Model output discussion - is the beast awakening?

[Anthony Burden]

GFS in reliable time frame shows low over northern U.K. at 120hrs slowly sinking south to 

draw in easterly winds at 168 hrs.After that guess work comes into the Synoptics lots of options 

possible in fantasy island one being ECM possible outlier,will be watching met office 30 day for

any change in Exeter Glosea 5.

[Chesil View]

Trying to put the pieces of the jigsaw together.  I would say that The models the met office use for their extended outlook see something generally akin to the GFS 06z but just a couple of hundred miles further south. 

[IDO]

gfs op -v- ensembles, def a synoptic difference as the mean suggests at d6-7:

So coincidence the op follows the ecm or are they driving the changes? Lots of variety at that point and there seems entropy as to the muddling Atlantic micro-scale features so really difficult to draw conclusions atm, apart from what we do not want!

 

[Battleground Snow]

Cold enough for everyone next weekend on para

 

[MJB]

A week today the Para gives us the chill

And snow hitting the East

[MJB]

The Control a week today

Edited January 31, 2021 by MJB

[kold weather]

7 minutes ago, IDO said:

gfs op -v- ensembles, def a synoptic difference as the mean suggests at d6-7:

So coincidence the op follows the ecm or are they driving the changes? Lots of variety at that point and there seems entropy as to the muddling Atlantic micro-scale features so really difficult to draw conclusions atm, apart from what we do not want!

 

What does worry me is the short term movement of the LP between 92-120hrs is a real definate shift towards the ECM. We then become dependent almost entirely on HLB being strong enough to shift the whole lot out of the way by force more or less.

As Singularity said earlier, the HLB behaves itself on the GFS 06z and shunts a good chunk of the country into a snowfest (apart from the south, which gets rain, a crappy fairly dry easterly (apart from maybe the N.Thames estuary region), 1hr of snow then more rain!)

However thats a hugely risky game to be playing, how many times have we seen HLB dissolve as we move closer into the timeframe. 

PS- if you want a worst case scenario, take a look at P9 on the 06z GFS ensembles. Shocker that one!

Edited January 31, 2021 by kold weather

[Battleground Snow]

Op borderline an outlier next weekend.

Great stuff. Mean of -9

 

[MattStoke]

Could be a ‘surprise’ dusting for some tonight according to the Arome.

 

Aperge pushes Tuesday’s snow risk southwards.

[MJB]

I'd fast forward to that at the blink of an eye 

The Control is a good un

Edited January 31, 2021 by MJB

[SLEETY]

gfs para even colder now than last nights run.

[Jason H]

Models moving to other models? Or the models just displaying their interpretation of the data it's fed? Fascinating stuff, no matter the semantics. Some places could get serious snowfall based on the latest GFS op.  Still heading towards cold for all is the general theme. How and for how long still to be resolved.

[JoeShmoe]

27 minutes ago, Tim Bland said:

GFS not snowy enough in Leicester Apart from the south east everyone should be happy with this outcome!

I appreciate a lot on this thread won't be affected but that would a large and disruptive amount of snowfall in the NE - 20-40cm widely and lord knows how much in the Cairngorms !

[Battleground Snow]

Para at 192!

 

[Cavehill Snow]

58 minutes ago, Man Without Beard said:

Had a look at individual ECM ensembles at T162.

Only 3 out of 51 were close to the op run in terms of that low over northern Scotland.

The far more likely way we'll avoid the easterly, according to the ensembles, is by the low clearly too quickly, leaving us under high pressure (though still probably cold).

I feel fairly content having seen the ensembles one by one that the ECM op is going to be too far north with that low between D6 and D7.

Good info update. Btw, do you know what are the resolution levels for the op & ensembles?

We know often the various Ops toy with a new evolutions, running with it sometimes, other times dropping it and exploring something new.

We always look at how the EC Op differs from the other model Ops - would you have any past experience of at what timeframe the EC ensembles may be expected to fall into line when the EC Op latches on to a correct evolution? TIA

Edited January 31, 2021 by Cavehill Snow

[sheikhy]

Just now, MattStoke said:

Could be a ‘surprise’ dusting for some tonight according to the Arome.

