Model Output Discussion - Staying cold into the new year

[Kasim Awan]

Why would one say "no, it's not conducive for much snow", only to then post examples of snow from the same run?

[Snowman.]

1 minute ago, mountain shadow said:

Disappointing end to the ECM after a promising day 8 chart as a deepish low forms to the North West with a West based -NAO.

Real cold still in FI.

I've scrapped that GL block, im looking East now, that high is on a war path and with heights still favourable in the mid atlantic I'm looking for it to be dragged over.

ECM is okay, I would prefer stronger heights NE dipping down somewhat to get some better focing and really drive those colder uppers west. The seperation of the russian high from its warm source will be key. 

[northwestsnow]

10 minutes ago, radiohead said:

Day 10 could be interesting in places...

Blizzards and heavy rain and wind oh my

 

Another horrendous chart for the long suffering people in the south east though.

Let's see where the det sits ens wise ...

[Tim Bland]

3 minutes ago, Daniel* said:

I recommend people don’t take ECM too literally for small details outside very near term, with showing rain/snow, better to look at high res models such as ARPEGE which shows supportive dew points for many in contrast to ECM. I know for especially maritime places like Cornwall especially the ECM model severely overdoes Atlantic modification, quite often with cold nights ect, the higher res models are much better to look at in that regard. 

Main difference is the source of air - North of east on the Aperge. ECM is more East which is sourced from Southern Europe 

[phil nw.]

With such differences after day 5 it may be wise not too over analyse later operational charts at this point. 

I believe the pattern is still evolving but we can see enough from the general nh set up and ens. trends that we face a cold and wintery outlook. 

I am happy with the shorter term. 

They are all showing colder uppers from day 3 and the onset of the easterly by Sunday. 

It is a good trend and knowing the pv is a badly wounded beast should keep us optimistic that we are likely to be in a blocked Atlantic pattern for some time.

[Cold Winter]

Some newer members must be wondering what the heck is going on with one post saying snowfest and the next saying all rain. The reason we’re seeing this is the big differences from one model to another and often from one run to the next including upper air and dew points cycling between being snowy/marginal/rainy. No member is wrong or right, it’s just interpretations of different models at this stage. 

[chris55]

Why are so many using snowfall charts at days 5 +?  We all know the models struggle to predict snow/sleet at day 1 let alone days 7-8-9-10!! It’s meaningless!

Yes, we would love to see -20 850s and be done with it, but we need to be pragmatic. Lets see how the broad-scale pattern evolves and we’ll see snowfall totals (or lack of) on the day.  

Edited December 30, 2020 by chris55

[Tim Bland]

4 minutes ago, Kasim Awan said:

Why would one say "no, it's not conducive for much snow", only to then post examples of snow from the same run?

If you are referring to me I was talking about the easterly next week not being conducive but then said ‘it gets there in the end’ and then posted the snow charts for day 9-10. 
 

just for Clarity I’m not making a forecast for next week and saying it will be rain for the east,  I’m just commenting on what this particular ECM run shows which is mainly rain until days 9&10. Coldies are so sensitive. Saying it’s not going to snow in here is like going onto someone’s Facebook and calling their wife ugly  

Edited December 30, 2020 by Tim Bland

[pureasthedriven]

25 minutes ago, Kasim Awan said:

192h is a snow party

Depends where you live. Not in my manor it isn’t! 

[Scott Ingham]

16 minutes ago, Kasim Awan said:

192-208h brings a reasonable intensity snow band across the country.

Over depending on snow accumulation charts at that range is futuile imo. The synoptic trend which this run is aligning to is highly wintry, so this joins the "snow party" in terms of a statistical trend.

Agreed.

What may show as no snow now on the ecm i believe would be much snowier come inside 72-144 as more disturbances are picked up and upper temp and heights are looked at by the model in more detail.

Anything past 72 hours is up for grabs snowfall wise we arent even close to knowing what the pattern is going forward its all a huge mess. 

But we have a bit eamt event, at the same time as the end of a tropical wane period at the same time as probably some dripping of the atmosphere from the strat event after the 5th coupled with lower strat near record speeds.

If anyone is brave enough to chuck out a forecast your braver than i am!

Sit back n observe is my advice!

Ps 

I can understand if you live in the south you dont like the run. I wouldnt if i lived in the south but midlands north if you live there it would throw out many chances of snow

Edited December 30, 2020 by Scott Ingham

[Kasim Awan]

3 minutes ago, Tim Bland said:

If you are referring to me I was talking about the easterly next week not being conducive but then said ‘it gets there in the end’ and then posted the snow charts for day 9-10. 

