Model Output Discussion 1st January 2014-06z onwards.

[snowice]

DO WE THINK FI IS T+120HRS AND WOULD ANY ONE CARE TO GIVE US THE ODDS ON THE MODELS FLIPING BACK TO THE EASTERLY OPTION?

[Matty M]

The ENS stamps @ 120hrs are a mess. Could go either way yet. 

 

[Stuie]

 

Hi everyone. Here is my evening report on the outputs from the NWP for today Thursday January 9th 2014 lifted from my website at http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

 

All models currently show the UK under gently rising pressure as a weak ridge crosses East over the UK overnight ahead of a weakening cold front moving steadily East across the UK tomorrow bringing an area of showery rain with it clearing from the West later in the day. saturday's charts from all models show a fine and dry day as a strong ridge of High pressure crosses East bringing colder air with a sharp frost and fog patches possible on Saturday Night. The respite from the rain then ends on Sunday as after a dry start a new Atlantic depression pushes wind and rain NE across the UK later in the day, heavy in places.

 

GFS then shows a very unsettled week next week as Low pressure slides South down the Western side of the UK through the period bringing rain and showers at times all week with the heaviest rain and showers reserved for Western and SW areas in temperatures close to normal. Northern and Eastern parts will be colder for a time with the risk of some of the precipitation falling as snow over the hills. Through the extended outlook the model shows the Azores High building NE across the UK to bring drier weather with temperatures close to normal across England and Wales before Atlantic Westerlies strengthen over the North with rain at times to end the run.

 

The GFS Ensembles tonight has evaporated the previously predicted cold spell to nothing as it now looks the changeable but largely unsettled spell will continue through the next two weeks though with less rainfall overall than lately.

 

UKMO tonight closes it's run next Wednesday with Low pressure with a deep Low pressure to the West of Ireland and showers or longer spells of rain over all areas through the day in temperatures close to average.

 

GEM tonight shows deeply unsettled weather with Low pressure areas sliding SE over the SW of the UK and bringing strong SE and occasionally cold east winds with rain copious in amounts at times and some snow on hills too at times as cold continental air flows West on the Northern flank of the Low pressure areas.

 

NAVGEM tonight is in the Atlantic camp as it brings deep Low pressure slowly East into the UK from the West through next week filling it gently as it comes in. the net result will be a lot of showers and longer spells of heavy rain at times with average temperatures and ongoing flooding issues almost anywhere.

 

ECM tonight remains poor news for those in the SW looking for flood relief as most of next week continues to show Low pressure close by with areas of rain and showers spiraling around various centres of Low pressure all week. It looks poor news too for cold fans away from NE Britain as too much Atlantic influence brings rain rather than snow in temperatures marginally colder than of late but at least far less windy. The run closes with the threat of colder conditions finally seeping West from Europe on slowly backing winds towards the East and with Low pressure still in close proximity to the South and SW some of the rain could begin to turn to snow over the hills.

 

The ECM 9 and 10 Day Mean Chart show a UK trough in response to High pressure likely to be near NE Europe in 10 days time with rain at times in winds from a Southerly aspect the most likely result.

 

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

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

 

The Jet Stream shows the flow crossing the Atlantic next week and staying well South over Europe as a result of High pressure over Northern Europe. The problem is with an Azores High the trajectory of the flow over the Atlantic becomes problematic for the UK to tap into anything cold from the East.

 

In Summary tonight the spectre has fallen on anticipated cold weather next week as most output now shows unsettled and often wet conditions in temperatures close to average. Some particularly wet charts are shown which if verified would exasipate flooding issues with very little opportunity for anything profoundly dry for any length of time in any one place. However, despite the pattern between the models being generally similar the specifics are quite different in the period from midweek next week which indicates the models have not got a handle on longer term evolutions on tonight's outputs.

 

Regarding the GEM Martin, it is the only model that seems to flow through the T120+ mark in a "normal" fashion. It doesn`t weirdly detach and shove the low pressure SSW against the Azores high like the other models. The angle of the low is also better. Not straw clutching but it does seem more realistic at the 120+ juncture. 

A certain laid back approach from the GEM.

 

Edit:

ECM 168

GEM 168

Edited January 9, 2014 by StuieW

[Man With Beard]

Well having talked up the ECM mean earlier today, I am relieved that it has been consistent and kept the the slider low this evening! Though the high pressure over Scandinavia has clearly gone further east in line with other models, making the evolution just a little more precarious in terms of getting a stable easterly:

 

Some snowy possibilities there, particularly midlands north.

 

A quick look back through the other op runs for comparison - it isn't a million miles away from GEM, ECM op, JMA and UKMO is it, just tiny matters making the difference between an easterly and a southerly flow.

 

So, although the output is not quite as good this evening as, say, yesterday lunchtime, and the opportunity for deep cold may have passed for now, it's still all to play for with the snow/rain battleground, no clear winner yet, and the charts above suggest, again, that there will be a battle somewhere over the UK.

[LomondSnowstorm]

The ENS stamps @ 120hrs are a mess. Could go either way yet. 

