Model output discussion 02/02/20

[Nick F]

Ahead of Thursday's low potentially bringing a wintry mix across the south in the morning, besides sleet and snow showers for the usual suspects of Scotland, Ireland/N. Ireland and N England in a cold W or NWly flow, a cold front pushes E/SE tomorrow afternoon across UK with winds veering from westerly ahead the CF to northwesterly behind it introducing increasingly cold air with showers turning increasingly wintry across all parts in the evening and Tuesday night.

So don't be surprised even in the south to see some wet snow in the heavier showers after dark - as a few troughs bring bands of showers through. IMO even a dusting possible in some spots in the south overnight, but probably mainly over hills. Bigger accumulations over western and northern hills - as to be expected in this regime.

Edited February 24, 2020 by Nick F

[feb1991blizzard]

33 minutes ago, Mike Poole said:

Good to see we've got some wintry stuff to talk about at long last!  

I'm

Gope for upgrades!!

That chart is an absolute stonker!

[Mike Poole]

2 minutes ago, feb1991blizzard said:

That chart is an absolute stonker!

Yes, feb, well we can wish can't we!! 

[feb1991blizzard]

1 minute ago, Mike Poole said:

Yes, feb, well we can wish can't we!! 

Even this is a stonker for my location - zero chance of it verifying.

[Mike Poole]

ICON 18z take on Thursdays feature, T60:

The air isn't cold enough...is it, or maybe, in the morning, people have been wrong before about this sort of thing, so I'll say publicly that it won't snow in the south on Thursday, there, I've said it. That should sort the dew points out....

Edited February 24, 2020 by Mike Poole

[tight isobar]

15 minutes ago, Mike Poole said:

say publicly that it won't snow in the south on Thursday, there, I've said it. That should sort the dew points out....

Whoaa.....very premature mike .....these are indeed marginal formats...the meareast tweaks count for massive overheads\@ground level accomplishments...and @2\3day s out...A MASSIVE call.....plus...@this range my experience tells me the track will only fall further...on a southerly trajectory...     And I'm personally going to scrutinise every run leading forward....including the possibility of fun and games come the weekend....and indeed beyond..?

Edited February 24, 2020 by tight isobar

[Mike Poole]

6 minutes ago, tight isobar said:

Whoaa.....very premature mike .....these are indeed marginal firmats...the meareast tweaks count for massive overhead @groundground level accomplishments...and @w\edayw\edays out...A MASSIVE call.....plus...@this range my experience tells me the track will only fall further...on a southerly trajectory...

Yes I know that. But I was just playing devils advocate, and .... the percentages!!

Edited February 24, 2020 by Mike Poole

[nick sussex]

The ICON EU model develops the snow a bit later so as the low starts to clear east .

It does show a band of snow running from around Bristol into the London area around the M4 south .

Some more scattered snow showing up further north .

 

Edited February 24, 2020 by nick sussex

[feb1991blizzard]

6 minutes ago, tight isobar said:

Whoaa.....very premature mike .....these are indeed marginal formats...the meareast tweaks count for massive overheads\@ground level accomplishments...and @2\3day s out...A MASSIVE call.....plus...@this range my experience tells me the track will only fall further...on a southerly trajectory...     And I'm personally going to scrutinise every run leading forward....including the possibility of fun and games come the weekend....and indeed beyond..?

Yes but if it goes much more, you will have no PPN so its a lose lose situation.

[tight isobar]

5 minutes ago, feb1991blizzard said:

Yes but if it goes much more, you will have no PPN so its a lose lose situation.

 

5 minutes ago, feb1991blizzard said:

Yes but if it goes much more, you will have no PPN so its a lose lose situation.

I get that...however..we know it's going to bounce up and down...and maybe just for nowcast when it comes down to the wire....but I'd guarantee some will benefit in snow accumulation terms....it just geographically pin-pointing as per...it's I'm sure not a miss -and redirect feature this!!.. Ppn @no issue.

Edited February 24, 2020 by tight isobar

[nick sussex]

I think the Channel Low isn’t one of those that moves into sufficient cold at the surface so it’s unlikely to be all snow affair unless you have decent elevation . It seems as the system edges east on the more nw flank of that colder 850s head se and undercut the precip.

Edited February 24, 2020 by nick sussex

[Mike Poole]

Pub run take on the channel runner...T60, 63, first heights, then T850s:

Screams marginal to me, that isn't to say there won't be any snow action, just that it really is too close to call at the moment....watch this space!

[nick sussex]

The return of the wedge ! 

