Model output discussion - deep cold inbound?

[radiohead]

Why worry about a breakdown at 168+ when there are already significant changes on the model at 120. There will be further changes to come. Yes, a breakdown will happen at some stage but there's a good chance it will get delayed or some unforseen changes will crop up in the days ahead. Either way, we will have at least a few days of very cold and snowy weather to enjoy.

The para run is already showing other more interesting possibilites than the op...

Vs

Edited February 3, 2021 by radiohead

[danm]

1 hour ago, CreweCold said:

Yep and this is the point I am trying to make. A more protracted spell suits everyone better but given those in the E are 100% nailed to see snow, a shorter spell doesn't affect them as much.

Still, the responses in this thread to a genuine piece of model commentary has reminded me why I don't post in here as much anymore.

Nothing wrong with what you’re posting mate, it is the model discussion thread after all. I just think some are commenting that there are a fair few days of proper cold and snow being modelled before that point and any breakdown is still 7/8 days away, so probably a bit too far out to get overly concerned with at the moment. 

I know for those further west, easterlies aren’t always as good so can appreciate the concern from your back yard, however even in such scenarios we’ve seen over the years small disturbances and troughs forming that do push west, and whenever that breakdown inevitably comes it could still turn into a snowy battleground that would impact the west rather than a quick return to mild. Plenty of water to flow under the bridge until then. 

Edited February 3, 2021 by danm

[ICE COLD]

The para is a snorter . That’s how we prolong the cold spell

[Guest]

2 minutes ago, Mike Poole said:

Look, you can shoot me down, call me whatever you want if I’m wrong about this, but it isn’t going down like this:

T174 that big fish ain’t happening. Learning point, ECM and UKMO can handle sliding lows...

If that monster low can slide it'll bring the house down. Just need some lower heights in Iberia and voila you've got winter wonderland for a good while.

[Alexis]

GFS Parallel demonstrating what we want to happen - the dartboard low stalling and filling south of Greenland and spawning off a system to slide under the UK.

[Mark wheeler]

6 minutes ago, DCee said:

Cold is definitely digging further south on this run. Possibility here of a good extension of the cold, depends on the behaviour of that dartboard low...

Finally , you see the trend it’s been on the cards for 48 hours at least just not on the Goofus . 

[Timmytour]

I wouldn't trust the models beyond five days whether they show continuing cold or a breakdown.

Simply because these synoptics are so rare their experience of handling them will surely be minimal 

 

[Mike Poole]

1 minute ago, DCee said:

If that monster low can slide it'll bring the house down. Just need some lower heights in Iberia and voila you've got winter wonderland for a good while.

[Griff]

// 204

Edited February 3, 2021 by Griff

[kold weather]

GFS para looks far more realistic in terms of how its handling the upper low out west.

A reminder that the stretched out LP last Sunday was originally forecasted to be a bowling ball low right upto 96hrs. In the end it was about as stretched out as things could get.

[MKN]

I said it earlier but still applies. The area circled is key. If higher pressure remains in that area then the easterly lasts longer. 

[East_England_Stormchaser91]

When it’s upgrade after upgrade, you know it’s gonna be a big one!! 48 hours to go everyone. Hope everyone gets their fair share of the snow. Preparing for an absolute hammering here In the Wash area! Good luck all. 

[chionomaniac]

3 minutes ago, ICE COLD said:

What’s your take  on what happens ie breakdown please edd ? Gfs 18z doesn’t steam roll that low in now . 

My experience of these type of scenarios, is that every 6 hours when the next model run is available to view, the cold spell gets prolonged by 3-5 hours.  So it gets pushed back in time but eventually arrives. In the same way as cold charts are always 10 days or so away, the models tend to be over progressive initially at any breakdown. But then when it reels in to more reliable timeframes it is wallop and a quick breakdown results.

[DAVE_ALLEN]

7 minutes ago, ICE COLD said:

What’s your take  on what happens ie breakdown please edd ? Gfs 18z doesn’t steam roll that low in now . 

Probably a Slack foggy HP cell will form over UK ?

[nick sussex]

Just think in some winters you’d be lucky to get 5 days in total of proper cold.

It’s a lot of fun to see how this plays out and how much snow falls , I was minded to put possible snow amounts in my earlier post but then realized that’s asking for trouble in here ! Lol 

[Mucka]

Does anyone know why GFS parallel keeps going offline?

I assume it is to tweak the algorithms but just guessing.

It may well just be coincidence that it is having much more trouble sweeping the cold away since it came back online.

But I would imagine the Atlantic won't just sweep everything East at 2nd attempt as much of the out put has shown.

[Guest]

Could be a memorable event this one. The extension of cold is all to play for I would say. What a rare treat, be like Japan for a while!

[Buzz]

Just now, danm said:

Nothing wrong with what you’re posting mate, it is the model discussion thread after all. I just think some are commenting that there are a fair few days of proper cold and snow being modelled before that point and any breakdown is still 7/8 days away, so probably a bit too far out to get overly concerned with at the moment. 

I know for those further west, easterlies aren’t always as good so can appreciate the concern from your back yard, however even in such scenarios we’ve seen over the years small disturbances and troughs forming that do push west, and whenever that breakdown inevitably comes it could still turn into a snot battleground that would impact the west rather than a quick return to mild. Plenty of water to flow under the bridge until then. 

Yeah, I'm not so sure that any of us wants a SNOT battleground, thanks all the same.

But back to the models, the GFS parallel, as already pointed out, is looking very good indeed with the cold prolonged until at least the end of next week (if it's correct).

[Tim Bland]

Not going to make it on this run but the breakdown is delayed even further than GFS. Compare the 12z to 18z and you can imagine where we might be in a Couple of days with the runs for late next week...

[radiohead]

18Z GEFS out to 132 is an upgrade on the 12Z. The mean has uppers 2 degrees colder for most places at that stage.

Edited February 3, 2021 by radiohead

[MP-R]

16 minutes ago, goosey007 said:

Yes our only chance is to get the cold well established and then Atlantic tries but fails and stalls over the west......first few days likely to be just dry and really cold in the west looking at it.

Lots of outcomes will be toyed with over the coming days. More unstable the easterly the better. I think it’s also guaranteed that at least one Atlantic attack will fail miserably and bring a successful battleground scenario from midweek onwards - in what manner though... who knows.

[Matt H]

The GEFS 18z ensemble mean is rock solid out to t132 with sub -8C uppers covering the majority of the country!

 

Edited February 3, 2021 by Frosty Winter

[ICE COLD]

Yep upgrade on the mean . 
 

18z mean -

12z mean

[Daniel]

Classic 18z upgrade on the ensembles a large cluster now going below -10 at 850hpa

[Johnp]

Just had a quick peruse of GEFS and operation extend the cold spell seems to have commenced.