Model Output Discussion - A cold start to Spring?

[Stuie]

UKMO has some pretty cold 850`s on Weds.

[BremX]

Snow is also notoriously difficult to forecast for the models. A lot of the time it's a nowcast rather than a forecast. 

[Mucka]

Models do seem to be firming up on a breakdown from the S around the 10th now with ECM still to come.

There is still some uncertainty how far N the milder air will get and if the cold will be completely swept away from the N, although the output taken as a whole has generally been more progressive with the Atlantic over the last couple of days.

Nothing set ins tone but the output has been sliding the wrong way for cold and snow fans yet there is still just enough time for the output to correct back S

[danm]

1 hour ago, MATTWOLVES 3 said:

I think some are over reacting to every op run with this event. The truth is we could be much further North again come the 18s...and then further South come the 0zs.

If this does stay South we keep locked in the cold air and await the next attempt and there will be others towards the backend of next week..keeping the colder air in place for longer will help entrench it and make it harder to shift. Some are missing the bigger picture.

 

Keeping cold entrenched at this time of year doesn’t have the same impact or outcome as it would have done a month or two ago. As we progress through March into April it’s increasingly like pushing water up a hill for anything more than transitory wintry-ness. 

[Tim Bland]

15 minutes ago, Ali1977 said:

Nope , not for Thurs 

Ah ok fair enough. Only goes to 120hrs on WX , Looks good for the north, esp high ground 

[MattStoke]

25 minutes ago, mountain shadow said:

I'm not sure anything was hyped. Many, many runs were showing fairly widespread snow.

Now, just as we enter the fairly reliable, the widespread snow has disappeared like, well, like sna' aff a dyke. 

Was referring more to the SSW. Some talk as if it’s an automatic ticket to Narnia when each event is different and there are other factors involved that get less or no attention. We had months of social media posts about it that helped fuel the nonsense paper headlines. Weather prediction is not y + x = z

Charts showing widespread snow almost always get ‘watered’ down as they move into the more reliable timeframe. The newer GFS seems to have even more of a cold bias which doesn’t help. Again, so many social media posts lately where people have cherry picked charts that show what they want only to end up disappointed (As usual).

Talking mostly about what I’ve seen on social media. I’ve not been on this forum much the past few months.

[alexisj9]

Ok ßhort term ens for East Kent show only a few stragglers going north now, main convergence keeps the cold in, and looking at the snow row, looks roughly 50 50 on whether the snow reaches us or goes under. Re Wednesday's low, not looking further still too much noise.

Edited March 4, 2023 by alexisj9

[gig1968]

It does look to me that next week might turn out to be a disappointing one for the majority of us. It may be cold but that's about all it will be.

[northwestsnow]

6 minutes ago, gig1968 said:

It does look to me that next week might turn out to be a disappointing one for the majority of us. It may be cold but that's about all it will be.

Parts of Scotland could do very well ..

[Daniel*]

Tuesday is looking a convective day to me. If this isn’t generating widespread convection along North Sea in early spring I’m not sure what will. The strengthening sun and these low 500hPa temps ripe for big shower clouds I’d say. It is not December. Models usually have difficultly pushing sea convection inland and simulating inland convection especially earlier in season. I would expect significant accumulations in NE Scotland with a frigid windchill the snow will be drifting. Possible amber worthy. 

[snowbob]

The last few days I have read more posts about the cold breakdown than anything else 

Cmon people let it get here first

snow in December was never forecast in any models but yet look at what fell

the cold may retreat next weekend it may not.no model knows just yet.

Nowcast from Sunday night as far as I can see 

that is the most accurate model

your window.

 

[MJB]

GFS Control 

Monday evening cold front moves South wintry mix on it 

Early hours of Tuesday snow edges South 

Breakfast time Tuesday Snow clears the South snow showers around coastal regions 

Lunchtime Tuesday, Snow into Western areas 

Tuesday Evening Snow across large parts of Southern England and Wales

Friday lunchtime Snow into the West , ahead of the rain

Friday evening a few hours of snow across England and Wales before turning back to rain

Nowhere near as exciting as this mornings 0z but it can change as we know , it really is JFF 

At least we will get some snow falling 

Edited March 4, 2023 by MJB

[MJB]

Just gone through the PPN charts  GEFS 6h - 192h and there are lots with more snow than the Control or the OP , all is not lost , loads to play for yet IMO 

[Harsh Climate]

2 years ago we had two big falls of snow here, 6" and 8" from a very similar set-up

The models handled it very badly, a few days out we were too far north or too far south then down to 48 hours started showing us in the sweet spot.

Someone in england is gonna get hammered next week, looked like midlands south at first, now more northernmost parts of england/scotland. I think there will be corrections further south and northern england get a hammering some stage next week. Just going on past experecences, we usually do well from this kind of set-up.

Edited March 4, 2023 by Harsh Climate

[Polaris]

1 hour ago, NewEra21 said:

Been saying it for days now but the initial northerly that was shown a few days ago was a very convective one with showers and features coming down the UK all over the place.

That has gradually been shortened and downgraded over the past few days, as we just don't maintain the flow long enough anymore before it goes all slack.

Good post. I remember only a few days ago that Tuesday was shown as LP/ disturbance running down from the north. 
Away from Scotland and Eastern costal counties it looks very dry on this Saturday evening for next week 

[Harsh Climate]

16 minutes ago, MJB said:

Just gone through the PPN charts  GEFS 6h - 192h and there are lots with more snow than the Control or the OP , all is not lost , loads to play for yet IMO 

I think most of the doom and gloom on here is because there is an awful lot of people who live south of the midlands. Yes if you live south of midlands things are looking very bad at the moment .

Looks great for Scottish continguent, they must be licking there lips at latest runs, not just that their haggis is ready! 

[Ali1977]

This looks much better for a snow event  I hope so anyway, doesn’t look as flat as the UKMO 

Edited March 4, 2023 by Ali1977

[minus10]

Well the way things are going i will be glad of just having some rain...🌧 ...although that isnt guaranteed...(still hoping for a bit of the white stuff though)

..noticed at the end of the last few runs the gfs trying to bring back the signal for scandi high of sorts..dont know whether that has anything to do with factoring in high amp mjo 7/8 and ssw downwellings?

...also the gfs 12z op right up there in outlier territory from 13th with the mean dropping soon after...

this is an evolving situation so i suppose we just have to ...keep calm and go with the flow..

 

[Ali1977]

Well ECM north, UKMO south!! So going if that we may end up somewhere in the middle snow event on ECM I think , if it makes it 

Edited March 4, 2023 by Ali1977

[KTtom]

13 hours ago, NewEra21 said:

 

I think next Weds possible event will be it for the south..If it misses to the south that will be it, uppers far to warm by the time the next system arrives.

[Jeremy Shockey]

ECM 12z @ 96hrs

 

GFS 12z @ 96hrs

 

UKMO 12z @ 96hrs

 

OK game on for me now. All 3 showing fantastic charts and very cold uppers within the reliable timeframe @ 96 hrs

On to the short range models and the regional threads very soon

regards JS

[northwestsnow]

At first glance EC looks a bit sparse on the snow front..

[mulzy]

ECM day 6 - health warning before viewing!  It’s ghastly…

[Mike Poole]

Just now, mulzy said:

ECM day 6 - health warning before viewing!  It’s ghastly…

But it’s ghastly in a completely different way to how the other runs were ghastly.  Just highlighting the uncertainty, for me.

[northwestsnow]

1 minute ago, mulzy said:

ECM day 6 - health warning before viewing!  It’s ghastly…

Hope it's wrong, looks very wet by Friday for most ..