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Paul

Please ensure that the majority of your posts in this thread are model related - a theme of model discussion needs to run throughout.
Some off topic chat and reactions are ok, but please use other, more relevant threads for entirely off-topic chat (such as snow reports, met office forecasts and general chat/moans about the weather or this winter).

For more no banter and just model discussion please head to the new focused model thread - this is also a great place to post (or cross post) your longer model summaries or thoughts around the models.

Message added by Paul

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2 minutes ago, kold weather said:

What I think is more telling is the GFSP has shifted south, the higher resolution version of the GFS (supposed to be better...and to be fair was one of the first models to clock the possible southward swing of the LP.)

That literally leaves the GFS against every other model. now its not impossible the GFS is right, however when we add into the mix the known bias the GFS OP has with pushing energy far too fast north and east, it begins to look like the GFS may be going up the wrong path here.

It's a different setup, but I recall the same claims being made about storm Emma last year; the GFS was consistently pushing it further north than the other models and at that time I remember many people saying the the GFS was over-egging it.

Not saying the GFS is correct of course, but it doesn't always get it wrong!

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Just now, feb1991blizzard said:

Not sure if you can, see your point but dont forget there will be different intensities, subtle changes from member to member will make a difference, trust me this will be further South, much weaker, more fragmented, and thinner, i have seen it too many times before.

The problem is the GFS may not quite have the resolution to see the small secondary depressions moving through the system and so keeps the LP as one cohesive ball of low pressure until the secondary depression becomes more obvious.

The other models are typically at better resolution and so are clocking these little disturbances better and that slightly changes the shape of the LP meaning it isn't so flat as the GFS has it.

Normally you wouldn't notice that flaw, its only when we hjave real knife edge issues that the resolution becomes an issue.

Its also why IMO the higher resolution GFSP has been toying with the idea of going further south, and again on the 18z run is further south.

Be interesting to see whether the 18z ECM goes even more south, it often follows/leads the ICON.

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10 minutes ago, kold weather said:

What I think is more telling is the GFSP has shifted south.

That literally leaves the GFS against every other model. now its not impossible the GFS is right, however when we add into the mix the known bias the GFS OP has with pushing energy far too fast north and east, it begins to look like the GFS may be going up the wrong path here.

WRF, UKMO (the middle ground and most likely, stopping just short of North Yorkshire), GEM, JMA, even the mighty NAVGEM etc. are akin to GFS. Action after the pivot is more diverse so when that happens there’s a greater split. I’m not trying to be contrary, just as I pointed out in recent days that the supposed corrections south for tomorrow were only 50/50.

Edited by ukpaul

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8 minutes ago, ukpaul said:

I would have posted the Panel GEFS to show that but that isn’t possible - or is there a way of doing that?

 

4 minutes ago, feb1991blizzard said:

Not sure if you can, 

gens_panel_snv7.thumb.png.e96d44e50b98e851bf8768450f3af355.pnggens_panel_kiv5.thumb.png.66952a8d80060739463ab67fa807415a.pnggens_panel_svd4.thumb.png.3ab0071b25814c4b617f041d446012db.pnggens_panel_qrd4.thumb.png.ab7b7e6abb1996529e9a93ff59e35354.pnggens_panel_dly5.thumb.png.2746451f2e30ee23192419a84e0fdbdc.png 

still time for adjustments north / south of the main frontal rain / snowfall and also the chance of snow showers feeding in from the NE / E if winds end up going in that direction

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9 minutes ago, feb1991blizzard said:

Not sure if you can, see your point but dont forget there will be different intensities, subtle changes from member to member will make a difference, trust me this will be further South, much weaker, more fragmented, and thinner, i have seen it too many times before.

If anything you get snow bands diminishing as more mixed signals take over. To keep them solid at a three day range is a pretty good show of consistency.

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Just now, Kirkcaldy Weather said:

 

gens_panel_snv7.thumb.png.e96d44e50b98e851bf8768450f3af355.pnggens_panel_kiv5.thumb.png.66952a8d80060739463ab67fa807415a.pnggens_panel_svd4.thumb.png.3ab0071b25814c4b617f041d446012db.pnggens_panel_qrd4.thumb.png.ab7b7e6abb1996529e9a93ff59e35354.pnggens_panel_dly5.thumb.png.2746451f2e30ee23192419a84e0fdbdc.png 

still time for adjustments north / south of the main frontal rain / snowfall and also the chance of snow showers feeding in from the NE / E if winds end up going in that direction

How did did you do that? What’s the secret button I have to press?!?

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5 minutes ago, ukpaul said:

WRF, UKMO (the middle ground and most likely, stopping just short of North Yorkshire), GEM, JMA, even the moghty NAVGEM etc. are akin to GFS. Action after the pivot is more diverse so when that happens there’s a greater split.

