Model output discussion 25th Jan onwards

[damianslaw]

I haven't looked at any of the models this morning, as it is a volatile uncertain outlook and I am expecting them to show wild swings from run to the next, as everything hinges on the position and depth of the trough come Wednesday and also the position of heights to our east, which at this stage has to be guess work. So consequently no-one should be getting too hung up on the output post 72-96hrs at best.

 

I said yesterday - the signals are for a significant pattern change over USA/Canada next week with a strong NE Pacific High this is very likely to change the pattern over the Atlantic with strong heights building over eastern seaboard. With such a pattern I can see the longwave trough anchoring itself further to our west pulling in a southerly before being forced SE into France/Iberia thanks to a weakening in the PV, those heights to our east would in tandem move NW towards Norway exposing the UK to a much colder continental feed. I don't expect low pressure to power its way across the country towards Scandi- trough disruption remains the order of the day.

Edited January 26, 2014 by damianslaw

[phil nw.]

In the short term Phil we may well get some clues from the fronts expected to cross Germany in the next 24-36hrs.  On the face of it their progress eastwards seems fairly easy, despite temps of -10 to -15c now being in place, so whilst not exactly in our neck of the woods we may well learn some interesting lessons regarding the models/block durability.

Yes the fax's are the ones to follow for that extra imput from the forecasters.

This evenings T120hrs should give us more of a clue for later in the week re.the block's durability.

A fascinating week to come watching for developments.

[karlos1983]

In the short term Phil we may well get some clues from the fronts expected to cross Germany in the next 24-36hrs.  On the face of it their progress eastwards seems fairly easy, despite temps of -10 to -15c now being in place, so whilst not exactly in our neck of the woods we may well learn some interesting lessons regarding the models/block durability.

 

Shed have you been drawing fronts on the Fax charts, 

[shaky]

Ecm mean at 144 hours much better!!Would probably give plenty of snowfall widely down the spine of the uk!!

[TEITS]

For the sake of the Mods and members I hope arguing doesn't ruin this thread.

 

Lets be honest here whether you prefer cold or mild weather nobody can really say which model is more likely to be correct due to the uncertainty. If we compare this mornings UKMO to last nights 12Z then that says it all.

 

Any newcomers to this forum must be rather confused but sadly this model uncertainty always happens when we have blocking to our E. This is less so when blocking is over Greenland. In my opinion its a flaw in the programming of these models.

 

I shall finally add that im obviously biased towards cold but when I post my interpretations of the output I try to be unbiased.

[Summer Sun]

UKMO 850's are cold again at t96 and t120, especially the further east you go

 

 

By t144 low pressure starts to move into the west

 

[That ECM]

GFS at t60 on o6z is slightly further west IMO. Little changes make big differences in this sort of set up. Also would add, I think some will be surprised in the morning to see some snow. Not just the favoured areas but places much further south than many may think.

[stratty]

Ha Ha so the UKMO changes its mind from last nights awful 12Z and goes back to having the block further W than the ECM/GFS. Before anyone says the ECM/GFS is more likely to be correct then lets cast our minds back a bit.

 

At +72 all models agree with the LP sinking S. However it was the UKMO that modelled this consistently, whilst I recall the ECM & GFS especially flapped around with this. I should add the JMA was also consistent with this.

 

Trying to base a forecast on the output is a nightmare to be honest. Now like I said yesterday I wasn't convinced of a classic type E,ly i.e cold uppers, snow showers because the block would not be far enough W. However I certainly don't buy the W-E movement of LPs and SW,ly winds like the ECM is showing. I still feel the likely outlook is the block will prove more resistant and LPs will be sliders which will increase the risk of snowfall and keep the UK on the cold side.

 

The GEM is my favourite this morning as we see a slider followed by the block advancing W!

 

http://modeles.meteociel.fr/modeles/gem/runs/2014012600/gem-0-240.png?00

 

.

.............that looks a classic easterly to me old boy! bring it on!

Are you becoming more convinced that something like this could still come off?

Edited January 26, 2014 by stratty

[AWD]

The spread on the EC ens post T144 highlight the uncertainty well with ref to Atlantic v block;

This also highlighted in graphical format for both a northeastern location, Newcastle;

And a southwestern location, Bristol;

Plenty of interest for both locations there still, obviously greater the further north east you go.

[Captain Shortwave]

Better run from the GFS so far in the 3 key areas (upstream, east of the UK and the Pacific ridge). Now as that low disrupts what will the shortwave in the Atlantic do, will it cause the whole lot to barrel around or will it with the flatter Azores high drop into Europe without much of a fuss.

Day 5

 

At this point there is no way the Atlantic is getting through, just a case of where the line between rain and snow is. 

Edited January 26, 2014 by Captain shortwave

[chionomaniac]

Quite a shift west already on the 6Z GFS - those colder -10ºC 850's over Scandi are closing in on the UK!