 

 

Five clusters and some fairly notable differences within each cluster tells the story here - many options still on the table, a good number of them still cold and snowy, moreso the further north and east you go but certainly not exclusively. All to play for tomorrow.

[Whether Idle]

The ENS stamps @ 120hrs are a mess. Could go either way yet. 

 

Cluster 2 (13/50) is favourable for a decent cold blast at day 6 or 7.  That's about a 1 in 4 or 5 chance so 20%. 80% chance of something less pleasing.

[nick sussex]

The ECM postage stamps don't inspire much confidence in terms of what to expect at day 5:

 

http://www.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2014010912!!/

 

A mixed bag of solutions with the control supporting the operational run for that shortwave energy to dive se into France, even at T72hrs theres some marked differences with the tilt of the troughing.

 

Now heres a very interesting thing,theres a good correlation between the tilt of the troughing at that timeframe with how the synoptics can develop

 

So this is the deal if the ECM is correct with its tilt of troughing and placement of high to the ne then you can throw out at least ten of those ensembles because they will not verify if they are wrong at T72hrs. Those with the positive tilt generally have the pattern so far east at 120hrs that its a hard slog back to cold from there.

 

Relatively small margins earlier on that are making a big difference later and for this reason I'd be viewing the T72hrs as where FI begins , there is also another issue upstream and that's phasing of energy and what time it takes place and crucially whether the low near the UK becomes the lead or the one further upstream at T96hrs.

Edited January 9, 2014 by nick sussex

[Man With Beard]

The ENS stamps @ 120hrs are a mess. Could go either way yet. 

 

Actually I don't agree that they are that scattered, let's study them a bit more. All members have some sort of block to the N or NE of the UK. All have a series of depressions which seem to be angled from the NW through the UK towards the SE. The -6C line on the T850s is angled from Greenland across to central Eastern Europe, mostly clipping NE Scotland but a few pulling much further down across the UK.

In contrast to the GFS ensembles, where we saw raging zonality, northerlies, southerlies, Bartletts, Scandi Highs, you name it, it was in there by T144! 

Edited January 9, 2014 by rjbw

[phil nw.]

I don't think much has changed for the next few days if we consider the uncertainty that has always been showing.

The Jet still fragments in the E.Atlantic as the high builds to the ne.next week.

The battle between their relative strengths still to be fought out over the UK local as we go into next week.In this setup modeling will continue to calculate different projections.

 

The concern on the UK model is that heavy band of rain approaching the west by Monday,something we could do without.

http://www.meteociel.fr/ukmo/runs/2014010912/UW72-594.GIF?09-18

 

this looks like pushing through and it's beyond this that things get more complicated with the next trough and it's development.

 

The ECM mean looks like pushing this more se than the op run which indicates the blocking to the east will become more influencial.

http://www.meteociel.fr/modeles/ecmwf/runs/2014010912/EDM1-120.GIF?09-0

 

OK maybe no raging easterly but an interesting change to our current pattern which brings something colder towards the UK.

A look at the T96+ T120hrs hrs fax's later will give us some further in sight into the Met Office views.

Edited January 9, 2014 by phil nw.

[DAVID SNOW]

Cluster 2 (13/50) is favourable for a decent cold blast at day 6 or 7.  That's about a 1 in 4 or 5 chance so 20%. 80% chance of something less pleasing.

 

 I remember several days ago Ian F saying only about 20% MOGREPS  and other in house models 'going for ' an easterly flow....

[Whether Idle]

 I remember several days ago Ian F saying only about 20% MOGREPS  and other in house models 'going for ' an easterly flow....

 MOGREPS seems fairly well programmed.  Shame we don't get to see it.

[Stuie]

I don't think much has changed for the next few days if we consider the uncertainty that has always been showing.

The Jet still fragments in the E.Atlantic as the high builds to the ne.next week.

The battle between their relative strengths still to be fought out over the UK local as we go into next week.In this setup modeling will continue to calculate different projections.

 

The concern on the UK model is that heavy band of rain approaching the west by Monday,something we could do without.

http://www.meteociel.fr/ukmo/runs/2014010912/UW72-594.GIF?09-18

 

this looks like pushing through and it's beyond this that things get more complicated with the next trough and it's development.

 

The ECM mean looks like pushing this more se than the op run which indicates the blocking to the east will become more influencial.

http://www.meteociel.fr/modeles/ecmwf/runs/2014010912/EDM1-120.GIF?09-0

 

OK maybe no raging easterly but an interesting change to our current pattern which brings something colder towards the UK.

A look at the T96+ T120hrs hrs later will give us some further in sight into the Met Office views.

A cold wall as good as an Easterly? 

[bryan629]

DO WE THINK FI IS T+120HRS AND WOULD ANY ONE CARE TO GIVE US THE ODDS ON THE MODELS FLIPING BACK TO THE EASTERLY OPTION?

close Si.... yesterday it looked like FI was @t196....but todays runs put it at more like t+72/96... lots of changes in the runs to come over next couple of days...don't take anything as gospel till end of weekend.... but enjoy what gets churned out until then 

Edited January 9, 2014 by bryan629

[Biggin]

 I remember several days ago Ian F saying only about 20% MOGREPS  and other in house models 'going for ' an easterly flow....