UKMO is quite a way short of there UKPAUL, doesn't get much north of Hull-Liverpool...and looks VERY close to the ECM in fact.

GEM suffers same issues as the GFS in its overprogressive usually, plus courser resolution.

JMA - same issue with course resolution.

NAVGEM - Same issue with course resolution.

WRF is just a variation of the GFS and uses GFS data...therefore what the op shows, the WRF will 95% time mirror it.

Its interesting that all the models with lower resolution do the same thing, all the higher resolution models are taking the system more elongated and to the south.

May be coincidence, but probably not!

Still, I'm certainly not going to just dismiss the GFS, its quite possible for it to be right and at this point within the range of the envelope for sure. Plus I was wrong in saying it was all alone, I hadn't checked those models apart from the GEM simply because at this point they aren't likely to be a huge amount of use with this type of system for the reason explained above.

Edited by kold weather

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1 minute ago, ukpaul said:

How did did you do that? What’s the secret button I have to press?!?

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=2&ech=6 🙂 (you will find the h slot next to the Echéance in the top right part of the screen)

Edited by Kirkcaldy Weather

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3 minutes ago, ukpaul said:

If anything you get snow bands diminishing as more mixed signals take over. To keep them solid at a three day range is a pretty good show of consistency.

We will see but any bands that get further North than the midlands will be very fragmented.

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29 minutes ago, feb1991blizzard said:

Gutted about the EC46.

Yep - sharp change of signal. No high lat block with any undercut of impact. Been mulling about this all evening really - the nature of the SSW this year, with it being such a slow process, has thrown semi predictability into chaos. I guess that leaves some gentle optimism that this set of charts may be no more accurate than the last lot, but really we only have the MetO now offering any coherent suggestion of cold and we cannot see their data. I have a feeling they wont take long to alter that 30 day text.

MJO peaks for cold interest in about a week and then will fade away through phase 8 to 1. 

twc_globe_mjo_vp200tx.thumb.png.6a32c7df2994da675d2dfca0e8497576.png

10 day mid strat image shows clearly revitalisation of westerlies over the Greenland area

ecmwf70f2440.thumb.gif.83c6d03bd98b3926c1a8e2d3dd7b6707.gif

And at the bottom of the strat any suggestion of a blocking high has gone with the Euro trough easing east. Heights gently building over the UK from the SW.

ecmwf150f2r40.thumb.gif.69c7cef04464a19fb810099ee9723942.gif

Essentially a return to average with a +NAO signature. However no raging atlantic assault - the SSW has put paid to that prospect for the rest of winter.....so probably a relatively benign pattern.

The only path to cold I can see from here for mid Feb would be the AH ridging over to Scandy and forcing atlantic energy underneath if the block extends far enough west. There is a suggestion that this isn't out of the question both from MJO progression, GLAAM profiles as a more meridional forcing once again applies itself to the NH and the vortex formation.....but i'm feeling like a very cracked vinyl picture disc in saying this and unless something significant strikes in the next week (MetO text ensures a glimmer of hope in this regard....) then the first week or more of Feb looks unattractive. Outer edge of GEFS is still smelling something

gfs-ens_z500a_nhem_65.thumb.png.40dc934f98d11b34a55c91e9752f1c46.png

= another glimmer of hope that may be reflective of UKMO thinking. We have taken an exhausting pummelling this winter in terms of expectation/product and this GEFS extended may be nothing more than the final kick in the teeth via non arrival. However being the snow hunters we are, I'm sure we shall remain glued throughout February - either in the hope of a final click to things, or another bit of late winter in March. The last 6 years have produced 2 wintry March months, which is not bad recent odds.

 

 

 

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Well ive seen baseball snowflakes, any other white stuff seems a bonus!!

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1 minute ago, Catacol said:

Y

 

Yes, you have pretty much nailed it there, we would need an about turn on the eps pretty soon, still can't completely give up as you say, the vortex will be weak and we cannot tell what MJO, AAM signal and who knows what strat signal for late feb March but it doesn't currently look good.

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5 minutes ago, feb1991blizzard said:

We will see but any bands that get further North than the midlands will be very fragmented.

Yep, I should also add I think the ICON is a fair bit too far south tonight, I think the UKMO/ECM are probably fairly close to the truth, and the GFSP looking also quite a lot like those two models, which is a decent middle ground against the southerly ICON and northerly GFS.

If I had to make a call, I wouldn't be that shocked to see the bands get further north than forecasted and into Yorkshire and even S.Cumbria, BUT the main story to be south of Hull-Liverpool line. I think the ICON will b more likely to snap back north than to gain more support, however I've thought that before about the ICON but its actually been pretty good in our neck of the woods recently.

