Model Output Discussion - 10th Jan Onwards

[nick sussex]

The ECM T240 mean has the Scandi high disappearing east by D10:  EDM1-240 (4).gif

 

Very consistent with the ops from the various models with PV reorganised to our NW, AH ridging NE and the UK somewhere in a zonal flow.

Thats probably right unfortunately, the stalemate of last night was never going to last, either the block would win or the models would usher it east.

 

All the models have been woeful in terms of the high to the ne, couldn't even model that correctly at just T96hrs! 

[Captain Shortwave]

Well the ECM ens have flipped just like the op this morning, now favouring a return to a westerly set-up. I guess one could say that there is huge volatility in the output. On the other I just feel that this has been slipping away for days now. The models frankly have been dreadful and this latest tease will unbelievably mean that the ECM will be beaten in the 5 day verification stats by the lowly NAVGEM if the return to westerly scenario is correct.

Can't just have a go at the ECM, it's ironic that the GFS also got seduced by a pattern, which the model rarely goes for and frequently has to backtrack to in embarrassing fashion.

Edited January 12, 2014 by Captain shortwave

[Frosty.]

The ECM T240 mean has the Scandi high disappearing east by D10:  EDM1-240 (4).gif

 

Very consistent with the ops from the various models with PV reorganised to our NW, AH ridging NE and the UK somewhere in a zonal flow.

The Ecm has again been a huge let down, like slowly releasing the air from a balloon it has gone from mega wintry charts to non descript. The Gfs is constantly slated on here which really makes me angry because it's the ecm which is the biggest con of them all.

[bobbydog]

just for any newer members who might have been worried by this post-

The GFS is awful for coldies and for people flooded out of their houses, it continues to bring low after low after low.

 

thats not what the GFS is showing.

 

this is a more accurate description-

 

Looking ahead, there are no weather warnings so it looks like a more typical spell of gernerally unsettled weather with occasional drier and brighter days, there is a risk of snow on northern hills at times and some night frosts during the quieter interludes.

 

what its actually showing during the low resolution part (the slightly more believable bit) is a slow moving trough to the west, bringing some rain next week, interspersed with drier, brighter spells. rainfall totals (whilst unwelcome to some) shouldn't be worrying amounts, with some snow on high ground in the north.

its not showing mild either. it won't be siberia but it will be cold.

it even ends up in FI with a feeble easterly which though not snowy would be very chilly

[IDO]

just for any newer members who might have been worried by this post-

 

thats not what the GFS is showing.

 

 

 

Yes not a zonal flow but still worrying bearing in mind the state of the ground for many in the west. A trough to the west can still bring in weather fronts and GFS total rainfall for the next 8 days:

 

 

To the west some areas getting over 60% of their monthly rainfall in just over a week.

 

Fingers crossed that week 2 will bring some respite.

[Purga]

ENS fully in accord with the Op runs so pretty much game over for any cold at all.

 

ECM ensembles (Reading) showing a mild picture with median >10C

GFS loses any cold members

 

So zonal mild and wet is the best call for the foreseeable with some big precipitation spikes possible.

 

Good old British winter - the eternal Autumn.

Edited January 12, 2014 by Purga

[bobbydog]

Yes not a zonal flow but still worrying bearing in mind the state of the ground for many in the west. A trough to the west can still bring in weather fronts and GFS total rainfall for the next 8 days:

 

gfsopuktotpcp192 (1).gif

 

To the west some areas getting over 60% of their monthly rainfall in just over a week.

 

Fingers crossed that week 2 will bring some respite.

 

of course, there will be the odd bout of heavier rain which won't help those in the worst hit areas but it won't be relentless like it has been. also as you say, week 2 looks much calmer.

[Man With Beard]

Today's ECM mean for this Wednesday:

This is what it was showing for Wednesday 72 hours ago

Calling a spade a spade, it was a mile off. 72 hours ago, the chart was showing an easterly certainly midlands north, but today the easterly is over Iceland!

[SMU]

My last post for a while

Rjbw ^^^^ scandi shortwave

Other than that the h5 anomalies are the same

Confidence today

80% mobility from the atlantic

20% something less mobile from the east

People slating the ECM are only looking at the UK under the microscope

If your going to do that you may as well only go to t 60 on the models

All models came up with the same solution then once the scandi shortwave was 'seen' it was game over as there was no infill of pressure moving west to force the atlantic low south

Simple as really -

S

Edited January 12, 2014 by Steve Murr

[Fozfoster]

My last post for a whileRjbw ^^^^ scandi shortwaveOther than that the h5 anomalies are the sameConfidence today80% mobility from the atlantic20% something less mobile from the eastS

I think this sums up the mood perfectly......over and out...........

