Model Output Discussion - Colder spell ending, what's to follow?

[Penicuikblizzard]

13 minutes ago, dragan said:

indeed, i’m not sure you would want what the very end of yesterday’s gfs (i think 0z) was showing.

I mean imagine trying to get up Queensway at Tesco penicuik!!

Yeah that would be tricky thankfully I live along the road at Straiton now

[LRD]

GFS Ensembles

Nothing dramatic yet but the slide in 850s continues and is gradually moving to the left of that grid. Let's see if anything dramatic pops up and/or that dip in 850s continues to move to the left

In the meantime, an inevitable milder spell. Not especially mobile. Lows are getting stuck over us or to our West. Not much getting past the meridian

[Eagle Eye]

Some deep lows here an incredible set up for Winter would be nice, hang on am I ramping something do I actually trust these models, well No but still an interesting deep low.

Accompanied by, nothing. Well perhaps someone else has got some good models because Winter is coming, i can see a Westernly ridge setting up, with an Easternly and as my profile pic says just you Wait.

Anomaly says that we could have cold walking out from that, well pressing the UK, we will be looking to Hassenhuttl to get Southampton Pressing Like That.

[Alexis]

I like the 0z GFS simply because it shows a route to cold, which we haven't seen since the northern hemisphere started to arrange itself theoretically positively.

 

[Methuselah]

6 minutes ago, blizzard81 said:

Yep, quite a major earth bound solar flare. Possible impact tomorrow or Thursday. Not good news at all. Really bad timing and solar activity has increased quite markedly over the last 2 to 3 weeks. From past experience, I wouldn't be surprised to see the NWP move away from any potential end of December cold by this coming weekend. We will then be looking into Jan. Still early days of course but I'm getting that slippery slope kind of feeling. 

Personally, I can't see it making one iota of difference?

[fromey]

So this is the CFS bias corrected zonal winds at 10HPA

and a snippet from Simon lee which peaked my interest.

seems to go along with a few members thoughts.

interesting to see how this pans out over the next few weeks

Edited December 8, 2020 by fromey
spelling

[heath]

The invisible line isn't straight on ECMF op day 10, with UK on the western side. Another UK trough to follow in the week before Christmas? And then wait and see. Still not a flat profile. 

[Eagle Eye]

a quick overview so far

GFS is going for a double ridge I may have only been alive for shorter than one of Eric Clapton's solo's but I know that's unlikely.

Ecmwf is a bit like a Badger all round not hated but loved by few as well.

[StephenL]

16 minutes ago, General Cluster said:

Personally, I can't see it making one iota of difference?

For a newbie - is there evidence that solar flares can have an impact on the weather?

[Frosty.]

I was curious as to whether there was any support for the developing epic end to the GFS 0z operational from the ensembles...and there is some good news..although not as stunning as the op, there are several members showing similar ingredients..so there is potential!!  

[Methuselah]

4 minutes ago, StephenL said:

For a newbie - is there evidence that solar flares can have an impact on the weather?

Not unless you're a follower of Piers Corbyn, there isn't... Welcome to netweather btw!

[StephenL]

Just now, General Cluster said:

Not unless you're a follower of Piers Corbyn, there isn't... Welcome to netweather btw!

That's good to know :-). And thanks GC!

[swfc]

Looking at the gfs 6z at the 144-150 hr mark there's a subtle difference coming of the esb. Ridging is building be it slight and forcing the PV further north. Mabye nothing but it's there ie better Heighths towards Greenland 

Edited December 8, 2020 by swfc

[Matt H]

 

[Cold Winter]

Bit of ridging towards Greenland and energy sinking further south over Europe at T160-170 on GFS 6z...

[swfc]

Just now, Frosty Winter said:

Yes that's the one. Began 144 hrs

[IDO]

3 minutes ago, swfc said:

Looking at the gfs 6z at the 144-150 hr mark there's a subtle difference coming of the esb. Ridging is building be it slight and forcing the PV further north. Mabye nothing but it's there

Yep, subtle differences make changes run to run as the gefs are showing:

06z> 0z>

Quite whether that will change the long wave pattern is anyone's guess, or indeed if the 06z is just another option with more to come? What is clear it does not take much to alter the wedges, the tPV is very pliant to even light forcing.

