Model output discussion - here comes the beast!

[chris78]

4 minutes ago, frosty ground said:

So the goal post have now moved, from Cold being pushed back to Snowy charts being pushed back.

again I feel that experienced members of this thread still do not understand that you can not predict snow that far out.

But Frosty again this is only directed at people pointing out less snowy charts,  there is a post a few below yours pointing out snow depths, several posters have like it...nobody has pointed out how hard snow is to forecast.     For learners this massively effects the usefulness of the thread.   When its a poster saying no or little snow on a run, mods and others are keen to tell them not to mislead learners, when its the other way round there are no such warnings, this results in a thread were people are free to ramp snow, but worried about criticism for pointing out less snowy charts. 

[Coopsy]

13 minutes ago, TEITS said:

You are right all outcomes should be discussed in this thread. One problem though none of the models are showing a failed E,ly!

They wouldn't. By nature a failed easterly is one that was modelled and doesn't happen. If it was showing it wouldn't be failed. Oh I'm getting confused - its the change in air pressure from the failed incoming beast  ;-)

[Youcan'tbecirrus]

9 minutes ago, Steve Murr said:

last one before later-

Each run of the GFS is edging to the UKMO- minimal mention of this run however again if you compare 00z GFS mean V 06z GFS mean @72 its gradually sharpening up the curvature of the CAA to more of a straight easterly -

The UKMO @midnight 00z Monday 

Has moderate snow showers pushing in from the continent - 

The -12c Isotherm is over the midlands-

So rough approximations would say the based on the UKMO the -10c line would arrive across EA by 2pm-

The arrival of snow flurries ~ 6pm.

Any notion that the cold spell is being pushed back is incorrect-

What the models are doing now ahead of the wave that I keep referring to - are developing a very shallow feature that would have a small milder sector of around -8 to -10c @850 - however importantly this is coming into 950 MB air / surface air & dewpoints that are already mixed to a PC airmass - meaning all the indicators for snow are perfect - The TheteE chart sums this up well-

So this event would be all snow ushering in more snow-

The wave behind it introduces the Vmax instability you can get -

~ 

* -16 c air 

* North sea Track over ~ 6-7c

* Thermal Gradien 23c

* Very Low heights / steep lapse rates

T192

 

Look at these 2 charts - If anyone draws a conclusion that it would be snowing in MOST places then thats a big misjudgement-

** Notice the -20c just in view at the top right **

Have a great day

S

 

 

Last para Steve did you mean to say "if anyone draws a conclusion that it would NOT be snowing" ?

[Captain Shortwave]

To set something straight here. I would suggest using the -8c isothern as the goal post as this has been a lot nore consistent in when it arrives. The ECM has pretty much suggested that this will arrive some time on Monday for instance.

Worth noting that whilst the coldest air initially mixes out, it more than compensates for this in terms of a widespread snow event.

[Yarmy]

The runs that brought the cold in quicker also ended it quicker. Using the example given above, the GFS 0z on the 18th:

...3 days later, the high sinks into Russia and it's all over...

 

So you're welcome to that. Be careful what you wish for.

[bobbydog]

11 minutes ago, Weather Wonder said:

Having watched many successful and failed easterlies, more failed than successfull I should add. This is a classic sign of a failed easterly, if this continues the easterly may never arrive or be a blink and you’ll miss it affair.

would add I would like to be wrong on this but this is model output discussion so all outcomes showing in the models should be able to be discussed here.

classic failed easterly? we are almost in an easterly as i type

in 48 hours the easterly is in full flow for the southern half of the country

how can something fail whilst its actually happening? 

 

[No Balls Like Snow Balls]

I really really really really don't get the cold has been delayed malarky. It has always been progged to come Sunday/Monday!

Perhaps some people are starting to crack under the pressure, which is fine, each to their own. 

The MET have even been showing videos on Twitter for a while now showing the cold moving in at the end of the weekend/early next week.

