Model Output Discussion - 8th - 14th January

[Cloud 10]

thats the 12z. the parallel is out after midnight.

Doh!

I'll give myself a yellow card for that.

[camiscool]

When does the 00z come out? Thanks

[OldMetMan]

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.

I notice the early run of the GEM was suggesting a similar development.

Clearly a new trend is developing. The synoptic pattern up to 7 days looks quite reasonable for both the GFS and ECM; HP breaking down and LP moving in from the W, by which time it should be clearer if the deep cold air is starting to develop to our NE and E.

One current feature which I think might add some credibility to what the above model output is saying is what the WV imagery is showing. The sub-tropical jet that has been running at some speed across N Africa for weeks now appears to be fading, which suggests to me that the polar jet will move a lot further south in our longitude. At the same time, there is a lot of sub-tropical activity further W over the E Pacific and Caribbean. This might possibly mean a much greater long-wave amplitude - strong ridge over the E US with a deep and broad trough over much of the central and east Atlantic, with LP tracking much further south.

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.

[Snowy Easterly]

When does the 00z come out? Thanks

About 3:30

[SP1986]

Just looked at the control run and it is bizarre, totally flat - you wouldn't know there was a potential pattern change on the way.

[TEITS]

Many positives today in the output. All GFS outputs have continued with the same trend and even more importantly the ECM control followed the OP. What is even more pleasing is even if this E,ly fails to arrive the stratospheric warming suggests further opportunities later on.

Going to be interesting viewing tomorrows 0Zs although I have absolutely no idea what they will show. At this stage im not ruling anything out!

[DaBrigg]

I rarely post, but the latest developments in the models interest me.

We should all keep in mind just how badly the models seem to handle blocking to our NE.

Even if the overall pattern change is picked up well in advance, the models have been notorious for backtracking or changing the western and southern limits of the cold as late t+72 hours. The infamous scenario of frigid air ending up in Greece, seemed to happen all-to-often a few years back.

The Arctic high ridging southward into Scandi around t+168 is an unusual pattern, rather like January 1987.

It's very rare for such a scenario to deliver the goods here. Many easterlies have tended to come about from the text-book Russian high building westward, and some less potent easterlies even began with a mild mid-latitude or Atlantic high eventually drifting into Scandi.

Whatever happens, a pattern change from the relentless wind and damp that we've had for weeks seems very likely to me. I've been keeping an eye on the SSW thread, keep up the good work guys.

Edited January 8, 2012 by DaBrigg

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2012010800/ECH1-144.GIF?08-12

nose of high pressure over the UK looks spot on for ridging Northwards-

S

http://www.meteociel.fr/modeles/ecmwf/runs/2012010800/ECH1-168.GIF?08-12

phase 2 jet over the atlantic looks PERFECT for the undercut with then ridging over the top towards Southern Greenland-

S

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2012010800/ECH1-192.GIF?08-12

Snow into England especially the NE E & SE

S

[winterof79]

Oh my....that is nicehttp://www.wetterzentrale.de/pics/Recm2162.gif(even if i cant post the link).I do like the output this morning,winter has awoken.

The big three models agree for a change at 120z,with the nose of high pressure ridging northwards.Contryfile forecast might be worth a goosy in its latter stages.

Edited January 8, 2012 by winterof79

[snow drift]

Well the models runs over night are still showing cold coming to our shores. A few more runs needed, continued consistency and the Meto will start to reflect this in their outlooks, and it’s at this point when I can really start to gain confidence.

It is at least interesting at this stage, I look forward to the future runs and the rollercoaster is just about to really start. Who will be the first to ask if it will snow IMBY? Hope you experienced posters are ready for the onslaught of questions!!

Hold on tight, here we go!!!!!!

[Tom Quintavalle]

Large portion of No.10 please, with a pinch of salt and two bites of the cherry for dessert. That will do me thanks

http://www.meteociel.fr/modeles/gefs_cartes.php?code=10&ech=192&mode=0&carte=1

No doubt plenty see-sawing of emotions this coming week. Still very happy with trends this morning.

Off to work in a bit. Play nicely, want to come home to a pleasant, relaxed Thread!

Regards,

Tom

Edited January 8, 2012 by TomSE20

[nick sussex]

The hope killer rides in to town today just as it has done so on many previous occasions regarding easterlies:

Yes its the UKMO which looks a damp squib at 144hrs!

http://www.meteociel.fr/modeles/ukmo2.php?nh=1&ech=144&carte=1021

You have to have this model on side, we've been here before with the UKMO, as you can see its much flatter upstream, and you wont get enough dig and trough disruption, the GFS is another plausible scenario , the GEM backs the ECM in terms of digging and trough disruption, the rest don't want to know.

As ever if you like cold and snow and looking for easterlies to deliver it becomes a nerve shredding experience!

Given the timeframes we should have a resolution this evening at least in terms of the upstream pattern within 144hrs.

[Iceberg]

As always the key are the ensembles for these set ups and they say that a change to cold weather within T168 is still unlikely. However they agree with a change from around the 17th onwards.

IMO what we are seeing is simply the models starting to open the doors to the possibility that a none zonal pattern might occur, it will take 4 or 5 days for them to come to grips with it. The most positive thing for me are the longer range 30hpa charts which show for the first time this winter the gradual distintegration of the PV and the upper low to the NW of the UK, rather than the -70's we are seeing -40 and -50 being forecasted.

Now might be a good time to remind peeps that the changes are coming from upper forcing factors and not lower meso features so run to run changes are not important but daily multi day trends probably are.