[SMU]

As ever in a *potential* cold scenario with some -AO blocking the GFS is creeping along towards what we want.

As mentioned last night its latched onto the troughing over Svalbard sinking South & now increases the heights over Greenland East

Its not a million miles away from the UKMO now...

[SqueakheartLW]

A nice selection of easterlies with the latest Christmas Day charts from the GFS extended from least cold to coldest option

Member 23

A quite drab example of an easterly here with milder uppers in the mix. Could have a little surface cold with this one but that's probably the best you'll get from this setup

Member 20

A bit better than the first option with colder uppers and at least the prospect of proper cold to come with that deeper cold pool waiting over Scandinavia and E Europe to move over to us if the pattern can stick

Member 25

Although personally colder for us in the UK compared with Member 20 the drawback to this option is that the colder pool is much further away and there's less of it. This one requires more patience to wait for the cold to build and arrive

Member 19

A better version of Member 20. We are already in some colder air by Christmas here and there's also a nice colder pool waiting to our east too

Member 5

This option is good for the cold we already have in the UK but less of a colder pool to the east. More of a cold settled option here than some of the others with frost the most likely white stuff you'll see here

Member 30

Similar to Member 5 in cold already established in the UK but with a much more significant cold pool making its way out of Russia into E Europe and if this pattern can hold then eventually deep cold arriving in the UK too

Member 11

Last but by no means least we have the proper beasterly option in Member 11. Very cold air has already arrived by Christmas Day and no doubt the east is getting hit here by heavy snow showers and temperatures no doubt struggling to get above freezing too

Summary

A total of 7 of the 31 options showing easterlies of some variety is actually a good portion of the total considering the usual domination of the zonal westerlies. This is the biggest total of easterly options so far this month and could be showing a growing support for this sort of pattern later in December

[feb1991blizzard]

3 minutes ago, Steve Murr said:

As ever in a *potential* cold scenario with some -AO blocking the GFS is creeping along towards what we want.

As mentioned last night its latched onto the troughing over Svalbard sinking South & now increases the heights over Greenland East

Its not a million miles away from the UKMO now...

Could end up being a snorting long fetch NE flow this 6z run.

Dependent on the areas of troughing to completely disengage from each other and a bigger height rise to the N to ensue.

Edited December 8, 2020 by feb1991blizzard

[mushymanrob]

2 hours ago, mb018538 said:

Hang in there @northwestsnow!



All 51 members of the ECM 00z ensemble go for a very blocked outlook in the days leading up to xmas. Looks stonking to me!
 

this begs the question.... why are the ecm operational runs at odds with this at t240?

[feb1991blizzard]

Just now, mushymanrob said:

this begs the question.... why are the ecm operational runs at odds with this at t240?

because D10 ops are much less reliable than means, spreads and clusters, 10% verification rate for a 240 op.

[mushymanrob]

2 minutes ago, feb1991blizzard said:

because D10 ops are much less reliable than means, spreads and clusters, 10% verification rate for a 240 op.

............. i get that, but why?  i dont get why the more unreliable ops ignore the more reliable spreads and clusters..

[Cold Winter]

Quick reminder on how different one run to the next can be once you get past T144...... particularly when you’re thinking about the micro-effects on our little slice of the world.

 

Edited December 8, 2020 by Cold Winter

[feb1991blizzard]

Just now, mushymanrob said:

............. i get that, but why?  i dont get why the more unreliable ops ignore the more reliable spreads and clusters..

because its so more volatile as it is just 1 run, ENS suites are adjusted to take into account tiny miniscule features skewing a whole run in the wrong direction, of course even those can be such a mess that they are useless as well due to complex setups usually, unfortunately blocking to the N of the UK and undercuts are one of those things hard to model.