Model Output Discussion 19th January 2014-18z onwards.

[MR EXTREMES]

^{anyone order a jma special}

[fergieweather]

Cheers for that, I just don't see what all the hype was about tonight, the current models look very average on the whole with the real cold too far east, we get rain and a bit of wet hill snow. More flooding looks likely than anything else in the next 7-10 days.

...and yet we have UKMO just now describing early next week as "stormy"; noting how any low as per ENS in N Sea could yield "considerable disruption" to coastal fringes; plus how even EC's westerly flow looks "unusually cold for the direction... bringing higher risk of ice/snow than would be normal (from that direction) in late Jan/early Feb.. "None of which shouts 'average' in my book.... Edited January 21, 2014 by fergieweather

[ZONE 51]

 

 

 "unusually cold for the direction...

So the westerly flow would be  picking up a colder than normal [airmass]in it's circulation then would usually be the case, bringing a higher risk of rain turning to snow.

 

Interesting post makes for a more exciting model watch having some unusual elements added into the mix.

Edited January 21, 2014 by ElectricSnowStorm

[LomondSnowstorm]

The main difference between any projected cold from here and the FI charts the ECM has occasionally churned out is that we actually do (in spite of the pessimism and constant talk of dominant zonality) have a block in situ:

Whereas before we were looking for some kind of height rise to our north to stop the Atlantic train, we're at least in with a shot of seeing some colder air being advected our way in the next few days, particularly because, while they're often very fickle in their evolution, Scandi highs are also more difficult to shift than the modelling tends to suggest. I don't know how many times Steve has posted similar charts over the years with a D7 zonal GFS chart turning into something at least a bit more amplified closer to the time but it happens frequently, and even moreso when we don't actually need massive changes to get to a colder setup.

The amazing thing is that there's now more snow potential at +72 than there was in a good number of the GEFS FI perturbation charts that kept some of the more optimistic cold watchers' spirits up. It may not be a full blown easterly, but we do have a trough disrupting under a block with some Polar Maritime air meeting the proper cold sitting tantalisingly close over Norway, bringing it even closer and perhaps even reaching the east coast for a time. This is likely to bring some kind of snowfall event, and believe it or not it might be the first proper low ground snowfall of the winter even here in Scotland (it's hardly been a brilliant winter for snow lovers up here either as a visit to our regional thread will confirm).

The bit that's throwing some people is the 'return to mild' - yes, after some decent resistance it does look likely that the next low will be that bit too powerful to hold west of the meridian, but the troughing is sufficiently 'vertical' to advect a very decent amount of WAA (albeit some of it will be flying directly over our heads) up into the Arctic, where the next piece of the puzzle comes into play - the Arctic high:

At a minimum, what this, along with the remains of the Scandi high, does, is force the jet southwards on a NW-SE tilt and bring in some more Polar Maritime air, with the risk of at least some below average temperatures and wintriness for northern and western parts:

At best, with a bit of help from just a bit more amplification upstream, our Azores high will become our best friend, pumping WAA into Southern Greenland and bringing the snowmaggedon big style:

Whereas two or three weeks ago we needed a huge number of things to go right to get any meaningful snow and cold, now we only need maybe one or two additional shoves in the right direction. The pieces to the jigsaw are all there, quite clear to see, and there are even a number of plausible ways to put them together. Short range - somewhat below average temperature-wise with the chance of some snow before turning a bit milder again by the weekend.

Longer term - up for grabs, but far, far more promising than anything we've seen in the entire winter to date. The MO obviously won't start shouting about snowmaggedon at this stage or, to be fair, ever, they're professional forecasters and it would be pretty irresponsible of them to do so at this range even if we had 100% model support for the beast to end all beasterlies at D6. But there are mentions of cold and even wintriness in both the short and longer range outlook. At this range, that's fine, and at least shows that the models we don't have access to are at least not entirely dismissive of a colder outlook. The rest, as Ian says, is as much fair game for them as for us, but with the added bonus that we aren't responsible for anyone other than our own and maybe our family's disappointment when the big snowfall doesn't come off as planned.

Edited January 21, 2014 by LomondSnowstorm

[ZONE 51]

Just looking at the ECM @192hrs (next Tue) low sitting over N.Sea with associated cold pool:

SP

Height 500hpa can see the cold pool 528dm.

SP+850s ( -5 )

 

Interesting times ahead!

[Eskimo]

0z almost identical to the 18z in the hi-res. 

[geordiekev]

Now that's what I call a dartboard low meandering towards us over the weekend on the 0z gfs. As the scandi block slows its eastward movement it could cause some major problems as it slowly moves south through the uk. I can see why Ian F and the meto are concerned about coastal problems not to mention rainfall amounts.

