Model output discussion - proper cold spell inbound?

[Nick F]

Although the upper pattern looks disappointing later next week, not entirely convinced of the rounded vortex over Greenland and flattening out to zonal flow the GFS and EC seem keen on. A look at the EPS clusters suggest good support for trough disruption to continue in vicinity of the UK later in the week, with perhaps an underestimation from operational output of the positive height anomalies to our NE from WAA and surface cold block, thus overeagerness to push through Atlantic westerlies into NE Atlantic and NW Europe.

It has been noted elsewhere, namely from U.S. mets, that the model output today, particularly EC, seems to be contrary to what the analogs for the MJO phase response of the upper patterns should be. So we should perhaps be wary of looking past day 5/6 and as a result we may see some changes tomorrow to less zonal looking outlook beyond day 5.

But even if we do return to a more mobile and less cold pattern later next week, I feel fairly confident it will be short lived, as the upper pattern response to MJO through 7 to 8 and ensemble guidance points to blocking reasserting close to the NE from mid-month, which could be further bolstered by a SSW.

[Nick F]

Please could we discuss the models and not the BBC forecasts, there is a thread for that ... there has been plenty of warnings from the mods to keep on topic yet people still are ignoring it!

[blizzard81]

10 minutes ago, Nick F said:

Although the upper pattern looks disappointing later next week, not entirely convinced of the rounded vortex over Greenland and flattening out to zonal flow the GFS and EC seem keen on. A look at the EPS clusters suggest good support for trough disruption to continue in vicinity of the UK later in the week, with perhaps an underestimation from operational output of the positive height anomalies to our NE from WAA and surface cold block, thus overeagerness to push through Atlantic westerlies into NE Atlantic and NW Europe.

It has been noted elsewhere, namely from U.S. mets, that the model output today, particularly EC, seems to be contrary to what the analogs for the MJO phase response of the upper patterns should be. So we should perhaps be wary of looking past day 5/6 and as a result we may see some changes tomorrow to less zonal looking outlook beyond day 5.

But even if we do return to a more mobile and less cold pattern later next week, I feel fairly confident it will be short lived, as the upper pattern response to MJO through 7 to 8 and ensemble guidance points to blocking reasserting close to the NE from mid-month, which could be further bolstered by a SSW.

The GFS 18z control seems to concur with your thoughts. Greater trough disruption and the almighty pv to our north west curling up tight and not knowing what to do with itself. A little like the position it finds itself over the next couple of days. It loses it at 180hrs though. 

Edited February 2, 2018 by blizzard81

[blizzard81]

Lol ? Anyway, the gfs 18z mean shows a clear fight back from the east in around 2 weeks from now. Here's hoping

[ITSY]

To add to nicks point, and to my post last night about the latter stage impacts of the next MJO phase and SSW, see the emerging trend in the far flung reaches of FI. (Before criticism rains down, I know these charts won’t verify - there are here merely as an indicator that longer term changes towards Mid and High Latitude Blocking could, as per meto forecasts, start to emerge in near future runs)

 

[blizzard81]

18z ensembles look reasonable enough. Tailing off towards the end again. In line with meto's thoughts. 

[MildCarlilse]

In these troubled times I quote loosely John Holmes and his opinions of what the 500mb charts were showing...no blocking.

[comet]

History shows us that our coldest winter weather has come from strat warmings (not all I know). The warming and split being modelled is almost off the scale and if we are to see a severe winter cold spell then this is what you would need and want to see.

 

 

[shetland islands]

Week ahead. Cold = yes, significant snow and a memorable event = no! 

[ICE COLD]

3 minutes ago, MildCarlilse said:

In these troubled times I quote loosely John Holmes and his opinions of what the 500mb charts were showing...no blocking.

Troubled times ?? And he also said there would be no easterly . 

But there is , isn't there . 

[ICE COLD]

8 minutes ago, blizzard81 said:

18z ensembles look reasonable enough. Tailing off towards the end again. In line with meto's thoughts. 

Yep pretty decent . That mild sector around the 9th still has a lot of spread . 

[davehsug]

2 minutes ago, ICE COLD said:

Troubled times ?? And he also said there would be no easterly . 

But there is , isn't there . 

Come on, there's a world of difference between an "Easterly" as it would be understood by most weather savvy people, and winds coming from the East as a result of the alignment of different weather systems.

[ICE COLD]

2 minutes ago, davehsug said:

Come on, there's a world of difference between an "Easterly" as it would be understood by most weather savvy people, and winds coming from the East as a result of the alignment of different weather systems.

But it is a easterly . No not a raging beast 80s style but still it is and it's pretty cold . 

[MildCarlilse]

23 minutes ago, ICE COLD said:

Troubled times ?? And he also said there would be no easterly . 

But there is , isn't there . 

My friend,the easterly is there,over south east England and based on those charts,hardly blocking is it? 

[Penrith Snow]

So much hype on here yesterday it had to end in tears and so it has.

No model predicted widespread snow but you wouldn't believe that reading some of the threads.

So back on planet Earth the outlook is one of cold conditions with some sleet and snow but a prolonged nationwide cold spell it ain't and never was.

Andy

[Mucka]

2 hours ago, karlos1983 said:

De Bilt 

That suggests the Atlantic will get in from around the 10th but it doesn't look like it gets things all its own away thereafter according to these.

