Model Output Discussion - 10th Jan Onwards

[lorenzo]

In relation to the MJO, I have been wondering about the analogs for this over the weekend, and asked about on Twitter re: what we are seeing on the CPC Plots across the models, in terms of how this could aid HLB.

 

From the projections below varying degrees of the MJO in Phase 6 eastward progression from maritimes to West Pacific, the plots then moving in reverse and the MJO signal is lost as it recurves from Phase 7 back to Phase 6 looping towards the origin.

 

ECM / GEFS Control Run / GEFS

 

GFS Op / UKMO Ensemble

 

With respect to the signal, here are a couple of further plots of Kelvin Waves and MJO, with the thoughts being that the signal propagating onto the above plots is more Kelvin Wave oriented than the actual MJO itself, thereby a faster signal for height rises which will in turn decay more quickly. Kelvin waves travelling at twice the speed of the slow moving MJO.

 

The MJO itself looking to put in a re-appearance in the second week of Feb developing over the Indian Ocean - Phases 2-3, so as SSW finalises the timeframe between the initial trop. response and further downwelling will include further model variability and MJO forcing, 

 

The January composite for Phase 6 looks like this.

 

It was really Phase 7 we were looking for !

 

ECM on the AO falling back a little in the 48hrs after spotting the huge negative AO, just to leave us chasing the runs around and wonder about amplification. Also below height anomalies for mid January, just for comparison in a couple of weeks time.

 

And, if that isn't everything to be going on with, GWO heading for another torque event in the latest GEFS.

 

One things for sure model's don't like vortex splits, let alone vortex splits where the whole lot is getting bunched over to the Atlantic, with some questionable tropical forcing mixed in. A right headache of a February forecast..

 

 

 

 

[karlos1983]

In the Style of Barry Scott

Bang and the PV's gone!

[Long haul to mild]

In the Style of Barry ScottBang and the PV's gone!

Think it may have relocated over the top of us, judging by that chart!

[Frosty.]

In the Style of Barry Scott

Bang and the PV's gone!

I feel it's appropriate to have a BOOM 

[karlos1983]

Think it may have relocated over the top of us, judging by that chart!

Indeed, but importantly not over West Greenland/canada. Caveat being it's in deepest fl, but it's there so I'll mention it!

[SMU]

Huge swing to the UKMO in the 06z ENS.

 

S

[Cloud 10]

So then- remember there is usually 1 main trend of the day ( possibly 2)

 

the AM trend is one of moving the UKMO from the 3 runs-

 

GFS from very poor 0z to a mediocre middle ground @ 126 ( correction around 200 miles SW)

http://modeles.meteociel.fr/modeles/gfs/runs/2014011906/gfsnh-0-132.png?6

 

NAVGEM - almost 100% swing with a battleground scenario @ 138- just the uppers not quite as cold ( Correction ~ 600 miles west)

http://modeles.meteociel.fr/modeles/navgem/runs/2014011906/navgemnh-0-138.png?19-11

 

JMA 00z only goes to 84 but looks tasty as well.

http://www.meteociel.fr/modeles/jma/runs/2014011900/JN84-21.GIF?19-0

 

I think we should start concentrating on the 126 timeframe -....

 

S

 

A nice swing towards the UKMO from the gfs 06z ensemble mean compared to the 00z..

 

00z..  06z..

 

 

lol,beaten to it. 

Edited January 19, 2014 by Cloud 10

[Tamara]

 Its usually a good idea in my experience (usually in the morning) to look at the modelling first before reading the comments on here which, totally forgivably, could give one the wrong impression if you hadn't seen it all before

 

First of all, as stated repeatedly over recent days, - the Canadian sector of the vortex remains as ever the conundrum to our downstream pattern. Also, as stated often in recent days there is a programmed change underway over the polar field as pressure rises there for the first time this winter. The balance of the equation lies in how this pressure rise plays out across the arctic and how consequentially we might extract potential (yes that word again! ) amplification from the pattern to be sent downstream to improve the prospects of trough disruption in our atlantic sector.

 

Up to now we are fully aware that there has simply been too much vorticity in association with the upper trough to the NW to allow trough disruption. We see in the shorter term modelling that this process continues further and we should view the UKMO as unlikely this morning.

 

This then takes us to all the uncertainties of the further outlook.... Once more, as often suggested would occur over the last week or so, a further jet streak is consistently programmed to exit from NE Canada and the question continues to be how the models will handle this energy transport based on the omni presence of the heights to the NE and the beginnings of pressure rises over the pole.

 

There continues in my opinion, and meant in the nicest way to be far too much assessment and worry over intra output details and I think it also remains a waiting game with ensemble data too. In the circumstances of the complexity of the pattern and assessing these over at least dual ouput, one set may be skewed too flat and another too amplified. The pendulum of model output swings between both extremes, and taking each at face value leads in my opinion to needless and punch drunk analysis in the current circumstances. Yesterday I mentioned watching the trends over a matter of some days and looking for consistent themes. The details may be changing quite significantly from one output to another (what should we expect!! ) but from what I can see at least, the theme is proving very consistent.

