Focussed Model Discussion

[bryan629]

9 hours ago, bryan629 said:

May be barking up the wrong tree but something that has caught my eye is the development of a strong Russian high and seemingly westward movement across towards Scandi. 

Is it possible this could retrogress even further west across the top of the deep Euro low ? 

Below are the EC anomaly charts from the 0z days 9 and 10 , maybe clutching at straws but it is also visible on the GEM ( very last frames ) and the GFS just before it goes into low res and flattens the high. 

  

 

Hmmm , now ukmo catching onto a scrussian ridge and GFS too, baby steps i know, but downwelling has to start to show up somewhere  ....  cant wait for the ECM now 

[bluearmy]

Trending the right way .... wonder if ecm or the gfsp will pick up on either the draining of low heights or repeat the scrussian ridge scenario .... there’s a lot going on !

[knocker]

Interesting the gfs this evening has the major trough to our east stuck in sito at t162 by the the European high wedging ridging to the east. Which means that the next trough driven around the Atlantic high merely reinforces it and you end up with this interesting surface analysis.which would portend some very unsettled weather

Edited January 21, 2019 by knocker

[kold weather]

Plenty of cyclonic activity within the constant NW airflows we get, with the caveat being the GFS is nearly always a solid 1-2C too cold on this sort of flow, hence why the GFS had backend snow for tonight whilst all the others models showed nothing of the sort.

Looks to be a very frustrating pattern for us in the south, little to look forward to other than copious amount of rain and maybe the odd wintry trough working through.

As has been said, everything sets up a little too far NE and flabby, so whilst we do get a brief, much needed shot of deep cold into our area, its soon forced away. The ECM ensembles that I looked through earlier broadly did the same thing.

[Man With Beard]

The GFSP was not looked at enough last week, and aside a few runs on Friday it was pretty accurate - as for the rest of January, well it really is Groundhog Day every few days - lots of PM incursions, good snow potential for Scotland and high ground, perfection will be required for lowland England and Wales (not impossible though). Such a different story having minus 6 uppers on a NWly compared with a SEly! 

It does have a lot of snowfall nationwide tomorrow, though? 

 

Edited January 21, 2019 by Man With Beard

[booferking]

1 minute ago, Man With Beard said:

The GFSP was not looked at enough last week, and aside a few runs on Friday it was pretty accurate - as for the rest of January, well it really is Groundhog Day every few days - lots of PM incursions, good snow potential for Scotland and high ground, perfection will be required for lowland England and Wales (not impossible though). Such a different story having minus 6 uppers on a NWly compared with a SEly! 

 

Yep looked to led the way and Icon not bad either.

[Singularity]

Agreed regarding a Scrussian ridge pattern gaining ground as we see the Azores High increasingly subdued. It may have some relation to the MJO struggling to make it past P6; with a Nino background the composite looks supportive while with a neutral one it also is but without the crucial low heights over Europe for us so let's hope the Nino state puts up enough of a fight;

 

...not that these are to be taken too directly anyway, but I do think they can be of some use when considering the validity of certain model trends.

If we are to be heading down that route, then reasonable to expect that GFS will lag UKMO and ECM as it's always had trouble with splitting the jet around such features. GEM tends to be on-and-off but when 'on' it tends to outperform GFS quite a bit - which makes the D5+ progression of the 12z of great interest, albeit after allowing for the overcooked N. Atlantic troughs when it comes to D7+.

Interesting that the P6 ENSO+ MJO composite is friendly to mid-Atlantic ridges making it a good way north - it suggests that GFS' repeated attempts of late may in fact represent the model seeing the Atlantic part of a combined route forward that sees troughs becoming temporarily 'enclosed' across mainland Europe by ridges on both sides and to some extent to the north, with the transfers from the Canadian vortex separated by longer pauses during which more of a cold continental feed can feature for the UK.

