Model output discussion - 7th January onwards

[BLAST FROM THE PAST]

44 minutes ago, January Snowstorm said:

And at 240hrs the ecm has lost all heights to our North. Bitterly cold over England though with ice day likely. Scope for upgrades later.....We need them

Yes bitterly cold but there are heights to the north east.  However, and I’ve mentioned this a bit, the heights will be under attack but in our favour as the surface heights enough to keep the disruption and deflective angle of attack. Expect another arctic attack from displaced PV plunging NW/SE.  With deep cold over us and very low surface temps....l anticipate a very wintry scene towards months end....  indeed which could be on top of a pretty wintry scene beforehand.

This morning imo we have the best support across the board for a very cold outbreak to start next week....it’s getting close now

 

BFTP

Edited January 18, 2019 by BLAST FROM THE PAST

[karlos1983]

Crikey! Not sure how anyone musters up anything negative about the overnight runs.

1. Did the UKMO improve? Check  

2. Do the ECM and GFS still show and easterly? Check

3. Are we very much in the winter games for the first time this winter? Check

EC mean at 144 (important time frame)

BINGO

ps some of you wake up far too early to look at the models. I’d have to peel my eyes open and nail them to my forehead at that hour. 

[WhiteFox]

3 minutes ago, PersianPaladin said:

Yes, the trends continue in much the same way but as I said yesterday - the set-up is precarious and highly changeable within a short time-frame. I don't know about how the different models resolve the resolution of the upper-troughing west of Greenland or over N.Canada, but I'm suspect of this pattern. I think given the record in these situations, the extent of that cold air will end up producing sufficient cyclogenesis in the N.Atlantic to erode heights over Scandi, where quite frankly we need them if we are to have any snow except the SOUTH of the country. Too many a time have we ended up with a weak block collapsing over the UK with shortwaves over the top, flurries for the far SE and the main LOW heading off south towards Italy and Greece. I predict the same to happen in this scenario.

Only if that signal for the Euro trough disappears. The ECM almost takes it too far south, but this is no ordinary setup which we've seen in that past.

[northwestsnow]

EC mean solidly COLD...

[chris78]

1 minute ago, kold weather said:

Of course not, just commenting on what I've seen. The ECM is great, but verbatim it's not that snowy...and could easily go wrong that's all.

One last time, ECM is GREAT this run! 

I have very little understanding of the charts, so I appreciate you pointing out what could go wrong, much better than everyone just ramping the charts and then it being a total shock when its not a repeat of 1947.   

I have no problem with people getting very  exited about good charts, but that means people must also be allowed to be down about poor ones or even point out the odd flaw in otherwise good one.   We could have a very boring 100% neutral thread, I dont thing ppl want that, but  if we are going to give emotional reactions to charts, it must work both ways, far too many of you are more than happy to jump on the BOOM train, but immediately criticise caution. 

 

[PersianPaladin]

1 minute ago, WhiteFox said:

Only if that signal for the Euro trough disappears. The ECM almost takes it too far south, but this is no ordinary setup which we've seen in that past.

Yes, the evolution is different but essentially the same dynamics and rules apply in terms of cold-advection. I'm currently more interested in that Greenland low and to what extent it actually produces snow for the country. It might be more surprising than forecast.

[Kentish Snowman in Yorks]

Beginners guide to the psyche of a model watcher in Winter.....

1) A cold spell is shown in FI - "it will never verify it will all go pear shaped"

2) A cold spell moves into the reliable timeframe - "that run looks very dry hardly any snow showing there"

3) The snow arrives after the commencement of said cold spell - "it maybe snowing outside but this cold spell looks like it will be finished next week"

 

We are at Stage 2 at the moment!

A very decent start to the day today model wise.  I would be very happy in the event the ECM verified and it would seem that all roads lead to cold this morning.  Indeed the GEM is a cracker following the durge it produced last night!

But will it snow IMBY?  

Edited January 18, 2019 by Kentish Snowman

[kold weather]

Solid mean at 144hrs.

Edited January 18, 2019 by kold weather

[saintkip]

GFS is cold but dry, gone from 16cm of snow to none on tuesday.

[kold weather]

12 minutes ago, BLAST FROM THE PAST said:

Yes bitterly cold but there are heights to the north east.  However, and I’ve mentioned this a bit, the heights will be under attack but in our favour as the surface heights enough to keep the disruption and deflective angle of attack. Expect another arctic attack from displaced PV plunging NW/SE.  With deep cold over us and very low surface temps....l anticipate a very wintry scene towards months end....  indeed which could be on top of a pretty wintry scene beforehand.

This morning imo we have the best support across the board for a very cold outbreak to start next week....it’s getting close now

 

BFTP

I think your analysis is spot on. If you really want a long cold spell which doesn't dry up you do need the upper high decaying to the east of us and to have a trigger low setup a Greenland high. IF we get lucky,  we could fr one cold spell right into another.

KS, definitely at stage 2. I have no doubt there will be snow, just the models at the moment are very sparse.

Edited January 18, 2019 by kold weather

[mulzy]

1 minute ago, saintkip said:

GFS is cold but dry, gone from 16cm of snow to none on tuesday.

Precipitation charts are largely useless at that range.  You should be concentrating on the overall pattern - focus on precipitation within 72 hours.