Hopefully we will have something more positive cold wise after the next set of storms move through. I think a lot of coldies have that half way holiday head on at the minute where you know the holiday is due to come to an end but we all know from recent years the cold weather does not follow the meteorological calendar.

On a side note we had an inch of snow/hail in benidorm in november. First time in 40 years. Definitely a strange winter for the record.

http://www.elmundo.es/comunidad-valenciana/2013/11/27/5296161d63fd3dea388b4573.html

Edited January 21, 2014 by geordiekev

[Mucka]

0z almost identical to the 18z in the hi-res. 

 

It still doesn't seem to have a handle on how to model high pressure across the Arctic that's for sure.

 

GEM is a bit far East with the pattern but it was till looking pretty good out to day 6 until falls apart later by refusing to pushing the trough into Europe as you would expect and instead stalls and fills it over the UK. (seem familiar?) I really hope that doesn't happen again some peoples heads will explode for sure.

 

 

UKMO looks pretty decent too with the pattern further West than GEM but we could still do with more amplification upstream.

 

Edited January 21, 2014 by Mucka

[Cecil Hogmanay Melchett]

Not overly impressed with the 0z runs if im being honest-

The opportunity exists for northern elevated areas as we head through next week but for those in the south and i dare say most of England and Wales its just unsettled cold rain im afraid.

Quick check of the uppers on the UKMO 0z run leaves me underwhelmed for the friday rain to rain event.

We have ECM to come but yesterdays optimism has dropped a bit,we just cant seem to shake that spawn of satan Polar Vortex,if i see oranges and yellows up there in spring/summer my head will explode with rage!

[Cecil Hogmanay Melchett]

It still doesn't seem to have a handle on how to model high pressure across the Arctic that's for sure.

 

GEM is a bit far East with the pattern but it was till looking pretty good out to day 6 until falls apart later by refusing to pushing the trough into Europe as you would expect and instead stalls and fills it over the UK. (seem familiar?) I really hope that doesn't happen again some peoples heads will explode for sure.

 

 

UKMO looks pretty decent too with the pattern further West than GEM but we could still do with more amplification upstream.

 

Dont see much 'decent' about the ukmo mucka? Maybe the zonality which will follow will be of a cooler variety but i'd imagine it will be nothing but a pain in the backside for soggy Britain(or 99%of it).

Some really cold Ens at around T200, many with cold and quite strong Easterly flows

Trouble is we never see them on the op runs!!!!

[Mucka]

Some really cold Ens at around T200, many with cold and quite strong Easterly flows

 

 

Yes the first couple of perturbations to usher in a prolonged cold spell have arrived this morning, 9 and 16 though others are generally on the cool/cold side at times.

 

 

I dare say the SE would be buried if 16 verified.

 

Coldest set of ensembles for some time. 

SE England

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=297&y=126

http://www.meteociel.fr/cartes_obs/gens_display.php?x=297&y=126&run=0&runpara=0&type=3&ext=1

 

NW England

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=236&y=37

http://www.meteociel.fr/cartes_obs/gens_display.php?x=236&y=37&run=0&runpara=0&type=3&ext=1

Edited January 21, 2014 by Mucka

[Weather-history]

In the interest of balance- for the mild fans I feel it only fair to pluck some eye candy from the ensembles. Possibly the most +AO chart I have ever see. PV almost totally circular. http://modeles.meteociel.fr/modeles/gens/run/gensnh-9-1-372.png?12 SPS yes chiono

Lol That now shows high pressure to the north of the UK with an easterly flow.

[Mucka]

Dont see much 'decent' about the ukmo mucka? Maybe the zonality which will follow will be of a cooler variety but i'd imagine it will be nothing but a pain in the backside for soggy Britain(or 99%of it).

 

 

Well it would be better if the trough was disrupting more efficiently with more energy getting under the block and some more amplification upstream and even more Westward shift wouldn't go amiss certainly but so long as the low cleared SE into Europe and didn't stall over the UK like the GEM we would have a decent chance.

 

The Atlantic will undoubtedly get in anyway around the mid range and we've known that for sometime, it is all about clearing the energy SE into Europe and getting a decent ridge behind and there is no way of knowing how well UKMO achieves either of those as we would need another 2 charts but it is a sound run on the basis of the Arctic high linking strongly with the Scandi ridge so there can be no typical zonal conditions in that sense - the low can only stall or be forced SE.

