Model output discussion - here comes the beast!

[Smiler1709]

Im on the fence here tbh, going to enjoy the next few days with my little one and hopefully she gets some snow. I hope the models correct themselves by tomorrow's runs otherwise it could be the new trend. Have a nice evening folks

[Daniel*]

Just now, danm said:

Can I ask why you’re so sure of this? It’s not publicly available. 

Earlier in the day I read a tweet it’s unlikely for it to have flipped to other side of extreme. And if there was a sense of uncertainty Met Office written outlook wouldn’t be so bullish with cold and wintry conditions persisting. 

[Stu_London]

A shorter severe spell will undoubtedly be preferable for wildlife, the elderly, the economy, daffodils etc, so some relief from the models tonight in that respect. Personally whilst I’ve found the build up fascinating, more than 1 day of disruptive snow becomes a little tedious for me. Not withstanding that there remains significant uncertainty, we can perhaps hope that members have learned from the experience and remember next time that output past about 120 hours remains notoriously difficult to project for this little island climate of ours.

[Djdazzle]

5 minutes ago, Daniel* said:

Earlier in the day I read a tweet it’s unlikely for it to have flipped to other side of extreme. And if there was a sense of uncertainty Met Office written outlook wouldn’t be so bullish with cold and wintry conditions persisting. 

 But your post implied that you knew the MOGREPS output. A bit misleading.

[BOMBHEADS]

i usually don't write in this thread, i usually just enjoy reading the posts here as i'm no expert.  But, does this not all hinge on how quickly the cold air passes by the UK, and how quickly it engages the low pressure, and if it interacts with it??? to my untrained eye, the more the low interacts the more likely it is to travel north as it winds itself up.  Please correct me if i'm wrong.

[karyo]

4 minutes ago, Stu_London said:

A shorter severe spell will undoubtedly be preferable for wildlife, the elderly, the economy, daffodils etc, so some relief from the models tonight in that respect. Personally whilst I’ve found the build up fascinating, more than 1 day of disruptive snow becomes a little tedious for me. Not withstanding that there remains significant uncertainty, we can perhaps hope that members have learned from the experience and remember next time that output past about 120 hours remains notoriously difficult to project for this little island climate of ours.

Tell me now, that we should be happy for the daffodils! 

Hopefully, the models have over reated to a signal and they will correct the low southwards from tomorrow. 

[Met4Cast]

I'm personally not convinced that the OP models have this wrong - Whilst historically it usually corrects South, that isn't always the case and with heights retrogressing towards Greenland there is a good chance the high could be far enough North to allow the low next Friday to move further North, a trough develops to the West of the UK and we see milder air move Northwards as per GFS/ECM. 

The step towards the GFS from the ECM suggests this is a very real, possible outcome. 

We have a week of snow until that happens though. We'll see what the ensembles show.

[Summer Sun]

UKMO extended (right) weakens the low out over the UK still some precipitation around but less than D6

 

[Man With Beard]

I think we have to accept that the "Iberian low" is now the preferred option. Three UKMOs have gone for it in a row, more as quickly as the ECM tonight, but it does goes there.

However, what's not decided is how it will happen. The GFS now suggests a north/south split eventually. The UKMO, not sure, could potentially get enough cold into the low for it to stay all snow and then move on east. The ECM, for now, has to be treated as an outlier as it did not reflect any of its ensembles or previous ops - and therefore needs to be put in the "pending" file until the next two runs have passed. It does occasionally throw out nutty runs at T144 and beyond.

But one thing's consistent tonight across all output - a snowstorm for the southern half of the country (at least) on Thursday or Friday - which will add to the almost nationwide snow events of the start of the week.

[Joe Levy]

Just to inject a bit of perspective, I don't think many of us truly believed that we'd be seeing uppers like the ones shown below on tonight's ECM within 48 hours! Yes, the low pressure at the end of the week is a bit of a headache for forecasting, but actually there's bound to be a lot of excitement between now and then on account of unusually low uppers and low thicknesses, especially from Tuesday onwards. This is such a contrast to the situations we've had over the past few winters, which is probably what's putting people's nerves on edge. Let's try and enjoy this period and see what happens!

