Model Output Discussion - cold spell to end Autumn

[Derecho]

In the end the undercut didn't work out... for the low pressure to move towards the UK the high to our SW needs to be weak so the low can cut through. In the earlier stages of the GFS the high is too strong and the undercutting low gets stuck. Just one run though, it may change tomorrow 

Edited December 3, 2017 by Quicksilver1989

[Ben Sainsbury]

Clearly some differences appearing as we edge towards T144, at least as Day 10 has shown with T96 regarding the current setup is that we have good agreement tho the GFS having pushed the low further east compared to UKMO and ECMWF. 

[Snowmadsam]

Hello, yes it's really me. 

I'm back for a short while! Can I just say for the newbies here. Please don't get carried away by one run. Especially in the territory these charts are in at the moment (very unfamiliar). We are experiencing something very different to what we have been used to for a number of years. But we must not get carried away. The pattern at the moment looks different, and what really happens post friday, is well anyones guess.

If I was to place a bet, I'd be thinking of a mixed month with a NW-SE jet being suggested. Many model outcomes have been suggesting this scenario on and off.

Let's wait and see what happens - REMEMBER: It's only the first week of winter! So please have some chill!

[captaincroc]

3 minutes ago, nick sussex said:

The PV is more bloated here but before it gets ideas above its station a re-load of the positive PNA takes place with a some great amplification working in from the Pacific.

Factor in some GFS bias and edge the pattern further west.

 

I agree that the 18z - for me - isn't as good as the 12z but it looks like the models are toying with height rises over Scandinavia and are stuggling to decide what is going to happen. As the charts just don't look 'real' from 144 onwards. Not saying what is going to happen but I have a feeling better heights will be shown in time and as you said things will back west in future runs. Just my hunch.  

[Man With Beard]

EC clusters at T168

[andymusic]

5 minutes ago, MKN said:

For less than 15% of the UK that maybe the case but for the majority a typical largely dry northerly followed by a more westerly influence into day 8/9. 

d'you mind - 3 and a half (don't forget the half) million peeps and 8 million sheep in Wales lol - the GFS/ECM/UKMO deliver the goods nicely thanks!

[northwestsnow]

5 minutes ago, January Snowstorm said:

Folks if that's not a toppler I don't know what is......potent with snow for some though.

Looks like a reset then going forward but decent outlook hard to attain

Of course its a toppler ...i think we all know that!! Its a mid Atlantic high...

[SMU]

Goodnight vortex- totally shredded both sides of the pole

[bluearmy]

4 minutes ago, Man With Beard said:

EC clusters at T168

Sadly wrong again after day 10! 

Interestng that the op cluster looks more troughy than the op ! 

[igloo]

1 minute ago, January Snowstorm said:

Folks if that's not a toppler I don't know what is......potent with snow for some though.

Looks like a reset then going forward but decent outlook hard to attain

three days of very cold with snow showers followed by cold zonal looks like the most favored outcome thats my take on todays outputs some places can do well from cold zonal type setups hilly areas and northern areas could well get a few inches over the next fortnight the met office updates also suggest such thing going forward but it doesnt look like we will have any major blocking

[Allseasons-Si]

I know it's at day ten but look at the heights builing to the north of us,i circled that area on my previous post,i just got a shiver there

Edited December 3, 2017 by Allseasons-si

[Frosty.]

1 minute ago, Allseasons-si said:

I know it's at day ten but look at the heights builing to the north of us,i cirlcled that area on my previous post,i just got a shiver there

Much better than the benign mild dross we have now..

Edited December 3, 2017 by Frosty.

[SMU]

26 minutes ago, January Snowstorm said:

Folks if that's not a toppler I don't know what is......potent with snow for some though.

Looks like a reset then going forward but decent outlook hard to attain

Its not a standard toppler im afraid -

A standard one has the jet roaring over the top & over the UK-

This scenario has one system sliding through the high as an undercut then the jet reinvigorates alligned towards Spain pulling everything that way-

we may end up for a short period of time slightly less cold but it wont last long-

[MKN]

9 minutes ago, SteveB said:

And of course we all know day 8 & 9 verify

Im not saying it always does. Its the most likely scenario from dissecting the model outputs now though. Hopefully the northerly throws up some nice surprises before we get to then  

[Day 10]

Deep FI now, but is the Northerly just the key to the door of the famous Winter of 2017/18

[Duane S.]

No decent mid range slider (to bring snow to the masses).

Compared to the 00z which had a much less well organised vortex to our NW

But that's only one run, bound to change. And even if it's a way forward, likelihood is cold and potential snow for anywhere is merely delayed with the current state of the NH and this set up.

 

[Methuselah]

I know. It's too far out to take too seriously.

[Allseasons-Si]

The pv is wasted on this run,bye! bye! pv

Edited December 3, 2017 by Allseasons-si

[nick sussex]

Some very unusual and welcome synoptics showing up.

Great to see these trends in early December and very happy with tonights outputs. The PV blob has no chance as long as you get that re-load of the positive PNA as that pulls the PV lobe towards Canada and helps to separate the low tracking se from the PV mothership.

Then positive heights to the ne can build sw.

 

[Derecho]

The high pressure doesn't intensify later on allowing the jet to dive southwards which is what we want to see if the northerly is swept away. Great chart but all the way out at T300.

When you have low SLP to the south/SE of the UK the potential is often there to develop another spell of cold. 

The theme has been for northerlies repeating and lower SLP to our south has been fairly common so lets hope if the Atlantic does wake up we don't see the high pressure building around Italy.

[Duane S.]

Like I said, all good things come to those who wait...

 

18z, far flung FI but oh my... what-a-chart!

Edited December 3, 2017 by s4lancia

[Scandinavian High.]

Very interesting December coming I think. End of week tuning much much colder with snow in places as we move on that high pressure to the north east over Russia looks be pushing west maybe beast from east could pay us a visit...

[blizzard81]

10 minutes ago, s4lancia said:

No decent mid range slider (to bring snow to the masses).

Compared to the 00z which had a much less well organised vortex to our NW

But that's only one run, bound to change. And even if it's a way forward, likelihood is cold and potential snow for anywhere is merely delayed with the current state of the NH and this set up.

 

I mentioned this about the ecm op tonight. Much stronger pv over north east Canada. The gfs 18z has followed suit. Not good news at all. Some bargaining on the positive pna but if that trend of growing pv over NE Canada carries on then things will change very quickly in the long term  modelling. And not a nice change for coldies. 

Edited December 3, 2017 by blizzard81

[Team Jo]

Nearly 300 people reading at the moment. On a schoolnight too! 

All kinds of solutions being offered up right now for late next week, just worthwhile considering that there is quite a lot of contradictory posting which is pretty confusing if you’ve not spent much time in here before, so be kind, and don’t get too hung up on one run  

[BLAST FROM THE PAST]

Backend of this week a touch of a surprise but generally ‘rhythm of winter’ looks good.  Main features are HP to NW and deep LPs / displaced PV episodes to E/NE during periods of this winter.  Next thrust for me was mid month Dec....GFS showing this in FI in various runs and thus keep an eye on this after this week’s excitement.....big heights to follow to NE?  Not for me but nice to be wrong if it happens......many on here talking of reload Atlantic rigging with +pna re-in forcing as such.....so all in all reasonable support imo, I think we have a pretty interesting month ahead......and RJS lowered his CET to 1.9c. 

 

I really like the ECM 

 

BFTP

Edited December 3, 2017 by BLAST FROM THE PAST