Model Output Discussion - Stormy Period Inbound...

[Dr. Astro]

Surely the top chart is mis leading.

If we want cold n/e or easterlies, then the above charts wont be that cold.

You would need to look at the temp anolomy  from say the 18th onwards.

 

The top chart is the 2m anomaly, from 13th January to the 21st January.

[Frosty.]

6z parallel is nothing short of SENSATIONAL..it's yet another upgrade on the wintry theme of earlier output, a significantly upgraded Northerly with -10 T850 hPa flooding south. We have Northerlies and Easterlies on this run, it's almost perfect in my opinion and an enormous improvement from last winters and early this winters Atlantic dross...mild sectors are snuffed out which is great news for coldies...I'm looking forward to the snow, ice and a sharp frosts during the weeks ahead.

[Stormyking]

Some fantastics charts this morning from GFS, GFS P and even the ECM is on board with the idea! Its also nice to these changes occuring in the closer time frame aswell! Come onn, everything is crossed for this too happen!

[Smiler1709]

If these current outputs verify then what are the chances on snow on the south Coast, desperate for my 2 year old to see some of the White stuff, any info would be much appreciated.

[bluearmy]

Hadn't noticed that WSI tweeted the ecm wns mean/anomoly D15 yesterday's 12z run

The 00z not as good but I would caution it also isn't necessarily consistent with previous runs.

[nick sussex]

Are you expecting an easterly like that though nick? A Scandi high based easterly?

A euro trough of some kind seems reliable so that means we don't need a strong easterly to deliver wintry Sypnotics.

Plenty of water to flow under the mid term bridge at this stage though.

Any easterly will do! Regardless of whether its one based with high centre to the north rather than Scandi, the former at this point more likely.

 

I agree though re the Euro trough, as long as that's there it will be on the wintry side, still a lot of outputs to get through however so we'll just see how things evolve.

[SE Blizzards]

Oh no! don't say that! lol Easterlies are the least reliable synoptics to verify, it doesn't matter if you have total agreement at T144hrs.

 

I'd advise people to not get drawn into early celebrations. The easterly is coming when its shown within T96hrs and normally to be 100% sure its best to wait to T72hrs.

 

Wise words there nick.

 

GFS 6Z ENS 2M Temps Central England..

 

 

Without doubt the coldest set of the Winter thus far, with a few very frigid runs starting to appear.

 

I see this mornings output a bit like the end of the 1966 World cup Final -

 

At the moment we're all (apart from IDO and Knocker) on the pitch (i.e getting ready to celebrate), we're all hoping that it's all over (i.e we're all hoping this time it's for real), and in the next 48 hours or so we'll find out whether Geoff Hurst completes his hat-trick, and if he does we can all say... ''It is Now'' (i.e it's coming!

Edited January 13, 2015 by SE Blizzards

[nick sussex]

If these current outputs verify then what are the chances on snow on the south Coast, desperate for my 2 year old to see some of the White stuff, any info would be much appreciated.

Of course it's a big if but the ECM/ GFS's would deliver snow. The GFS's with that strong easterly flow would likely bring some decent snow showers. There might also be some more organised precip working westwards. Although you're inland and further west experience from living down that way if I was still there I certainly would be happy to see the GFS's verify.

 

The ECM is a bit more complex and with shortwaves running se on the eastern flank likely snow, that could bring significant snow to favoured areas.

 

The ECM however is more messier and risky, if I had to choose which I'd prefer to see verify it would be the GFS trend if only because its less stressful !

 

I should add if I was living in the west I'd go for the ECM with a westwards correction, generally if the models start increasing the blocking signal to the ne then normally this gathers pace with westwards corrections.

Edited January 13, 2015 by nick sussex

[terrier]

Some nice charts this morning. Gfs gfsp and ECM all seem in agreement about something colder heading for our shores. But still a huge slice of caution from myself. Until we see the met office come on board I will remain sceptical for now. Especially were a easterly is concerned.

[bluearmy]

Some nice charts this morning. Gfs gfsp and ECM all seem in agreement about something colder heading for our shores. But still a huge slice of caution from myself. Until we see the met office come on board I will remain sceptical for now. Especially were a easterly is concerned.

 

you're onboard then mate - read their update  (from the android ap 6/15 dayer)

 

There is also a low risk of some more persistent rain and perhaps snow moving across southern and central areas for a time. Through next week, there is a trend towards generally colder conditions than of late bringing an increased risk of snow, more especially in northern and eastern areas. Temperatures will be generally below average with overnight frosts, locally severe.