 

I'm not in love with it but it's a decent chart IMO

[ZONE 51]

0z almost identical to the 18z in the hi-res. 

And what was the18z like to be "almost" identical to the 00z? some viewers might have missed outputs.

 

Certainly interesting is the BIG word today.

[Mucka]

Fairly decent agreement between ECM and UKMO at 120h with GFS more progressive and really struggling with the Arctic high even by 120h it seems.

 

 

 

Edit

 

 

ECM 144h again decent agreement with UKMO on overall synoptic but marginally better in some key areas so it will be interesting to see how this run evolves from here. I'm hopeful of a JMA type run but will that low clear into Europe efficiently?

Edited January 21, 2014 by Mucka

[ZONE 51]

@192/GFS 00z:

***snowrisk***

 

 

 

[Mucka]

ECM 168h looks like the fuse is lit, can we get a Boom at 192?

 

 

Need the low over the UK to clear South and low pressure to the NW stall and disrupt on SW tip of Greenland with most of the energy being forced NE

 

Edit

 

Just realised I've been commentating, sorry about that. Anyway here is the ECM 192h - not quite there.

 

Edited January 21, 2014 by Mucka

[winterof79]

Nice way for the run to end

http://www.meteociel.fr/modeles/ecmwf/runs/2014012100/ECH1-216.GIF?21-12

A few more headaches for the UKMO this morning.1050Mb High thats what i call flexing ones muscles.

Edited January 21, 2014 by winterof79

[mulzy]

ECM run very decent this morning.

 

The wretched Azores High has moved away to the SW in the latter stages of the run - even though there is some energy crossing the Atlantic, there is scope for favourable trough disruption.

Edited January 21, 2014 by mulzy

[snowbob]

Think model fatigue has def kicked in this morning

The ECM is a very good run for the 0z much better than of late

Dare I say even agreement with the ukmo @120

Think this is what Steve m was saying with looking for evolution

Hoping for a boom set of 12z

More twists and turns to come but happy that ECM is smelling the coffee

All IMO of course

Edited January 21, 2014 by snowbob

[That ECM]

ECM run very decent this morning. The wretched Azores High has moved away to the SW in the latter stages of the run - even though there is some energy crossing the Atlantic, there is scope for favourable trough disruption.

http://images.meteociel.fr/im/6114/ECH1-216_cmy4.GIFhttp://images.meteociel.fr/im/6067/gfsnh-0-216_krg8.pngInteresting, differences at T 216 as one would expect but high pressure to the ne on both. Still think we will need a couple more days to see some consistency in terms of what happens to the low and how far south it goes. The end of the month is still looking good IMO.

[Jason M]

Quite a lot of support in the GEFS this morning for the low to drop south and pull in a lee easterly. Most members quickly ramp up the Atlantic thereafter but that's normal.

I'd say the opp doesn't have much support really and taking into account the other models something like ECM shows must be the form horse.

Overall then, good this morning and I'd say best outputs this winter. That's probably not a great benchmark to use though :-)

[Cecil Hogmanay Melchett]

Well after the despair of GFS0Z comes the good news...

ECM is loaded with potential:D

And the GEFS have trended colder.

 

Can we/dare we hope??

[TEITS]

Some excellent runs this morning and you have to say what the ECM is predicting is the most likely based on the model runs over the past few days. My only reservation is something I mentioned many days ago and that is the importance of the LP moving S of the UK. The UKMO is also heading the same way as the ECM.

 

Looking at the GEFS ensembles I think this is the first time this winter the mean has dropped below -5C for my location. Just shows what a crap winter it has been so far!

 

http://cdn.nwstatic.co.uk/ensimages/ens.20140121/00/t850Cambridgeshire.png

 

I can see the Met O outlook changing to a more wintry outlook. Have to be honest I haven't agreed with there outlook these past few days as it appears out of kilter with the model output.

[Cecil Hogmanay Melchett]

Some excellent runs this morning and you have to say what the ECM is predicting is the most likely based on the model runs over the past few days. My only reservation is something I mentioned many days ago and that is the importance of the LP moving S of the UK. The UKMO is also heading the same way as the ECM.

 

Looking at the GEFS ensembles I think this is the first time this winter the mean has dropped below -5C for my location. Just shows what a crap winter it has been so far!

 

http://cdn.nwstatic.co.uk/ensimages/ens.20140121/00/t850Cambridgeshire.png

 

I can see the Met O outlook changing to a more wintry outlook. Have to be honest I haven't agreed with there outlook these past few days as it appears out of kilter with the model output.

Agreed TEITS-Surely the meto have to take into account GEFS0Z and the ECM?