Model Output Discussion - 8th - 14th January

[ITSY]

Let's see what the next few days bring first - I suspect it will indeed be so close so far, given the projected power of the Atlantic, but let's wait and see before reaching for pills or sledges!

[Harsh Climate]

I think before we get any real deep cold it will take 2 or even 3 bites at the cherry. I just can't see the perfect scandinavian high setting up in one go and with full force . Like many have said, we need that PV to weaken over greenland or move out of the way first. I think that's a real possibility now though, I think the atlantic's attempts to push in will only aid in weakening the PV! I think at some stage we will end up with a chart like this:

Note the high over the Uk, with what appears like all the cold air going south of us. I think as lows try and make inroads into this high they will get sheared off north towards greenland dragging up yet more WAA into the troublesome weakening or already destroyed PV over greenland. This would be then all that's needed to allow heights to build and that region. If so we could then very easily end up with a chart like this:

And with then all the ingredients firmly in place, I think it could then be a februrary to remember

Just like to add, only 2 days ago we were starring into the abyss, bartless, endless mild south westerlies then BOOM!.. out of nowhere we have charts that the experts can really stick their teeth into. Just goes to show how dramatically the models can change.

Edited January 8, 2012 by Harsh Climate

[ITSY]

Edit: differences present by +102, with scandi low further south and slightly less clear WAA? Not sure on impact - heights over Greenland aren't as strong (10mbs less in fact) 4 days out

[bluearmy]

looking at the naefs 00z update and the parallel gefs, it appears to me that the naefs shown on meteociel are using the parallel gefs for their input. anyway, the model has a large clustering of low heights over the uk days 8 thru 10. potentially stormy and potentially very snowy across scotland.

variation on a theme with the 06z. less WAA from the atlantic trough disruption but a better build of heights to the northeast from the arctic high influence. will be interesting nevertheless to see if we can get to a cold solution via a different route.

[ITSY]

Impossible to know where this run is going - some elements seem favourable others fustratingly not so!

[stewfox]

Just like to add, only 2 days ago we were starring into the abyss, bartless, endless mild south westerlies then BOOM!.. out of nowhere we have charts that the experts can really stick their teeth into. Just goes to show how dramatically the models can change.

Actually 2 days ago most people were talking about a pattern change, but the only short range model support was a few ensemble members showing cold outliers.

Many had written of January.

I think it was JH said pattern changes can and often do happen quickly.

Regardless of what the current pattern change brings I'm delighted to see a potential quick turn around.

The day one can say the next 4 weeks are nailed come back early February will be a sad day for model watching.

Edited January 8, 2012 by stewfox

[Buzz]

Impossible to know where this run is going - some elements seem favourable others fustratingly not so!

No need to analyse every little change as every run WILL be different. Just look at the general pattern and, dare I say it, the 'trend'.

[ITSY]

Takes us to spaghetti junction again - the low in the mid Atlantic could be crucial - if it prevents the HP to the south taking over. As buzz said, one run and roughly the same sort of theme so far - still p

[kev238]

Clearly there is more potential than there has been for weeks just looking at the charts in the range 144- 216 hrs. However, there is far from cross model agreement and I always think that there is a need to see the great charts on the ukmo 144 and lower in order to start to believe it!

The gfs 6z shows a near miss but the gfs often overdoes the jet at that sort of range so there is still a trend of blocking to the North East. However any mentions of Jan 87 or feb 86 (which were mentioned yesterday by some respected posters) look very premature at this stage!

[SP1986]

Anyone got an emotion defibrillator?

One thing that strikes me is initially the jet isn't just going to lie down and whimper.. I'd be surprised if anyone thought it was just going to give up. I agree with the assessment that it will need two or three bites in order to undergo transformation to the pattern change.

[kold weather]

The jet does look quite strong still on the GFS, however I'm also wary that the GFS has a habit of overdoing the jet sometimes in these set-ups.

Take the 06z at face value and FI is actually fairly mild bar a very brief NW intrusion, so hopefully it won't be a case of decent synoptics being overwhelmed by other factors.

ECM is a wonderful run though with regards to that, i'm not sure it has all that much support at the moment and my gut feeling is its too progressive.

[mcweather]

Anyone got an emotion defibrillator?