[johnholmes]

Yes, it's not looking great across the board for coldies, the 00z runs appeared to have been fed data that suggests even more energy in the upper flow coming out of NE N America. 

 

You may have seen John Holmes mention the spacing between the Rossby Waves, which is too wide by t+144 over the N Atlantic sector between the eastern NOAM trough and the European trough:

 

wwjet_144.png

 

Ideally need to see the gap close between the Euro and eastern N American trough. Unfortunately the American trough flattens out as it enters the N Atlantic on the 00z - so not the amplification that's needed to get an easterly.

 

Not a great deal of joy from the 00Z GEFS either ...

 

regarding this spacing the output from ECMWF-GFS this morning continues with something they, rather more so than NOAA (althoug the chart projection on this makes it less easy to see) had started a day or so ago, see below. That is the major trough pattern is almost just 3! The European one is more just an extension, not very stron at that this morning, of the eastern arm of the Canadian vortex/trough. If this warming out of that trough continues then a 500mb westerly flow MIGHT rebuild. It needs watching on these outputs to see if that does occur.

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

[UV-RAY]

Today's ECM mean for this Wednesday:

This is what it was showing for Wednesday 72 hours ago

Calling a spade a spade, it was a mile off. 72 hours ago, the chart was showing an easterly certainly midlands north, but today the easterly is over Iceland!

Quite a few hundred of them to be precise. Well the hunt for cold continues but this is shaping up to be a nineties, noughties type winter with promises of cold in FI that never come to fruition.  Hopefully February will bring us a change of fortunes but for now the winds may have slackened but the rain looks like intensifying over the coming weeks.

[ANYWEATHER]

Well the ECM ens have flipped just like the op this morning, now favouring a return to a westerly set-up. I guess one could say that there is huge volatility in the output. On the other I just feel that this has been slipping away for days now. The models frankly have been dreadful and this latest tease will unbelievably mean that the ECM will be beaten in the 5 day verification stats by the lowly NAVGEM if the return to westerly scenario is correct.Can't just have a go at the ECM, it's ironic that the GFS also got seduced by a pattern, which the model rarely goes for and frequently has to backtrack to in embarrassing fashion.

Well we have been here many times over the years, and this year is no exception! The very cold block does not go anywhere in a hurry and the problem is that the models are not correctly modelling the energy from the Atlantic correctly,hence weaker Atlantic, and a model output showing much colder contions from the East etc.it may be a little while yet to see if the models handle the energy correctly from what has been an unusually strong jet stream this year.Dont discount the cold because its not what the models are showing at the moment,there will be a lot of swapping and changing this coming week.... Edited January 12, 2014 by ANYWEATHER

[Gibby]

Good morning. Here is the report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Sunday January 12th 2014 taken from http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

 

All models show another period of unsettled weather knocking on the door of the West as I type with a trough of Low pressure moving East across the UK later today and tonight with a spell of rain moving over all areas with clear spells and showers overnight. Tomorrow shows another trough moving East through the day with more extensive showers crossing most areas perhaps heavy with hail and thunder in the SW. By Tuesday a weak ridge is shown to cross Eastwards with sunshine and a largely dry window of weather through the day. However, by midweek Low pressure deepens to the NW and brings strong winds and rain NE across all areas through the day. Throughout this period temperatures will be close to average but cold enough at times for some snow over Northern high hills and mountains.

 

GFS then shows the latter end of the week remaining unsettled and sometimes wet as the model shows Low pressure persisting over or near the UK in largely Westerly winds never too strong but never too warm either. In the second half of the run today the weather still remains unsettled as further Low pressure moves ESE across the North before a system moves more directly SE across Britain and into Europe with pressure rising from the NW with a cold NE flow developing in the South at the end of the run with wintry showers and sharp frosts over the North.

 

The GFS Ensembles show the wet January persisting with Low pressure after Low pressure continuing to flow across the Atlantic and the UK maintaining the very tight and average range between the members with regard to uppers and offering little chance of cold and snow.

 

UKMO closes it's run on Day 6 with Low pressure slow moving and straddled down over Western Britain with a Southerly drift for many and troughs also embedded in the flow with rain, heavy at times commonplace especially towards the South and West, just where it is not needed.

 

GEM today shows the unsettled flow persisting over the UK under Low pressure or a Westerly flow in association with Low pressure to the North. This would mean a continuation of wet and sometimes windy weather throughout the latter section of the run.

