Model Output Discussion - A cold start to Spring?

[throwoff]

Just now, chapmanslade said:

Looks pretty good to me, especially when you look at the visible sat as well.

Agreed, looks pretty spot on to me...

[Updated_Weather]

ECM upgrades!

[Alexis]

5 minutes ago, throwoff said:

Agreed, looks pretty spot on to me...

What? The precipitation covering the entire of Northern England is mostly absent.

 

We'd be blanketed in snow if it was cold enough.

Edited March 6, 2023 by Alexis

[Tim Bland]

GFS has a brief warm up at the end of the week but by end of the weekend the cold is headed back south with more snow opportunities including the far south 

[nick sussex]

You can see the wave and how it ripples eastwards here .

So the wave develops towards Bristol on the T24hrs chart .

 

In the T36hrs chart you can see the wave towards the Low Countries .

The wave slows the front and also helps to intensify the precip .

You also have a slack flow north of the front with little mixing so evaporative cooling comes into play.

In 12 hrs the front has only edged about 50 miles south.

 

Edited March 6, 2023 by nick sussex

[Stuie]

3 minutes ago, nick sussex said:

You can see the wave and how it ripples eastwards here .

So the wave develops towards Bristol on the T24hrs chart .

 

In the T36hrs chart you can see the wave towards the Low Countries .

The wave slows the front and also helps to intensify the precip .

You also have a slack flow north of the front with little mixing so evaporative cooling comes into play.

 

Did they forget to put the DAM line in the 24hr?

[throwoff]

3 minutes ago, nick sussex said:

You can see the wave and how it ripples eastwards here .

So the wave develops towards Bristol on the T24hrs chart .

 

In the T36hrs chart you can see the wave towards the Low Countries .

The wave slows the front and also helps to intensify the precip .

You also have a slack flow north of the front with little mixing so evaporative cooling comes into play.

In 12 hrs the front has only edged about 50 miles south.

 

So Nick I am right in reading this as the new updates for the south and south east are actually looking more likely?

[Purga]

Another possible pasting for the south next week.

[nick sussex]

Just now, Stuie said:

Did they forget to put the DAM line in the 24hr?

They normally only show them from T36 hrs .

Colder air uncercutting precip is a difficult forecast . If the wave develops as shown and we get a good undercut then I’d expect the warning to be upgraded .

[Rain All Night]

Just now, nick sussex said:

They normally only show them from T36 hrs .

Any idea why?

[snowking]

9 minutes ago, Updated_Weather said:

ECM upgrades!

Just to put this into context, this means that the entirety of the ECMWF Ens suite will be higher in horizontal resolution than any operational run from any other medium range suite. And we now get access to the lot. There's more to it than just horizontal resolution but in effect we'll have an additional 50 deterministic runs to mull over. Weather nerds assemble.

[Stuie]

1 minute ago, nick sussex said:

They normally only show them from T36 hrs .

Colder air uncercutting precip is a difficult forecast . If the wave develops as shown and we get a good undercut then I’d expect the warning to be upgraded .

Ah ok cheers. Will just take it as the same as yesterday i.e. very close to you. Yep, looking forward to the 12z`s.

[nick sussex]

3 minutes ago, throwoff said:

So Nick I am right in reading this as the new updates for the south and south east are actually looking more likely?

Hi at the moment the heaviest precip and highest risk of snow is more towards the south of the region because the colder air has more time to catch up with the front and that wave which develops will help intensify the precip rate and slow the front . I’ll stress though it’s a difficult forecast and we definitely need that wave to turn up . I would hope that would verify given its only at T24 hrs !

[Updated_Weather]

1 minute ago, snowking said:

Just to put this into context, this means that the entirety of the ECMWF Ens suite will be higher in horizontal resolution than any operational run from any other medium range suite. And we now get access to the lot. There's more to it than just horizontal resolution but in effect we'll have an additional 50 deterministic runs to mull over. Weather nerds assemble.

Looking forward to the upgrade, expected in June 2023. 

Just hope it doesn't do a GFS and make it worse!

2 minutes ago, goosey007 said:

no the warning is just for wales 

nope!

[throwoff]

Just now, nick sussex said:

Hi at the moment the heaviest precip and highest risk of snow is more towards the south of the region because the colder air has more time to catch up with the front and that wave which develops will help intensify the precip rate and slow the front . I’ll stress though it’s a difficult forecast and we definitely need that wave to turn up . I would hope that would verify given its only at T24 hrs !

With my IMBY hat on that sounds good as someone in Medway, though the combined might of all the models is leaning towards it now. I was excited this morning to see how it played out from a distance but knowing it might actually arrive here makes it a different chase.

The wording of the METO warning is interesting -

'hills and perhaps to lower levels in places. Many areas will see little or no accumulations of snow, but 1 to 2 cm could settle in some spots, most likely over high ground and southern parts of the warning area. The rain and snow is then expected to turn light and patchy as it slowly clears southern England on Tuesday. As skies clear overnight, ice is also likely to form readily on untreated surfaces.'

Leaning more into ice conditions at the moment.

[Rain All Night]

3 minutes ago, camturbo said:

I assume my location will be rain or is there a chance of snow albeit slim 

Here is the ECMWF view on your chances:
https://charts.ecmwf.int/products/opencharts_ptype_meteogram?base_time=202303060000&lat=50.9667&lon=-2.75&station_name=Martock

[Paul_1978]

Well what I'm taking from the GFS so far this morning is that is that it's going to be a week of fluctuations. The snow line will be in various places across the country over the week - there will be cold periods with snow, and less cold periods with rain. For those who like snow, we will get some; for those who don't you'll get your less cold spells with rain. 

Overall an interesting week ahead and that's why we're all here because we love the weather.

Personally I'll have to keep watching the forecast as I am supposed to be in London on Wednesday, travelling down from Yorkshire and back again later in the day. Could be a bit dodgy... we shall see!

[EML Network]

GFS control @ 120 !

did not expect to see that

[Ali1977]

2 minutes ago, EML Network said:

GFS control @ 120 !

did not expect to see that

A very snowy Fri/sat down south on the Control 

[Stuie]

9 minutes ago, nick sussex said:

Hi at the moment the heaviest precip and highest risk of snow is more towards the south of the region because the colder air has more time to catch up with the front and that wave which develops will help intensify the precip rate and slow the front . I’ll stress though it’s a difficult forecast and we definitely need that wave to turn up . I would hope that would verify given its only at T24 hrs !

Can`t get a closer time apart from midnight but the wet bulb at 9am does take it`s time overnight to get to this which may mean some slowing of the cold front.

 

[cheshire snow]

Hi

Get all the excitement about meto warnings ETC but is it possible to discuss in the regionals as to if its going to snow IMBY it is going to be a busy week as it is trying to keep up.

[Man With Beard]

Some of the modelled snow looks outrageously marginal. Take ARPEGE for Wednesday night in the south. Snow with 0C uppers!

[Turnedoutniceagain]

Tasty if this drops for the weekend 

[Ali1977]

Well on a personnel level this morning has been great for snow chances, but I still think anywhere over the next week could get a dumping - if the cold battles back those pivot points may do very well 

Edited March 6, 2023 by Ali1977

[IDO]

A good GFS in FI this run:

A couple of trigger lows dropping and pulling in cold air.