Cold Snap, T0-180Hours Only

ninebeanrows

DM2

Nuts charts.

That end to the GFS would give feet and feet of snow, blizzards and much of the country would be like a scene from the day after tomorrow

darkman2

Weathercheck wrote: »

DM2

Nuts charts.

That end to the GFS would give feet and feet of snow, blizzards and much of the country would be like a scene from the day after tomorrow

It does not even succeed in shifting entrenched cold air so we get another go a day or two later. Sweet dreams;)

rKossi

good lord!

pistolpetes11

Video comparison 18Z V 12Z

https://www.youtube.com/watch?v=0yzpQ9oAL4c

BEASTERLY

Once again the 18z has poor ensemble support, maybe 5 out of 20. Bit better than the 12z. But it's lost the support of the control run.

@Darkman2: I literally drooled at that blizzard chart. Be careful what you wish for and all that...

darkman2

BEASTERLY wrote: »

Once again the 18z has poor ensemble support, maybe 5 out of 20. Bit better than the 12z. But it's lost the support of the control run.

Yes but it has broad support of the ECM operational which is also of significance. But once again this is not clear cut yet. There are still divergences within and between models.

BEASTERLY

darkman2 wrote: »

Yes but it has broad support of the ECM operational which is also of significance. But once again this is not clear cut yet. There are still divergences within and between models.

ECM seems to have ensemble support until FI as well

Irish Steve

rKossi wrote: »

good lord!

Ok,looking at the big picture here, and getting slightly sweaty palmed at the potential for I'm not sure what right now, there is clearly a humungous pool of cold over Siberia, at what stage does that really cold air start wrapping round the massive Scandinavian high that at the moment seems to be realtively warm, or are we going to start seeing some of that cold wrapped round the low pressure areas that are rattling out of Canada and Greenland.

Either way, it's looking like we're in the firing line for cold air from one direction or the other, or maybe even from both, which seems to be a slightly crazy picture.

Am I reading it wrong, or has the weather decided to make up for the months of dreary miserable nothing that's been plaguing us all winter, and now it's making up for it all ways.

Any and all flaws in this view accepted without argument right now, it's kind of hard to make sense of such a massive cold pool that sitting on top of both high and low pressure in the way that this seems to be.

Deep Easterly

darkman2 wrote: »

Yes but it has broad support of the ECM operational which is also of significance. But once again this is not clear cut yet. There are still divergences within and between models.

Although the ECMWF op run tonight has very little support from its own Ensembles past 144hs. Having said that, I'd not say no to Member 24!

M.T. Cranium

cross-posted from chat thread ...

I'm just hoping for model consensus by 00z, with this potential major weather event just five to ten days out, we need to have a reliable basis for alerts and warnings. At the moment, I would agree that the range of outcomes is just about the entire spectrum from nothing much to a crippling snowstorm with severe cold.

By the way, this is not so much a case of late delivery as missing shipments, when I made my seasonal long-range forecast I was expecting two or three outbreaks like this from mid-January to about the time scale of this predicted blast, then a milder end to February. Instead we saw one weak cold spell (stronger in the UK) two weeks ago, then back to the Atlantic which seemed wounded but still in control, now this beast looming.

I would have to say, this Siberian-Russian high looks strong enough to have its way with a rather puny Atlantic so I rather expect the GFS solution to be closer to the eventual outcome than the Euro, but the interesting thing is that a blend of the two would actually give more snow to Ireland than either of the models themselves. I will cross-post this in the other thread since I got into a model discussion.

alfa beta

Not model discussion as such (sorry) - but this is probably the best place to ask:

what time approx would I see the 0z models running out on meteociel?

(just debating whether to stay up or not)

ta

K_1

I think its around 3.30am it starts to roll out.

Nabber

Will this rain frontal stall?
If it does, and the cold hasn't reached, could we see flooding in the East & South East?

rc28

alfa beta wrote: »

Not model discussion as such (sorry) - but this is probably the best place to ask:

what time approx would I see the 0z models running out on meteociel?