Edited January 8, 2012 by Iceberg

[bluearmy]

The hope killer rides in to town today just as it has done so on many previous occasions regarding easterlies:

Yes its the UKMO which looks a damp squib at 144hrs!

http://www.meteociel...=144&carte=1021

You have to have this model on side, we've been here before with the UKMO, as you can see its much flatter upstream, and you wont get enough dig and trough disruption, the GFS is another plausible scenario , the GEM backs the ECM in terms of digging and trough disruption, the rest don't want to know.

As ever if you like cold and snow and looking for easterlies to deliver it becomes a nerve shredding experience!

Given the timeframes we should have a resolution this evening at least in terms of the upstream pattern within 144hrs.

the other 'decent' model that doesn't have the same shape to the trough disruption is the BOM which is the same system as the ukmo but at a lower res. i suspect that we are onto a decent pattern here nick. maybe the first push will fail but even if it does, another depression is coming along and the will hopefully do a better job of the WAA. given the timescale, i see this development as a bonus anyway.

the spreads on ecm a little less chaotic than yesterday 12z, but still with the same three clusters (bit less marked). the spread on uppers is far less convincing about advecting any cold sw and its not until post T192 that we see this. either the ens are slow on the uptake (probably) or the op is a bit progressive with the pattern (possibly).

[nick sussex]

The ECM ensemble maps show why the ensemble mean looks so poor for 168hrs, there are a spread of solutions with one smaller clustering likely to bring in the easterly and a mixture of other solutions suggesting from cooler zonality to limpet high still to the south.

Generally when dealing with trough disruption the operational does often have a better handle especially within 168hrs but the problem is that UKMO output.

In terms of the upstream pattern and that important troughing in ne Canada, NOAA go with the ECM operational run upto day 5 then switch to a blend of the ensemble means because of growing uncertainty.

I'm certainly less optimistic today for an easterly than yesterday evening, of course theres still a chance but regardless of what the GFS 06hrs run shows we'll have to wait till this evening, in this instance this chance of an easterly won't be along drawn out process like many in the past which have imploded after days of model watching.

Events within 144hrs will determine whether we see this easterly or have to wait for another opportunity.

[tinybill]

thanks f1 that a nice surprise this morning for the cold lovers eastil fron now were over night, plus snow lets hope their no down grades or people will start looking for the rope again!!

[Tim Bland]

Thanks Nick. As you have always said, with an easterly you need the UKMO on board so I'll keep the champers on ice. Personaly I'm over the moon with the output as I'm skiing in Scotland 19th to 23rd so even cool zonality will do!

[Cloud 10]

The parallel gefs control run looks more promising.

Meteociel - Cartes Ensemble GFS (ENS/GEFS)

Lets try that again!

Meteociel - Cartes Ensemble GFS (ENS/GEFS)

[dixonoid]

GFS definitley looking better in the higher resolution but not as good as the 18z and gives us this :

And in deepest FI still looking good for signs of changes to very cold:

And the ecm :

So there is going to be a few ups and downs, but the pattern change does look like it is imminent, and although these are only taken from one set of runs and can't be taken as granted, very pleasing to see! And ensembles taking a slow direction towards cold and not as mixed up in the low resolution as they have been, telling me that the pattern is going to change to a less mobile one:

Edited January 8, 2012 by dixonoid

[Duane S.]

[nick sussex]

Thanks Nick. As you have always said, with an easterly you need the UKMO on board so I'll keep the champers on ice. Personaly I'm over the moon with the output as I'm skiing in Scotland 19th to 23rd so even cool zonality will do!

Yes that model is always a pain with easterlies!

That was the biggest disappointment this morning but we still have a chance and I am pleased that we'll get a quick resolution to this, the differences in terms of amplification start quite early.

On a more positive note I was a little surprised to see the control run of the ECM solidly behind the operational run at least to bring that easterly into De Bilt.

http://www.weerplaza.nl/15daagseverwachting/default.asp?type=eps_pluim

We can see with those ensembles that the easterly doesn't last too long, after that theres a spread of solutions.

[Tim Bland]

Wow a semi positive post from IB it must be good! Shame the ECM ensembles only show the beasterly lasting a few days. At least the heights to our north will still be there and the PV pushed NW and fragmented, so plenty of chances for reloads and northerly outbreaks to follow.

[johnholmes]

I've never placed much faith in the UKMO at T144, it plays catch up in these situations.

The main thing is that yesterdays trend in the models has continued today, we need to see future runs backing the PV West and the pressure raise close to the UK, to form a link with pressure rise to the NE and getting this to happen far enough North and West to achieve the curveback. It remains a long shot.

a rather sweeping and somewhat inaccurate statement Ian if one uses the NOAA stats at that range; short term it certainly wobbled a day or two ago but in general it outperforms GFS and is not far behind ECMWF, at least in the hemisphere view of things.

the link

http://www.emc.ncep....TATS/STATS.html

looking at the wider picture using the 500mb anomaly charts and they are not that reliable over the last day or two. Too many differences from day to day between the same model, especially the ECMWF version, GFS, right or wrong, does seem more stable.

NOAA continues to show the large +ve area off the west coast of the states arcing over and extending back into Greenland, almost linking with the +ve area around 50N 30-40W all 3 have shown for some time.

I would not place any bets on the outcome at the 10-15 days range other than it seems odds on that it will be less mild!

Edited January 8, 2012 by johnholmes

[KTtom]

I think all this talk of a 'beasterly' is a little missleading for those looking for guidence here as not one model actually shows a full on easterly. ECM @192 being the closest. To me all the data at hand looks a close but no cigar for the UK as the cold stays to the east and the Atlantic systems continue to be too close. Not to say there won't be a more successful attempt later in the month.

Edit: 06z looking to back up UKMO with trough further east preventing favourable ridging to develop.

Edited January 8, 2012 by KTtom