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Model output discussion - proper cold spell inbound?

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8 hours ago, Kentish Snowman said:

It's actually only 2/1 if there is a three way split!  Not bad!

I was  weighing the non cold solutions!

anyway, the differences between ecm and gfs are clear all the way up to 10hpa. I guess it depends which model has a better handle on what the strat response is re the warming and how the dominant Canadian segment interacts with the blocking. the sensible money up there would be on ecm, especially in a short timeframe. 

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2 minutes ago, Jemma Croton said:

Guys. Come on. The models are topsy turvy and swinging one way to the other but don’t get disheartened yet. The SSW isn’t underway yet and until it is I don’t think any models will have a proper handle on how things might progress. Ride it out and wait for the runs tomorrow onwards xx

Yes but we have been here before ecm now UKmo Gfs backing away not a good trend! 

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I’ve lurked on these forums for about 15 years and have seen these SSWs on several occasions and more appear to miss than hit in terms of the U.K. 

I recall high levels of SSW ramping in Feb 09 after the cold spell in week 1, but it all came to nothing with a mild rest of winter.

All that said I do find it a bit odd that something that is supposed to enhance northern blocking, seems to enhance southern blocking on the ECM. Think it’s worth retaining a high level of scepticism for the next few days while we see how things unfold.

But in terms of the ability for an SSW to deliver a cold spell for the U.K., it’s far from a guarantee of anything cold, let alone epic 1947 style blocking.

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4 minutes ago, snowice said:

Yes but we have been here before ecm now UKmo Gfs backing away not a good trend! 

We have. I’ve sat through it all painfully year after year but this situation is markedly different. We know that this SSW is happening and, not only that, it’s set to last 10 bloody days. This is phenomenal stuff and there’s no reason right now to throw in the towel. Come on... cheer up Charlie etc xx

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Hmm, I wonder what has caused the ECM to go from a firm yes to an emphatic no.

Is it seeing something different in its modelling of the SSW or teleconnections (after all a few days ago we were highlighting how it should it model the effects of the SSW more accurately due to better resolution/layers etc).
Or, does it suggest that upstream differences such as how a low behaves can actually play the winning card.
(Edit, Bluearmy gives a clue, differences in the strat right up to 10hpa.)

ECM vs GFS at T+192

ECMOPEU00_192_1.pngGFSOPEU00_192_1.png

Maybe we'd just be taking the longer route, but I don't like doing that. The sun is strengthening, and it gives us more time to get lost and run out of petrol.
Something that seems to happen quite a lot for us.

So in these circumstances I can't get excited. There would be a time that I can, e.g. when all models agree on a cold snowy easterly within T+120 :good:

Time to enjoy today's unusually chilly westerly with a risk of snow showers even here in the SW.

Edited by Evening thunder

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None of our models go out as far the projected effect of a SSW. The time lag is to great so really no point looking at these models until the event has taken place. Yes there has been talk of a 7day delay etc but its really going to be closer to 14days delay. 

 

Alot of pessimism exsists on this thread with no good reason. Patience. MJO and trends in he AO lead the way. Forget the run by run approach. Your just torturing yourselves needlessly. 

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It could just be that the SSW isn't going to have a positive affect on us as far as cold is concerned. Not everywhere in the Northern hemisphere will see bitter cold conditions from it. Somewhere is going to miss out, and if your a betting man you would favour our locale  over places like USA or Eastern Europe etc etc.

 

Edited by SteveB

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I think the ECM has this correct, big shift in the ensembles overnight towards the ECM like solution... 

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19 minutes ago, markw2680 said:

Why don’t we just enjoy this potentially wintery week coming up rather than obsessing about this ssw when the models haven’t got a clue about how that will play out. I can almost guarantee the dates will be put back for the effects of that as I said a few days ago. It’s always the same on here to much looking at stuff 8 days plus away

The much touted ssw does this every year almost, when there's any kind of warming imminent but the last 5 years any kind of midwinter warming has failed to downwell, I recognise this year is very different with the strength of it a lot stronger along with all the other drivers in our favour but it guarantees nothing.

