Model Output Discussion - Colder but how cold and for how long?

[Drifter]

1 minute ago, Mike Poole said:

UKMO still persisting with a much more amplified pattern at T120:

That’s still quite a difference compared to GFS:

Ooh, the 144 chart could be interesting if that ridge can hold. 

[Rocheydub]

GFS 12z definitely more amplified around Greenland than it was on the 6z.

[MR_E]

Question regarding some of the changes with how north the low goes. With the 12z GFS it’s looking more north than previously. My question is how much do these things tend to correct run to run? For example, let’s say that low went high enough for midlands to get snow, would we see each model run pushing it further and further north or would one run just change it completely?

[Duane S.]

Ref the edging back north of the tracking of the system on Wednesday… Why oh why the surprise??  The 12z Icon and GFS Ops are still well within the envelope of eventual outcome. For the umpteenth time, it will carry on waxing and waning south/North from run to run for a while yet.

It must be exhausting being some people on here

[Rocheydub]

2 minutes ago, MR_E said:

Question regarding some of the changes with how north the low goes. With the 12z GFS it’s looking more north than previously. My question is how much do these things tend to correct run to run? For example, let’s say that low went high enough for midlands to get snow, would we see each model run pushing it further and further north or would one run just change it completely?

Increments on each run. Frankly can't see it going up to midlands. When it was prog'd first on the NWP it was midlands, I and many others said it would go south on each run, as is the form of these things. 

Edited January 13 by Rocheydub
poor spelling

[Frosty.]

If I was granted a wish from the genie in the bottle it would not be for a wishbone!.. honestly, why are u k winters so cruel to coldies?… but it does look  unseasonably cold for most of next week..which is a kind of victory when you consider global warming etc.. …….but now, I’m waffling..cut!

 

 

 

[Tim Bland]

Just now, MR_E said:

Question regarding some of the changes with how north the low goes. With the 12z GFS it’s looking more north than previously. My question is how much do these things tend to correct run to run? For example, let’s say that low went high enough for midlands to get snow, would we see each model run pushing it further and further north or would one run just change it completely?

Usually the envelope for change is smaller the closer you get. There’s still time for a 100 mile or so shift,  but it would need to be shown in the next 24hrs. From Hrs away from the event the shift is usually less than 50 miles  

[Taylorthesnowman]

10 minutes ago, Tim Bland said:

Not often we can say the south coast is the e sweet spot for snow this week (away from Scotland ) 

And the north west of England 

[sunnijim]

2 minutes ago, MR_E said:

Question regarding some of the changes with how north the low goes. With the 12z GFS it’s looking more north than previously. My question is how much do these things tend to correct run to run? For example, let’s say that low went high enough for midlands to get snow, would we see each model run pushing it further and further north or would one run just change it completely?

From my experience of past events with Lows modelled too far North at 10 days out, the correction South is too much in the eight to seven day time frame , then you get small corrections North as you close in on the event.

It is often then the case that the corrections North prove a little too far as the system moves in by about 30 miles or so.

I am a geek, I have years worth of notes on this stuff

[Eagle Eye]

Possible trend back to that shaving the south coast? Possibly. We'll have to see. If you think the handling of this low is gonna be correct at even a day before you're probably wrong, given the volatile model output, we're far away from the solution.

Just look at the difference between the latest GFS and last ECM (00Z, 12Z not on there yet). This is a positioning issue not a strength issue, it's therefore not really any model favoured here.

Welcome back on the madness train, calling at the south coast maybe but probably not Pembrokeshire. 

[Rocheydub]

Yet again, despite the impending bowling ball low (actually, medicine ball may be more appropriate, the sheer size of it) you can see models wishing to drain away the low heights from Scandy.

 

[Tim Bland]

3 minutes ago, Taylorthesnowman said:

And the north west of England 

Possibly but nose models have the main snow away from the populated areas eg north hit moors, peaks and Lake District. could see a dusting north Manchester, Leeds and Sheffield areas though 

[Harveyslugger]

1 minute ago, Eagle Eye said:

Possible trend back to that shaving the south coast? Possibly. We'll have to see. If you think the handling of this low is gonna be correct at even a day before you're probably wrong, given the volatile model output, we're far away from the solution.

Just look at the difference between the latest GFS and last ECM (00Z, 12Z not on there yet). This is a positioning issue not a strength issue, it's therefore not really any model favoured here.

Welcome back on the madness train, calling at the south coast maybe but probably not Pembrokeshire. 

Weather gods bring it to Pembrokeshire please

[MATTWOLVES 3]

This ain't a bad 144hr by UKMO..pv not rampant and some decent Ural Heights in there for good measure..I've a feeling there's more miles to run in this saga just yet!

[That ECM]

Just now, MATTWOLVES 3 said:

This ain't a bad 144hr by UKMO..pv not rampant and some decent Ural Heights in there for good measure..I've a feeling there's more miles to run in this saga just yet!

I think the cold is going but I would like this to be near the mark. Far less wind and rain than what gfs is showing.

[Rocheydub]

Is it going to blow up heights in Scandy on this run? Not far off it. Next few frames will tell. Pretty consistent modelling for that area of late.

[LetItSnow!]

5 minutes ago, MATTWOLVES 3 said:

This ain't a bad 144hr by UKMO..pv not rampant and some decent Ural Heights in there for good measure..I've a feeling there's more miles to run in this saga just yet!

Still cold at the surface as the high behind the low isn't associated with mild air so still cold at the surface come the 19th and probably 20th.

[The Northern Ramper]

46 minutes ago, That ECM said:

@Tamara  sorry you’re not going to win my post of the day award. This will win whatever is written.

 

Also looks good for NW England.

[Rocheydub]

8 minutes ago, Rocheydub said:

Is it going to blow up heights in Scandy on this run? Not far off it. Next few frames will tell. Pretty consistent modelling for that area of late.

Not on this run. But I can feel it in my waters! A watching brief continues!

[winterof79]

9 minutes ago, The Northern Ramper said:

Also looks good for NW England.

Rain, sleet and snow on Tuesday, with travel disruption possible. Drier and sunnier on Wednesday. Cold with frost and ice.

Met think so for lancs

"Risk of some disruptive snow on Tuesday, before returning to more cold sunshine Wednesday."

And yorks

 

 

We will see as the unstable cold gets going 

Edited January 13 by winterof79

[ICE COLD]

Interesting split pv again on the gfs at day 10 . Hopefully the next chase is not to far away

[That ECM]

Gefs mean

Edited January 13 by That ECM

[LetItSnow!]

Just now, ICE COLD said:

Interesting split pv again on the gfs at day 10 . Hopefully the next chase is not to far away

Odd looking how the cold pattern in Europe and the USA is seemingly blown away in seconds and back to a mild flow. Odd doesn't always equate to impossible, and a less cold spell will follow, but I wouldn't be surprised to see some tweaks in the next five days. I don't feel as though it will pan out as is showing now, but I admit that could be plain ole' unscientific denial - but I say watch this space and take heed of the experts.

[Chrisover93]

51 minutes ago, Harveyslugger said:

I agree

No we didn’t southern coastal counties haven’t seen snow since 2018

[Harveyslugger]

1 minute ago, Chrisover93 said:

No we didn’t southern coastal counties haven’t seen snow since 2018

Here in Pembrokeshire we didn't even get any snow from the beast from the east