Model Output Discussion - 16th Jan 12z onwards - Smile While You Post!

[BLAST FROM THE PAST]

Trouble is though Fred there is nothing severe showing on the ECM run upto +240. Weatherwise you would see snow showers for Scotland especially higher ground but for some parts especially the S the max temps would still reach around 5C.

 

I still stand by my point that we need high pressure developing to our N to bring any sustained, very cold period. At the moment the NW,ly does look fairly certain but nothing severe except maybe some strong winds to accompany those snow showers in Scotland. Beyond this is hard to predict but I am concerned by the 06Z very mild pattern in F.I because some GEFS members have been hinting at this.

 

Sorry for being negative but im just trying to keep members feet on the ground and not give them false hope. If you remember I said the same on this thread with regards to our current cold spell and judging by members views on this current cold spell I was right to be cautious.

Hi Dave

This from my posts in Seasonal thread

 

I still feel Feb will be domianted by flow from NW to N to at times NE quadrant and remain that it will come in below average, no change there but sustained cold is not as likely as very sharp impactual bursts interrupted by less cold NW sectors. 

 

I agree with your sentiments of sustained prolonged cold and what is needed.  However, with the trough plunging in NW Europe/Scandi to our East we are likely to have far more potent cold air plunging over us than previous set ups with trough to our NW.  We could get a repeating pattern and would bring a very cold regime and a northerly with true arctic air in the mix would bring snow....but yes N, NW and NE coasts would benefit and N Wales, N Ireland Scotland and NE England are best served here.  If we get Polar lows in the mix then game on. 

 

BFTP

[Weather-history]

That would be close to record breaking, Azores highs of that intensity, displaced or not are rare.

I'll repeat this post.

That looks overblown to me by GFS. Azores highs of that intensity and displaced in that position of that intensity are rare to non existent.

In any case at 384hrs, I would not pay much attention to it.

Edited January 23, 2015 by Weather-history

[nick sussex]

This place can be quite strange sometimes! The Euro troughing isn't even in place, we still don't know what the models will do with low heights to the north in terms of splitting them or moving another pulse from the Siberian side and yet apparently a return to milder conditions is set in place because of the GFS well into FI.

 

To illustrate why I'd like to see the GFS shelve its post T240hrs output because it gets too much attention and ends up turning this place into even more of an emotional rollercoaster!

 

This was the GFS projection from exactly the same time last week projected out to day 14:

 

 

And this is todays projection for T168hrs which takes us to the same time:

 

 

 

 

 

 

[Tamara]

There is little value in detailed assessing of face value output and looking for intra day suite upgrade/downgrade nuances at day 10 (and much further out judging from posts in the last hour!). I am speaking most especially with regard to individual 4 X daily GFS operational.

 

Focussing on the continuing trends offered by the overall modelling is all that matters at this stage...which solidly continue to advertise amplification to the west and troughing digging south through Europe to our east.

 

Stratospheric full support for this vortex displacement development. With high agreement both tropospherically and stratospherically for the overall pattern, we can let the closer details take care of themselves as time gets much closer

 

In respect of this trending towards the overall firming up of the cyclonic northerly this morning, I would be encouraged by the emphasis towards rather upping the amplification potential and consequently on a UK wide basis ( not regionally IMBY) the overall chances for penetrating south of the cold air advection.

 

The suggestion of secondary features developing within vectors of polar origin add extra wintry interest beyond common wishbone effect northerly humdrum....But again, we cannot dissect the possibility of these in detail so early.

 

What matters from now on in future modelling is seeing how the amplification orientates itself in allowing as clear a path as possible for the very cold uppers embedded to the north of the cyclonic curvature to advect south

 

We know that even an amplified ridge (as distinct from a HLB) can deliver potent arctic incursions - and unlike other amplified ridges this one is occurring in tandem with a strong displaced vortex signal which makes usual 'toppling out' harder to achieve so quickly. It also is sharpening up the depth of our cold to our NE to take advantage of any E of N vector that might align itself. The GEM hints at this overall scenario maybe developing.