Shame then they cant feed MOGREPS n GLOSEA9 ))) into the models or even them n all the models into one forecast ?? Then we would only have one model to moan at...

[winterof79]

http://www.knmi.nl/library/php/resample_image.php?filename=/exp/pluim/Data/pluim_06260_0_12_60.png&width=692

Major differences next week.Could go either way

Edited January 9, 2014 by winterof79

[shaky]

http://www.knmi.nl/library/php/resample_image.php?filename=/exp/pluim/Data/pluim_06260_0_12_60.png&width=692Major differences next week.Could go either way

those ensembles look brilliant compared to the gfs ones!!more tightly grouped aswell!

[karlos1983]

http://www.knmi.nl/library/php/resample_image.php?filename=/exp/pluim/Data/pluim_06260_0_12_60.png&width=692

Major differences next week.Could go either way

Indeed, not much clarification there. sure is going to make for some great viewing, much welcomed after the past few weeks

[terrier]

Still think we will see a few more twist and turns with the models yet. Although the ensembles don't paint a great picture tonight. The thing that is worrying at the moment regarding the cold is that the met 16/30 day seems to have trended away from the colder outlook in the longer term. Maybe Ian could shed some light on this? Is the mogreps model pointing towards a mobile outlook for later jan now perhaps?

[bradymk]

those ensembles look brilliant compared to the gfs ones!!more tightly grouped aswell!

They are for Holland though so more likely to be affected by continental flow meaning lower temps. London ens later will give a better indication, not a bad set of EC ENS though..

[AWD]

http://www.knmi.nl/library/php/resample_image.php?filename=/exp/pluim/Data/pluim_06260_0_12_60.png&width=692Major differences next week.Could go either way

There is actually modest agreement on the wind direction for De Bilt being from an easterly quadrant there.When looking at the temperature plots, bear in mind these are for De Bilt and not the UK.There is a rough 50/50 split there (give or take slightly). From the 50% of members that do being in a more pronounced colder airmass, another 20% (again a rough estimate) are likely to have the boundary somewhere between De Bilt and the UK, therefore whilst they look cold on the De Bilt ens, they would look less appetising on the London ens say.So that leaves us with an approx 30% of members to play with.Therefore my rough guess what the London ens will say later will be a 70/30 split, the lesser in favour of a more pronounced colder airmass, the greater a less cold airmass.Off course, I could be totally wrong. We will find out at 23:00ish. Edited January 9, 2014 by AWD

[Essan]

Shame then they cant feed MOGREPS n GLOSEA9 ))) into the models or even them n all the models into one forecast ?? Then we would only have one model to moan at...

 

It's GLOSEA4 and the clue is in the name - a global seasonal model.

But I know what you mean

[East_England_Stormchaser91]

Still think we will see a few more twist and turns with the models yet. Although the ensembles don't paint a great picture tonight. The thing that is worrying at the moment regarding the cold is that the met 16/30 day seems to have trended away from the colder outlook in the longer term. Maybe Ian could shed some light on this? Is the mogreps model pointing towards a mobile outlook for later jan now perhaps?

Forecasting up to 16 days out is nigh on impossible. Who even saw the potential for cold prior to these recent outputs? Pretty sure it was not even trending long term.

Its even hard enough to forecast 24 hours out, let alone half a month. 

[Earth Wind and Snow]

ECMWF ensembles are relatively positive.

 

Lots of potential for a return to colder synoptics.

 

The Day 7 Ensemble mean could be a lot worse..

 

We would all gladly have taken that chart as a 7 day mean only a few days ago..........lots more chopping and changing to come

 

Chins up folks

 

EWS

[bluearmy]

quite honestly, this is getting difficult. the ecm ens mean jet takes the southern split into iberia and north of the uk approaching its latter stages of high res. in low res post day 10, the jet makes progress across the atlantic but still looks unconvincing by day 15 with a continental push fighting back into southeastern uk in two weeks time against the widespread jet energy. this does look to be splitting ne and sw. note that there is a connect off the eastern seaboard into the southern arm which is taking some of the energy away from the northern arm.

 

the general theme is a slowly developing large euro trough which gradually fills somewhat and drifts east. the atlantic high also drifting east and extending ne, to join loosely with the n scandi/nw russian heights which are weakening but still evident in two weeks. this allows for many solutions, an mlb, a mean soueaster, a mean easterly, even a mean noreaster, troughing dropping in from the nw with warm sectors, maybe without warm sectors depending on the track.  this wide range of possibilities was the basis behind my post of earlier where i queried exeters thoughts that mobility would return in the 10/15 day period.  i've stated for days now that although the ext ens show a more mobile atlantic, it has never looked convincing to me, especially the jet profile.

 

to be fair to the met office, ian did post that they have an array of solutions showing and they do need to make a prediction.  unless mogreps-15 is going to go solidly behind the mobility, i dont envy them their task at the moment.

[fergieweather]

 

It's GLOSEA4 and the clue is in the name - a global seasonal model.

But I know what you mean

It's actually GloSea5 now (introduced last year) - just to be a pedant ;-)