Model output discussion 10/02/21

[Mike Poole]

29 minutes ago, Ramp said:

I don’t have the knowledge in this field, mainly due to them being as rare as hens teeth. 

Yes, in my time on here, I’ve only ever seen 1 polar low, it was the one we tracked real time on here, which was interesting because they don’t normally show up on the models in advance, and this one did, just.  Can’t remember which year it was, maybe someone can remember?  I seem to remember @chionomaniac posting a lot about it?

Edited March 31, 2021 by Mike Poole

[Iceman2606]

From summer like low twenties and sunshine to temperatures struggling to get above 6C at best with the chance of snow next week.

You’ve just got to love UK weather.

[Mr Frost]

Quite incredible models/charts for next week if you enjoy a bit of the cold/wintry showers/kitchen sink type weather! 

April showers anyone!? 

UKV snapshots - Monday 15:00:

 

Models usually underestimate convective weather so that would be a good starting point above - still a wee while to go before we can be super confident on this happening...but the current signs are very promising! 

Great stuff on this thread for the last week - warm/cold charts worthy of proper discussion! 

Cheers.

Edited March 31, 2021 by Mr Frost

[ANYWEATHER]

33 minutes ago, Mike Poole said:

Yes, in my time on here, I’ve only ever seen 1 polar low, it was the one we tracked real time on here, which was interesting because they don’t normally show up on the models in advance, and this one did, just.  Can’t remember which year it was, maybe someone can remember?  I seem to remember @chionomaniac posting a lot about it?

January 2004....

[Mike Poole]

3 minutes ago, ANYWEATHER said:

January 2004....

Thanks!  But definitely before my time!  There was one in the last few years.

Edited March 31, 2021 by Mike Poole

[emmett garland]

The Iclandic met office show temperatures of - 5 to -15 widely over the whole country on Easter Monday . These are the lowest I have seen in a long time so very very cold air heading our way and I totally agree with mr frost the convective showers could be epic along with any kind of polar low.. This could produce a memorable spell.

[Frosty.]

The ECM 12z charts for Easter Monday  takes my breath away..they have the WOW factor for sure!...that, with the wind-chill factor would feel absolutely bitterly cold...it’s amazing to think we’ve seen almost 25c 77f in parts of the south and yet early next week we could be talking about drifting snow, severe frosts etc...wow wow wow..the duality of spring in a nutshell..these charts are nuts!!! ️ 

 

Edited March 31, 2021 by Jon Snow

[Mike Poole]

ECM mean T144:

The cold is coming, what is not clear at all is whether this will be a blink and you miss it cold snap, or a more prolonged affair...we will see...

[stodge]

I'm certainly expecting some heavy downpours in lowland east London with hail or thunder.

Snow? No, in all honesty - maybe a flake or two falling but nothing settling.

-8 850s across most of the country by Monday.

[Dancerwithwings]

All Easter egg hunts will require hats and gloves kids.

That is if the 12z ECM mean has anything to do with it

You don’t see many Easter days like this 

[Mike Poole]

ECM 12z clusters, first the T120-T168 one:

Variations on a theme i would suggest, cold and unstable airflow from the north.  

T192-T240:

They don’t actually look that different, to be honest, UK in trough, high lat blocking to our east and west.  Pick the bones out of that!

[LRD]

5 minutes ago, Dancerwithwings said:

All Easter egg hunts will require hats and gloves kids.

That is if the 12z ECM mean has anything to do with it

You don’t see many Easter days like this 

Erm, don't like to point it out but Easter Day in the South will be pleasant enough for an Easter Egg hunt. BH Monday might be different though, granted

[LRD]

2 minutes ago, Mike Poole said:

ECM 12z clusters, first the T120-T168 one:

Variations on a theme i would suggest, cold and unstable airflow from the north.  

T192-T240:

They don’t actually look that different, to be honest, UK in trough, high lat blocking to our east and west.  Pick the bones out of that!

Pretty representative of the operational 12z ECM. A cold unpleasant 3 or 4 days from Monday and then it goes west-based and more Atlantic influenced (and still quite unpleasant!) for the southern half of the UK. All in FI so little confidence in that of course but that's what we have in the models at the moment

[Frosty.]

WOW just WOW this is the ECM 12z ensemble mean, astonishing!...looking at the bigger picture I think support is growing for the cold to persist all next week following the initial very powerful cold surge...spring in the good old  u k..don’t you just love it!  ...ps..hot topic again, well done guys!  

Edited March 31, 2021 by Jon Snow

[LRD]

3 minutes ago, LRD said:

Pretty representative of the operational 12z ECM. A cold unpleasant 3 or 4 days from Monday and then it goes west-based and more Atlantic influenced (and still quite unpleasant!) for the southern half of the UK. All in FI so little confidence in that of course but that's what we have in the models at the moment

In graph form:

Op yet again at the coldest end of the envelope but it's nailed on for a cold three or four days next week

[Dancerwithwings]

8 minutes ago, LRD said:

Erm, don't like to point it out but Easter Day in the South will be pleasant enough for an Easter Egg hunt. BH Monday might be different though, granted

Granted, it’s all to see regarding the output, it’s a long way to go yet, but Easter eggs could be not milk chocolate .....but white chocolate

[minus10]

28 minutes ago, stodge said:

I'm certainly expecting some heavy downpours in lowland east London with hail or thunder.

