Model output discussion 25th Jan - The final third of winter beckons..

[Ali1977]

Mean ECM art 144 is v good

168 still v good 

And 192 deserves a BOOOM

And would you believe it - ECM op is a warm outlier...awesome

its time this cold spell got a METO mention with some conviction maybe. 

Edited February 3, 2017 by Ali1977

[Allseasons-Si]

And still good at 240

6-10 and 8-14 dayers from NOAA

oh!,yes please

Edited February 3, 2017 by Allseasons-si

[Newberryone]

Easily said I admit, but my recent OTT statement re Feb 1st in relation to season change was only a desperate attempt or indeed classic eg of reverse psychology. Looking at the 12z's I think it may not have been in vain, except that begrudgingly I also have to admit, as in times past, that with these kind of synoptics the best we in Ireland can expect are those infamous leftover scraps. 

[ANYWEATHER]

Anyone throwing the towel in a few days ago as regards some decent wintry weather for the Uk may want to get the towel back out! Decent  agreement on gfs and ecm from  next week that we get an easterly Super Charged with cold. Lots of questions from there on but after all the let downs this Winter I should imagine we are in for at least a shout  ,after all we deserve it! The Easterly is coming in ....How much it effects us is still up to the jury

[nick sussex]

I think the ECM ensembles show how volatile the outputs are re that cold pool. Looking at the spreads that shows a cluster running sw into the UK and the 850s show that the GEM might not be going mad.

 I think we need to see a shift in the GFS18hrs run to give us more hope for tomorrows in terms of that deeper cold pool.

Edited February 3, 2017 by nick sussex

[Ali1977]

Well with those means I wouldn't be surprised if there's a few runs that mirror or are v close to the GEM, clusters would be great to see. Bluearmy, have you just broke that fence you were sat on - or am I being a bit to confident?

Moving abroad to the med with work next 3 years so this is last chance saloon territory!! Hopefully the Solar minimum is still here Winter 20/21!!

[bluearmy]

Pretty amazing to see a distinct upper cold pool on the eps mean at day 6 heading this way (those colder Dutch clusters reflect that I guess)

the spreads support a fairly strong push from the east days 6 through 9 and I suspect someone will tweet about the clusters later 

now I'm getting interested as the near term continues to tease re snow potential though the longer term looks like it could go MLB although possible that lobe  hanging in Russia could feed into the circulation. 

Edited February 3, 2017 by bluearmy

[Frosty.]

10 minutes ago, Ali1977 said:

Mean ECM art 144 is v good

168 still v good 

And 192 deserves a BOOOM

And would you believe it - ECM op is a warm outlier...awesome

its time this cold spell got a METO mention with some conviction maybe. 

Stunning Ecm 12z ens mean, even better than the 00z which in itself was excellent! This could be a better cold spell than some think!

[Singularity]

1 minute ago, nick sussex said:

I think the ECM ensembles show how volatile the outputs are re that cold pool. Looking at the spreads that shows a cluster running sw into the U.K. and the 850s show that the GEM might not be going mad.

It hasn't escaped my notice that the models have in general become more marginal i.e. unconvincing with the interaction of that seconday low with the main vortex lobe over W Asia.

Its surely too much to reasonably hope for, but at least history tells us it can happen... but very, very rarely!

[Duane S.]

7 minutes ago, Newberryone said:

Easily said I admit, but my recent OTT statement re Feb 1st in relation to season change was only a desperate attempt or indeed classic eg of reverse psychology. Looking at the 12z's I think it may not have been in vain, except that begrudgingly I also have to admit, as in times past, that with these kind of synoptics the best we in Ireland can expect are those infamous leftover scraps. 

This is best chance of a decent Easterly for years. Of course, plenty can (and dare I say, probably will) go wrong but on the flip side, there is, albeit very much an outside, chance of a GEM esque outcome here. The ECM will do.

Also, Dublin can do very well from an Easterly.

[Jason M]

Must admit that I feared the worst when I saw the GFS this evening. Not that it was terrible of itself, more the trend towards a MLB. With GEM, ECM, JMA and the means quoted the trend has reversed somewhat. You can't ignore any model at days 4-6 (except NAVGEM).

Want to see a good pub run and a decent set of runs in the morning before I buy into this though. I still have that nagging MLB doubt though.

 

[Allseasons-Si]

Yes better mean and op on the 12z ecm compared to the 00z

 

[Bobafet]

May I take this opportunity to thank the countless posters who take the time to explain and help newbies like myself to have a better understanding and things to look out for with regards the weather charts.

My take on things is that I believe we could be on the cusp of some very welcome wintry weather and it is nice to see charts looking this promising.

@nicksussex any chance of some of your scores out of 10 for each model, certainly enjoy reading these when you do them.

keep up the good work all!

[Stozzy]

best ecm mean of the season ? Defo . Let's hope the ecm 0z turns  into the gem 12z with the monster cold pool 

[Man With Beard]

1 hour ago, -uksnow- said:

UKMO @168 - Also a corker, low off the NW corner of spain, further east than the ECM so less chance of it swinging down to the azores a la ECM at 192, thus propping up our high.