The easterly next week is conducive for snow inland above 100m with uppers of -7, 20-100m at -7.5 and coast under -7.8 ish. Heights higher and this easterly will have a largely adiabatic dew point profile, i.e. a lack of inverted cold surface dew points due to the North Sea run. Surface snow conditions here depends largely on precip intensity & whether a UKMO source verifies which would increase chances in marginal zones. A middle ground option seems more feasible, gfs is not far from this mark so expect marginality with some opportunity. 

Not realistic to make bold snow predictions beyond this, the D7-12 outlook is remaining cold. The magnitude of snow & thus cold at 5 days out is far from resolved so trying to narrow this down at day 8 seems futile.

Edited December 30, 2020 by Kasim Awan

[Daniel*]

7 minutes ago, Tim Bland said:

Main difference is the source of air - North of east on the Aperge. ECM is more East which is sourced from Southern Europe 

Still sourced from eastern med on ARPEGE they’re really not that different at all. 

 

and thanks @Mr Frost people talk about snow starved they have no idea.. it’s coming up 3 years since my part of London has seen laying snow. Could very easily be negative and cynical but that’s not healthy. I understand it’s also important to be realistic, but in this hobby you always need to try to find some positives or you’ll go mad! 

Edited December 30, 2020 by Daniel*

[Frosty.]

Ohh la la..I just love meteociel, it’s just so french isn’t it!..anyway, I love the ECM 12z op too, it’s cold isn’t it?..and I think Janvier could bring some snow..watch this space..........

[PolarWarsaw]

4 minutes ago, Scott Ingham said:

Agreed.

What may show as no snow now on the ecm i believe would be much snowier come inside 72-144 as more disturbances are picked up and upper temp and heights are looked at by the model in more detail.

Anything past 72 hours is up for grabs snowfall wise we arent even close to knowing what the pattern is going forward its all a huge mess. 

But we have a bit eamt event, at the same time as the end of a tropical wane period at the same time as probably some dripping of the atmosphere from the strat event after the 5th coupled with lower strat near record speeds.

If anyone is brave enough to chuck out a forecast your braver than i am!

Sit back n observe is my advice!

Ps 

I can understand if you live in the south you dont like the run. I wouldnt if i lived in the south but midlands north if you live there it would throw out many chances of snow

Interesting this part mate, are you not feeling the same about this month as you were many times during the last few weeks/week? 

Obviously the type of SSW we may have been looking at has downgraded to a displacement, rather than the split we all wanted. 

Not much talk of an SSW in a positive light in here today?

Honestly, I don't think that's a bad thing either. If we can squeeze something more out of next week's pattern, there would probably be enough snow and cold in there to consider it the 'best spell' of the winter - SSW or not. 

[East_England_Stormchaser91]

Looks as if it’s going to be very marginal for the snow showers in the east. I’m hoping the models may be overestimating the dew points coming in off the continent. 

Perhaps I might do something that I’ve never done too often, and that is a winter storm chase (snow shower chasing)! 

As for future runs. With this uncertainty, look no further than 90-120hrs. Anything can crop up within that time that can change the complexion and game completely! 

Edited December 30, 2020 by East_England_Stormchaser91

[nick sussex]

Will that shortwave energy to the north remain that shallow initially before dropping south .

Not convinced . And typically now that the cold is building up to the east , it’s not able to edge west .

This halfway house solution with the UK used as a shortwave punchbag between both blocks is fraught with risk.

Whilst the ECM might deliver some snow later on the evolution to that point could unravel if that shortwave energy deepens too much initially . The ECM salvages things by delaying that .

I think a scenario where the ridge to the east is further west with some shallower features dropping se would be less stressful for coldies , so that bowling ball low shown needs to scarper off .

 

[pinball wizard]

2 hours ago, Tim Bland said:

Awesome GFSp with snow opportunities galore. I get the nervousness when one or two models go wrong but I think we are just spoilt these days with too many models to view. It’s a bit like looking at all the ensembles from a. Model and focusing on the bad ones. If each model was an ensemble - We would be saying that the icon is a mild outlier and the GFS is at the top of the pack and unlikely ...

The other day there was some discussion of how the gfs and gfsp differ in their modelling of the upper layers of the atmosphere, which of the two has most detail?

Edited December 30, 2020 by pinball wizard

[blizzard81]

14 minutes ago, Kasim Awan said:

You and others are failing to see the bigger picture. The general evolution D6 on wards with the retogression, Artic plunge & maritime influence is generally one which produces good snow risk. Plus, who said we were looking at widespread heavy powdery snow? No one, including me, have. So I suggest please, keep this realism in mind.