 

Aperge pushes Tuesday’s snow risk southwards.

More in line with ukmo!!!!!man this forum is lit and this is what we thrive on cliffhanger moments such as the one we are about to witness this evening on the 12zs!!love it!!

[The Giant Daddy Jackpot]

Seems that the 'Beast' opened one eye, yawned and went back to sleep again.

How many times has it been said that putting too much emphasis past D06 is a mistake?

[IDO]

2 minutes ago, kold weather said:

What does worry me is the short term movement of the LP between 92-120hrs is a real definate shift towards the ECM. We then become dependent almost entirely on HLB being strong enough to shift the whole lot out of the way by force more or less.

As Singularity said earlier, the HLB behaves itself on the GFS 06z and shunts a good chunk of the country into a snowfest (apart from the south, which gets rain, a crappy fairly dry easterly (apart from maybe the N.Thames estuary region), 1hr of snow then more rain!)

However thats a hugely risky game to be playing, how many times have we seen HLB dissolve as we move closer into the timeframe. 

Yes, we have gone from the models relatively persuasive solid gold cold-synoptic to a watered down version and now a cold spell dependent on micro features behaving! 

That seems the modus operandi of models; post-d10 we get clean, almost perfect cold charts. Then at around d7-8 we get macro changes that downgrade the potential, then at d5 we get the spoilers that can scupper the whole cold spell. It is a masochistic pastime for sure!

[Man With Beard]

4 minutes ago, MattStoke said:

Could be a ‘surprise’ dusting for some tonight according to the Arome.

 

Aperge pushes Tuesday’s snow risk southwards.

I'm dewpoint of 0.5C at the moment and I'm near the south coast. I think a lot of areas will see snow today (though probably not me).

[kold weather]

2 minutes ago, JoeShmoe said:

I appreciate a lot on this thread won't be affected but that would a large and disruptive amount of snowfall in the NE - 20-40cm widely and lord knows how much in the Cairngorms !

Yeah its an exceptional event for the NE. The pattern is somewhat similar to what Spain saw a few weeks ago.

The thing is the GFS has been pretty keen on setting up a frontal boundary somewhere in our neck of the woods in the last few days. Its been everywhere from N.France to now N.England on this run, but its been on all of the last 4 runs somewhere. GEM has been on and off with it as well to be fair the last few suites.

 

[Smoggieontour]

The 6z Op looks like an outlier for much of the short-medium term. For example, the mean 850 temp is a good 5c colder than the Op for NE England by the 6th/7th of Feb. It is also a huge outlier in terms of PPN.

So as much as I'd like to see this run come off from an IMBY point of view as I'd see about a foot of snow, it looks miles out in terms of the position of the front.

So that's an outlier from ECM and an outlier from GFS this morning.

[That ECM]

1 minute ago, IDO said:

Yes, we have gone from the models relatively persuasive solid gold cold-synoptic to a watered down version and now a cold spell dependent on micro features behaving! 

That seems the modus operandi of models; post-d10 we get clean, almost perfect cold charts. Then at around d7-8 we get macro changes that downgrade the potential, then at d5 we get the spoilers that can scupper the whole cold spell. It is a masochistic pastime for sure!

ECM has shown solid gold cold? You love a dramatic build up and then find the misery gfs 06z is fine. Let’s see where we are after the 12z’s.

[Man With Beard]

I'd still give the GFS 6z a 6 or 7 out of 10 for southern regions regarding cold prospects. Of course, not like the 10 out of 10 for northern areas, or recent parallel runs. But there's still a lot of messy slightly marginal snow events.

[MJB]

Control could be looking North 

[nick sussex]

The ensembles seem to be going one way and the ops in a different direction.

The concern is that the higher resolution ops should normally have a better handle on shorter term set ups .

I think tonight is going to be either a capitulation by the ops towards the colder solutions or we’re going to see the ensembles to start jumping ship.

I can’t see much middle ground here because of the nature of the set up . 

Edited January 31, 2021 by nick sussex