Edited January 13, 2015 by bluearmy

[TEITS]

Just a word of caution for those in the W with regards to a possible slider LP.

 

What has basically happened since I noted the potential since yesterday morning is the models ,especially GFS, are trending towards more significant high pressure to our N with the slider LP backing further W. So with this trend developing what could happen is the Low pressure misses the UK as it tracks W of the UK on a SE,ly trajectory. The positive of this is a stronger more sustained colder spell beginning with a N,ly before veering to a NE/E,ly.

[legritter]

good afternoon ,my practice on chart downloading is nearly complete ,just need to get the chart to appear on my post .we are i feel sat watching the possible change we were all hoping for and todays models are delivering .As other posters have pointed out we dont need a big block situated in a clasic synoptic situation just some reasonable low temperatures if a trough front approaches aligned correctly .A Historical example would be Feb 18th 1978 ,low tracking s/east then east /s east to our s west ,it was a surface high on near continent that gave us the temp for a pasting for some .i do so much like todays ECM ,hoping tonight will be a big upgrade of sorts in its later frames .Gfs a very usefull tool for finer detail sometimes and of course Met Office Faxes very handy for getting a feel on how things are changing during the 24hr period .Another point regarding current possible synoptics is that we can get situations say 4 days ahead which look good for snow then it is taken away ,but another good possibility arrives because of that developing situation ,all very frustrating but we are weather watchers ,so i will finish and await this evenings model runs ,  

[winterof79]

you're onboard then mate - read their update  (from the android ap 6/15 dayer)

 

There is also a low risk of some more persistent rain and perhaps snow moving across southern and central areas for a time. Through next week, there is a trend towards generally colder conditions than of late bringing an increased risk of snow, more especially in northern and eastern areas. Temperatures will be generally below average with overnight frosts, locally severe.

Glad to see yours has updated i am still on this mornings 02.05 am

[snowangel32]

Hope the ecm is the winner shows more disruption and more snow. An easterly can sometimes be good but overall they mainly bring dry and cold conditions with wintry showers to the east coasts. Sooo come on ecm bring the snow.

[Frosty.]

the met office 6-15 day update is going to show a marked change very soon.

Met office latest update is a lot more wintry.. it looks like the Gfs parallel output in particular should be applauded this afternoon, and of course the Ecm 00z..yipeeeee

Edited January 13, 2015 by Frosty.

[MR EXTREMES]

Met office have not updated there outlook since this early hours of this morning!.

But what I have noticed is the shift of cold goes from the west side to the Eastern side so that tells me a northerly and North easterly.

To be realistic they also mention milder during rain this of coarse is the warm sector issues.

It's also worth noting that before Christmas all models were onboard with a colder outlook only for the whole lot to collapse.

But is this the work of wave 1&2 strat activity certainly looks that way.

The one positive for coldies is the removal of higher heights into Central Europe and lower heights to our East for now with the Azores out the way to the south east although I still don't fancy the chances on Greenland heights although back in 09/10 winter the initial signs were not far of what it's like now was stormy wet and slowly but surely gathered pace !.

It's possible but I'm absolutely a nervous reck because we been here before.

Although seeing the ukmo in a good position for cold fills me with hope but also caution as last night NOAA ditched the ukmo!.

Did the ukmo have its raw output modified or did they go with the raw output?.

[fergieweather]

That is exactly the hope - with the main strat vortex shoved over to russia - there could be enough in there for the UK. So far we have seen the positive height anomalies hogged by the Pacific. That is not neccessarily a bad thing - but only if the vortex is weak enough to also allow Atlantic based height rises. I'm sure we are reaping the rewards of the 1/2 SSW (my term!) earlier in the month.

UKMO indicate it is thought to be MJO-related in their latest assessment. They note the risk of a more blocked scenario establishing (as per some DET runs and also EC-EPS members), at least for a while, with enhanced likelihood frost/snow, especially in E re latter. However they also advise on 'fine balance' UK sits in re any blocking to E versus mobility from W... no high confidence yet on which will prevail.

[Neilsouth]

[knocker]

UKMO indicate it is thought to be MJO-related in their latest assessment. They note the risk of a more blocked scenario establishing (as per some DET runs and also EC-EPS members), at least for a while, with enhanced likelihood frost/snow, especially in E re latter. However they also advise on 'fine balance' UK sits in re any blocking to E versus mobility from W... no high confidence yet on which will prevail.

