Cold hunt - models and chat

[swfc]

28 minutes ago, alexisj9 said:

Where?

That was on the gFS 12z

[kold weather]

I'm thinking the writing may well be on the wall again for this attempt at a long sustained deep cold spell other than maybe that NW shot, which of course could provide something decent. Will probably be another 7-10 days before the pattern may shift favourably again.

GEM is all worlds of awful tonight by the way, really bad!

So that's the ECM, GFS op/control + 40% ensembles, GEM op and UKMO all very much on the same page around 144hrs with how they handle that upper low over Canada. Getting to be some strong agreement there.

 

[mulzy]

The evolution from day 6 to day 7 looks suspect on the ECM 12z.  The trough disruption which looked odds on at day 6 just doesn’t happen.

At day 7 it becomes a poor run but will it be right?  I say no!!

Edited January 23, 2019 by mulzy

[blizzard81]

1 minute ago, Mike Poole said:

ECM too far west on T216.  

On the other hand JMA T192 spectacular, so it is possible!

Remember the stonking jma runs a week or so ago? I'll say no more

[snowking]

11 minutes ago, Daniel* said:

ECM really piles it up further south too think it’s lost the plot crazy amounts along a narrow corridor..

Bear in mind these run with a 10:1 snow to rain ratio - not often we see those sorts of ratios in the UK and especially not from a northerly....so those amounts will be massively overstated in terms of the specific scale....still some decent totals though, even if it is all just for fun at this stage 

[chris55]

Oh no....ECM 216 shows MILD how will we cope. 

 

[blizzard81]

1 minute ago, chris55 said:

Oh no....ECM 216 shows MILD how will we cope. 

 

We are numb to it now lol. 

[Snowman.]

With the ECM 240 I'm tempted to throw in the towel for Greenie height rises and focus on the NE.

Looks like it might be building a nice block there. 

[Matty M]

It would be just our luck of late if that trough stalled to the west at 192hrs like on this evening's EC

[Purga]

25 minutes ago, Man With Beard said:

Now this is more like it ECM. Southerly tracking jet, no time for mild sectors to bed in before the next NWly. The snow is really going to pile up in the north on this run. 

You spoke too soon - ECM is not a good run.....

[kold weather]

Just now, mulzy said:

The evolution from day 6 to day 7 looks suspect on the ECM 12z.  The trough disruption which looked odds on at day 6 just didn’t happen.

At day 7 it becomes a poor run but will it be right?  I say no!!

It was never going to disrupt because there is a weak ridge to the SE, you don't tend to get trough disruption into an upper ridge, so it held together.

Anyway 240hrs has a decent mild flow in place but its not the worst ending point actually and I can see an evolution that eventually gets us into at least *surface* cold via a Scandinavian high, but it'd probably not be the deep cold variety.

[Chesil View]

Luckily FI is about 120/144 at the moment so we don,t have to worry about the latter stages of tonight's ECM which is just as well.

[blizzard81]

Another c**p ecm op that ends with the promise of a relatively mild easterly

 

[chris55]

Way to much emphasis/confidence  being placed on operational and ensemble data at 120h plus. This synoptic pattern is away from the norm, the standard westerly flow is disrupted, the models will struggle to pick out the correct solution at this range in this pattern. 

Changes will be coming daily beyond 120.

edit.

^^^ I hadn’t seen Matts tweets before my post so it seems I’m on the same page lol.

Edited January 23, 2019 by chris55

[Frosty.]

No words necessary..next please!

[booferking]

8 minutes ago, P-M said:

UK wide?

Snow almost anywhere to Wednesday then up in the air from there with the way that low handles itself.

[Methuselah]

9 minutes ago, chris55 said:

Oh no....ECM 216 shows MILD how will we cope. 

 

We bin it!

[Matty M]

The temperatures shown above illustrate the EC Op will be a wild outlier later on.

 

Uncertainty still very very high.

[weirpig]

Decent  ecm  with potential for snow   in the short term        goes yampy  in its later stages however that will change  from run to run   happy with that 

[blizzard81]

There have been downgrades in the very short term. These seem to have gone under the radar on here. One of the best examples is the updated 72hr fax chart for Saturday. Compare it the 96hr for the same day from yesterday. The new update is much flatter and much less inspiring for cold further down the line. 

[kold weather]

Just now, Matty M said:

The temperatures shown above illustrate the EC Op will be a wild outlier later on.

 

Uncertainty still very very high.

Yeah it may well be too mild.

BUT that is run No.5 showing more or less the same evolution of the LP. Its getting hard to simply dimiss it as a bad run, especially when UKMO, GFS and GEM all evolve in broadly the same way, not exactly, but broadly. My bet is its caught onto something and got it on lock now.

Hope I'm wrong though!

[Met4Cast]

I think we're in a situation where none of the models are going to be particularly useful beyond day 5. There is so much going on within the atmosphere at the moment that subtle changes lead to very big changes down the road, especially for our tiny little island.

The ECM is a perfect example, completely different from it's 00z run with no inter-run consistency. If you want to avoid the "YAY GOOD CHARTS" followed by "WINTERS OVER" charts then I'd suggest paying attention to the ensemble means between days 5-10 and ignore pretty much anything beyond day 10 or treat it as a "just for fun but it wont happen" type thing. 

There's lots to be happy about over the next 7-10 days

[kold weather]

4 minutes ago, weirpig said:

Decent  ecm  with potential for snow   in the short term        goes yampy  in its later stages however that will change  from run to run   happy with that 

Yeah there are probably 3 decent snow events before the whole thing goes wrong, in that regrard the shorter range is quite a decent upgrade compared to the 00z.

Maybe it might be best to forget about that cold northerly that was previously forecasted and just focus on the nearer time which has got some potential, if marginal, snow events. We may miss something right in front of us whilst trying to reach for the impossible?

Edited January 23, 2019 by kold weather

[booferking]

2 minutes ago, blizzard81 said:

There have been downgrades in the very short term. These seem to have gone under the radar on here. One of the best examples is the updated 72hr fax chart for Saturday. Compare it the 96hr for the same day from yesterday. The new update is much flatter and much less inspiring for cold further down the line. 

I would just say delayed 12hr or so.

[snowy36]

6 minutes ago, blizzard81 said:

There have been downgrades in the very short term. These seem to have gone under the radar on here. One of the best examples is the updated 72hr fax chart for Saturday. Compare it the 96hr for the same day from yesterday. The new update is much flatter and much less inspiring for cold further down the line. 

How can that be so different to the ECW, the ukmo is so different even at 72 hours temp wise