[bluearmy]

12 minutes ago, Man With Beard said:

The GFSP was not looked at enough last week, and aside a few runs on Friday it was pretty accurate - as for the rest of January, well it really is Groundhog Day every few days - lots of PM incursions, good snow potential for Scotland and high ground, perfection will be required for lowland England and Wales (not impossible though). Such a different story having minus 6 uppers on a NWly compared with a SEly! 

It does have a lot of snowfall nationwide tomorrow, though? 

 

Have you looked at the para archive runs ? Did it just not pick up the amplification post the diving trough  or was it actually picking up the verified pattern ??  There is a big difference!

[booferking]

1 minute ago, bluearmy said:

Have you looked at the para archive runs ? Did it just not pick up the amplification post the diving trough  or was it actually picking up the verified pattern ??  There is a big difference!

Was never really keen on the phantom Easterly while ECM and GFS throw out Narnia charts i will be taking more consideration in what it shows that's for sure..

[knocker]

Not dissimilar to this morning's EPS and pretty much where the det run headed

 

Edited January 21, 2019 by knocker

[Derecho]

The 12z swingometers are now out and they don't look the most exciting it must be said. The very cold runs have proved harder to come by and the end of January is turning increasingly cyclonic if the GEFS is to be believed. Rather cold but messy is the way I'd some up the end of January, no easterlies sadly. P6 tries to build a Scandi high.

 

For February 5th it looks a real mixed bag at the moment which is to be expected but not much in the way of blocking at the moment. Those who fancy an early taste of Spring will like the P4 chart below. Knowing this winter that will be the chart that verifies!

 

The global temperature anomaly plot is pretty sobering for our cold weather prospects, a very cold NW North Atlantic so I expect a very strong westerly pattern to set up into February though some of these may be rather cold they don't really offer much away from the NW UK.

Starting to get a bit bored of this winter now but will hold out hope until early February. If the charts continue to look underwhelming I may start having one eye on Spring.

[Jason M]

GEM ensembles are giving some support to an easterly. These tend to come courtesy of a ridge thrown towards Scandinavia from the Russian high. The only downside to this of course is that it tends to mean the wind direction is somewhat south of east so its not as likely to get very cold. Feels like a plausible way forward to me. The question then comes as to will it be cold enough.

[winterof79]

Looking good up n/e slider of the year ?

Edited January 21, 2019 by winterof79

[phil nw.]

Looking at the gefs day 6-10 and then 11-15 suggests it may be worth a glance at the Scrussian ridge as the +ve ht anomalies extend westwards.

A little retrogression in the  NH pattern by the looks of the westwards placements of the main troughs/ridges.The Azores high further away.Our trough with it's nw/se feed still lurking but signs of shrinking.

Edited January 21, 2019 by phil nw.

[kold weather]

ECM truly is awful for sustained cold. It may well evolve a decent block eventually but the Atlantic tracking LP's would suggest that even if a block does get into place there would be a real lack of any cold to tap into, especially if we do go into a Scandi based pattern, the LPs will just rotate and disrupt SE drawing in too mild air from Europe.

Worst run I've seen for a long time in terms of potential for cold in the longer term. Maybe that's too negative, but this run really would put any sustained cold spell another 15-20 days away IMO...though could argue that the NW part of the country wouldn't be too bothered after this week.

Edited January 21, 2019 by kold weather

[WhiteFox]

1 hour ago, Singularity said:

Agreed regarding a Scrussian ridge pattern gaining ground as we see the Azores High increasingly subdued. It may have some relation to the MJO struggling to make it past P6; with a Nino background the composite looks supportive while with a neutral one it also is but without the crucial low heights over Europe for us so let's hope the Nino state puts up enough of a fight;

 

...not that these are to be taken too directly anyway, but I do think they can be of some use when considering the validity of certain model trends.