Snow? No, in all honesty - maybe a flake or two falling but nothing settling.

-8 850s across most of the country by Monday.

On that point the latest met office 10 day trend is showing the northerly with the 'wish bone effect' with regards to showers. Other models are showing showers countrywide.  Surely now that we have stronger solar radiation I thought it was expected that if you have a robust northerly in place there will be considerable instability at this time of year. So what is behind the met office's thinking that showers will mostly be confined to coasts still ? Any ideas?..

[damianslaw]

ECM joining GFS and UKMO this evening, all show a direct potent, very potent arctic blast by Easter Monday. Significant wind chill whill feel bitter despite the strength of the sunshine, and I would expect plenty of convection thanks to the added heat from the sun.

Both ECM and GFS locking the cold in place for a few days, signs of a shortwave development over Iceland, polar low anyone, dropping into very low uppers, could be some significant low level snow from that feature - all conjecture though at this stage.

Look at forecast dewpoints exceptional stuff, evaporative cooling will be in free fall, this will increase likelihood of low level snowfall.

 

[LRD]

2 minutes ago, Dancerwithwings said:

Granted, it’s all to see regarding the output, it’s a long way to go yet, but Easter eggs could be not milk chocolate .....but white chocolate

Sorry, what I meant is you showed a chart for Monday and Easter Day (traditionally egg hunt day) is Sunday - which is still showing up as ok in the southern half of the UK. In fact most of the holiday weekend is looking alright for southern/central Britain. Monday looks awful of course

The hail and rain fest starts Monday (snow possible if you're north of Manchester)

[Griff]

6 minutes ago, minus10 said:

On that point the latest met office 10 day trend is showing the northerly with the 'wish bone effect' with regards to showers. Other models are showing showers countrywide.  Surely now that we have stronger solar radiation I thought it was expected that if you have a robust northerly in place there will be considerable instability at this time of year. So what is behind the met office's thinking that showers will mostly be confined to coasts still ? Any ideas?..

Probably like the cold earlier this year which was supposed to have showers limited to the East coast that made it all the way to the Midlands west....  

[LRD]

9 minutes ago, minus10 said:

On that point the latest met office 10 day trend is showing the northerly with the 'wish bone effect' with regards to showers. Other models are showing showers countrywide.  Surely now that we have stronger solar radiation I thought it was expected that if you have a robust northerly in place there will be considerable instability at this time of year. So what is behind the met office's thinking that showers will mostly be confined to coasts still ? Any ideas?..

Got to be honest and I don't want to be a killjoy here but I don't think you nor I, in our respective locations, will see an awful lot of snow anyway. If GFS is correct some lows crashing into colder air will give us more chance late on next week

The north, in places, look like getting something significant out of this, however

[LRD]

2 minutes ago, Mr Frost said:

Indeed - Easter Sunday looks lovely down there! Mid teens and sunshine for many!

 

Also later that night into the early hours of Easter Monday...watch out for some back edge snowfall/wintry mix in the SW/S/SE. (Especially East Anglia)

Cold air is not far behind at this stage.

Monday 00:00:

Purely speculation at this timeframe of course - interesting none the less. 

Yep, agreed. That is going to be quite squally overnight Sunday into Monday down here. I want it to delay until Monday morning just to witness what it produces rather than sleep through it. For me the change is unwelcome but as someone interested in weather it'd still be interesting to watch it unfold

[Dancerwithwings]

9 minutes ago, LRD said:

Sorry, what I meant is you showed a chart for Monday and Easter Day (traditionally egg hunt day) is Sunday - which is still showing up as ok in the southern half of the UK. In fact most of the holiday weekend is looking alright for southern/central Britain. Monday looks awful of course

The hail and rain fest starts Monday (snow possible if you're north of Manchester)

Correct, how wrong of me Easter is on a Sunday and I’ve kids as well

[Cloud 10]

11 minutes ago, damianslaw said:

ECM joining GFS and UKMO this evening, all show a direct potent, very potent arctic blast by Easter Monday. Significant wind chill whill feel bitter despite the strength of the sunshine, and I would expect plenty of convection thanks to the added heat from the sun.

Both ECM and GFS locking the cold in place for a few days, signs of a shortwave development over Iceland, polar low anyone, dropping into very low uppers, could be some significant low level snow from that feature - all conjecture though at this stage.

Look at forecast dewpoints exceptional stuff, evaporative cooling will be in free fall, this will increase likelihood of low level snowfall.

 

 

Yes,low dew-points a good test of how potent a Northerly really is,and the one coming up gets an A+.

 

[LRD]

1 minute ago, Dancerwithwings said:

Correct, how wrong of me Easter is on a Sunday and I’ve kids as well

Ha! No worries mate! I've only got one who is young enough for that sort of stuff now.

Sorry mods. Delete if necessary