Model Output Discussion - 10th Jan Onwards

[somersetsnow]

I'm trying to remain as reserved as possible here re any colder weather because we've all been put through the mill over the last week. But the early timeframe here is so crucial to how the pattern could develop, for newbies I'd advise you to keep a close eye on this area circled red:

 

ECH1-96.gif

 

As you can see on this chart you've got the darker blues , so you lose some of the forcing on the low, essentially here we're trying to get that low further south and west.

 

So we would need to see the high further nw and extending a ridge into that area this acts like a weight pressing down on the low and increasing the chance of it disrupting sooner.

 

If you look at those ECM postage stamps you will likely find a strong correlation between where the high is and how it ridges across to that area with the colder outcome, of course we also have upstream changes we'd like to see but in terms of the early part of the outputs that circled red area is certainly very important.

Thank you!!!!!!!!  Had not a clue as to what on earth was going on!!!! Makes sense. Newbie and have been a lurker on here for a few years .

[TSNWK]

Good afternoon folks. I was wondering if anyone had seen the latest Met-office 6d - 15 forecast today, I think it is driven by the MOGREPS model and if so this is our only way of taking a peep into MOGREPS world.

 

Sorry, for the life of me I cannot find it myself.

 

Cheers

[Timmytour]

I'm trying to remain as reserved as possible here re any colder weather because we've all been put through the mill over the last week. But the early timeframe here is so crucial to how the pattern could develop, for newbies I'd advise you to keep a close eye on this area circled red:

 

ECH1-96.gif

 

As you can see on this chart you've got the darker blues , so you lose some of the forcing on the low, essentially here we're trying to get that low further south and west.

 

So we would need to see the high further nw and extending a ridge into that area this acts like a weight pressing down on the low and increasing the chance of it disrupting sooner.

 

If you look at those ECM postage stamps you will likely find a strong correlation between where the high is and how it ridges across to that area with the colder outcome, of course we also have upstream changes we'd like to see but in terms of the early part of the outputs that circled red area is certainly very important.

I'm trying to stay positive Nick, but it's getting to the stage where I look at that chart and all I can see is a cat riding a motorbike while a car passes in the opposite direction.... 

Edited January 13, 2014 by Timmytour

[Bobby]

Good afternoon folks. I was wondering if anyone had seen the latest Met-office 6d - 15 forecast today, I think it is driven by the MOGREPS model and if so this is our only way of taking a peep into MOGREPS world.

 

Sorry, for the life of me I cannot find it myself.

 

Cheers

 

I believe they use a combination of MOGREPS, ECM (and ensembles), UKMO and GloSea5 for those medium range forecasts. Think they have the DECIDER model as well although not sure what that is used for exactly.

[SHM040519]

Lets see what the 12z from the GFS brings today then, further towards ECM? Exciting times ahead 

[Summer Sun]

Latest NAO update shows it will be heading to neutral within the next 3 days or so after which it looks like staying for now

 

 

Latest AO update looks like staying negative

 

[Mucka]

Should be some interest again in this evenings runs then.

Not sure too much emphasis isn't being put on the strength of the PV and lack of amplification as the cause for the demise of the deep cold that was being modelled for around mid month. It seems to me the jet was relatively quiet and southerly that it was simply a case of not getting enough energy under the block which as we can see from the protracted battle for supremacy of air masses in our vicinity was lost by very fine margins.

If it was simply a case of too much energy coming from the Atlantic one would expect the jet to quickly ride north and the block to flatten but what we got was a stalemate with a slow filling trough which fails to split energy and send some SE as was originally modelled. One could argue that the lack of amplification upstream aided this by resupplying the trough with shortwave energy but there is no raging Atlantic here for me causing the blocking to fail - the block is in place.

Of course the less energy coming across the Atlantic the slower and more amplified the pattern is likely to be which would allow blocking to be stronger and become the dominant factor but sometimes the distribution of energy is as important as the amount of energy when determining whether high pressure or low pressure can dictate the pattern and we can not predict that by saying there is X amount of energy in the PV so blocking will fail. If we could we should be working for NASA because these super computers, carrying out millions of computations per second, designed specifically for the job are having a hell of a time with it.

Edited January 13, 2014 by Mucka

[tonbridgemole]

12 GFS low pressure from the north west ?

[MR EXTREMES]

pretty close from the gfs

[nick sussex]

You need that shortwave energy to clear so as not to phase with the approaching low at around T156hrs, there are still differences again between the GFS and the UKMO upstream at T120hrs , the UKMO has that shortwave about to run into the trough, the GFS has already done that about a day earlier.

 

The timing of this is important because the UKMO looks better at T120hrs than the GFS in terms of the troughing but then looks flatter. we certainly don't want a football shaped low over the UK as the low approaches at T144hrs on that.

 

I'm afraid this is going to be yet another model drama, who has the stamina for this after the last week?

[SHM040519]

Can anyone say what's happening on the 12z GFS? Thanks

[Bobby]

How are we going to get the cold from the east to Blighty? Even if we get an easterly of some sort such as what the ECM is showing the cold is too far away and it looks likely westerlies will return eventually anyway. It seems the models are trying to torment us with just enough hints of promise to keep us chasing the carrot, only to keep pulling it away, with the carrot never getting close enough to get really excited about. Hmmph.

I think the GFS 12z is a plausible scenario of what will eventually happen really...

Edited January 13, 2014 by Bobby

[snowbob]

Think I can take another few model teasers yet

One of them is gonna be right at least once this winter

Surely

[mountain shadow]

Can anyone say what's happening on the 12z GFS? Thanks

 

Zonal throughout, temperatures average to slightly below.