One thing that strikes me is initially the jet isn't just going to lie down and whimper.. I'd be surprised if anyone thought it was just going to give up. I agree with the assessment that it will need two or three bites in order to undergo transformation to the pattern change.

I would agree with this too SP after the coming week of mild is out of the way. I see a number of attacks from both the east and the north taking us to a colder regime.

[kold weather]

The emergence of a possible Arctic High is a foe not a friend.

Thats a mad statement, the reason why the models don't give us any cold is simply because the jet is too strong. With this set-up it really could go either way, I've seen it both come off in the past but I've also seen other times where the jet was just too strong and prevented any cold air bleeding into our part of Europe.

What i will say is some of these ensemble members and indeed some operational runs are living in lalaland still...until they get a PROPER grip on the AO, then they can be ruled out...I said this a few days and whilst they are improving in that respect I still don't feel they are getting really to grips with the situation. I'm not saying the vortex will die away, I suspect it'll remain for a little bit yet, but some ensembles still keep the AO positive!! Somehow!

[shedhead]

Thats a mad statement, the reason why the models don't give us any cold is simply because the jet is too strong. With this set-up it really could go either way, I've seen it both come off in the past but I've also seen other times where the jet was just too strong and prevented any cold air bleeding into our part of Europe.

What i will say is some of these ensemble members and indeed some operational runs are living in lalaland still...until they get a PROPER grip on the AO, then they can be ruled out...I said this a few days and whilst they are improving in that respect I still don't feel they are getting really to grips with the situation. I'm not saying the vortex will die away, I suspect it'll remain for a little bit yet, but some ensembles still keep the AO positive!! Somehow!

Think you need to read this page Nick, you are getting a bit confused about who said what.

[Nick F]

I think the crucial point to where we go mid-Jan onwards is around t+144, there is some uncertainty to how the amplifying trough arriving to the west of the UK next w/e disrupts. ECM has a much more -ve tilt to the trough than GFS as it arrives to the west, with less energy behind it, so this allows a mid-latitude high to build in behind the the cut-off trough which ejects SE across SW Europe and merges with low pressure over the Med.

We need to see much less energy in the jet behind this trough arriving next weekend, for any chance of a cold easterly. Even ECM is close but no cigar with the deep cold which floods SW rather than west across Europe, though obviously we don't know how this new development will evolve yet for a few days at least, so potential for things to evolve more favourably.

[BLAST FROM THE PAST]

Very interesting to see 498dm thickness values moving into E Europe on todays' GFS end-of-run, must be the first time this winter. After weeks of persistent zonality it begs the question as to why it is now taking this trend. Such a scenario would quite probably drag very cold air towards us if it happened.

Interesting too is the ECM's HP over Scandinavia in 10 days, again something of a departure from previous days' runs.

Meanwhile, a few quiet days make a welcome change - the model output give weak fronts within the HP so little chance of clearer air from the near continent to give any cold nights.

Hi OMM

A quiet few days weatherwise, not on here if the model output remains on same path. The models as predicted chomping at the bit this weekend to show cold solutions. ECM now 'suddenly' quickly brings the cold set up as close T168 but the 2-3 days before this scenario is already in the pipeline. I said 2days ago that in a day or two I wouldn't be surprised to see the cold set up suddenly appear at T144, well almost its t168.

You asked/mentioned why models are now 'suddenly' picked this view/trend up, I have my views and indeed RJS predicted this....we're not there yet but huge improvement, but I go back to posts saying that the PV will be really hard to breakdown. Well if there are forces/influences timed not to break it down until approaching mid Jan, and we see it collapsing before our eye...is it really hard to break down? Or were there just no 'forces' at all into place to make any real atttempt until now and it never really was due to change until now? What I'm saying is take RJS theory, if it doesn't break down, move , split as aroungd his timings or of course GPs method then maybe yes its hard to breakdown.

Looking NE as the initial thrust looks good at this stage and I would put a good easterly outbreak as having every chance of coming ofsecond half of this month...remember folks my post that I promised by 6 year old we'll be getting snow come mid Jan period.....I have to keep my promise :smilz38:

It is good that we see a continued theme on the 00z models, I agree that we need UKMO on board as Nick S pointed out and maybe in a 2 days we will if that T168 of ECM comes to the t120/144 range.