 

However in my experience even with the built in stratospheric resolution within the models, I can't remember a year when the models worked out the trop response before the warming actually happened, the bench Mark was always 21 days or so for a trop response after the warming unless of course we had a quick trop response within 5 days or so but even then models would suddenly flip after the warming, and I'm expecting the same this year, we can all try and work out where the blocking will take hold but it very very rarely plays out as one would hope to the book.

But I'm more confident of seeing lots of northern blocking prevalent in the northern hemisphere in the coming weeks, whether it correlates to deep cold and easterly winds is another thing but we live in hope!

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5 minutes ago, Weathizard said:

I think the ECM has this correct, big shift in the ensembles overnight towards the ECM like solution... 

From days 6 into 7 the ECM is barely part of its own ensemble 

355BCC66-FA47-4595-87FB-DA1B903C3976.jpeg

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Just now, Severe Siberian icy blast said:

The much touted ssw does this every year almost, when there's any kind of warming imminent but the last 5 years any kind of midwinter warming has failed to downwell, I recognise this year is very different with the strength of it a lot stronger along with all the other drivers in our favour but it guarantees nothing.

 

However in my experience even with the built in stratospheric resolution within the models, I can't remember a year when the models worked out the trop response before the warming actually happened, the bench Mark was always 21 days or so for a trop response after the warming unless of course we had a quick trop response within 5 days or so but even then models would suddenly flip after the warming, and I'm expecting the same this year, we can all try and work out where the blocking will take hold but it very very rarely plays out as one would hope to the book.

But I'm more confident of seeing lots of northern blocking prevalent in the northern hemisphere in the coming weeks, whether it correlates to deep cold and easterly winds is another thing but we live in hope!

As far as I'm aware the last SSW was January 2013? 

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If it snows Monday week....and I think there will be some significant falls, it will not be the first time this winter I've seen the models more accurate from 250-360 hours away than from 150 to 240 hours away

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2 minutes ago, Severe Siberian icy blast said:

The much touted ssw does this every year almost, when there's any kind of warming imminent but the last 5 years any kind of midwinter warming has failed to downwell, I recognise this year is very different with the strength of it a lot stronger along with all the other drivers in our favour but it guarantees nothing.

 

However in my experience even with the built in stratospheric resolution within the models, I can't remember a year when the models worked out the trop response before the warming actually happened, the bench Mark was always 21 days or so for a trop response after the warming unless of course we had a quick trop response within 5 days or so but even then models would suddenly flip after the warming, and I'm expecting the same this year, we can all try and work out where the blocking will take hold but it very very rarely plays out as one would hope to the book.

But I'm more confident of seeing lots of northern blocking prevalent in the northern hemisphere in the coming weeks, whether it correlates to deep cold and easterly winds is another thing but we live in hope!

Yes but it’s all too let’s look at stuff a week away which is mad when we have a wintery week right before our eyes, many winters gone by without such a week. Let’s enjoy this week and remember ITS THE WEATHER! Many more important things going on in our lives I’m sure

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30 minutes ago, Broadmayne blizzard said:

The current unparalleled events regarding the polar vortex are a blessing and a curse. The blessing is that they will almost certainly lead to cold/snowy conditions coming to the uk via Hlb.

The curse is two fold firstly we have known about it well in advance so we hang on every chart out put willing it to appear which it has done in the gfs but not so much in the ecm.

Also the nwp in general is having to deal with unprecedented zonal wind reversal and I doubt that the algorithims used no matter how good they are will be programmed to deal with this particularly well.

FWIW I wouldn,t expect the nwp to get a decent handle on this until midweek at the eariest.

Hang on a minute B.B. ...................

I could almost go with the cold but the snowy is a big leap of faith.

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17 minutes ago, Jemma Croton said:

We have. I’ve sat through it all painfully year after year but this situation is markedly different. We know that this SSW is happening and, not only that, it’s set to last 10 bloody days. This is phenomenal stuff and there’s no reason right now to throw in the towel. Come on... cheer up Charlie etc xx

As I have said many times in the past. It doesn't matter how good the background signals are, it means absolutely nothing if these aren't translated into decent charts in the model output at a sensible timeframe.

If the ECM is right then my word we still have so much to learn!

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14 minutes ago, Weather-history said:

As far as I'm aware the last SSW was January 2013? 

Maybe official but even last year we had major warming, just not official because we didn't quite get a reversal of winds.