Edited January 18, 2019 by mulzy

[Met4Cast]

The latest Precip type update shows the band quickly fizzing out as it crosses into Central parts, snow risk fairly limited away from Wales/Higher ground today it would seem

[karlos1983]

Outlier? I prefer the term trend setter ?

 

[Tim Bland]

Those who are worried about lack of snow - Models are not good at picking up convection and troughs in the flow from an easterly. With slack low pressure, very cold uppers and warmer than average sea temps there will be plenty of the white stuff!

[Sky Full]

3 minutes ago, saintkip said:

GFS is cold but dry, gone from 16cm of snow to none on tuesday.

Don't forget the old adage: "Get the cold in first....."!

.... Once the cold air is established the snow is bound to follow  

 

[saintkip]

1 minute ago, Tim Bland said:

Those who are worried about lack of snow - Models are not good at picking up convection and troughs in the flow from an easterly. With slack low pressure, very cold uppers and warmer than average sea temps there will be plenty of the white stuff!

Its the initial front on tuesday thats lost all its snow.

[kold weather]

5 minutes ago, karlos1983 said:

Outlier? I prefer the term trend setter ?

 

Probably suggestive of an attempt to flatten pattern and losing the colder uppers to the south, that's what the means suggest by 216hrs anyway. The GFS ensembles do the same fwiw.

As suggested by others, may just be the transition towards a northerly pattern. That is what I hope anyway! Won't know till I look through though.

Edited January 18, 2019 by kold weather

[MattStoke]

8 minutes ago, saintkip said:

GFS is cold but dry, gone from 16cm of snow to none on tuesday.

It has a front crossing the UK, followed by wintry showers. Not dry at all.

[snowking]

Not to suggest that this would be what actually happens in reality, especially given those uppers over the North Sea, but you would imagine with higher pressure over our shores that cloud development would be somewhat limited in terms of height - and we see thus manifested in just some light streamers in the usual spots exposed to a NEly flow:

This is, of course, all theoretical for now, and there are some other snow events across the NW as fronts attempt to encroach

[saintkip]

1 minute ago, MattStoke said:

It has a front crossing the UK, followed by wintry showers. Not dry at all.

The net weather forecast which is from the GFS has nothing for me now  for tuesday but had 16cm last night, I know that will change but a tad dissapointing

[nick sussex]

An over riding sense of relief this morning !

The UKMO is an improvement even though it takes some shortwave energy east not as much as last night.

You’d still want more margin of error though . 

Overall the models that weren’t interested are now moving in the right direction .

The ECM and GFS are variations on the same theme from last night . In terms of snow off any easterly to be honest it’s pointless worrying about convective potential at this stage . Two reasons models are hopeless at picking that up in the longer range and we don’t know the exact strength of the flow and other factors this far out .

I still think we need one more full set of runs just to be sure and hopefully we can have no more dramas!

 

Edited January 18, 2019 by nick sussex

[MattStoke]

Can’t tell you number of times I’ve seen cold spells forecast to be dry only to see large amounts of widespread snow and vice versa. Or the number of times rain has been predicted only for it to fall as snow or vice vesa.

Snow is very difficult to predict even at short range in this country. Pointless looking at such detail at this range. You’ll drive yourself nuts!

Edited January 18, 2019 by MattStoke

[kold weather]

8 minutes ago, snowking said:

Not to suggest that this would be what actually happens in reality, especially given those uppers over the North Sea, but you would imagine with higher pressure over our shores that cloud development would be somewhat limited in terms of height - and we see thus manifested in just some light streamers in the usual spots exposed to a NEly flow:

This is, of course, all theoretical for now, and there are some other snow events across the NW as fronts attempt to encroach

Totally agree, best shot at snow is right at the start when the flow is nice and cyclonic. Models maybe underestimating precip, but the ECM in particular has got enough resolution to at least give a decent idea.

Matt, yep I've also seen the models for a poor job, unfortunately bothbl ways. I particularly remember Feb 05 was meant to snow and we ended up with sleet and gales, horrid.

Anyways, 240hrs mean looks suggestiv of a northerly attempt. It's a weak signal but definitely there!

Edited January 18, 2019 by kold weather

[chris55]

Still a long way to go regarding this potential spell.  Cool to cold in the short to mid term but the very coldest charts are still quite a way out at days 7 plus on EC and gfs. 

Although the overall trend is excellent the details and eventual outcome still to be decided.

The fact EC46 and the recent SSW are major factors in this does give me more confidence in the longer term, but you never can be certain eh! 

 

[nick sussex]

Just now, MattStoke said:

Can’t tell you number of times I’ve seen cold spells forecast to be dry only to see large amounts of widespread snow and vice. Or the number of times rain has been predicted only for it to fall as snow or vice vesa.

Snow is very difficult to predict even at short range in this country. Pointless looking at such detail at this range. You’ll drive yourself nuts!

Good advice let’s hope people take it on board !

You know in an ever changing world good to see this forum remains the same ! The course of events normally happens like this .

Easterly shown , before its even hundred percent sure to land worries start over whether it will be dry .

And then easterly implodes and the debate over any snow then seems rather pointless .

Not saying this easterly will hit the buffers but I’d be more worried about landing it first than worrying about some dodgy precip charts at longer range .