Model output discussion - 7th January onwards

[bluearmy]

29 minutes ago, Glacier Point said:

Your challenge Nick answered by another question. How many in that period have had Modki / weak / moderate end Ninos / low solar / coming after strong sustained weakening of the SPV ?

Indeed - a rare combination of background factors - perhaps unprecedented.... and by that very nature, nothing to use as an analogue either !

29 minutes ago, mountain shadow said:

How does the toppling/dumbelling keep the uk wintry though? Would we not get milder Atlantic being brought into the mix? You would have a kind of snow/rain/snow/rain scenario?

Get the Atlantic disrupting/diving into the broad trough just to our west or traversing around the top of the topple so it comes in off the continent (less likely to stay cold but possible) ..... the gfs op shows the pattern too far to the east without enough Atlantic amplification but that’s the gfs low res so not to be dissected ....

i agree that some ‘warm sectors’ could be a problem but if the surface was cold enough then they might be coped with ok 

As Stewart said earlier, the Canadian vortex and the sceuro trough - fill in the gaps ! 

[Methuselah]

What calamity, disaster and grief: everything's still pointing toward a colder pattern setting-in around or just after Jan 20th. What doom-and-gloom...Ignore the ongoing SSW and other teleconnections, and watch the seagulls instead...?

[weirpig]

1 minute ago, Vikos said:

I am beeing an optimist about it...

 

I hope im wrong but im starting to think the Para may have a snow bias  similiar to the Arpege with windspeeds.   lets hope not  

[northwestsnow]

FWIW 6Z GIVES A RIGHT DOLLOPING OF SNOW for many in FI..

Edited January 10, 2019 by northwestsnow

[Weathizard]

6 minutes ago, Daniel Smith said:

Thank you!!

That’s all i’m seeing too, I’m really struggling to understand the excitement. It’ll be below average & cold, exceptionally so? Unlikely. Widespread heavy snowfall? Unlikely. 

If you’re in the North & living on a hill then be excited, but if you’re in the South I can’t see it, mid Atlantic blocks & Northerlies rarely produce widely. 

The models show colder weather, but nothing to match the level of excitement.. 

It WILL BE will it? Thanks, can I have your crystal ball? Sod all the multi million pound models if you know what’s going to happen 10 days away why are we all bothering?

The met office models are on board so clearly something is going on and with SSW reversal anything can happen... I don’t mind if you’re opinion is that nothing will come about but to make statements with such certainty is totally foolish.

[Stormeh]

I have been reading various articles about the GFS being affected by the US government shutdown. Does anyone know anymore on this or is it just a lot of nonsense?

[swfc]

Having looked at the models over the last 24 hours it does seem the strong pv signal to the east is on its way out and grouping to the north west.Ithink gp and ba have aluded to this? even at the end of the gfs 6z look east pressure is on the up,be it fi.

[Met4Cast]

1 minute ago, Weathizard said:

It WILL BE will it? Thanks, can I have your crystal ball? Sod all the multi million pound models if you know what’s going to happen 10 days away why are we all bothering?

The met office models are on board so clearly something is going on and with SSW reversal anything can happen... I don’t mind if you’re opinion is that nothing will come about but to make statements with such certainty is totally foolish.

To be fair the Met Office have been “on board”

since about mid-December, their extended outlooks have flip flopped as much as a single GFS Op run. 

Just saying it as I see it within the models.. and as things currently stand, nothing “exciting”

within the next 10-15 days.. 

[summer blizzard]

I would worry less about the front producing snow and put more focus on the westerly element behind. That even puts places like Leeds in the fray for showers.

[Lloyds32]

23 minutes ago, TEITS said:

I haven't had chance to view the models for a few days but im disappointed with the output.

Turning colder? Yes

Chance of snow? Yes

Possible weak blocking bringing temporary colder N/E,lys? Yes

Chance of robust blocking bringing prolonged cold spell? NO chance!

For the next 2 weeks all I see is brief outbreaks of relatively cool/cold weather with greatest chance of snow for the N and higher ground. Problem is no signicant blocking is likely to develop in the key areas that will bring a prolonged cold spell. The ECM is obviously very different but how many times do we see potential in the latter frames of the ECM?? Answer too many times and I always distrust the ECM especially at +216/+240.

Very good post. Sums up the situation perfectly. We might go 'below average' but that doesn't mean snow to low levels or the conditions hoped for post SSW.

[Weathizard]

2 minutes ago, Daniel Smith said:

To be fair the Met Office have been “on board”

since about mid-December, their extended outlooks have flip flopped as much as a single GFS Op run. 

Just saying it as I see it within the models.. and as things currently stand, nothing “exciting”

within the next 10-15 days.. 

In recent weeks their outlook has actually been remarkably consistent but that’s for another thread, fact is they would never make the comments they have unless there was a strong signal.

Making confident predictions like that for 10-15 days out is fraught with danger as it is, and given the current conditions, background signals and uncertainty regarding the SSW, along with the amount of ensembles showing interest to me it’s nonsense to say nothing ‘exciting’ within a 10-15 day period, but that’s just me.

[Jonathan Rhodri Roberts]

GFS 6z continues with the settled weather in the south especially until around the middle of next week, after that low pressure albeit slack moves in bringing some wet weather which then moves away by next weekend to allow a ridge of high pressure again but at the same time, the jet stream is strengthening and shortly after, a deeper low arrives. So it looks like we could be seeing the last of the prolonged fine spells of weather for a while. The temperature swings between quite cold and fairly mild look to continue throughout though 

[northwestsnow]

Unfortunately locations might well have a big part to play over the 10 days or so post mid Jan- in a PM environment hillier areas in NW Britain will of course be a potentially different animal to lowland Southern Britain..

