Model Output Discussion - 14th Jan 12z Onwards

[Thunder Snow]

Look again. But let's not get too hung up on individual runs.

Have I misread them? Am I wrong

[knocker]

The GFS take on the slider lows is slightly different this morning  It has the first one sliding down the west of the country and it then turns NE and the next  low swivels around it before moving off Se and bringing easterlys to the UK for a very brief period before the Azores ridge takes over.Quite cold and no point guessing snowfalls. After that back to zonal with LP to the NW and HP to SW but the situation  is so fluid there is still no certainty of next week so no point in going there.

Charts courtesy weatherbell

Edited January 15, 2015 by knocker

[Ali1977]

Not looking as good as last night with the GFS or UKMO, the long drawn Easterly that was bringing the real cold has gone. Hopefully the ECM and next GFS bring it back.

[knocker]

For the weekend I'll stick with the latest METO fax charts.

 

[SMU]

The short term ECM is much better than the 12z ECM & alligned to the GEFS suite trending which is to leave the shallow low over the north sea in situ for longer providing a colder surface feed -

In turn the slider has become even more elongated & has split to 3 vortices with the first @ 120 being 1000 MB allowing for minimal mixing ahead of it.

You can see this because the -6 c isotherm stays in the SE for that timeframe.

By 144 the secondary is sliding through ireland & is slightly deeper, however crucially ( mainly for the SE ) the third low sits in the continent blocking a southerly onshore flow

This could be the difference between rain or snow.

ECM + UKMO Alligned again at 144 with ukmo shallower....

For those wanting more snow the trending is better today with the eCMs third vortice exactly what we need -

S

[winterof79]

Heights reaching out to each other over the NH in a bid to separate the PV

Edited January 15, 2015 by winterof79

[West is Best]

There may be a little disappointment about the 0z GFS for long-term prognosis and the slider situation is a series of messy charts. However, there's actually considerable snow potential for Saturday through Wednesday from that run. I find the GFS snow risk tab pretty accurate and in terms of that there's a big step forward. 

 

ECM is a belter of a run for cold: at T192 through T240 showing a cold continental easterly.

 

UKMO I don't really know because I'm finding the data hard to extract. Looks okay to me but what's going on with their output?

 

Overall, despite the long term GFS outlook there's significant snow potential in the short to medium term.

[shaky]

Another good model output this morning! ! Ecm is much better uppers wisw for the south and is more in line with the 12z ensembles!! So maybe a dumping of snow for more southern areas!! Ukmo looks brilliant with a scandi high and shallower low!! Gfs same although now takes front further east for Monday and Tuesday although some are saying they would take the gfs cos of the amount of snow its showing!!

[Severe Siberian icy blast]

There may be a little disappointment about the 0z GFS for long-term prognosis and the slider situation is a series of messy charts. However, there's actually considerable snow potential for Saturday through Wednesday from that run. I find the GFS snow risk tab pretty accurate and in terms of that there's a big step forward. 

 

ECM is a belter of a run for cold: at T192 through T240 showing a cold continental easterly.

 

UKMO I don't really know because I'm finding the data hard to extract. Looks okay to me but what's going on with their output?

 

Overall, despite the long term GFS outlook there's significant snow potential in the short to medium term.

Mate iv been having a right mere with meteociel for the ukmo , can't see the data on there

[terrier]

This mornings output is the reason I didn't get carried away last night. The ukmo and gfs is very messy indeed this morning with warm sectors moving into next week for the South bringing rain and sleet. Think these slider lows are fraught with danger. And I think we all need to be very cautious still. As they say if the charts look too good to be true then they probably are especially in the uk.

[shaky]

Steve whats the snow line on the ukmo and ecm chart you think?

[PompeyFC]

Another good model output this morning! ! Ecm is much better uppers wisw for the south and is more in line with the 12z ensembles!! So maybe a dumping of snow for more southern areas!! Ukmo looks brilliant with a scandi high and shallower low!! Gfs same although now takes front further east for Monday and Tuesday although some are saying they would take the gfs cos of the amount of snow its showing!!

 

Looking at meteocial - the GFS doesn't show that much snow for the whole country just midalands Northwards - alot of it looks rainy/sleety further south you get.  Still along way to go until next week yet and plenty of upgrades / downgrades will happen I suspect whilst the models struggle to deal with the evolution come the week-end and beyond

[Severe Siberian icy blast]

This mornings output is the reason I didn't get carried away last night. The ukmo and gfs is very messy indeed this morning with warm sectors moving into next week for the South bringing rain and sleet. Think these slider lows are fraught with danger. And I think we all need to be very cautious still. As they say if the charts look too good to be true then they probably are especially in the uk.