 

In the context of a possible higher pressure scenario to follow the cold disturbed pattern at the turn of the month and into February, I certainly wouldn't be worrying about one GFS output showing a strong high to the south of the UK so far out, as much as we constantly see Teflon coated Greenland High blocks in similar t250 to t300 lower resolution modelling and they are often (alas) fantasy.

 

The possibilities to follow early February northerly incursions were muted yesterday, and are the same today as they were yesterday. .

 

In this respect, its eyes focussed as far as I am concerned in the 'usual places' (beyond actual modelling suites) in the coming days and letting each day add further colour spectrum to the picture.
The extended outlook takes care of itself in this way

 

In view of the winter trend so far, and, at least as I see it, the persistence of suggestions towards a more meridional February (which would be quite different to the flatter faster westerly pattern that has (mostly) dominated thus far, then at this distance, that is plenty of interest to go forward with at the moment - and which could develop further in days to come

 

@ Steve I think many (on here) are frustrated at the way things have gone (so far). I've given enough of my own reasoning as to why. Ian has pointed to the 'enigmatic' nature of the winter in terms of how METO have assessed it. I'm staying open minded about Feb for all those reasons given. Whatever happens, I remain fascinated and interested in how this will play out. Much to keep learning from as I see it

Edited January 23, 2015 by Tamara

[nick sussex]

Heres the GFS 06hrs to the same time:

 

 

I had to post it here because it won't let me edit with a new attachment but I hope this goes some way to highlighting my point re the futility of following these outputs in distant FI.

Edited January 23, 2015 by nick sussex

[SMU]

There is little value in detailed assessing of face value output and looking for intra day suite upgrade/downgrade nuances at day 10 (and much further out judging from posts in the last hour!). I am speaking most especially with regard to individual 4 X daily GFS operational.

 

Focussing on the continuing trends offered by the overall modelling is all that matters at this stage...which solidly continue to advertise amplification to the west and troughing digging south through Europe to our east.

 

Stratospheric full support for this vortex displacement development. With high agreement both tropospherically and stratospherically for the overall pattern, we can let the closer details take care of themselves as time gets much closer

 

In respect of this trending towards the overall firming up of the cyclonic northerly this morning, I would be encouraged by the emphasis towards rather upping the amplification potential and consequently on a UK wide basis ( not regionally IMBY) the overall chances for penetrating south of the cold air advection.

 

The suggestion of secondary features developing within vectors of polar origin add extra wintry interest beyond common wishbone effect northerly humdrum....But again, we cannot dissect the possibility of these in detail so early.

 

What matters from now on in future modelling is seeing how the amplification orientates itself in allowing as clear a path as possible for the very cold uppers embedded to the north of the cyclonic curvature to advect south

 

We know that even an amplified ridge (as distinct from a HLB) can deliver potent arctic incursions - and unlike other amplified ridges this one is occurring in tandem with a strong displaced vortex signal which makes usual 'toppling out' harder to achieve so quickly. It also is sharpening up the depth of our cold to our NE to take advantage of any E of N vector that might align itself. The GEM hints at this overall scenario maybe developing.

 

In the context of a possible higher pressure scenario to follow the cold disturbed pattern at the turn of the month and into February, I certainly wouldn't be worrying about one GFS output showing a strong high to the south of the UK so far out, as much as we constantly see Teflon coated Greenland High blocks in similar t250 to t300 lower resolution modelling and they are often (alas) fantasy.

 

The possibilities to follow early February northerly incursions were muted yesterday, and are the same today as they were yesterday. .

 

In this respect, its eyes focussed as far as I am concerned in the 'usual places' (beyond actual modelling suites) in the coming days and letting each day add further colour spectrum to the picture.

The extended outlook takes care of itself in this way

 

In view of the winter trend so far, and, at least as I see it, the persistence of suggestions towards a more meridional February (which would be quite different to the flatter faster westerly pattern that has (mostly) dominated thus far, then at this distance, that is plenty of interest to go forward with at the moment - and which could develop further in days to come

 

 

Hi Tamara - A nicely put post, however this winter thus far hasn't delivered ANY of the expectation laid out by the winter forecasts of indeed any of the hype / analysis presented in the stratosphere thread either-  A few flirts with a 2 wave pattern in December which didn't land either-

A lesson to everyone that the modelling of the stratosphere & even then the downwelling & coupling of Strat V trop doesn't always deliver.