Another strange looking run , shortwaves all over the place , a slack pattern over the UK .

Could get interesting later .

Damn that stupid shortwave to the north which phases with the upstream trough !

Edited February 24, 2020 by nick sussex

[Allseasons-Si]

Another runner for next Mon also heading further south than the 12z but where have them height's come from to the north,mmm.

18z 156 v's 12z 162

a lot of interest this week coming up me thinks.

 

Edited February 24, 2020 by Allseasons-si

[Allseasons-Si]

6 minutes ago, nick sussex said:

The return of the wedge ! 

Another strange looking run , shortwaves all over the place , a slack pattern over the UK .

Could get interesting later .

Damn that stupid shortwave to the north which phases with the upstream trough !

I think a few more tweaks here and there and we could see something special Nick if the synoptic's play ball

there is some interest to talk about at least.

[tight isobar]

The chaos via the 18z gfs just reinforcing the miss dynamics at this point...but lots and lots of likely opportunity....near...and latter term....at last some real model viewing with large scale possibility \possibilities!...no deep cold .but SNOW ❄ well and truly on the menu!

Edited February 24, 2020 by tight isobar

[Allseasons-Si]

The 18z is quiet similar to the 12z control run but with height's to the NE,this will in turn force the jet NW>SE,no warm outlier on this run and should fit in with the gefs ens this time.

Edit:but then as i mention this,it goes t*ts up because the shortwave doesn't break off the parent low in the Atlantic, this is what we want to see to get amplification in the Atlantic NW of the UK,all academic at this range with such discrepancies earlier than that.

Edited February 24, 2020 by Allseasons-si

[Beanz]

1 hour ago, tight isobar said:

 

I get that...however..we know it's going to bounce up and down...and maybe just for nowcast when it comes down to the wire....but I'd guarantee some will benefit in snow accumulation terms....it just geographically pin-pointing as per...it's I'm sure not a miss -and redirect feature this!!.. Ppn @no issue.

I think Mike is probably right, I’m not entirely sure what weight your guarantee holds but looking at what’s on offer in the models at the moment, it’s not worth much.  
 

I’m calling Thursday a ‘non-event’ - as much as I’d love it to be otherwise.  

[snowray]

Arpege has the low much further north on its 18z run, out to T60, wasn't showing much in the way of snow until tonight.

ICON has the chance of snow especially as the low clears SE in the heavier ppn and the colder air digs in, some settling snow shown for the North Downs, so Steve M might be ok up there where he is on the Kent Alps. 

[tight isobar]

10 minutes ago, Beanz said:

I think Mike is probably right, I’m not entirely sure what weight your guarantee holds but looking at what’s on offer in the models at the moment, it’s not worth much.  
 

I’m calling Thursday a ‘non-event’ - as much as I’d love it to be otherwise.  

What weight..and what's on offer is my exact prognosis...we are not in situ of established cold overheads of any significant description....so it's indeed marginal \hopeful....but some of the best snow events have\do come from this evoling scenarios...where all points and processes fall into line at exactment...you do not need -8\12hpa in place for a decent\surprised SNOW event...and thermodynamics will be the Lord of the manor @5\10hrshrs out..as well as obvious feature format....id be not surprised AT ALL for an upgrade of all above current synoptics....and I for 1 adore this kind of borderline chase....that could 'again for some' reward well!......please save this post for reference!!!!!!!

Edited February 24, 2020 by tight isobar

[SMU]

Yes Mate 230M just up the road

[Allseasons-Si]

There is little pockets of height's/wedges of high pressure and trough disruptions to keep us entertained in our neck of the woods,whether we will benefit from those we will have to wait and see

and as Nick F says earlier in his post,there is interest Tue evening/Wed morning for a surprise or two even as far as the SW

i am going to chalk this one off for now,bed calling,hang in there peeps you may see something solid falling from the sky near you but i hope it isn't this,

i saw lumps of ice falling from the sky this morning and it was quiet slippy.

night all.

 

Edited February 24, 2020 by Allseasons-si

[feb1991blizzard]

smallest 850hpa spread ever in the history of ensemble forecasting.

 

[snowray]

11 minutes ago, feb1991blizzard said:

smallest 850hpa spread ever in the history of ensemble forecasting.

 

Yes quite incredible that, and snow chances all the way to the end.

[tight isobar]

20 minutes ago, feb1991blizzard said:

smallest 850hpa spread ever in the history of ensemble forecasting.

 

Some real worry for those awaiting an early spring....or anything remotely like it tbh!!!!

Edited February 24, 2020 by tight isobar