Edited February 21, 2018 by No Balls Like Snow Balls

[Timmytour]

Personally the ICON has lost all credibility with me. I was following it avidly as it was one of the first ones to consistently show an easterly coming, but I'm sure one of its runs showed it snowing as early as today. Once I looked out of the window I knew it was a busted flush.

I'm leaning more now towards the model showing the cold getting delayed til saturday week. This is because I am away in Austria from saturday for a week and don't want anything significant to happen until I get back.   I'd be grateful if anyone could point me in the direction of a model that satisfies my every wish and whim with every single one of its runs.....thank you

[Captain Shortwave]

To set something straight here. I would suggest using the -8c isothern as the goal post as this has been a lot nore consistent in when it arrives. The ECM has pretty much suggested that this will arrive some time on Monday for instance.

Worth noting that whilst the coldest air initially mixes out, it more than compensates for this in terms of a widespread snow event.

[frosty ground]

1 minute ago, chris78 said:

But Frosty again this is only directed at people pointing out less snowy charts,  there is a post a few below yours pointing out snow depths, several posters have like it...nobody has pointed out how hard snow is to forecast.     For learners this massively effects the usefulness of the thread.   When its a poster saying no or little snow on a run, mods and others are keen to tell them not to mislead learners, when its the other way round there are no such warnings, this results in a thread were people are free to ramp snow, but worried about criticism for pointing out less snowy charts. 

Chris i suggest you reread what I have been talking about, Firstly posters have been seeing things that are not there and making multiple post on it. secondary posting what the models show is not stating something will or won't happen. 

The goal post got moved from cold to snow by experienced members that should know better, the only people creating confusion are those people.

[Northern Sky]

10 minutes ago, Summer Sun said:

Some substantial snow on the 06z and that is without the potential for lake effect snow in the east!

My house is under that blue bit, think I better nip to the supermarket!

For those worrying about a delay to the coldest uppers, I would say it depends what you are wanting - are you looking for cold records or are you looking for cold and snow? I suspect many of us are looking for the latter in which case I wouldn't worry so much, even with uppers a fair bit higher than those progged it would still be snow.

Cold arriving on Sun/Mon as shown for a while now. It looks almost certain the cold will stay for at least 4-5 days during which any precipitation that falls will be of snow. So even if the uppers become moderated it would take a significant shift to rule out any snow chances.

[East_England_Stormchaser91]

We get a polar low blizzard modelled that would send this country into a state of oblivion. But here I am reading posts which quite frankly are utter drivel saying it will be a failed E'ly..? Words are failing me here. 

[karlos1983]

6 minutes ago, No Balls Like Snow Balls said:

I really really really really don't get the cold has been delayed malarky. It has always been progged to come Sunday/Monday!

Perhaps some people are starting to crack under the pressure, which is fine, each to their own. 

LOL so very true !! 

I think we need some form of VAR.... because there’s more differing opinions on here than down the pub after a cup final being officiated by Mike Dein! 

Edited February 21, 2018 by karlos1983

[SMU]

8 minutes ago, Youcan'tbecirrus said:

Last para Steve did you mean to say "if anyone draws a conclusion that it would NOT be snowing" ?

yes lol NOT be

[Nick F]

00z EC op was at the warm end of the spread after the 28th looking at the London T2m, this is when the flow backs to a less cold NLy. 

[Paul]

Here's a look at the 00z forecasts for 1200 Monday, from the last 11 days on the GFS and Ensembles, plus the last 5 on the ECM. 

Yesterday the GFS and Ensembles did have the cold coming a touch faster, but in the main you'd mostly call it variations on a theme, barring a few big wobbles here and there. The ECM has had the odd wobble but has actually been more solid on the timing of the deeper cold, if anything bringing it forward a tiny amount today. 

GFS

GEFS (ensembles)

ECMWF

[bluearmy]

Here are the facts

THERE WILL BE AN EASTERLY - i know that because we already have one !

