Model output discussion 24/01/21

[Allseasons-Si]

ECM at 144,...DISRUPT!!!

[northwestsnow]

12z looks grim at 144 but still enough energy going SE to make things interesting,I hope....

[nick sussex]

The problem is look ne that chunk of deeper vorticity stops any ridging there between Norway and Greenland , we need to see a gap there .

The upstream low would disrupt if there was more forcing from the ne , the low itself isn’t the issue . 

[winterof79]

1 minute ago, northwestsnow said:

12z looks grim at 144 but still enough energy going SE to make things interesting,I hope....

Grim?? Slider snow machine

[I remember Atlantic 252]

1 minute ago, northwestsnow said:

12z looks grim at 144 but still enough energy going SE to make things interesting,I hope....

I was just thinking it was better angle, certainly than 00Z

 

[Tim Bland]

I think the cold spell at the weekend with winds from the east / north east is fairly nailed on. I suspect a warm up (briefly) thereafter probably is as well though ..

[Ice Day]

Yes, the GEFS in FI are excellent - loads of sub -8 options 

[Kentish Snowman in Yorks]

Looks like the trend with the models today is very much the cold air filtering further and further South.

My area (central UK) was forecast to hit double figures by Thursday only yesterday.  Now we have a stalling front and cold air filtering South and West.

Any modelling showing the Atlantic barrelling through West to East needs to be taken with a truck load of salt.  It seems that each low modelled slides more and more the nearer the time frame we get.

ECM looks very promising for the UK being the centre of a snowy battleground over the next week

[Allseasons-Si]

The ECM is better with the neg tilted low at 144 than the UKMO and gfs.

 

 

[MJB]

5 minutes ago, Vikos said:

The BOOM! is for Germany I take it 

[Tim Bland]

6 minutes ago, winterof79 said:

Grim?? Slider snow machine

Doesn’t slide, goes north east ...

Edited January 25, 2021 by Tim Bland

[winterof79]

4 minutes ago, Tim Bland said:

Doesn’t slide, goes north east ...

Hey ho. So did GFS// AND gfs turned out nice though

Edited January 25, 2021 by winterof79

[ItNeverSnowsInWindsor]

2 minutes ago, Kentish Snowman in Yorks said:

Looks like the trend with the models today is very much the cold air filtering further and further South.

My area (central UK) was forecast to hit double figures by Thursday only yesterday.  Now we have a stalling front and cold air filtering South and West.

Any modelling showing the Atlantic barrelling through West to East needs to be taken with a truck load of salt.  It seems that each low modelled slides more and more the nearer the time frame we get.

ECM looks very promising for the UK being the centre of a snowy battleground over the next week

Yes, the momentum has definitely swung towards cold air winning out with the North England also staying in the cold air now as well as Scotland.

If the trend continues then the Midlands could also follow!

[Kentish Snowman in Yorks]

2 minutes ago, Tim Bland said:

Doesn’t slide, goes north east ...

For now

[ItNeverSnowsInWindsor]

With the model volatility, FI begins at 72 hrs. I’m more optimistic than I’ve been all winter.

[topo]

Ι am expecting ECM to be an extremely warm outlier especially for Scandi.

 

[Phil Blake]

20 minutes ago, Tim Bland said:

Anything is possible but at the moment that snow early Thurs is very short lived and soon turns to rain. Best hope for anyone south of the Pennines is to look south at the weekend 

Could be good for the Durham area though 

[Allseasons-Si]

The latest UKMO fax charts stalls the fronts further SW than previous,...

isn't model drama good hey!

[nick sussex]

There’s still time to salvage day 6 . The upstream low approaches at a decent angle , the troublemaker is that shortwave to the ne .

You need a decent gap between that and the upstream low , that’s where we need even a mini wedge of heights .

That will stop the phasing of energy between both at the key timeframe  , the phasing action causes a ne push of energy on the approaching low .

Small margins can make a big difference in terms of where the energy goes .

Look out for the ECM ensemble spreads to see if we see some of that heading se in towards France day 6 into 7 and also look out for any spread to the ne.

 

Edited January 25, 2021 by nick sussex

[sebastiaan1973]

4 minutes ago, nick sussex said:

There’s still time to salvage day 6 . The upstream low approaches at a decent angle , the troublemaker is that shortwave to the ne .

You need a decent gap between that and the upstream low , that’s where we need even a mini wedge of heights .

That will stop the phasing of energy between both , the phasing action causes a ne push of energy on the approaching low .

Small margins can make a big difference in terms of where the energy goes .

Look our for the ECM spreads to see if we see some of that heading se in towards France day 6 into 7 and also look out for any spread to the ne 

 

i guess you mean this area. So, what do we need? It must move? Disappear? I fear that EC is right, it repeats itself. Not a good sign.

Edited January 25, 2021 by sebastiaan1973

[nick sussex]

1 minute ago, sebastiaan1973 said:

i guess you mean this area. So, what do we need? It must move? Disappear? I fear that EC is right, it repeats itself. Not a good sign.

Yes , thanks for posting that . Even if it’s further east or north , we need some ridging to get nw towards Iceland and keep the shortwave and the approaching low much further apart .

[Vikos]

Comparisson +d10 EC 12z yesterday/today

Edited January 25, 2021 by Vikos

[Cloud 10]

10 minutes ago, nick sussex said:

There’s still time to salvage day 6 . The upstream low approaches at a decent angle , the troublemaker is that shortwave to the ne .

You need a decent gap between that and the upstream low , that’s where we need even a mini wedge of heights .

That will stop the phasing of energy between both , the phasing action causes a ne push of energy on the approaching low .

Small margins can make a big difference in terms of where the energy goes .

Look out for the ECM ensemble spreads to see if we see some of that heading se in towards France day 6 into 7 and also look out for any spread to the ne 

 

 

Day 6 from ECM and GEM.

 

This is the GEM's  big chance for stardom.

 

[Anthony Burden]

Next weekend still to be settled by the charts let alone the following week.Gem is a peach

but on it’s own still you just can’t discount it totaly.GFS and ECM going for the continuation 

of Atlantic low pressure’s running the show.

[Uncertainty]

Notwithstanding the fascinating permutations up to day 7, the thing to look for in the coming days to set up the longer term ‘proper cold’ is the amplification set up by the low off the Eastern Seaboard at day 10

The ECM has it, as do many of the GEFS perturbations that go on to produce big time blocking 2-3 days later. I’m not certain the EC would, though you would think so... but the trend is also apparent on the GFS suite including both ops and fits with the MJO lag. Worth noting that this scenario has been signposted frequently this winter and the ‘bridge’ between the Atlantic amplification and Scandi heights has never quite made it into the reliable, or even to 120 for that matter. I suppose we haven’t had the MJO momentum kick to back it up mind...
 

Alternatively, there are also hints tonight that the day 6 low could disrupt as Nick has described it. Given the last few days have seen the cold trend southward and disruption and SErly movement increase with time there’s every reason to think that might be the case for that low too. JMA a good example of this, with barely a wedge to send it under

 

We’ve all seen how snowy that scenario could be ala GEM so plenty to sink our eyes into over the coming days, with a particularly big 46 coming up too give us some clarity as to where this is all headed...