Catacol, agreed. I'm not sure who said it but it feels like we have just been picking up scraps all winter, indeed I think we've done well to pick up this scrap this week and making the most of it.

I wonder whether the SSW was so strong it split the PV into so many fragments that it was hard to completely get rid of them and hence kept the flow net westerly for far longer at lower levels then would normally be the case? There little PV features preventing ridging from subtropical highs. I've always found we have better results here when the vortex isn't totally shredded into many lobes.

Edited by kold weather

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Don’t think anyone has posted FI from 18z GFS. Shows how much interest there is in the immediate term!  

BFC97D11-0FC7-43DD-B374-BF0FAA72DE11.png

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1 minute ago, Catacol said:

Yep - sharp change of signal. No high lat block with any undercut of impact. Been mulling about this all evening really - the nature of the SSW this year, with it being such a slow process, has thrown semi predictability into chaos. I guess that leaves some gentle optimism that this set of charts may be no more accurate than the last lot, but really we only have the MetO now offering any coherent suggestion of cold and we cannot see their data. I have a feeling they wont take long to alter that 30 day text.

MJO peaks for cold interest in about a week and then will fade away through phase 8 to 1. 

twc_globe_mjo_vp200tx.thumb.png.6a32c7df2994da675d2dfca0e8497576.png

10 day mid strat image shows clearly revitalisation of westerlies over the Greenland area

ecmwf70f2440.thumb.gif.83c6d03bd98b3926c1a8e2d3dd7b6707.gif

And at the bottom of the strat any suggestion of a blocking high has gone with the Euro trough easing east. Heights gently building over the UK from the SW.

ecmwf150f2r40.thumb.gif.69c7cef04464a19fb810099ee9723942.gif

Essentially a return to average with a +NAO signature. However no raging atlantic assault - the SSW has put paid to that prospect for the rest of winter.....so probably a relatively benign pattern.

The only path to cold I can see from here for mid Feb would be the AH ridging over to Scandy and forcing atlantic energy underneath if the block extends far enough west. There is a suggestion that this isn't out of the question both from MJO progression, GLAAM profiles as a more meridional forcing once again applies itself to the NH and the vortex formation.....but i'm feeling like a very cracked vinyl picture disc in saying this and unless something significant strikes in the next week (MetO text ensures a glimmer of hope in this regard....) then the first week or more of Feb looks unattractive. Outer edge of GEFS is still smelling something

gfs-ens_z500a_nhem_65.thumb.png.40dc934f98d11b34a55c91e9752f1c46.png

= another glimmer of hope that may be reflective of UKMO thinking. We have taken an exhausting pummelling this winter in terms of expectation/product and this GEFS extended may be nothing more than the final kick in the teeth via non arrival. However being the snow hunters we are, I'm sure we shall remain glued throughout February - either in the hope of a final click to things, or another bit of late winter in March. The last 6 years have produced 2 wintry March months, which is not bad recent odds.

 

 

 

Very sobering really in many ways. 

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4 minutes ago, kold weather said:

UKMO is quite a way short of there UKPAUL, doesn't get much north of Hull-Liverpool...and looks VERY close to the ECM in fact.

GEM suffers same issues as the GFS in its overprogressive usually, plus courser resolution.

JMA - same issue with course resolution.

NAVGEM - Same issue with course resolution.

WRF is just a variation of the GFS and uses GFS data...therefore what the op shows, the WRF will 95% time mirror it.

Its interesting that all the models with lower resolution do the same thing, all the higher resolution models are taking the system more elongated and to the south.

May be coincidence, but probably not!

Still, I'm certainly not going to just dismiss the GFS, its quite possible for it to be right and at this point within the range of the envelope for sure.

The UKMO breaks up a bit but does reach there by end of Thursday, still too far out anyway to approach it with any certainty. The supposed higher resolution models of ICON, Arpege, Hirlam, are pretty poor performers for this part of the world I’ve always found. Euro4 is pretty decent though. If Met Office forecasts shift from their current status then we’d know if their internal models are seeing different but nothing so far on that.

 

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So in essence.. the "background" signals have been fairly useless in predicting any real cold for the UK.. 

Probably one to remember for next winter when the "background signals" are all screaming High Lat blocks and cold Easterlies. Still, at least we've got this weeks snow risk!

The EC46 has shown it can be pretty awful too, week after week it's been consistent in forecasting high latitude blocking that has never actually developed. Weeks 3/4 on that model are utter rubbish!