I agree that the charts look a tad messy but there's plenty of time for changes still , next wk looks cold and wintry , whether that be heavy settling snow or wet sleet and snow nobody knows yet , but enjoy the ride!

Edited January 15, 2015 by Severe Siberian icy blast

[The Beast From The East]

The GFS take on the slider lows is slightly different this morning  It has the first one sliding down the west of the country and it then turns NE and the next  low swivels around it before moving off Se and bringing easterlys to the UK for a very brief period before the Azores ridge takes over.Quite cold and no point guessing snowfalls. After that back to zonal with LP to the NW and HP to SW but the situation  is so fluid there is still no certainty of next week so no point in going there.

Charts courtesy weatherbell

Good morning

I wonder if that is what the met office were seeing when they wrote there update yesterday ?

"UK Outlook for Monday 19 Jan 2015 to Wednesday 28 Jan 2015:

Dry, cold and clear for much of central Britain on Monday and Tuesday with showers affecting many coastal counties away from the south, readily falling as sleet and snow. There will be a widespread frost overnight and some localised patches of freezing fog which may be slow to clear through the day. Through the rest of next week, the general cold conditions will persist bringing an ongoing risk of snow, more especially in northern and eastern areas. Temperatures will be generally below average with overnight frosts, locally severe. Towards the end of the period there looks to be a possible return to more generally unsettled conditions with rain, strong winds and temperatures perhaps nearer to normal for the time of year."

Hope we get a decent cold spell. ⛄

[fergieweather]

Reasonable agreement in assessment of 00z UKMO and other output for the scope of Mon-Tues evolution but still only broad-brush detail possible. Without describing all the rationale and diagnostics, we expect essentially a risk of (perhaps significant) snow Wales/Midlands northwards. Marked uncertainty how long the cold weather lasts before a return to around average temperatures.

Edited January 15, 2015 by fergieweather

[Ali1977]

Going off the METO update above, and the charts this morning the beast doesn't look like materialising as shown last night, the ECM tries but it looks like heading South rather than directly into the East coast. Lots will change I'm sure, I'd just be surprised if it's for the better....Maybe Ian F will shed some light from this mornings thoughts from Exeter!!

[MR EXTREMES]

This mornings output is the reason I didn't get carried away last night. The ukmo and gfs is very messy indeed this morning with warm sectors moving into next week for the South bringing rain and sleet. Think these slider lows are fraught with danger. And I think we all need to be very cautious still. As they say if the charts look too good to be true then they probably are especially in the uk.

dont think everyone should worry as steve murr suggested in lastnights posts he did suggest favoured areas.

the models have downgraded some what but not to the point where cold has gone,

its more to the point that realistically the higher heights just start to sink the pattern.

 

but alot will and have experienced something alot colder.

im skeptical of anything for the south and southeast we need enriched cold upper air embedded from the east and north east steve was right last night it was close a few runs ago but has some what declined not for all.

[winterof79]

This mornings output is the reason I didn't get carried away last night. The ukmo and gfs is very messy indeed this morning with warm sectors moving into next week for the South bringing rain and sleet. Think these slider lows are fraught with danger. And I think we all need to be very cautious still. As they say if the charts look too good to be true then they probably are especially in the uk.

 

 

Height rises to ou N/E halting the sliders progression east

 

And to some extent the ECM which goes on to build these and who knows what if it extended.Its a good situation if thats all we have to complain about thats complicating matters 

 

[snowangel32]

Where is that stunning easterly gone i knew this was not a done deal. And still further upgrade and downgrades to come and as for snow not looking as good as warm sectors look to be mixed in so its hit and miss to who gets snow and who gets rain. But looking further ahead into late jan, feb the pv looks on its legs just needs a knockout blow and a bit of luck for us to be on the right side of it.