Some odd comments above this one. I'm not sure what people expect from UK cold spells but temps for central England are forecast to barely get above freezing for 5 days with hard frosts at night and snow in the forecast - if only that were our ordinary winter weather.

We go whole winters only dreaming of a synoptic such as this do we not?

Edited February 3, 2018 by Mucka

[Daniel*]

1 hour ago, Richard Fisher said:

Not even a cold spell really,  just normal Feb weather.  

Could you please, add some meat to the bones to back up that assertion? Perfectly normal February weather, perhaps you are living in a parallel universe, nothing to see here? 

Only 10C departure from norm in two days time in upper temps through large swathes of the country. Something you do not see often I tell you that, that is very infrequent and anomalously cold a fairly rare visitor. The things I read on here, by god. Next week by and large is looking very cold, coldest spell of the winter for most. One doesn’t need the beeb to know how cold it will be, and whether there will be snow, we have the ‘tools’ just as they do. The NWP reflects a good chance of snow potentially widespread opportunities, not limited to here and there as is often the case. Initially snow will be largely confined for the E/SE in form of showers, tentative signs of some really interesting wintry weather Sunday night into Monday across the snow starved SE quadrant. So much going on for us coldies. Deep breaths people! 

Edited February 3, 2018 by Daniel*

[Daniel*]

2 hours ago, davehsug said:

Come on, there's a world of difference between an "Easterly" as it would be understood by most weather savvy people, and winds coming from the East as a result of the alignment of different weather systems.

It has not come from nowhere and isn’t a blink and you’ll miss it, we have a blocking ridge that extends to NE it is an “easterly” and there is a blocking high, in the true sense of the word.

CAA is funnelled right at us beneath ridge, how many times in recent winters have seen the very cold go to SE of us, change in that sense is imminent. It doesn’t last long in that aesthetic form, but cold air has established in that time. And what the models show now, I’m really quite sure the progressiveness is overdone seen it too much, this has been happening in the last few days the models have been trending fronts making less and less eastern progression suggestive cold air will put on more of a fight. I notice GFS and ECM especially made note of quire a noticeable mild sector giving rain midweek, only for the ensembles to show they sat right at the top in the least support. IMO I can see it being squeezed out. Showing the greater infulence of cold block to the NE. And because of all that snow rather than rain will be the ‘headline’ next week. 

T48 what a wonderful winter chart to have very cold air has origins from frigid Russian continent. Snow showers starting to feed in the SE possibly streamer(s), quite powdery in nature. 

 

[Daniel*]

9 minutes ago, Fender.. said:

Well first of all the NWP is pretty poor at predicting snowfall.  Secondly you cant seriously compare  professional  forecasts from the BBC, with armature hopecasting from snow staved members on here..  Finally 3/5c  daytime temperatures in early Feb are nothing special.  The uppers may be pretty frigid, but the 2m temperatures are not.

It will be on the cold side, but many places will see little in the way of snow.  Now of course all this is subject to change, but thats the way its looking at the moment

.  

Isn’t that ironic? Would that make you even more dubious if there is a lack of a snow signal? Yes, you seriously can okay not everyone on here if you know who to look for then you’re set, but there are many that go by that amateur title, and they’ve just as much knowledgable and passionate as those in Exeter - so many can attest to this do not disrespect them like that. Even GFS I notice doesn’t have highs as high as that if you only went by televised forecasts I too indeed would be, what is the fuss about next week? But annoyingly as is often the case, it’s not in sync with what the models show. I’m seeing 7C forecast on beeb Sunday for London and there’s a greater chance of hell freezing over. The 2m temperatures will be very cold next week, this is not deeper in Spring this is the first week of Feb prime time for very cold wintry conditions.

 

Edited February 3, 2018 by Daniel*

[Daniel*]

T+90 comparison between 18z and 00z note the Azores high more pulled back - this is better and less positively slanted. 

Edited February 3, 2018 by Daniel*

[Daniel*]

Certainly less progressive so an upgrade of sorts so far however that is not surprise when seeing where GFS 18z op sat.

[Mucka]

Fair to say UKMO would be even colder than GFS at 144 with a more direct polar flow and less mixing. snow showers for the NW after band of rain/sleet/snow has passed through.

 

GFS still too flat IMO but even so the Russian high is much further East than previous runs by day 8

Edited February 3, 2018 by Mucka

[Always a red]

40 minutes ago, Mucka said:

Fair to say UKMO would be even colder than GFS at 144 with a more direct polar flow and less mixing. snow showers for the NW after band of rain/sleet/snow has passed through.

 

GFS still too flat IMO but even so the Russian high is much further East than previous runs by day 8

Russian high being further east a good or bad thing for cold hopes Mucka? I`m guessing bad??

[jvenge]

GFS teases with height rises throughout the unreliable. With an amusing switch to the Iceland/Greenland route towards the end.

In the middle of the run, this air chart tells the story. It isn't mild in Europe, but also a lack of frigid air. Leading to conditions I will technically describe as "meh"

 

 

[Mucka]

8 minutes ago, Always a red said:

Russian high being further east a good or bad thing for cold hopes Mucka? I`m guessing bad??

Oops, I meant further West, so a good thing. Can't edit now either. 

Edited February 3, 2018 by Mucka