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The ECM is like a bad dream this morning!

The problem with it is you're a very long way from anything remotely cold by day ten, even though its a milder outlier later the op continues to plow out underwhelming runs and I thought last nights was bad.

The GFS is less amplified and seems to be going backwards in the earlier timeframe.

The SSW hasn't happened yet so I'd give it a few more runs before reaching for the Prozac but we don't have weeks to wait for a trop response that can deliver.

 

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Disappointing medium range charts this morning.  ECM Det continues with it's flatter evolution which has support from its ensemble suite.

It's fair to say this could be a slow burner...

EPS Day 10 mean

EDH1-240.GIF

GEFS Day 10 Mean

gensnh-21-1-240.png

GEPS Day 10 Mean

gensnh-21-1-240.png

 

Edited by mulzy

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15 minutes ago, TEITS said:

As I have said many times in the past. It doesn't matter how good the background signals are, it means absolutely nothing if these aren't translated into decent charts in the model output at a sensible timeframe.

If the ECM is right then my word we still have so much to learn!

Indeed, the Ecm shows an early taste of spring, the polar opposite of the background signals, you could say the Ecm has gone teits up in a manner of speaking!:D

Edited by Frosty.

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3 minutes ago, nick sussex said:

The ECM is like a bad dream this morning!

The problem with it is you're a very long way from anything remotely cold by day ten, even though its a milder outlier later the op continues to plow out underwhelming runs and I thought last nights was bad.

The GFS is less amplified and seems to be going backwards in the earlier timeframe.

The SSW hasn't happened yet so I'd give it a few more runs before reaching for the Prozac but we don't have weeks to wait for a trop response that can deliver.

 

And that is the concern nick . The tweet from IF says the ecm just brings the easterlies in later but it's hard to see on the day 10 chart how we go cold from there ? 

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4 minutes ago, mulzy said:

Disappointing medium range charts this morning.  ECM Det continues with it's flatter evolution which has support from its ensemble suite.

It's fair to say this could be a slow burner...

EPS Day 10 mean

EDH1-240.GIF

GEFS Day 10 Mean

gensnh-21-1-240.png

GEPS Day 10 Mean

gensnh-21-1-240.png

 

Maybe things will take a little more time to affect the output. 

9FDD6D94-75CB-48FD-90A8-4F919AA1036C.png

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For cold the ECM is awful no doubt about it.  Even in the nearish term.  The GFS has watered a little as has the GEM though they build the block and Easterlies come.  Yesterday’s GFS was utter perfection, and that is the point there.  I think like the rest of winter the models will move from each end of the scales to find a middle ground

 

BFTP

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1 hour ago, s4lancia said:

Well this morning’s runs will do nothing to quell the nerves of us long suffering snow seekers. Under more normal circumstances, following on from yesterday, this would have to be considered as a potential trend for the worse.

But... these are ANYTHING but normal circumstances. We have a record breaking wind reversal about to take place in the next 24 hours and currently forecast to remain reversed for a stunning 10 days or so. This combined with the highly amplified MJO currently causing havoc to the Nina state in the Pacific and sending waves polewards through the sub tropics. A second warming due in ten days. An already record breaking eddy heat flux. This is fairly exceptional.

This is not only going to have a major impact on default weather patterns but right here right now have a major impact on the forecast models. This is unprecedented in modern times, we cannot expect any model to be able to get a firm grip yet.

We need to wait at least another couple of days to let the upper warming actually commence and for it to be in the input data. Only then will we, potentially only start to see, how this will start to pan out. 

To say this is a highly dynamic situation does not due it justice.

Great post and completely agree. The above is exactly why the models are basically all over the place, expect more wild swings in the coming days. Try not to get too emotional with each and every days runs until we get some consistent clarity. Don't forget snow in the forecast for some today, tomorrow, Tuesday and who knows after that.

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16 minutes ago, shotski said:

Maybe things will take a little more time to affect the output. 

9FDD6D94-75CB-48FD-90A8-4F919AA1036C.png

A reason to stay positive this morning. Thanks for posting that. The question is, why were so many of the experts so confident of a qtr? The ecm is really gunning for a lagged response now to around 2 weeks from now. Let's just hope that doesn't keep getting put back and back until it is too late. 

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