 

Also I don't think barring maybe 1 or 2 runs that the GFS has modelled any Greenland heights this winter, its been 100% mobility all the way-

 

The OPI has been wrong & along with it Cohens forecast, (  & of course mine + NW & the idiot Madden who forecasts the same thing every winter )

 

A very muted signal for Northern blocking which may improve into Feb, although its not the favourite as it stands...

S

[Froze were the Days]

Hi Tamara - A nicely put post, however this winter thus far hasn't delivered ANY of the expectation laid out by the winter forecasts of indeed any of the hype / analysis presented in the stratosphere thread either-  A few flirts with a 2 wave pattern in December which didn't land either-

A lesson to everyone that the modelling of the stratosphere & even then the downwelling & coupling of Strat V trop doesn't always deliver.

 

Also I don't think barring maybe 1 or 2 runs that the GFS has modelled any Greenland heights this winter, its been 100% mobility all the way-

 

The OPI has been wrong & along with it Cohens forecast, (  & of course mine + NW & the idiot Madden who forecasts the same thing every winter )

 

A very muted signal for Northern blocking which may improve into Feb, although its not the favourite as it stands...

S

 

Totally agree Steve - well summarised! and honesty to boot.  

Disappointed by the OPI to be frank, the first real winter it's come under scrutiny and it looks like it has already come undone.

Edited January 23, 2015 by Froze were the Days

[nick sussex]

Totally agree Steve - well summarised! and honesty to boot.

Yes Steve doesn't try and put any window dressing on whats been. The  truth is that for all the good background signals these have been overridden so far, at the end of the day its whats delivered on the ground and you can have all the best signals going but if they don't deliver some decent cold and snow then that's really the point.

 

Some have been lucky and seen some snow and there has been much more frost than last winter but IMO a decent cold spell is one which has the ability to deliver non-marginal snow to the majority.

 

For some members in higher elevated areas in the north they're probably feeling this winter has been okay however the majority have not had any lying snow and until that changes then this winter IMO will remain poor.

[karlos1983]

Hi Tamara - A nicely put post, however this winter thus far hasn't delivered ANY of the expectation laid out by the winter forecasts of indeed any of the hype / analysis presented in the stratosphere thread either-  A few flirts with a 2 wave pattern in December which didn't land either-

A lesson to everyone that the modelling of the stratosphere & even then the downwelling & coupling of Strat V trop doesn't always deliver.

 

Also I don't think barring maybe 1 or 2 runs that the GFS has modelled any Greenland heights this winter, its been 100% mobility all the way-

 

The OPI has been wrong & along with it Cohens forecast, (  & of course mine + NW & the idiot Madden who forecasts the same thing every winter )

 

A very muted signal for Northern blocking which may improve into Feb, although its not the favourite as it stands...

S

 

And it has to be said, the MetO  have pretty much nailed this winter in terms of the forecast they put out!

[IDO]

^^^ As Steve says, sometimes no matter what the signals are behind the scene the weather will do what it wants. Something, whether its a low anomaly over the BK Sea or a piece of PV over Baffin Bay, all rather inauspicious, they will throw all the other cold variables into the wind. The potential has been there since mid-December for a uk wide cold spell but it has been to date an average winter at best for the north and another stinker for the south.

 

Plenty of time to go, but the pattern of this winter does not look like changing. No HLB looking to establish that will favour the UK (any heights trended over the Pacific). Another sinking ridge for 8-10 days time but the GEFS have been suggesting this as transient for many runs. These "favourable"background signals have busted so far this winter, I for one are not expecting any change, especially as the general pattern seems to over ride them. Looking at the D16 mean from the 06z it sums it up well:

 

 

Any blocking over the other side of the NH with a zonal flow over the UK due to the PV to our NW.

[Tamara]

Yes Steve doesn't try and put any window dressing on whats been. The  truth is that for all the good background signals these have been overridden so far, at the end of the day its whats delivered on the ground and you can have all the best signals going but if they don't deliver some decent cold and snow then that's really the point.

 

Some have been lucky and seen some snow and there has been much more frost than last winter but IMO a decent cold spell is one which has the ability to deliver non-marginal snow to the majority.