[I remember Atlantic 252]

Boxing day style a big possibility then? I'll settle for that, although northern areas did better

[MR EXTREMES]

Where is that stunning easterly gone i knew this was not a done deal. And still further upgrade and downgrades to come and as for snow not looking as good as warm sectors look to be mixed in so its hit and miss to who gets snow and who gets rain. But looking further ahead into late jan, feb the pv looks on its legs just needs a knockout blow and a bit of luck for us to be on the right side of it.

i think the main problem is there is still just a little to much energy in the greenland area the slider is still on but it takes forever to clear to the south southeast.

could really do with a bit of a shift west or southwest of the slider to get the cold in first although still very cold surface temps.

 

but for the midlands south sw and se things dont look rosey it could well change but hey even if we lose the cold after day 8 theres always a chance feb could see a return.

[IDO]

As many said yesterday there are so many potential outcomes for Monday onwards, some good but some not so (for snow). The GEM highlights how it is easy for things to not go to plan even at this stage. It does not sink the first low at T90 and the following sliders just merge in situ over the UK:

 

 

Lots of mild sectors and the cold uppers get washed out some what.

 

Looking at the D8 GEFS still lots of very good runs and only a small cluster (expected) of spoilers so the UK is confined within some sort of trough with the continued modelling of the below average upper flow. That flow is very consistent (for London) around -5c for the 7 days from tomorrow. I was hoping that flow would get colder as it is borderline for snow at the moment:

 

 

ECM is consistently maintaining a theme and at D10: 

 

It is apparent that initial Atlantic low has caused most of the uncertainty. It is now not diving to Africa hence the consensus of the trough building but ECM is further south than GEM:

 

 

UKMO sends it further south than ECM: 

 

GFS pushes it further east allowing the Azores to ridge in and we don't get the amplification that the ECM/UKMO get:

 

 Control: 

 

The Control is closer to the ECM sending it to Portugal and we get a similar setup to the ECM, messier because of its lower resolution.

 

It will be interesting to see who has nailed this feature as clearly it will have a knock on effect. No clear sign of any longevity in the GEFS clustering, an Easterly does not look to have much support. So at the moment it looks like a 7 day cold hit with large uncertainty to how cold and how snowy.

 

 

 

 

Edited January 15, 2015 by i'm dreaming of...

[Frosty.]

As they say in game of thrones..winter is coming..we have cross model support for a very cold wintry spell next week, especially for the north & east.

[EML Network]

I know that everybody is excited, but I must be missing something. 

 

The pattern to me seems to flatten out very soon after an all too brief NE' sterly and we look to be back to square one all too quickly. 

 

 

 

Not only that but the ''slider'' isn't far enough West, you end up with a one or two day window , very similar to what happened over XMas and boxing day

 

.

 

I'm sure those in the usual places will get a pasting whilst us in the snow starved south will get naff all

 

Enjoy it whilst it lasts because if you ask me it aint gonna last long

I hate to say if, but after being gunned down yesterday for my post above I can't help but feel a tad smug this morning, although I would MUCH rather be proved wrong and have a shed load of snow.

 

Problem is with these sorts of sets ups especially when you're looking at a slider coming from the North West, is that if you don't have a sufficient block out to the East then the Low simply stalls over the UK for a day or so, warmer air mixes in and all too often you end up with a one day period of cold weather as the Low tracks SE of North Easterly and again if the block to the East isn't sufficiently strong then the Atlantic gathers pace and then you're looking at another 2 weeks before the next opportunity presents itself. 

 

The GFS Ensembles have given me hope this morning though, so there's still a lot to play for. 

 

I do think that we will all see something in the way of snow, before this month is out, even here along the S.Coast. 

 

If I have to get a coat on and take a wonder into the hills to see some of the white stuff falling from the sky then so be it. 

My ;pick of the bunch this morning is the ECM, can't see why folks are saying it's a downgrade from yesterday it's clearly not ?

 

It will keep the cold locked in for the entire length of the run, I really don't think a lot of posters understand how to read a chart  tbh

 

How is this a downgrade ??

[snowangel32]

i think the main problem is there is still just a little to much energy in the greenland area the slider is still on but it takes forever to clear to the south southeast.

could really do with a bit of a shift west or southwest of the slider to get the cold in first although still very cold surface temps.

 

but for the midlands south sw and se things dont look rosey it could well change but hey even if we lose the cold after day 8 theres always a chance feb could see a return.

Yh i agree the snowline looks at present as usual from about bristol north but could all change. And as for the pv and energy i do think it will move more towards siberia as i read yesterday a wave warming is likely so surely that will put even more pressure on it i dont think the models have taken that into account yet and like i said the pv is on its last legs. Really have a good feeling that feb could be special.