Edited by Daniel Smith

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1 minute ago, feb1991blizzard said:

Yes, you have pretty much nailed it there, we would need an about turn on the eps pretty soon, still can't completely give up as you say, the vortex will be weak and we cannot tell what MJO, AAM signal and who knows what strat signal for late feb March but it doesn't currently look good.

Sod's Law isn't it - cold signals all winter deliver little of interest....and you just KNOW that now a more default westerly pattern is being spied by NWP that this will end up coming to pass. 

It's Karma - a balancing of things by the weather gods after what we got in Feb/March 18. Too much of a good thing I can hear them say...……..

Wouldn't it be great to be Knocker? Year after year avoiding the cold and snow with only the occasional blip of misery!

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1 hour ago, ICE COLD said:

What Aaron ? Because my name is Aaron too (no joke ) . But I’m the nice Aaron , sorry Crewe 😂

So you're the good Aaron, Crewe's the bad Aaron.....why am I always the bloody ugly one?........I'll fetch me coat

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Would love to hear the updated thoughts of @Bring Back1962-63 as he seemed very positive regarding the ongoing effects of the SSW and how the models were struggling last time he posted?

The updated EC46 has certainly set a few nerves jangling in terms of February's prospects....

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4 minutes ago, Kentish Snowman said:

 

The updated EC46 has certainly set a few nerves jangling in terms of February's prospects....

Yep, it’s all going the wrong way from what we can see at least.  Winter 2018/19 for you......

Edited by Don

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20 minutes ago, kold weather said:

Catacol, agreed. I'm not sure who said it but it feels like we have just been picking up scraps all winter, indeed I think we've done well to pick up this scrap this week and making the most of it.

I wonder whether the SSW was so strong it split the PV into so many fragments that it was hard to completely get rid of them and hence kept the flow net westerly for far longer at lower levels then would normally be the case? There little PV features preventing ridging from subtropical highs. I've always found we have better results here when the vortex isn't totally shredded into many lobes.

Looking at the forecast zonal slice from Berlin I just think we haven't seen the reversal impact to any great extent on the trop. It is as simple as that. I don't know whether this is all a function of the QBO - but clearly seasonal models expected the downwell to impact as much as human enthusiasts and Met experts - and maybe I'm jumping the gun here and we will all find the downwell hit hard from mid Feb - but these net flow figures from ECM for 6th Feb dont fill me with great joy. There is a net easterly at 70N, but everywhere else we have positive flow and that suggests even the projected arctic high is struggling to get a grip

ecmwfzm_u_f240.thumb.gif.8306f68e2cf51a893fadb41ad456842b.gif

Looking at the 500hpa charts from ECM it looks to me as though that negative 70N easterly is most anchored in the trough in the N Pacific - it certainly doesn't look to be centred to our north with an atlantic trough plonked out to the west and the upper flow continuing through on a positive tilt to Scandy. Nothing much to get excited about there.

ecmwf-ens_z500aff_nhem_11.thumb.png.779a4aafa0e4264d102bd84b59ea1cb7.png

For my own sanity I might take a break from the models for a few days and stare out the window instead in case a few flakes fall. Might get a bit here in the SW on Friday if the low can elongate enough and come in at just the right trajectory - but without a block to disrupt against it is an incredibly delicate setup and likely to be transient. Still - snow is snow! - and beggars cant be choosers......

 

Edited by Catacol

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17 minutes ago, Daniel Smith said:

So in essence.. the "background" signals have been fairly useless in predicting any real cold for the UK.. 

Probably one to remember for next winter when the "background signals" are all screaming High Lat blocks and cold Easterlies. Still, at least we've got this weeks snow risk!

The EC46 has shown it can be pretty awful too, week after week it's been consistent in forecasting high latitude blocking that has never actually developed. Weeks 3/4 on that model are utter rubbish!

So basically this winter has been impossible to predict by any model or method, so a bit harsh to keep stomping on the background signals just because people have wrongly assumed that it guarantees a 1963 winter lol

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1 minute ago, Rambo said:

So basically this winter has been impossible to predict by any model or method, so a bit harsh to keep stomping on the background signals just because people have wrongly assumed that it guarantees a 1963 winter lol

Every winter is guaranteed to be 1947, or 1963, failing that its definitely a dec 2010,or march 2013

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6 minutes ago, Rambo said:

So basically this winter has been impossible to predict by any model or method, so a bit harsh to keep stomping on the background signals just because people have wrongly assumed that it guarantees a 1963 winter lol

Perhaps but it's shown you can have all background signals pointing towards cold, all models and a massive SSW to boot and still get the forecast completely and utterly wrong. My point was that far too much emphasis has been put on the "background signals" this winter with little to show for it. 

This is meant as no disrespect to the people who study and use that method of forecasting, but it has just as many failures as any other method, it seems

Edited by Daniel Smith

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