If your say, 150 m  + up a hill in the North west you could be hitting the jackpot very soon..if your 250 m i'd say start waxing the sledge..

[Polar Maritime]

Agree NorWestSnow, Always the case in a PM flow. Not that I'm grumbling.. All seems inline with the pro's outlook, With below avg temps overall.

Edited January 10, 2019 by Polar Maritime

[Ali1977]

9 minutes ago, northwestsnow said:

Unfortunately locations might well have a big part to play over the 10 days or so post mid Jan- in a PM environment hillier areas in NW Britain will of course be a potentially different animal to lowland Southern Britain..

If your say, 150 m  + up a hill in the North west you could be hitting the jackpot very soon..if your 250 m i'd say start waxing the sledge..

I’m guessing -6c uppers are good enough for snow at 200masl, so there’s plenty opportunities next week for the lucky ones!! Luckily I’m at 200m in East Cumbria 14-21st so my fingers are crossed.

 

Edited January 10, 2019 by Ali1977

[johnholmes]

27 minutes ago, Stormeh said:

I have been reading various articles about the GFS being affected by the US government shutdown. Does anyone know anymore on this or is it just a lot of nonsense?

This is what I found with a quick check

https://mashable.com/2018/01/19/government-shutdown-noaa-weather-warnings-forecasts/?europe=true

No effect is anticipated

[Vikos]

4 minutes ago, Ali1977 said:

I’m guessing -6c uppers are good enough for snow at 200masl, so there’s plenty opportunities next week for the lucky ones!! Luckily I’m at 200m in East Cumbria 14-21st so my fingers are crossed.

 

This chart shows the altitude for the 0°C-Line btw, so 200m could be a bit too low. it maybe snows but i wouldn't expect a snow layer lasting for too long

[Methuselah]

7 minutes ago, northwestsnow said:

Unfortunately locations might well have a big part to play over the 10 days or so post mid Jan- in a PM environment hillier areas in NW Britain will of course be a potentially different animal to lowland Southern Britain..

If your say, 150 m  + up a hill in the North west you could be hitting the jackpot very soon..if your 250 m i'd say start waxing the sledge..

Aye NWS, and beyond Day 10, any attempts at predicting much more than the overall pattern (and sometimes not even that?) encounters very poor verification stats...(if the ECM and UKMO allowed public access to what they showed, at T+384, I'm sure that they too would show the same failings).

Whoever it was that likened post-Day 10 charts to 'pin the tail on the donkey' was right on the money, IMO...

[shaky]

Control follows op with a bigger wedge at 192 hours!!could see upgrades this evening!!gfs 06z para loses the plot again and is different to the 00z run by quite a bit!

[northwestsnow]

5 minutes ago, Ali1977 said:

I’m guessing -6c uppers are good enough for snow at 200masl, so there’s plenty opportunities next week for the lucky ones!! Luckily I’m at 200m in East Cumbria 14-21st so my fingers are crossed.

 

Tricky one, lots of factors to play with so height required will be known closer to the time..

I have had rain with uppers of -8 from the NW before now, the Irish sea is a real pain for this part of the country- i think i vowed never to entertain a north westerly again after one such disaster!!
Then again Jan 1984 produced big time here and that was a north westerly-

Will be interesting how this all unfolds, i'd say 300 m + and your for sure getting a dumping, GFS as i posted above is very snowy at times in FI - perhaps Exeter will continue to suggest hill snow for the north..

[Weathizard]

Plenty of strong ridges amongst the ensembles, some calm is really needed on here at the moment, we are playing the long games.

Edited January 10, 2019 by Weathizard

[Jonathan Rhodri Roberts]

9 minutes ago, northwestsnow said:

Unfortunately locations might well have a big part to play over the 10 days or so post mid Jan- in a PM environment hillier areas in NW Britain will of course be a potentially different animal to lowland Southern Britain..

If your say, 150 m  + up a hill in the North west you could be hitting the jackpot very soon..if your 250 m i'd say start waxing the sledge..

Sometimes coasts exposed to the wind in a PM airmass can 'hit the jackpot' too but in a different way by getting thunder & lightning which can keep going on and off for hours bringing heavy rain, sleet and often hail, that's happened quite a few times when I go to Pembrokeshire especially between Nov-Jan. It's amazing to watch at night

[warrenb]

It is all down to where the split occurs. Unfortunately for us, is the Strato the split means multiple lobes of which one is over Canada. With that there, the temp differential will always fire up the jet stream no matter the forcings from other factors. Hence, we get a complete mix of ENS depending on where they decide to split at the Tropo.

[karlos1983]

Looking at the panel for +300 there's all forms of cold/colder/very Cold. So nothing decided yet. What does not look likely is anything that can be described as mild in the extended, more of a question of how cold.

The mean has the -4 850 line clearing the UK, so that's good!

Tight grouping going much colder towards the final third of the run!

 

Edited January 10, 2019 by karlos1983

[Matty88]

5 minutes ago, warrenb said:

It is all down to where the split occurs. Unfortunately for us, is the Strato the split means multiple lobes of which one is over Canada. With that there, the temp differential will always fire up the jet stream no matter the forcings from other factors. Hence, we get a complete mix of ENS depending on where they decide to split at the Tropo.

Nicely put, I'd say the predicted lobe of severe cold sliding into Canada/N America is definitely not a good factor (and never has been) in producing us a nice cold spell. Expect zonal cold 'snaps' until February and maybe beyond in my view - doesn't mean we won't see transient snow events though 

Edited January 10, 2019 by Matty88