[The Eagle]

JMA seems to back broadly the ECM evolution allbeit with a deeper shortwave.

 

[swfc]

2

1 minute ago, Daniel Smith said:

I'm personally not convinced that the OP models have this wrong - Whilst historically it usually corrects South, that isn't always the case and with heights retrogressing towards Greenland there is a good chance the high could be far enough North to allow the low next Friday to move further North, a trough develops to the West of the UK and we see milder air move Northwards as per GFS/ECM. 

The step towards the GFS from the ECM suggests this is a very real, possible outcome. 

We have a week of snow until that happens though. We'll see what the ensembles show.

That's what a lot are not seeing in regard to the heights ete.There not staying over Scandinavia and sustaining the easterly flow.In general any build towars Greenland is fine but the heights kind of drain away hence the low or lows can move more nne instead of travelling threw france and Iberia.Alot of the great blizzards had areas of low pressure moving in from the south west but were caused to stall and move away to the south.Long way to go but a slight change in the positioning of the high may nudge" the yet to form lows" away.

 

 

[Mokidugway]

Seems to be a wobble with the threat of deep cold leaving the south of the  uk  ,plenty of time for things to change and the prospect of a long cold spell , sit back  and enjoy ,lol

[bluearmy]

Not good on the mean - uppers 5c warmer in the south than the 00z run at day 6 .......

[LRD]

Just now, Reverse Zonality said:

I have no issue with your analysis. It is realistic and you've got your bases covered. Let's not personify a weather model though, like it 'needs a win'. As you reference is gets flak on here for a reason (a reason which has been fully justified recently,too).

Last word on this so as not to derail the thread - yes, agreed, GFS gets flak. So IF it is right, then it would have spotted this first and deserves credit. Not personifying anything. It's just a phrase. If something gets criticism it should also get credit. Can't work just one way

And this is from someone who thinks (knows!) that ECM is the best freely available model

[bluearmy]

Just now, LRD said:

Last word on this so as not to derail the thread - yes, agreed, GFS gets flak. So IF it is right, then it would have spotted this first and deserves credit. Not personifying anything. It's just a phrase. If something gets criticism it should also get credit. Can't work just one way

And this is from someone who thinks (knows!) that ECM is the best freely available model

There is the issue that gfs is nearly always progressive so when things breakdown it generally always spots it first 

[Guest]

1 minute ago, bluearmy said:

Not good on the mean - uppers 5c warmer in the south than the 00z run at day 6 .......

What will be of greater value is the mean further north seen as the ECM brought 0C uppers right up to Scotland in the op. 

[LRD]

1 minute ago, bluearmy said:

There is the issue that gfs is nearly always progressive so when things breakdown it generally always spots it first 

Fair point

[Summer Sun]

ECM mean already shifting the cold air further north than yesterday's run (right)

Edited February 24, 2018 by Summer Sun

[Paul]

It's going brilliantly tonight isn't it.

If you want to moan please head to the moans thread, no-one comes to this thread to see people throwing their toys about because the models don't show what they want them to. 

https://www.netweather.tv/forum/topic/86721-model-moans-ramps-and-banter/

It'll be unfortunate with us being on the cusp of a spell of weather many have been looking forward to, but if the moaning and sniping (and sniping about moaning, etc etc) carries on, then we're just going to end up restricting a whole bunch of accounts...

[Decemberof2010]

Just now, Summer Sun said:

ECM mean already shifting the cold air much further north than yesterday's run (right)

I'm still happy with that. Cold air should hold on in the north as per MO text

[ScottishSnowStorm]

1 minute ago, Summer Sun said:

ECM mean already shifting the cold air much further north than yesterday's run (right)

That because they are both a day apart

[Summer Sun]

1 minute ago, ScottishSnowStorm said:

That because they are both a day apart

Fixed

[Seasonal Trim]

3 minutes ago, Summer Sun said:

ECM mean already shifting the cold air much further north than yesterday's run (right)

Shouldn't you be comparing tonight's 96 with yesterdays 120?

[Daniel*]

T144 mean is fairly disappointing although less progressive than OP the west based NAO is not what we want to see. Could we see a revival of height rises to the north east?