Model Output Discussion - Cold spell ending - what next?

[Bats32]

20 minutes ago, Mcconnor8 said:

Storm for Sunday night looks even worse on the 12z! Hope it doesn't verify like this as would be a bad one.

Ouch, could we be looking at another 1987 here?

[Ice Day]

GFS and GEM are pretty similar at 210, interesting where this goes as it looks fairly primed to my untrained eyes!

 

Edited January 18, 2024 by Ice Day

[Battleground Snow]

1 minute ago, Ice Day said:

GFS and GEM are pretty similar at 210, interesting where this goes as it looks fairly primed to my untrained eyes!

 

Yes the charts are teasing us in the medium range.

The potential is there, but that mass to the northwest ideally just needs to drift a bit west to stop things from getting flattened.

[TSNWK]

Eyebrow raised - are ready for the final chase of core winter...

[Paul]

Arpege also windy on Sunday into Monday, but further north than the GFS. 

  

[Cold Winter Night]

GFS Op, like GEM, now has a Scandi High in place at Day 10 and it is beginning to advect cold Westward.
Good to see this signal repeated.

[Ice Day]

Given the GFS and GEM charts at day 10, I think we are officially now in the next chase.  However, there are almost countless ways this type of evolution can go wrong, so expect some wild swings from both the models and the emotions of the members on here!

  

[That ECM]

Interesting.

[Mike Poole]

Just now, Cold Winter Night said:

GFS Op, like GEM, now has a Scandi High in place at Day 10 and it is beginning to advect cold Westward.
Good to see this signal repeated.

Yes, GEM very much on the same page at T240:

Good to see these sorts of charts in the 10 day range.  Can we reel this one in?

[Lukesluckybunch]

Gfs setting up something special day 10 onwards!?

[Drifter]

Am I the only saddo that finds the formation of a Scandi high really fascinating? It’s highly satisfying watching the ridges shoot up along with the discontinuous trough disruption out west. 

Edited January 18, 2024 by Drifter

[northwestsnow]

4 minutes ago, Mike Poole said:

Yes, GEM very much on the same page at T240:

Good to see these sorts of charts in the 10 day range.  Can we reel this one in?

Well it would be lovely if a scandy high option suddenly started upgrading during the next few days Mike.

Watching brief here I've spent half my life chasing this cold spell since late Dec,exhausting !!

[Cold Winter Night]

1 minute ago, Mike Poole said:

Yes, GEM very much on the same page at T240:

Good to see these sorts of charts in the 10 day range.  Can we reel this one in?

It's right around the time renewed amplification was expected. We have the AAM increase supporting this, contrary to FI Scandi High output in past years. Now let's hope the stratosphere will behave well for once.

[Mcconnor8]

5 minutes ago, Paul said:

Arpege also windy on Sunday into Monday, but further north than the GFS. 

  

Yes Arpege deepens the low more to nearly 940mb bringing it further North.

UKMO looks roughly inline with GFS to me, if not worse to be honest! Going to be Storm Isha almost certainly.

 

[Wilxy]

Nice to see height rises towards Scandinavia, the ensembles have been toying with this idea for a few days now, feels like we could well be about to start the next cold chase! And fits in well with the MJO signal going forward! 

 

Edited January 18, 2024 by Wilxy

[Mike Poole]

3 minutes ago, Cold Winter Night said:

It's right around the time renewed amplification was expected. We have the AAM increase supporting this, contrary to FI Scandi High output in past years. Now let's hope the stratosphere will behave well for once.

Yes, if it wasn’t for the fact that we’re expecting this from the GSDM analyses and background signals, we wouldn’t give the odd run showing it at day 10 the time of day…but as it is…

[That ECM]

3 minutes ago, Mike Poole said:

Yes, if it wasn’t for the fact that we’re expecting this from the GSDM analyses and background signals, we wouldn’t give the odd run showing it at day 10 the time of day…but as it is…

T 168 you would choose ukmo over gfs at that point and gfs was good. Also  the met

Edited January 18, 2024 by That ECM

[Met4Cast]

7 hours ago, Met4Cast said:

I know some are downbeat about this current colder period due to the lack of snowfall (in southern areas, anyway) but the teleconnections advertised this period very well. 