For me the LP coming off Newfoundland and its track/trajectory is crucial as this 06z goes on to show compared to the 00z, inasmuch how quickly or not the cold set up digs in.

BFTP

Edited January 8, 2012 by BLAST FROM THE PAST

[SP1986]

Fred, is the PV breaking down though? possibly, but I see it like this, if you shoot a lazer at an asteroid, it breaks into pieces, how do you know one isn't heading in the wrong direction? The PV could set up in an equally as frustrating place.

I don't think it will per se, but you do have to exhaust every possible outcome of course.

It is more likely that something colder will emerge but nothing can be discounted at this stage.

(ps I like my fence)

[chionomaniac]

Thought I had just logged on to a bookmakers forum.

All bets off please.

Back to discussing the models. Thanks.

[BLAST FROM THE PAST]

Anyone got an emotion defibrillator?

One thing that strikes me is initially the jet isn't just going to lie down and whimper.. I'd be surprised if anyone thought it was just going to give up. I agree with the assessment that it will need two or three bites in order to undergo transformation to the pattern change.

Not necessarily an issue if it tracks further and further south, but next week its weaker and for GFS to fire it up again like 06z I'd be wary of. Having said that is this 06z considerably improved on yesterday's 06z ? I can't remember seeing it.

BFTP

Fred, is the PV breaking down though? possibly, but I see it like this, if you shoot a lazer at an asteroid, it breaks into pieces, how do you know one isn't heading in the wrong direction? The PV could set up in an equally as frustrating place.

I don't think it will per se, but you do have to exhaust every possible outcome of course.

It is more likely that something colder will emerge but nothing can be discounted at this stage.

(ps I like my fence)

So true, and should be caveated.

BFTP

Edited January 8, 2012 by BLAST FROM THE PAST

[Osbourne One-Nil]

A lot of posts have been better suited to the new Model Mood Thread, and have been moved there, allowing this to be used for actual model discussion. Please make an effort to use the right thread.

[Radiating Dendrite]

Nice to see the buzz back in this thread. If (IF) we do get an easterley, is this a pattern that could sustain itself, or would it more likely just be a cold blast as opposed to a cold spell?

With the PV also becomming less active in Feb anyway (normally) I imagine the ssw event could rip it apart? Would this then slow the jet or is this independent of the pv?

[SP1986]

Do we have a like for like model checker? I know we have the ability to see all the days runs, it would be handy to have yesterdays run too I agree.

As I remember I think yesterdays 6z run was flat compared to today, so it is marginally more favourable for the pattern change?

[gottolovethisweather]

For me the LP coming off Newfoundland and its track/trajectory is crucial as this 06z goes on to show compared to the 00z, inasmuch how quickly or not the cold set up digs in.

BFTP

Hi Blast,

What track would be most favourable for this low to enable a good result for coldies? Also, with other pieces of the weather puzzle fitting together, where in your opinion would the next attack of cold come from?

Questions, questions.

Cheers

gottolovethisweather

Edited January 8, 2012 by gottolovethisweather

[J10]

Do we have a like for like model checker? I know we have the ability to see all the days runs, it would be handy to have yesterdays run too I agree.

As I remember I think yesterdays 6z run was flat compared to today, so it is marginally more favourable for the pattern change?

Net Weather has got a 7 day history - so if we take 500HPa as an example.

For T+162. (To Next Sunday 00:00)

GFS

http://nwstatic.co.u...162/h500slp.png (06Hz today)

http://nwstatic.co.u...168/h500slp.png (00Hz today)

http://nwstatic.co.u...174/h500slp.png (18Hz yesterday)

http://nwstatic.co.u...180/h500slp.png (12Hz yesterday)

ECM

http://nwstatic.co.u.../ecm500.168.png (00Hz today)

http://nwstatic.co.u.../ecm500.168.png (12Hz yesterday)

[SP1986]

The 6z ensembles a little milder than previous attempts, however much less consistent too, with much disagreement between the members.

However the peaking a troughing nature of the ensembles suggests that the Atlantic stays in charge, with cold and warm sectors frequently moving across the UK.

There's nothing much we can gleen from the ensembles though this morning.

ps Thank you Julian.