 

NAVGEM today shows the UK as still the home to troughs of Low pressure ambling in from the Atlantic and stalling somewhat with rain at times in temperatures close to or perhaps a little below average, the latter more likely over the North and NE.

 

ECM today also shows changeable weather with rain at times in temperatures close to average under a persistent trough of Low pressure lying down over the UK. A window of drier weather is shown towards Day 10 as a ridge crosses East but the next trough is shown crossing the Atlantic to reach the  West and NW of the UK soon after the term of the run.

 

The ECM 9 and 10 Day Mean Chart today have declined away from last night's ridging with both charts indicating the most likely option being generally a Westerly flow with a continuation of rain at times for all.

 

http://www.wetterzentrale.de/pics/Reem2161.gif

http://www.wetterzentrale.de/pics/Reem2401.gif

 

The Jet Stream remains the reason for this continued unsettled pattern as it continues to pump across the Atlantic firstly to the South of the UK and Southern Europe before moving North to cross the UK later in the output.

 

In Summary today the weather looks almost certain to stay unsettled for the foreseeable future and sometimes thoroughly wet as Low pressure areas become strung out over the UK later this week before we probably drift into a more mobile Atlantic Westerly flow later in the run. As a result temperatures never look like being far from the seasonal average though it may feel somewhat chilly at times in the breeze and rain. There remains very little scope in the synoptic patterns as shown this morning for any drift into anything remotely very cold and wintry anytime soon and certainly not within the next 10-14 days.

[IDO]

The Dutch ECM extended ens:    

 

For mid/end Jan they are hard to take; very poor.

[Tamara]

 

 These differences in zonal energies in turn drive the strength of the vorticity of the upper air patterns and thus we see changes to the upper troughing 500mb level anomalies according to the ebbs and flows of this overall energy budget.

 

In this way, because the upper air tropospheric profile is not favourable, then in terms of the surface features we can see how we might be struggling to get the Scandi High to back the cold west - with the upper troughing pattern in the NH and the potential amplification of the pattern restricted by the relatively high energy budget still in the atmospheric system.  This is overly simplistic I know but hopefully it will do for these purposes

 

There continues to be good indications that the mid and upper stratosphere zonal winds are due to take quite a hit from potentially significant wave activity in the foresseable future - bluearmy makes a very good post f.e about this on the stratosphere thread and in line with his thinking which I believe is very true, then on this basis we can see not only why we have been struggling to get an easterly, but also maybe why some model and ensemble data is taking an initial response to this to actually increase westerly energy once more - and hence the suggested return of something more zonal (temporarily), albeit nothing of the intensity we have seen through much of the winter.

 

The reason? As stated above - the flushing down of those faster zonal winds from the upper stratosphere as further predicted warming activity takes place further up. This suggested warming is a forecast, and only that, but the early signs are that it may well be more consistent and significant than the latest one.

 

This leads to the intrigue and fascination I was talking about yesterday and the day before. Lets see how the present pattern manifests itself over the coming days, how the heights and cold pooling to the NE sustain themselves, and then lets see how the models handle this possible burst of zonal energy as it is forced to the surface. There are all kinds of possible solutions to this, and they sure needn't all be negative ones in terms of future cold potential

 

Things beyond any temporary zonal burst, assuming we get the forecasted strength of hit to the vortex, would look much easier than currently in terms of getting better service from the north and the east.  On this basis then I continue to think it best not to get hung up about any easterly - it was always a longer shot and simply a bonus along the path to, hopefully, a much more condusive pattern to colder weather.

 

 

This is quoted simply to underline exactly where we are today

 

Its still worth being very cautious about the energy budget I was talking about yesterday - the cold easterly in the coming week has proved too much of a stretch, much as believed it might (albeit hoped for better) but it is also very important to avoid knee jerk reactions about the return of the atlantic in terms of the explanations for this given yesterday.

 

Its simply the case that the first stage of breaking down a very formidable vortex has occured, but the task isn't completed, and we look to see how the modelling handles the next phase of energy transport across the pole of what could prove to be a final downwelling of positive zonal wind anomalies before the whole thing potentially detonates (yes possibly detonates) later this month and perhaps more especially into February. 

 

Any renewed atlantic period of weather this time is not the product of a maturing early winter time strong vortex, it is more likely to be a late gesture of defiance before very conceivably blowing itself out. We need to watch how this might develop - there is plenty to keep us interested there.

 

Its the case all the time anyway, but especially this time, we should avoid over reactions to face value model changes - even if we do have to keep waiting for the colder pattern

Edited January 12, 2014 by Tamara תָּמָר

[kev238]

Awesome summary Martin; your analysis is always spot on and balanced , not getting suckered in by cold charts that are in the minority.