 

Any wintryness confined to hills and mountains.

[shetland islands]

From the GFS and to an extend the UKMO provides us with cooler temperatures than of late, although the South looks pretty average. In terms of flow, it looks like any influence from the east will be weak and inaffective in bringing colder weather to the UK. The NE looks like there could be some snow, even at lower leves in N Scotland and Shetland.

[Staffordshire]

The lack of posts says it all really, any cold prospects just a bit 'meh' on both the 12z GFS and UKMO, I still have high hopes for something from mid feb

[Dancerwithwings]

How are we going to get the cold from the east to Blighty? Even if we get an easterly of some sort such as what the ECM is showing the cold is too far away and it looks likely westerlies will return eventually anyway. It seems the models are trying to torment us with just enough hints of [promise to keep us chasing the carrot, only to keep pulling it away, with the carrot never getting close enough to get really excited about. Hmmph.

I lthink the GFS is a plausible scenario of what will eventually happen really...

Lets see what the ECM will do for our appetite for this carrot/Easterly.^^^^ I'm tending to go with you on that one, But then again anything is plausible after 96h

[Summer Sun]

Latest 8 day temperature anomaly from GFS for the majority of England and wales it looks fairly average to marginally above in the south, the far north of England, Scotland (Excluding the NE, western Isles and the Shetlands) , Northern Ireland and Ireland stays slightly below average

 

[snow1975]

Apart from a limpet easterly attempt on the ECM/GFS early next week, the GFS 12Z becomes increasingly zonal in FI. Its IF I know, but it looks increasingly wintry the further north you go with plenty of snow for the ski centres.

 

Edited January 13, 2014 by snow1975

[Ali1977]

Several GEFS ens following this mornings ECM, still can't see it bringing in cold/snow potential even if it happens...we just need to get rid of all the energy over Greenland and the USA, and no model or long term model shows this happening unfortunately.

[Man With Beard]

Not very positive mood on here this afternoon but as long as pressure stays high to the east there's a chance of an easterly at any point beyond T120, no deep cold at the moment but a flow off the continent just needs a few days to get cold atm, as long as it isn't sourced from the med. GFS at T168 just a few hundred miles from getting us on the east of the low. UKMO also on the line at T144. 50/50 the ECM gives us another easterly tonight

[bluearmy]

no comment on the usually 'killjoy' ukmo at day 6 ??? perhaps even more retrogressive than the 00z ecm op at that timescale ?? and as slow upstream aswell.

as far as an easterly is concerned, the issue remains the uppers and the temp on the continent. it takes an enormous leap of faith to imagine the models finding a solution that will advect deep cold uppers this way. by the time they get to the position that its feasible, they have long gone. the north sea is not cold and as such any sea track flow will be modified. we would have to have a continent sub zero for the forecast uppers 0/-3c to deliver freezing daytime temps to here. however, if we get a short sea track, then the dp's would become more relevant than the uppers or even the surface temps. a long sea track would bring those dp's positive. going further into the distance, there will be a new feed of colder uppers into the block and that could advect our way. that a long way from where we are at the moment.

under a slack trough, things could become more interesting than with an easterly flow.

Edited January 13, 2014 by bluearmy

[nick sussex]

no comment on the usually 'killjoy' ukmo at day 6 ??? perhaps even more retrogressive than the 00z ecm op at that timescale ?? and as slow upstream aswell.as far as an easterly is concerned, the issue remains the uppers and the temp on the continent. it takes an enormous leap of faith to imagine the models finding a solution that will advect deep cold uppers this way. by the time they get to the position that its feasible, they have long gone. the north sea is not cold and as such any sea track flow will be modified. we would have to have a continent sub zero for the forecast uppers 0/-3c to deliver freezing daytime temps to here. however, if we get a short sea track, then the dp's would become more relevant than the uppers or even the surface temps. a long sea track would bring those dp's positive. going further into the distance, there will be a new feed of colder uppers into the block and that could advect our way. that a long way from where we are at the moment.under a slack trough, things could become more interesting than with an easterly flow.

I've had another look at the UKMO T144hrs and its a bit better than I first thought, the energy seems to be shearing away to the nw off the troughing and another piece running se into the sw side between 120 and 144hrs, its a shame we don't get the smaller steps rather than the 24hr ones after T72hrs.

Edited January 13, 2014 by nick sussex

[bluearmy]

 

BA do you remember when we had that day when there was a sudden change in the outputs in terms of the high and negative AO going quickly positive and the models really wanted to finish off any lingering hopes of something colder. Any ideas as to what happened, rogue output, poor data inclusion in the Arctic oceans, the models over reacting to an upstream signal?

 it was only yesterday morning nick !! and since that run, the ecm ens have taken it back to the 20th when they go back positive. i really have no idea why that suite was so progressive. incidentally, no appetite from the ecm ens to keep the AO particularly positive for very long.also, wrt to the lower strat zonal winds, looking through the daily berlin output back 10 days, it seems that the model is keen to increase the westerlies late in the run but they dont count down too well. a few day later, by the time we get to day 5/6 (which was the equiv day 9/10), there are blues popping up in the trop so it seems that the strat verification low down is not too good (which sort of makes sense as we are, in effect looking at the operational ecm run at days 7 thru 10 which we know is only 60% accurate at best re trop heights).

[nick sussex]

I can't take anymore ECM!!! lol you can see its high is the most favourably aligned and look towards  Denmark, the trough is beginning to disrupt at T120hrs.

 

In my excitement I got the times wrong its at T96hrs but you can see the difference at T120hrs compared to the other models.

Edited January 13, 2014 by nick sussex