 

A lot of criticism this morning f.e of the ECM  - well here is an example of where it gets assessed in terms of its surface cold potential for the UK in terms of what it shows at face value. The overall theme of the ECM this morning continues the theme of recent outputs (and including in this the much more appealing outputs in terms of surface detail and 'will it snow' in the UK). The sequence of high pressure to the NE, the programme of pressure rising over the pole, and the programmed energy transport from NE Canada are all there as usual. The differences from one another are in terms of the upstream jet stream pattern and how amplified or otherwise this becomes, or perhaps more to the point when this amplification may finally occur in the atlantic sector.

 

Remember, the changes in the vortex profile this winter are not being changed in one fell swoop like more favourable years for cold patterns. I think that, perhaps understandably, there is an expectation from members for this to happen - bearing in mind how poor this winter has been so far

 

I agree totally with a comment made earlier that the changes to overall NH hemisphere pattern, as described, mean that, despite further energy programmed to be sent downstream yet again, the jet patterns have to be different from the first half of the winter bearing in mind the changes we are seeing as described. In this sense there IS a pattern change occuring - I think the semantics of the debate that I see took place over this subject last night is more to do with whether it results in a UK cold spell or otherwise. There are various solutions as ever,  and the very least appealing ones would mean that surface conditions here in the UK might not seem too different from what we have endured. However such unwarranted negativity is as futile and lacking in objectivity as any fantasy cold ramping

 

Its very hard not to keep repeating the same thing really. As far as I am concerned at least, the changes in the pattern are there to be seen, and in terms of future cold potential *she uses the word twice* the prospects remain just the same.

 

I believe that the stratospheric forecasts could still play eventually into our hands. I mentioned yesterday sequential warmings as being the way that the Canadian vortex realistically looks to finally succumb, and this I think will remain the case.  The decaying part of the winter for the polar vortex is never the same year to year, and this year proves one of the hardest to try and begin to calculate.

 

Its worth remembering that programmed ebbs and flows of temperature (in simple terms) in the stratospheric layers can be a good thing, even though we would prefer an SSW detonation to hopefully blast the wretched thing to kingdom come . If it has been stable and cold and hence in a dormant and undisturbed state, then an injection of wave breaking will disturb those layers, and if this is then followed by a pause and then another one, this re-jigs the whole balance of energies once again. In this way, with each warming and each weakening, the faster zonal winds are expelled in phases into the troposphere.

 

We should think of the upcoming energy transport in those terms, and then see how we are placed afterwards. Pressure isn't consistently indicated to rise over the pole for nuffin. It means that that the PV is being overturned..we just have to be prepared for it to be requiring those sequential bites before it finally gives us a break.... I won't use the word Tut***e as I know I will be hung up to dry ..but I will say that there remains a fair bit of January,... and then I get my coat...

 

Edit: 'Patience' has now entered the realms of the swear filter !!

 

Edit 2: Some support for the UKMO evolving would be welcome obviously..maybe *unlikely* is premature

 

Edit 3: Very useful post from lorenzo to factor in

Edited January 19, 2014 by Tamara תָּמָר

[Purga]

A vaguely possible 'blink and you'll miss it' cold blip as the approaching trough moves through against the cold block. This is hinted at by some of the GEFS members

 

 

Also the uncertainty for Friday shown in the ECM ENS (Reading)

After that the 06z run is absolutely dire and offers no cold prospects of any significance right to the end.

Edited January 19, 2014 by Purga

[Frosty.]

One of the many things I loved about GP's posts was the impact of events in other parts of the world and how that would affect the uk, the knock on effect, there is a great big black hole now.

[karlos1983]

Mini ramp from Alex Deakin that cold wether could reach us by the end if the week. More in the weeks forecast at 1:10pm. Might have to watch that. The fact he mentions it, must mean it Carries some weight.?...

[supernova]

Would love to know why Piers Corbyn at Weather Action is saying his Feb 45 day forecast is the most important event since 2010 but I can't bring myself to spend £25 to find out…without being unfair to Mr Corbyn and revealing his forecast or offering anything too specific, does anyone have any idea what he's on about, i.e. is he predicting a particularly snowy month which is, I suppose, my inference due to the 2010 comparison? Piers_Corbyn tweet

BI FEB 45d IS LOADED "WA's most important fcst since Dec 2010"

Differences emerging between the big three even at 72 hrs which only exacerbates over time although this morning's GFS06z is slightly closer to UKMO than last night's run in the shorter term and as a result is less offensive later on, as others have mentioned, although as ever it goes bonkers in low res.