If we are to be heading down that route, then reasonable to expect that GFS will lag UKMO and ECM as it's always had trouble with splitting the jet around such features. GEM tends to be on-and-off but when 'on' it tends to outperform GFS quite a bit - which makes the D5+ progression of the 12z of great interest, albeit after allowing for the overcooked N. Atlantic troughs when it comes to D7+.

Interesting that the P6 ENSO+ MJO composite is friendly to mid-Atlantic ridges making it a good way north - it suggests that GFS' repeated attempts of late may in fact represent the model seeing the Atlantic part of a combined route forward that sees troughs becoming temporarily 'enclosed' across mainland Europe by ridges on both sides and to some extent to the north, with the transfers from the Canadian vortex separated by longer pauses during which more of a cold continental feed can feature for the UK.

Doesn't this appear to be part of the problem though? The Pacific pattern seems to have been stuck in more of a LN rather than EN state with a PNA only oscillating between slightly positive and slightly neutral.

 Also, the trade wind burst over the IDL leading to the MJO becoming subdued in phase 6 may impede blocking progress upstream.

Have to wait for the trade winds burst to work through before seeing a more favourable upstream pattern perhaps. Just musing....

Edited January 21, 2019 by WhiteFox
Typo

[Singularity]

ECM 12z has the strong blocking looking to build across Scandinavia from Russia and increasing heights just NW of the UK - so it would have looked a lot easier on the eyes D7+ had it not had two disturbances over E Canada and the far-western N. Atlantic merge into one unusually intense system which then distorted the downstream pattern toward more in the way of transitory ridges into the UK while also seeding a very rounded instead of disrupted though - though both these impacts seem overdone to me anyway.

An impressive Arctic High shaping up as of D10 too.

After some doubts crept in over the weekend, I'm seeing reasons to be a little more upbeat again regarding late Jan into Feb prospects, despite the model output becoming less appealing on the face of it.

After all, the trough dig-down this Tue-Wed has turned out to be very sharp in nature after all, despite all the wobbling away from it that we saw from the models as the U.S. storm behaviour adjusted from helpful to unhelpful. We're really unlucky not to see more from it but tomorrow may yet deliver some surprise accumulations in places, maybe even to low levels for a lucky few.

[Singularity]

4 minutes ago, WhiteFox said:

Doesn't this appear to be part of the problem though? The Pacific pattern seems to have been stuck in more of a LN rather than EN state with a PNA only oscillating between slightly positive and slightly neutral.

 Also, the trade wind burst over the IDL leading to the MJO becoming subdued in phase 6 may impede blocking progress upstream.

Have to wait for the trade winds burst to work through before seeing a more favourable upstream pattern perhaps. Just musing....

 

Positive signs today for both trade wind burst ceasing soon and MJO making more progress into P6 before being subdued. Both being intertwined.

The additional delay toward the final days of the month of the stratospheric downwell into the troposphere may actually have helped here; the MJO suppression is largely in response to that taking place.

[kold weather]

14 minutes ago, Singularity said:

ECM 12z has the strong blocking looking to build across Scandinavia from Russia and increasing heights just NW of the UK - so it would have looked a lot easier on the eyes D7+ had it not had two disturbances over E Canada and the far-western N. Atlantic merge into one unusually intense system which then distorted the downstream pattern toward more in the way of transitory ridges into the UK while also seeding a very rounded instead of disrupted though - though both these impacts seem overdone to me anyway.

An impressive Arctic High shaping up as of D10 too.

After some doubts crept in over the weekend, I'm seeing reasons to be a little more upbeat again regarding late Jan into Feb prospects, despite the model output becoming less appealing on the face of it.

After all, the trough dig-down this Tue-Wed has turned out to be very sharp in nature after all, despite all the wobbling away from it that we saw from the models as the U.S. storm behaviour adjusted from helpful to unhelpful. We're really unlucky not to see more from it but tomorrow may yet deliver some surprise accumulations in places, maybe even to low levels for a lucky few.