 

Looking at the ext EPS mean from 00z and the latest EC32 output I certainly wouldn't put money on extended blocking based on that.

[fergieweather]

Looking at the ext EPS mean from 00z and the latest EC32 output I certainly wouldn't put money on extended blocking based on that.

No. Exeter add signs of mobility return later in trend period.

Would you be kind enough to guide us on wether the forecasts have updated on line please,as some of us are not seeing an update as yet.

 

Many thanks

I've no idea. I believe those are a PWS task.

[Paul]

As much as I understand the wish to ask Ian F loads of questions when he comes online - can we try to keep it to the models, and not bombard him with general forecast questions and the like, for both his sake and the threads!

 

Thanks

 

Paul

[Mucka]

I don't think these have been posted yet, ECM London ensembles

 

 

Certainly cold but not quite in the freezer.

I think more people would rather have a snowy 2c than a dry -1c though and that is the most exciting (and possibly frustrating) part of the prolonged slider synoptic that ECM fancies.

There could be plenty of falls of snow but this time there would be more of W/E split than just N/S with the snow line again moving back and forth. Too far East and the West gets rain and the East snow, further West and the West gets snow and the East stay dry, too far West and we all stay mainly dry but colder.

 

As to whether we get a sustained blocking spell or the Atlantic pushes back in from the NW bringing a return to cold zonal (though possibly weaker with more disruption) is up in the air but a chilly spell of weather with rain/sleet and snow looks very likely now.

 

I posted about the possibility of low pressure disrupting SE quite some time ago but it wasn't favoured at that time, just a weak signal I saw within the ensembles and then again later about the possibility of a surprise Scandi high setting up in such conditions but I am surprised the rapid flip toward cold from last night even if GEM and GFS and other bits and pieces of output hinted at the possibility.

Probably GFS deserves the most praise for sniffing this out though GEM gets an honourable mention as it also sniffed the possibility but was far less consistent or coherent with the signal.

 

This is still a fairly precarious evolution so some caution required but if it survives through this evening and tomorrow I think we can start thinking about upgrades and seeing the sort of potential Blu Army mentioned earlier, height rises toward Greenland in the later timeframes.

Any Easterly could benefit the SE obviously but I would like to see it modelled at a higher latitude with better troughing to South. It is hard to see how an Easterly could be sustained for more than a few days with the jet running over the top so unless we see some upgrades a la ECM with undercut potential or a signals for heights to build toward Greenland later then deep cold long term could be elusive.

That is all just for MO enthusiasts though as there looks to be lots of chilly and potentially snowy weather just around the corner (current transient snow no t withstanding) to enjoy.

 

To all the snow starved weather geeks out there, good luck!

Edited January 13, 2015 by Mucka

[Frosty.]

Met office have not updated there outlook since this early hours of this morning!.

.

BA posted a snippet of their update which is a lot more wintry than previously, indeed, it's the most wintry update for a good few years, much more in line with gfs p and ecm

Im glad we are seeing an end to this daily switching of milder and cooler airmasses with cold air now likely to dig in from the weekend onwards with an increasing risk of snow and severe frosts.

Edited January 13, 2015 by Frosty.

[Ali1977]

 

If we can get a 4 or 5 day Cold spell I think that would be great considering it has only really jumped out the hat in the last 24 hours, the good thing with Easterlies is that when they do embed in they are sometimes hard to get rid of.  Now we just need the continent to cool down rapidly so that if the winds do veer E/NE they are slightly more potent.

[chionomaniac]

UKMO indicate it is thought to be MJO-related in their latest assessment. They note the risk of a more blocked scenario establishing (as per some DET runs and also EC-EPS members), at least for a while, with enhanced likelihood frost/snow, especially in E re latter. However they also advise on 'fine balance' UK sits in re any blocking to E versus mobility from W... no high confidence yet on which will prevail.

I think that it is great that they are using this behind the scenes. I guess that perhaps they are leaning more towards the ECM MJO forecasts as latests mogreps forecasts that we have access to show a rapid entry to the COD prior to phase 7 whereas the ECM ENS have more amplitude into phase 7 (better looking than a few days ago).

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

 

All good for those hoping for a bit of proper winter (and I wouldn't rule out some downwelling having an effect either)