And I know I mentioned this the other day as a result of some interesting posts from Kentish CZ amongst others but there really is, to my eye at least, a remarkable similarity between currently modelled solutions from GFS this morning and what it was saying this time exactly five years ago in 2009 when it modelled an over progressive zonal spread from the middle of Jan onwards only for the Azores high to wash over the UK, join the Scandi high and drag in a slider low which delivered a memorable first week of Feb. Well worth checking out the evolution which started here http://www.meteociel.fr/modeles/gfse_cartes.php?jour=26&mois=1&annee=2009&heure=6&archive=1&mode=0&ech=6&carte=0

See how it models it from this date, Jan 26 2009, then whiz forward to 30 or 31st Jan 2009 on the archive selector and see the difference - incredible.

Sadly can't seem to see the N Hem chart which would be really interesting - can anybody tell me if these archives are available anywhere, there is clearly the development of a Greenland high at some point as the Azores high links to it and puts us in the way of a fearsome north easterly plunge but it's hard to see how this evolves without the NH synoptics to hand?

Edited January 19, 2014 by supernova

[Dancerwithwings]

Mini ramp from Alex Deakin that cold wether could reach us by the end if the week. More in the weeks forecast at 1:10pm. Might have to watch that. The fact he mentions it, must mean it Carries some weight.?...

Tomasz Schafernaker Just said " and colder still as we go into the weekend"

[Froze were the Days]

Mini ramp from Alex Deakin that cold wether could reach us by the end if the week. More in the weeks forecast at 1:10pm. Might have to watch that. The fact he mentions it, must mean it Carries some weight.?...

 

Wouldn't get too carried away by this....they said something similar to this I think last weekend for the around this period, and what has materialized? not a lot.

[johnholmes]

 

 

many thanks for that post Lorenzo, it does look as if the pattern you show as relevant to MJO 6 is the current form horse. Certainly shows that on the anomaly charts. If I was a betting man I would say 70:30 in favour of that rather than the one I suppose most folk on here hope for, phase 7 and its relevant 500mb anomaly idea.

I keep saying it but it is true to anyone who enjoys watching the various models as they try to get a concencus into the realistic time frame of what the surface weather is going to be. I disagree with comments that suggest this or that run is crucial or that time frame is crucial. But do understand what leads to those posts. Keep watching folks it has some way to go before the actual weather will be revealed be it 5 days or 15 days.

[Dancerwithwings]

Wouldn't get too carried away by this....they said something similar to this I think last weekend for the around this period, and what has materialized? not a lot.

Absolutely...... staying with "mini ramp" for now

Edited January 19, 2014 by Dancerwithwings

[Newberryone]

Mini ramp from Alex Deakin that cold wether could reach us by the end if the week. More in the weeks forecast at 1:10pm. Might have to watch that. The fact he mentions it, must mean it Carries some weight.?...

Judging by the latest Ecm I can't see too much to ramp about for it just seems to point to more of the same, rinse and repeat, call it what you will. Cool/cold incursions but certainly nothing sustained 

[itsnowjoke]

Feeling very much like weve skipped a season...surely it wont be like this all Winter will it?

Edited January 19, 2014 by itsnowjoke

[bluearmy]

Tomasz Schafernaker Just said " and colder still as we go into the weekend"

That's interesting in that the London ecm ens show big spread for fri/sat/sun and not that many cold runs. Perhaps they feel 5/6 c with overnight frosts will be subjectively cold this winter!

[karlos1983]

Absolutely...... staying with "mini ramp" for now

Let's not forget the MOGREPS, could it be that....? Maybe Ian will be in and can comment.

As well as the UKMO from 00z and the ENS as mentioned by Steve. So there are signs to say it's certainly a plausible outcome.

Edited January 19, 2014 by karlos1983

[Frosty.]

Lol I thought there was little or no chance of anything even remotely wintry according to some. The plot thickens.

[karlos1983]

The plot thickens.

I will lose the plot soon that's for sure Edited January 19, 2014 by karlos1983

[Geordiesnow]

Lol I thought there was little or no chance of anything even remotely wintry according to some. The plot thickens.

 

Just because it may turn colder(and lets face it, only the UKMO shows this potential) does not mean there be much wintry weather.

 

Personally, the models are ramping up the Atlantic and as far as I can see, the potential for a reletively brief of proper mild TM air via an Azores high is looking more likely. Hopefully the models can trend towards the UKMO and the cold block can influence our weather a little bit more than the GFS/ECM indicates but I really am struggling too see much snow potential on this morning's runs.  

[Purga]

Lol I thought there was little or no chance of anything even remotely wintry according to some. The plot thickens.

it depends on how low you set the bar - LOL!

[Summer Sun]

Possibly some snow mainly in the north for a time later in the week according to the met office today

 

UK Outlook for Friday 24 Jan 2014 to Sunday 2 Feb 2014:

 

A cold start at first, especially in central and eastern areas, with a risk of fog, frost and ice. Rain spreading southeast over much of the UK through Friday however, bringing milder conditions for most, but possibly preceded by snow for a time, mainly in the north. Temperatures initially cold, returning to around normal from the northwest.

 

Its a case now of watching the models and seeing if we get any upgrades for the snow potential further south

Edited January 19, 2014 by Summer Sun