This current cold spell isn't over yet but already it seems a return to blocked/colder conditions is the broad direction of travel into February. The mechanism and drivers for this to occur are already in motion. 

The MJO looks to progress through the Maritimes into the western Pacific, with this frictional torque has risen with +MT following on behind. MT always follows FT. Westerly momentum is transferred from the earths rotation into the atmosphere and the response is AAM tendency goes up, driving total AAM upwards. Indeed, AAM tendency has recently turned positive once again in response to the MJO progression eastwards.

As the MJO continues into phase 6 (and possibly 7, this is more uncertain) we see a configuration favourable for high latitude blocking. It seems probable we'll see a period of mild (perhaps exceptionally so) weather as high pressure builds northwards through the UK but there is an increased likelihood of Scandinavian blocking & thus, colder easterly winds 6th - 15th February as a broad timeframe.

The starting pistol, to borrow a phrase from Tamara has been fired. NWP modelling isn't quite in range of this period yet however we're already seeing signs of pressure rising to the NE via a route through the UK, I suspect these runs are a little progressive in terms of timing but do advertise the broader direction of travel. 

Eyes down.. the next chase is about to begin.

Oh GEM you are a cheeky sausage. 

This is a great example on how following the GSDM/MJO & broader teleconnective drivers can give context to NWP modelling. 

We’d throw this out & ignore it, but given this is the exact pattern being advertised it gives it a little more credence.

EDIT: As outlined by @Mike Pooleabove! 

Edited January 18, 2024 by Met4Cast

[Cold Winter Night]

A run like GFS is also a good illustration of how quickly cold can return, as long as you have a strong and well-aligned Scandi High setting up.
That should calm the minds of those who lament the Eastern cold being driven out by the Westerlies.

T850's to the East, over Southern Sweden and Poland go from about +6c at 192h to -12c or lower at 264h, that's 3 days.

[northwestsnow]

It's just dawned on me ...

If EC goes down the GFS/GEM route by   day 10 I'm going to have to strat myself in,again..

[Lord Grogon]

51 minutes ago, Bats32 said:

Ouch, could we be looking at another 1987 here?

Not quite. These are gusts in kph. So if I'm reading correctly it's 70mph gusts along the coast. 50-60mph inland. With some inland locations poss a bit higher. 

A nasty event, but nothing ridiculously extreme in terms of windspeed. 

What's actually more impressive is the size of the windfield as it impacts all of England and Wales. Cetainly, you'd have the whole country under at least a yellow warning. Storm Henk this ceratainly isn't... 

[Tim M]

1 minute ago, Lord Grogon said:

Not quite. These are gusts in kph. So if I'm reading correctly it's 70mph gusts along the coast. 50-60mph inland. With some inland locations poss a bit higher. 

A nasty event, but nothing ridiculously extreme in terms of windspeed. 

What's actually more impressive is the size of the windfield as it impacts all of England and Wales. Cetainly, you'd have the whole country under at least a yellow warning. Storm Henk this ceratainly isn't... 

GFS just out has my area, Mansfield, North Midlands, down for 75mph gusts! To me that is ridiculous for our area. Hope GFS is overdoing it.

[That ECM]

Control 

[LetItSnow]

Just now, That ECM said:

Control 

Ever so close, ever so slowly. As long as we keep getting this theme within the day 10 frame (day 9 currently) then we could be in for some surprises. Slowly she goes...

[TSNWK]

3 minutes ago, LetItSnow! said:

Ever so close, ever so slowly. As long as we keep getting this theme within the day 10 frame (day 9 currently) then we could be in for some surprises. Slowly she goes...

Be good to see ecm starting to sniff around this opportunity day 9 and day 10