It does seem likely that the next week will be unsettled and wet, following that I fear Azores high ridging pushing in. If this happens could be the pattern into February.

It really does seem that snow is highly unlikely in the next fortnight and probably longer.

[Frosty.]

Yes Frosty very true,here are my own,and it has to be said very technical ratings of the model's at forecasting the non Easterly, using a range of smiley's :-

 

GFS- 

UKMO-  

ECM-       

BOM-   

The best model summary there snowmut, all we can do is laugh at this joke of a winter

[Bristawl Si]

[quote name="SLEETY" post="2893516" timestamp="1389515064"

 

so just forget this week and move on,as it looks like this winter will eventually turn very cold into feb,and it's been a very long time that we have had a severe feb.

[Frosty.]

......over and out...........

roger

[Summer Sun]

The GFS ensembles have very little scatter now out to the 27th, rainfall doesn't look as bad as it was during December but none the less it won't be welcome

 

[bluearmy]

BA don't you think this ties in with several of your posts  re the zonal winds and the signal for high pressure to be further south, that does seem a very plausible scenario for what we've seen, once those blues towards the pole started to turn red that it was a race against time to get the block in before that fed down.

 

it makes sense nick but then why didnt the ecm ens with their 'improved' view of the strat pick up on this flushing down of the westerlies. (i doubt this is too relevant but when the upgraded ecm ens were introduced in november, one of the areas where it didnt verify as well as the old model was the lower strat). the model is all one dynamic from my garden right up into the mesosphere. if should recognise the increased westerlies and the trop modelling should reflect their influence as they sink down. 

 

the gem op was always keen on the solution, as was the gfs, once it grasped the evolution. the ukmo, only going to day 6, never showed us how keen it would be and its first view of the general pattern looked encouraging. however, once again, it seemed the best model to follow re the n atlantic depressions and the linking up of the atlantic low heights with the scandi residual trough (related to steve's shortwave).

 

the gefs, gem and ecm ens all generally singing from a similar hymn sheet. (why slag off ecm so much karl?). as i mentioned yesterday, the gem ens much less cold than the others (model bias or good call? not proven at this time).  

 

the period post day 10 has seen the naefs (gem + gefs) continually blasting the northern arm back into life. its clear that they are now right but having had to put this back for several days, they called it too early.

 

this mornings output is consistent with yesterdays except for the behaviour of the atlantic ridge which is flattened completely (not allowed to ridge ne, join with the scandi ridge and cut off the euro trough) by the jet streak off the eastern seaboard. that effectively puts extra pressure on the scandi ridge which retreats further east. the jet profile for our side of the atlantic at day 10 on the ecm ens looks like previous days offerings on day 13/14. the only reason i can see for this change in the modelling is the behaviour of the canadian vortex which sticks out a mean lobe to its se at T192. (mean being 'average', not 'nasty'). this at the same time as its digging trough into the states is lifting out. thats just too much energy for the ridge and it capitulates completely. 

 

given that this behaviour of the canadian vortex is showing on the ens mean plus the gefs and gem, it really should be game over for this blocking to our ne. it will retreat into nw russia but it wont go away completely and if upstream changes, then it will likely return. just wait for the 12z's to seal this, given yesterdays runs.

 

looking into the depths of fi, the ecm and gem ens both want to split the vortex (canadian and east siberia). not a big ridge between but enough space to allow a neg AO to reform should other factors allow.  however, i'm not liking the proximity of the canadian vortex to the nw atlantic. hopefully, events high up will dictate some more changes.

[forecaster]

Just a quick look back in time. Older EC run valid for Tuesday:

 

 

 

FAX:

 

 

 

This, for Thursday, shows the EC perhaps 10C out in 850hPa temperatures:

 

Edited January 12, 2014 by forecaster

[bobbydog]

We'll I give up.

But looks like my writing of this winter was indeed worth a mention.

More rain wonderful I think the models over all have been awful they really bad when it comes to easterly 12hrs later they all flopped again.

I for one had enough of this winter.

 

well i don't.

 

we've gone from elation to despondency in just 3 days. considering there's 47 days left of winter (over half),

 

i think i'll give it a chance....

[Polar Maritime]

well i don't.

 

we've gone from elation to despondency in just 3 days. considering there's 47 days left of winter (over half),

 

i think i'll give it a chance....

 

Yes some very knee jerk reactions this morning, the models are still very volatile and nothing is set in stone.

 

It's that which makes Winter model watching in the UK so exiting.

Edited January 12, 2014 by Polar Maritime