Model Output Discussion - Into the new year

[I remember Atlantic 252]

1 minute ago, Mike Poole said:

I’m amazed we have been able to keep it to ourselves for so long! The express have had their hands full with covid nightmare stories to be fair!  

Anyway it has to happen yet, and this cold spell starts gently, will take a few bites at the cherry as it cools gradually and then freezes!

ECM T168:

Take that!

EC way better than other 2, at 144 anyway (ukmo)

[kold weather]

Eermmm ECM 12z!

Thats an outstanding event from Wednesday-Friday!

I'd have banked Wednesday's event anyway (I'd be right on the margins of where the snowline would be, but with the downs nearby, I don't mind too much) but Thursday then takes it upto 11.

Yeah, thats a ramp...sorry if its not objective, but that runs deserves a ramp even for that first part, regardless of how it evolves down the line

[Tim Bland]

4 minutes ago, Tim Bland said:

Here’s the full run of precip for Weds- Thurs. ECM has all of Wales across to East Anglia and all points south in with a chance of up to 10cm in 24hrs. If I was a betting man I’d say this will adjust south a bit over the next few runs. That would mean more areas in the south seeing snow rather than rain. It lalso means norther extent mid Wales to south midlands across to southern East Anglia 

OMG that low stalls just of East Anglia, it then turns round and heads south west! It gives 3 days of snow and up to 20cm for some!!  Never seen anything like it! Absolutely bonkers and probably way off the mark but shows what is possible!!

[blizzard81]

Ecm much better than gfs. The gfs op and control shot their loads too early with retrogression to Greenland. They got a bit over excited lol. Maybe they see the Greenland high signal but go with it way too early. I'm fairly sure the ecm has a better handle on this. Should be a brilliant run. 

 

[Harsh Climate]

192H O my, looks what's about to drop out of Svalbard 

[Cheshire Freeze]

Can we drop a trough down into Scandi and set up a GH?

[ICE COLD]

2 minutes ago, Tim Bland said:

OMG that low stalls just of East Anglia, it then turns round and heads south west! It gives 3 days of snow and up to 20cm for some!!  Never seen anything like it! Absolutely bonkers and probably way off the mark but shows what is possible!!

Rubbing my hands together Tim looks like we get a clobbering

[Skullzrulerz]

3 minutes ago, blizzard81 said:

Ecm much better than gfs. The gfs op and control shot their loads too early with retrogression to Greenland. They got a bit over excited lol. Maybe they see the Greenland high signal but go with it way too early. I'm fairly sure the ecm has a better handle on this. Should be a brilliant run. 

 

ECM does look great but if the easterly has mild air coming from the Mediterranean then that's something to watch out for ?

[kold weather]

7 minutes ago, Steve Murr said:

ECM 96 wrap around

Yeah for some areas around the pivot point its close to 24hrs of constant snow.

The thing is whilst it probably is somewhat extreme in just how far it swings the LP back SW, the general idea of the LP stalling out and maybe doing a cyclonic loop is certainly possible. Where that happens of course is where things are uncertain.

Also, the models do tentatively seem to be zoning in on the location as well. If I was somewhere along the M4 I'd be feeling increasingly confident of a snow event on Wednesday...but still time for it to slip too far south. That is where the error will be, if there is an error.

[Scott Ingham]

2 hours ago, Met4Cast said:

The GFS is surely showing a QTR to any potential SSW? Almost instantaneous, in fact. This is what a complete zonal and Atlantic shutdown looks like. Easterlies stretching from Russia to Canada!!!

Good post. This has all the hall marsk of reverse zonality

[Beanz]

11 minutes ago, Eskimo said:

ECM absolutely plasters the SE corner. 10-20cm. 

That is something else, and just 60hrs away...  

ECM Hi-res is killing it tonight! 

 

Edited December 28, 2020 by Beanz

[captaincroc]

4 minutes ago, Tim Bland said:

OMG that low stalls just of East Anglia, it then turns round and heads south west! It gives 3 days of snow and up to 20cm for some!!  Never seen anything like it! Absolutely bonkers and probably way off the mark but shows what is possible!!

We have all seen a low hanging about with a good 24+Hours of rain etc where you think, "If this was only snow?!"...looks like that could be the one! 

[North East Blizzard]

2 minutes ago, CreweCold said:

Can we drop a trough down into Scandi and set up a GH?

I think its coming next frame 

[Mike Poole]

ECM T192, retrogression?

[blizzard81]

1 minute ago, Skullzrulerz said:

ECM does look great but if the easterly has mild air coming from the Mediterranean then that's something to watch out for ?

The easterly will probably deliver didly squat. However, the easterly must happen if we are to get that severe cold to our north towards our shores in the long run via retrogression to Greenland. Think of the easterly (which is tepid for January) as a means to an end to achieve the proper cold jackpot. 

[kold weather]

That is a very tasty looking chart at 216hrs:

Its sooo close to something really special, might just need a slightly stronger trigger low running down the eastern side of the upper high...

[Mike Poole]

ECM T216:

Up she goes!

[winterof79]

2 minutes ago, Mike Poole said:

ECM T192, retrogression?

Any more and gfs snow bombs coming down

[Harsh Climate]

Euro4 showing nothing on wednesday apart from a little patchy rain in the channel   Must be way off.

In all serious, you can almost guarantee where most predicted snow charts are showing 48 hours out the places affected will almost be different 12 hours out. Will be a classic case of Nowcasting.

[Cheshire Freeze]

1 minute ago, blizzard81 said:

The easterly will probably deliver didly squat. However, the easterly must happen if we are to get that severe cold to our north towards our shores in the long run via retrogression to Greenland. Think of the easterly (which is tepid for January) as a means to an end to achieve the proper cold jackpot. 

The easterly will be raw and grey. It will be naggingly cold rather than severely so...but as you say, it's what happens thereafter that is of interest

[West is Best]

This may fall on deaf ears but I continue to urge caution. The easterly scenario is by no means nailed on. With these ensembles I continue to think it's 60:40 high pressure will settle (topple) back over the UK after the northerly:

 

[Mike Poole]

JMA only going the same way as ECM at T192.  

Plus the strat is in bits:

[Man With Beard]

18 minutes ago, Eskimo said:

ECM absolutely plasters the SE corner. 10-20cm. 

Would be an amazing run for somewhere like Reading. The snow comes Thursday, passes through, stalls, then comes back for seconds on Friday!

[kold weather]

2 minutes ago, Harsh Climate said:

Euro4 showing nothing on wednesday apart from a little patchy rain in the channel   Must be way off.

In all serious, you can almost guarantee where most predicted snow charts are showing 48 hours out the places affected will almost be different 12 hours out. Will be a classic case of Nowcasting.

Euro4 is just too far south and perhaps a little weaker as well than the other models.

Shift that area up about 100 miles and it wouldn't be all that different from the ECM, maybe just as I said a little weaker and not quite as extensive as a consequence.

Its within the range of what is possible, though thankfully right at the southern end of what is likely at this point it seems.

[blizzard81]

I like it. I like it a lot.