 

 

Now something to watch for here, something that has not been modelled yet, I think.

What normally happens to Iberian troughs in the end? They normally try to lift out, and often in our direction.

I've seen many models over the years try to keep an Iberian low in situ once FI appears - but so often it ends up coming our way instead. Not normally when cold snow is involved, which is why it may have escaped some attention.

Indeed, this is way that 1991 got very snowy.

Edited February 3, 2017 by Man With Beard

[Allseasons-Si]

8 minutes ago, Man With Beard said:

Now something to watch for here, something that has not been modelled yet, I think.

What normally happens to Iberian troughs in the end? They normally try to lift out, and often in our direction.

I've seen many models over the years try to keep an Iberian low in situ once FI appears - but so often it ends up coming our way instead. Not normally when cold snow is involved, which is why it may have escaped some attention.

Not in summer lol

it is a good point though but if the hp cell to the N/NE is strong enough then it should be kept supressed to our south,what some people have mentioned though already is on the eastern flank of this low might pump warmer air northwards out of the med,one blip to watch and doesn't come off.

Edited February 3, 2017 by Allseasons-si

[winterof79]

[Allseasons-Si]

Latest fron across the channel and i like it...A LOT,look at the solid spread on the easterlies,boom

[PersianPaladin]

T144 to T168 on the GFS gives a demonstration of the balancing-act required for the Atlantic jet-stream. We need enough amplification northward in the right location; albeit too much energy either way - and we cause an unstable ridge-trough pattern that simply won't hold our easterly synoptics in place. The short-wave circulation near northern Spain developing on the GFS in the medium time-frame originates as a break-away from an upper level trough (cold pool) near Greenland that lingers around for too long. We want it to displace much quicker to allow a more clean development of heights to our north. Given the lack of WAA in the Greenland-sector of the tropospheric vortex (though there is some ridging northward on both the GFS and ECM, but transitory) - whatever Easterly that does develop threatens to be a very short-lived affair. Forecasting the morphology and position of the PV is a global problem, and so neither the GFS and ECM are superior in this regard. Let's hope that should we get a Scandi-high established with a dry easterly, that eventually it holds for long enough while upstream conditions change and become less mobile.

Edited February 3, 2017 by PersianPaladin

[SMU]

13 minutes ago, Allseasons-si said:

Latest fron across the channel and i like it...A LOT,look at the solid spread on the easterlies,boom

Notice a few GEM runs in there ( middle graph ) sub -20 Dewpoints .....

more clustering towards those than the Op !!

[Summer Sun]

Looking at the ECM ens for London the 850's on the Op were on the warmer side of the mean

Pressure should begin to rise from around mid week

[nick sussex]

29 minutes ago, Boba fett said:

May I take this opportunity to thank the countless posters who take the time to explain and help newbies like myself to have a better understanding and things to look out for with regards the weather charts.

My take on things is that I believe we could be on the cusp of some very welcome wintry weather and it is nice to see charts looking this promising.

@nicksussex any chance of some of your scores out of 10 for each model, certainly enjoy reading these when you do them.

keep up the good work all!

Lol! In recent winters I had to discontinue them otherwise I would have bored people with constant zeros! I think taking a blended look at the outputs only upto day ten overall a 7/10, that goes up to 8 if we get the GEM cold pool and 8.5 if we see low pressure developing in the med.

This may sound a bit stingy but I'm looking for the models to try and force me to increase that!

To get to 9/10 that would mean a very high chance of UK wide snow and ice days over a large part of the country, 10/10 would need something sensational so a bit like SCD that only happens for a perfect Argentinian tango or in weather terms ice forming on the beaches and parts of rivers freezing up! lol

Edited February 3, 2017 by nick sussex

[Seasonality]

38 minutes ago, Ali1977 said:

Mean ECM art 144 is v good

168 still v good 

And 192 deserves a BOOOM

And would you believe it - ECM op is a warm outlier...awesome

its time this cold spell got a METO mention with some conviction maybe. 

Edited original post for ease of scrolling. Everything you say is correct. If it verified as modelled then it is indeed an excellent run for UK cold fans. People need to be realistic. The UK is not Siberia or even comparitively milder central Europe. Very nice result for the last stop to easterly cold central (apologies to the klf for shameless paraphrasing)

[chionomaniac]

I haven't been able to post much this week but I have been keeping a continual eye on the models. The wave 2 split in the vortex modelled initially last week has been reduced in intensity and hence we have seen fluctuations in the intensity of the Atlantic inroads. But crucially it is still there and is very much trop based so it is unlikely to disappear from the models. A week on from this being initially modelled and we are closer to achieving a classic easterly - it may or may not occur but we are still very much in the game. Spotting a split that upwells into the stratosphere gives us an opportunity to predict this type of scenario well before it is modelled in the troposphere so if anything can be learnt at this point it is to keep a constant look out for this type of scenario.

I still think that there is a good chance of special synoptics that we don't see too often - we still have the tickets for that once in a while lottery.

[Hammer50]

Bbc saying it might get cold but dry or it could be wet but mild.next week.