[karyo]

GFS at t60 on o6z is slightly further west IMO. Little changes make big differences in this sort of set up. Also would add, I think some will be surprised in the morning to see some snow. Not just the favoured areas but places much further south than many may think.

Yes much better and it makes a change in the outcome 96 hours. The first Atlantic front is better aligned north to south and it seems to be hitting a wall.

On the 0z it was coming with a more southwesterly angle.

 

Karyo

[Fozfoster]

Quite a shift west already on the 6Z GFS - those colder -10ºC 850's over Scandi are closing in on the UK!

Yeah and the high is at 1052!

[IDO]

You can see the differences with the trigger low at T120 (0z timing):

 

UKMO:   It continues within the confines of the PV

 

GFS:  It will either spill SE or more westerly.

 

Total different synoptics between the GFS and UKMO, so at the moment still not sure the UKMO has got the flow right.

[karyo]

By 123 hours the Atlantic low is much further south than it was on the 0z! 

[winterof79]

For the sake of the Mods and members I hope arguing doesn't ruin this thread.

 

Lets be honest here whether you prefer cold or mild weather nobody can really say which model is more likely to be correct due to the uncertainty. If we compare this mornings UKMO to last nights 12Z then that says it all.

 

Any newcomers to this forum must be rather confused but sadly this model uncertainty always happens when we have blocking to our E. This is less so when blocking is over Greenland. In my opinion its a flaw in the programming of these models.

 

I shall finally add that im obviously biased towards cold but when I post my interpretations of the output I try to be unbiased.

Well put accross TEITS.The problem we have is that in summer when the thread is full of those hunting for heat,coldies do not continually contradict those showing warmer charts.Indeed when the colder brigade post a cold chart in winter they do not follow it up with "another nail in the  barrelling atlantic this winter"etc

 

Back to the 06z and frontal snow Friday if you believe the GFS

http://modeles.meteociel.fr/modeles/gfs/runs/2014012606/gfs-2-126.png?6

Personally i think the block will correct westward as has been the case historically in the past.

[Purga]

Great uncertainty across various model outputs this morning, with the GEM the pick of the bunch especially longer term.

 

ENS showing some reasonable cold runs this time

 

A cracker P9

We can dream...

 

Anyway it's also nice to read METO referring to a 'wintry showers, bright spells and bitter east winds' by Thursday for the SE.

[forecaster]

Very disappointed with the ECM this morning not for what it is showing butfor its complete lack of consistency.You just can not trust its outputanymore.

 

To touch very briefly on this. Two images from work by Anders Persson (previously SMHI and ECMWF) regarding forecast consistency:

[chionomaniac]

Battleground scenario at T+126

 

Beautifully aligned negatively tilted Atlantic low meets the cold air - northern areas could see a bonanza

 

 

 

 

 

[MR EXTREMES]

For the sake of the Mods and members I hope arguing doesn't ruin this thread.

 

Lets be honest here whether you prefer cold or mild weather nobody can really say which model is more likely to be correct due to the uncertainty. If we compare this mornings UKMO to last nights 12Z then that says it all.

 

Any newcomers to this forum must be rather confused but sadly this model uncertainty always happens when we have blocking to our E. This is less so when blocking is over Greenland. In my opinion its a flaw in the programming of these models.

 

I shall finally add that im obviously biased towards cold but when I post my interpretations of the output I try to be unbiased.

that's a very important point tetis there is a clear trend showing that anything beyond 48hrs I feel is fi as has been suggested models don't deal well with the scandi blocks and slider lows, but the ukmo has done very well up until lastnight because it just does not know but is now reverting slowly back as each hour passes.

as low pressures moves se this week there will be so many different outcomes its a case of when one system moves threw then watch things change.

intresting.

Edited January 26, 2014 by emotional rollercoaster

[Liam J]

Better angle of attack as the low pressure smashes against the block, cold SE'ly winds ahead of the front. This chart would bring blizzard conditions in places. 

 

 

 

 

 

[cold snap]

GFS or UKMO are seriously wrong at 120 hour ,

It's almost like there's a glitch

Edited January 26, 2014 by cold snap

[stratty]

...........can we get that LP on Friday to slide!? 06z siding more with GEM in hinting this.................................

[SLEETY]

Great uncertainty across various model outputs this morning, with the GEM the pick of the bunch especially longer term.

 

ENS showing some reasonable cold runs this time

 

A cracker P9

We can dream...

 

Anyway it's also nice to read METO referring to a 'wintry showers, bright spells and bitter east winds' by Thursday for the SE.

might even see the word SNOW in the local forecasts soon.About time,been nearly a year already.

 

Where does the time go,lol

[cold snap]

Sorry off topic

But please when people state blizzards ,heavy snow ,can they state if its referring to sea level or mountains ,think this is causing serious confusion in the forum.