IT WILL BECOME COLD - likely very cold and perhaps exceptionally cold

IT WILL SNOW - but where and how much ? 

the answer to question 3 will slowly become clearer as we approach the weekend and even then we all know that proper snow forecasts are only reasonably reliable a day or so before. 

Sorry that so many on here need clarity - it just isn’t possible I’m afraid.

[weirpig]

Shows at least 10 days of uppers  that will accomodate snowfall

[Frosty.]

The GEFS 6z mean is showing nationwide bitter cold next week with Easterly / North Easterly winds and the wintry pattern continues out to T+300 plus hours..that's good enough for me!

Edited February 21, 2018 by Frosty.

[Optimus Prime]

12 minutes ago, East_England_Stormchaser91 said:

We get a polar low blizzard modelled that would send this country into a state of oblivion. But here I am reading posts which quite frankly are utter drivel saying it will be a failed E'ly..? Words are failing me here. 

People like technical terms, and as a narrative it certainly adds an essence of extremity to things. So whilst a 'polar low' sounds great in this case it is incorrect; can't get polar lows from an easterly.

Edited February 21, 2018 by Optimus Prime

[Coopsy]

2 minutes ago, bluearmy said:

Here are the facts

THERE WILL BE AN EASTERLY - i know that because we already have one !

IT WILL BECOME COLD - likely very cold and perhaps exceptionally cold

IT WILL SNOW - but where and how much ? 

the answer to question 3 will slowly become clearer as we approach the weekend and even then we all know that proper snow forecasts are only reasonably reliable a day or so before. 

Sorry that so many on here need clarity - it just isn’t possible I’m afraid.

Although we don't know how much and where, am I right in saying primarily its looking like convective snow showers from the easterly but anything is possible in this set up. From streamers to shortwaves to channel lows to polar lows in this type of set up? 

[Duane S.]

20 minutes ago, No Balls Like Snow Balls said:

I really really really really don't get the cold has been delayed malarky. It has always been progged to come Sunday/Monday!

Perhaps some people are starting to crack under the pressure, which is fine, each to their own. 

The MET have even been showing videos on Twitter for a while now showing the cold moving in at the end of the weekend/early next week.

Barring the odd genuine misunderstanding from a newbie, the only 'logical' reason why people post that is to get a reaction. Likewise any 'another failed easterly' posts.

It's been Sunday / Monday for what seems to be an eternity. A bit earlier here, a bit later there. But the 26th has been the day when the 'proper' cold hits for a long long time (in model terms).

The wind is feeling pretty cold and Continental out there already. And of course progged to get progressively colder (and colder)...

Edited February 21, 2018 by s4lancia

[WalsallWeather123]

Just catching up on the models. For me, the ICON 0z is perfection for snow lovers. At T162 you have minimum -8 uppers with a low moving across the country bringing widespread heavy snowfall. Then at T174 the entire country is draped with -16 uppers. The angle of attack is perfect to tap into bitter air from siberia. Then at T180 further precipation moves westwards from the North Sea. WIth -16 uppers it would be powdery snow which would accumulate very quickly. The high perfectly positioned in the north

[Duane S.]

9 minutes ago, bluearmy said:

Here are the facts

THERE WILL BE AN EASTERLY - i know that because we already have one !

IT WILL BECOME COLD - likely very cold and perhaps exceptionally cold

IT WILL SNOW - but where and how much ? 

the answer to question 3 will slowly become clearer as we approach the weekend and even then we all know that proper snow forecasts are only reasonably reliable a day or so before. 

Sorry that so many on here need clarity - it just isn’t possible I’m afraid.

Perfect concise summary BA!

Any chance you post that on here every hour from now until next Monday,? it may save both my head and the nearest brick wall.

[East_England_Stormchaser91]

3 minutes ago, Optimus Prime said:

People like technical terms, and as a narrative it certainly adds an essence of extremity to things. So whilst a 'polar low' sounds great in this case it is incorrect; can't get polar lows from an easterly.

It's came down from the north on that run though bud. Right down the spine of the country. The Pennines will be absolutely buried if that comes off.