mid February, when historically there is less energy from the northern hemisphere oceans.

 

[bluearmy]

Is that ecm op showing the sudden slowing of the trop zonal flow ?  We had a big spread to the west on the 00z run but that op stops the trough sharply .....

Ens out now ......not sure they will elicit a good response as mean looks very op like with that troughing ....

[ICE COLD]

4 minutes ago, bluearmy said:

Is that ecm op showing the sudden slowing of the trop zonal flow ?  We had a big spread to the west on the 00z run but that op stops the trough sharply .....

Ens out now ......not sure they will elicit a good response as mean looks very op like with that troughing ....

The mean is definitely better than the op tho Nick. 

Here is Day 9 and 10 

No SW mild there . 

Edited January 23, 2019 by ICE COLD

[knocker]

The ecm has an interesting complex scenario at T144 this evening  as it develops waves on the front as the upper trough slips down over the UK Temps are only around the 2-3C range so a rain, sleet and snow outcome is on the cards next Tuesday. This quickly clears to the east with another upper low established in the eastern Med and the next Atlantic trough runs south east to the west of Ireland  And from this point the trough  is subject to the double whammy of high pressure amplifying to the west and east which does initiate some WAA from the south west

[ICE COLD]

The down side to the ECM mean at T240 is all the cold is gone from Europe. 

[Frosty.]

Sigh of relief! tonight's Ecm 12z ensemble mean is colder longer term compared to the operational which was utter garbage longer term!

[Mike Poole]

Whilst the ECM mean at T216 looks quite promising I agree:

I think it may mask a wider malaise, we know from the Berlin charts at the same time, although yesterday's ECM 12z, that there are net easterly winds at various levels in the troposphere from the strat downwelling.

But that chart doesn't tell you where they are, the ECM mean chart does, they are on the other side of the NH with that arctic high, we may have some work to do to get some of that action this side.

 

Edited January 23, 2019 by Mike Poole

[Skullzrulerz]

ECM till FI is a lot better before you know what it goes crazy and then brings in milder air 

Through the mean is also good but as said not much cold air around Europe if to tap into

 

[bluearmy]

16 minutes ago, ICE COLD said:

The mean is definitely better than the op tho Nick. 

Here is Day 9 and 10 

No SW mild there . 

The mean hides the spreads and the spreads say ......some quite different clusters with quite differing consequences ......

need the op to jump to a more undercutting cluster tomorrow ....the extended ens smell sliders  though not clear where across the uk they would slide  

[snowray]

JMA looking great tonight at D8.

 

Still no consistency in the models although looking generally cold with some snow chances for most of us.

No deep freeze though, just yet.

[stodge]

Just now, bluearmy said:

The mean hides the spreads and the spreads say ......some quite different clusters with quite differing consequences ......

need the op to jump to a more undercutting cluster tomorrow ....the extended ens smell sliders  though not clear where across the uk they would slide  

We had some very good ECM ENS last night - the Control run being a very good example.

I don't share Kold Weather's extraordinarily downbeat analysis at this time - we need far more evidence over the next two or three days.

My take on the ECM 12Z OP, which is nowhere near as bad as is being portrayed, is it's a positive sign of a slowing Atlantic and it's worth noting the rise in heights to the NE over Finland indicative perhaps of the continental block pushing back against an amplified Atlantic which is a typical February situation when the Atlantic slows.

[kumquat]

Disappointing last frames on the ECM tonight. Not surprising to see such model volatility, however, considering the background signals.

The Devil is in the detail:

[kumquat]

3 minutes ago, Lloyds32 said:

What are the background signals

The somewhat erratic/delayed response to the effects of the SSW

[IDO]

 

[stodge]

Just to add to my previous, having skimmed the ECM members, there's a strong and perhaps growing signal for a substantial block to the NE out the Day 10-12 range. This is picked up by the 12Z OP and suggests to this observer the Atlantic could face a growing block to the east.

What that might mean is a milder interlude followed by a battleground as the east block pushes the Atlantic back west.

One to watch for fans of cold and not to get too upset by the odd milder chart.

[Flash bang flash bang etc]

Anyone heard anything about a possible medicane/cyclone occurring?

Theres a bit of a low over the Balearics at the moment and I saw ‘posible medicane’ on a Greek website link just now. Made me curious...

[Flash bang flash bang etc]

https://www.tiempo.com/ram/498791/posible-medicane-mediterraneo-central-jueves-24-de-enero-de-2019/

(haven’t tried to translate so apologies if it’s just someone taking about their Xmas holidays )

[winterof79]

The over riding signal is for an Arctic High to push in from the Pacific side

Where we go from there is up for grabs but we will be cold

Edited January 23, 2019 by winterof79

[bluearmy]

8 minutes ago, stodge said:

Just to add to my previous, having skimmed the ECM members, there's a strong and perhaps growing signal for a substantial block to the NE out the Day 10-12 range. This is picked up by the 12Z OP and suggests to this observer the Atlantic could face a growing block to the east.

What that might mean is a milder interlude followed by a battleground as the east block pushes the Atlantic back west.

One to watch for fans of cold and not to get too upset by the odd milder chart.

It’s the growing trend on the eps mean ......

[ANYWEATHER]

Evening as someone in a previous posted an undulating jet stream will confuse computer models.. The weekend is still in question....?