Coming down back to earth, this general trend towards a mixing cold airmass is certainly interesting from a snow perspective, that doesn't mean I'm forecastinf widespread powder snow. However, that isn't completely outside possibilities.

A more informative post here as I feel many misinterpreted / took my punch line post far too seriously. No worries, let's move on.

. Ecm says........ The UK and northern Europe are going into the freezer. The snow will come

[Scott Ingham]

8 minutes ago, PolarWarsaw said:

Interesting this part mate, are you not feeling the same about this month as you were many times during the last few weeks/week? 

Obviously the type of SSW we may have been looking at has downgraded to a displacement, rather than the split we all wanted. 

Not much talk of an SSW in a positive light in here today?

Honestly, I don't think that's a bad thing either. If we can squeeze something more out of next week's pattern, there would probably be enough snow and cold in there to consider it the 'best spell' of the winter - SSW or not. 

No i still think well see a full month of below average temperatures as i forecast but the minor detail of how we get there what areas will see snow. Will we see easterlies, a dropping bomb from the north, battleground events, low pressure from the the south hitting cold air.

All are possible.

The general consesnsus the same.

A very protracted spell of cold below average conditions for January and a good chunk of february.

Details???? You tell me!

Also its too early to say the ssw wont benefit us. It may still do. Theres no negativity from anyone really in regards thar because  no one really knows.

The likes of Matt Hugo think it will only reimforce current conditions and keep us in the game. I believe the same myself because of the state of the lower strat but its guess work atm it doesnt evem start till the 5th

Edited December 30, 2020 by Scott Ingham

[Mucka]

Well, the SHTF real quick in here.

ECM played out as expected out to 168 for me but we can break the output down into three phases.

The first is the Easterly feed in the reliable and whether there will be snow or not and the second is from 168+ when we get the likely phasing of the troughs N & S in the vicinity of UK and whether we can stay in the cold air and the snow chances therein and the third is where we go from there in deep FI.

Unfortunately there is no way any of those things can be called with any confidence at the moment and all we can say is that we will be in cold air for the foreseeable with marginal snow opportunities. Optimism or pessimism won't sway the output one way or the other. That is where we are.

If you haven't seen any snow falling yet you still have plenty of opportunity in the coming days and weeks, far more than in an ordinary Winter I would say.

If the only thing that floats your boat is -12 uppers, several inches of snow and huge drifts on a  long fetch Easterly then Winters in lowland England are going to be a very frustrating experience 99/100. Hope is great, but expectation is a killer.

[Sweatyman]

1 minute ago, blizzard81 said:

. Ecm says........ The UK and northern Europe are going into the freezer. The snow will come

ECM said i should be buried in snow by now according to charts last weekend so i doubt it

[pages]

8 minutes ago, northwestsnow said:

Another horrendous chart for the long suffering people in the south east though.

Let's see where the det sits ens wise ...

I am actually liking the ECM 192-240charts for South East. 

The 144 charts let alone the further out charts never verify as planned

Plenty of time for that low to be a lot further south and east.

Seen it so many times now where it looks ideal for South East at 144 only for the lows to go progressively to far south. Hopefully this time we see the corrections south east again.

 

[The Enforcer]

30 minutes ago, Tim Bland said:

Rain rain and more rain next week on the ECM next week unless you are on very high ground. Just need those DPs to 1c lower I reckon and eastern areas would be buried ! Sorry BA we were typing at the same time...both thinking the same thing ?

Given I can't trust a low-res precip chart within T+48, I'm not about to start doing so at T+168.

 

33 minutes ago, bluearmy said:

And the snow and precip totals by day 8 tell their own sorry tale for much of the country - you’d think we’d be buried !!

This one is even worse - accumulations right on coasts and ludicrously even over the sea, but none inland even at 250 metres.

[Neilsouth]

The low pressure system that traversed towards the south and then towards the South East never happened, it went into the channel, pretty much a changing forecast day by day even upto the day before. Yet here we are looking towards the weekend and next week. We are struggling to look towards our own lands, yet we try to look beyond what's happening across the world? Hmmm

[Kasim Awan]

Without getting scrutinized I would say many on here are experiencing reflex reactions to single operational runs.

These runs are part of a bigger computational modelling of the atmosphere at this time. This forms a collective range of possible surface conditions, within which the OP presumes a certain spot. There a plenty of other solutions modelled - and the fact is all look cold / hold snow potential. So the general computation remains cold & potentially wintry in places, using an ensemble logic my judgement is that it's looking positive from a snow perspective. 

Edited December 30, 2020 by Kasim Awan