(just debating whether to stay up or not)

ta

I think 0z GFS starts coming out at 3:30am and the ECM is about 6am. Don't stay up waiting, if there is a big downgrade it will drive you insane and set you off on a bad note for tomorrow!

Sponge Bob

Nabber wrote: »

Will this rain frontal stall?
If it does, and the cold hasn't reached, could we see flooding in the East & South East?

Based on observation it has been raining constantly all day in the west and rainfall readings in the hourlies ( northern half of the island) are around the 1mm mark.

I think that the ground has reasonable soakage capacity right now and can handle 24mm of rain in a day were the front to stall. For now the UKMO expects it over Wales tomorrow and as snow in parts and radar indicates no stalling. It is slow moving..but moving.



Soil Moisture Deficits, reported regularly by Met Eireann, are the best general indication of soakage capacity in the event of rain....as long as it doesn't absolutely bucket down for hours on end. Heavy rain on saturated ground where there is no deficit will lead to flooding. EG November 2009 in the Western Half of Ireland.

blackius

Nabber wrote: »

Will this rain frontal stall?
If it does, and the cold hasn't reached, could we see flooding in the East & South East?

I'll use met Eireann language...
Present indications suggest it will hang round the east all day tomorrow and slide into Britain on monday before sliding south soutwestwards drying out as it does so into munster I think and back to the atlantic.
It should fall as snow in wicklow above a 1000ft at times and definitely above 2000ft so quite a dumping up high.
Potentially a fair amount of rain too elsewhere lower down.
Thats what the ukmo faxes and bbc forecasts suggest anyhow.

Sponge Bob

The NOGAPS model shows a stalling front.

Su Campu

Here's the ECMWF snowfall prediction (3-hourly I think) for Monday morning, showing higher ground in western Britain getting the fun.



By the way, the Wunderground site has great ECMWF and GFS map overlays on Google maps here, with a host more ECMWF parameters available than anywhere else I know of.

Here's the beast from the east (T850), originating over eastern Siberia, near Lake Baikal.

Sponge Bob

Ooooh Su!

The Colours.:cool: The Colours :cool:

Here are the projected ECMWF 850 Temps for next weekend should some Atlantic Moisture kindly oblige them.

jo06555

Sponge Bob wrote: »

Ooooh Su!

The Colours.:cool: The Colours :cool:

Here are the projected ECMWF 850 Temps for next weekend should some Atlantic Moisture kindly oblige them.

So now its next weekend??? I don't know much about charts but I'm beginning to think relying on met eireann is safest bet as hopes are very quickly raised and dashed in here we will not see snow this winter IMHO

darkman2

Morning folks,

DWD is first model out this morning and it follows the ECM/GFS ops - quite an upgrade at 72 hrs.

mickger844posts

darkman2 wrote: »

Morning folks,

DWD is first model out this morning and it follows the ECM/GFS ops - quite an upgrade at 72 hrs.

Good to have DM2 on board for the GFS 0z run which will start rolling out shortly.:)

darkman2

Happy to be here. I can tell you the 00z GFS has already slightly increased the risk of sleet or snow in the East on Monday.

Redsunset

Tell you what wouldn't take a lot more push to give something special for east on Monday:D

mickger844posts

darkman2 wrote: »

Happy to be here. I can tell you the 00z GFS has already increased the risk of sleet or snow in the East on Monday.

Even in the early stages of the run the cold looks that bit further West compared to the 18z.

darkman2

00z is as you were. By Wednesday into the cold continental flow



Snow showers possible in the East by then.

premiercad

darkman2 wrote: »

00z is as you were. By Wednesday into the cold continental flow



Snow showers possible in the East by then.

Morning all, run so far is an upgrade for me, Siberian high comes steaming for Scandinavia which is better for us, gfs weaking adlantic systems

darkman2

You won't get closer to a perfect continental easterly then this.



Snow showers in the East at that stage.


The 00z brings in the cold uppers alot quicker (108hrs this is)

Duiske

Something "maybe" developing for those west of the Shannon @ 120 ?

Redsunset

Hold on the head of the high is being pulled toward Greenland. Everything bit more west