What is worrying is the fact alot of the GFS ensembles are also throwing out that rounded Atlantic low and it's been getting more and more support each run. Trend is not our friend 

On the face of it this has got potential still but I really worry that there just won't be the cold to tap into, especially further south and that we could end up with cracking northern blocking and STILL get shafted because of overly bloated Atlantic troughing that may not disrupt enough.

On the positive side, we would be hugely unlucky not get one decent countrywide snow opportunity, surely the upper trough won't be quite that circular. Plus the AO does look like it's heading into the cellar so the SSW looks like it's finally having a decent impact.

Edited January 21, 2019 by kold weather

[WhiteFox]

16 minutes ago, Singularity said:

 

Positive signs today for both trade wind burst ceasing soon and MJO making more progress into P6 before being subdued. Both being intertwined.

The additional delay toward the final days of the month of the stratospheric downwell into the troposphere may actually have helped here; the MJO suppression is largely in response to that taking place.

Interesting! It's new to me, so trying to get my head around it all!

BTW, where did you get the Hovmoller chart?

Edited January 21, 2019 by WhiteFox
Add

[Singularity]

4 minutes ago, WhiteFox said:

Interesting! It's new to me, so trying to get my head around it all!

BTW, where did you get the Hovmoller chart?

Good to see the enthusiasm 

This is a good site for keeping an eye on things. Some educational value too:

http://mikeventrice.weebly.com/hovmollers.html

[WhiteFox]

14 minutes ago, Singularity said:

Good to see the enthusiasm 

This is a good site for keeping an eye on things. Some educational value too:

http://mikeventrice.weebly.com/hovmollers.html

Thanks, duly bookmarked! A lot of the US sites Google directs me to are currently unavailable for obvious reasons!

It seems that this year's SSW is almost the opposite from last year in terms of affecting our weather. Should still be a good chance of something exciting cropping up soon!

[knocker]

The ext EPS this evening is much the same as this morning's. And tonight's det run was along these lines with troughs dipping well down into North Africa

 

[IDO]

The ECM op is as expected, not the specifics, just another option for the post-7-day pattern.

Entropy means we will get different op runs as the algorithms try to make sense of the complicated setup.

I knew the 0z would not be repeated and I expect the 0z will go on another journey tomorrow morning.

The GEFS highlight the difficulty in getting an NH pattern modelled where 3 blocks and 3 troughs are squeezing each other for space.

ECM 12z has modified the mid-latitude blocks at D10 compared to the overdone 0z and they may still alter the Pacific Heights and the Russian/Siberia High as I suspect they are still not on point. The Pacific region looks like the computer has lost the plot and as that has a direct impact on the E USA Trough and the Canadian PV, I would pass on the ECM 12z past D6.

The D10 mean on the ECM ease's the Russian high further east  (a la GFS) and is more in line with the 0z mean, with the similar UK mean uppers of -4c.

Despite all that, the way forward isn't that great with fine margins and spoilers that could easily derail a more interesting NW to SE energy cycle. Not really close to what I was hoping for as we head into February...

 

[kold weather]

5 minutes ago, WhiteFox said:

Thanks, duly bookmarked! A lot of the US sites Google directs me to are currently unavailable for obvious reasons!

It seems that this year's SSW is almost the opposite from last year in terms of affecting our weather. Should still be a good chance of something exciting cropping up soon!

Its certainly been a very lagged response, but perhaps that shouldn't be a surprise given the QBO we have at the moment. If I recall 2013 had a similar base state and that one took the best part of 2 months to get going. Of course once it did, it pretty much tanked the whole way through March, with locations Midlands north cashing in. Could quite easily still see a long period of -ve AO but that doesn't mean all that much.

I seem to recall a strong -ve AO happening in Jan 1998 and that was hardly inspiring either for us, unfortunately sometimes despite getting decent blocking in the Arctic, it just doesn't have an impact on us if other factors are dominating even more, such as that PV lobe over Canada.