 

For some members in higher elevated areas in the north they're probably feeling this winter has been okay however the majority have not had any lying snow and until that changes then this winter IMO will remain poor.

I know for my own part that the last thing I have done is put any window dressing on anything. Continually trying to provide evidential suggestions as to what has happened and why. As disappointing as it is has been however (from a MOD thread pov) so far, I think it is pointless any of us moaning about it in my honest opinion.

 

Its a fine balance on here between 'flying the flag' for colder weather and being objective at the same time. Its not all about 'will it snow' (as much as we might want it to) its trying to learn why it doesn't happen sometimes as much as knowing and learning what does make it snow in the UK - at least within the context of this thread anyway which generally has a bias towards looking for it.

 

On that balanced basis, evaluation of the 'background factors' has a very good place - if one wants to try and also learn something along the way while waiting for preferred weather type

 

I'm not personally going to give up trying to learn about any of these drivers just because they don't make it snow in any given winter

 

Edit, in answer to responses that have followed:

 

It has been through GWO and AAM modelling that it has been (personally) possible to identify the amplifications that have occurred this winter so far. The fact that these have been transitory and have not delivered to expectations of our audience does not devalue their worth. On this basis they have value to use as forecasting tools in any season - they are not, after all, devised specifically just for hunting cold weather, but tools to employ seasonally.

 

If we do not use them we cannot improve the standard of our forecasting. Similarly with stratospheric forecasting. This gets dissed on here selectively when it doesn't snow ...but is a great friend when it tropospherically delivers an arctic blast

 

if these tools were of so little value, why otherwise would the chief forecaster be discussing these complex drivers with his team at the METO? Much as Ian F alluded to only yesterday evening

Edited January 23, 2015 by Tamara

[craigore]

Hi Tamara - A nicely put post, however this winter thus far hasn't delivered ANY of the expectation laid out by the winter forecasts of indeed any of the hype / analysis presented in the stratosphere thread either-  A few flirts with a 2 wave pattern in December which didn't land either-

A lesson to everyone that the modelling of the stratosphere & even then the downwelling & coupling of Strat V trop doesn't always deliver.

 

Also I don't think barring maybe 1 or 2 runs that the GFS has modelled any Greenland heights this winter, its been 100% mobility all the way-

 

The OPI has been wrong & along with it Cohens forecast, (  & of course mine + NW & the idiot Madden who forecasts the same thing every winter )

 

A very muted signal for Northern blocking which may improve into Feb, although its not the favourite as it stands...

S

Why were net weather predicting Northern blocking and a scandy high in there February forecast just 6 days ago ??? or is it just wishful thinking , I am guided by these winter forecasts as much as anything for the job I do (landscape gardening } .. Surely there must have been something going on in the atmosphere for there predictions ???

[karlos1983]

some of the GEFS purbs give some mouth watering charts in deep fl and blocking does appear in one shape or another in most, as per Ian F comments earlier.

 

but just for fun, run P11 

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=11&ech=240&mode=0&carte=1 

[JoeShmoe]

That would be close to record breaking, Azores highs of that intensity, displaced or not are rare.

 

If only it was June ....

[Paul]

Why were net weather predicting Northern blocking and a scandy high in there February forecast just 6 days ago ??? or is it just wishful thinking , I am guided by these winter forecasts as much as anything for the job I do (landscape gardening } .. Surely there must have been something going on in the atmosphere for there predictions ???

 

We're getting miles off of the topic of the models here, but the forecast just suggests that a brief colder period is possible early feb - much as is being shown on some of the model output at the moment. We'll of course have to wait and see if that occurs. 

[BLAST FROM THE PAST]

Hi Tamara - A nicely put post, however this winter thus far hasn't delivered ANY of the expectation laid out by the winter forecasts of indeed any of the hype / analysis presented in the stratosphere thread either-  A few flirts with a 2 wave pattern in December which didn't land either-

A lesson to everyone that the modelling of the stratosphere & even then the downwelling & coupling of Strat V trop doesn't always deliver.

 

Also I don't think barring maybe 1 or 2 runs that the GFS has modelled any Greenland heights this winter, its been 100% mobility all the way-

 

The OPI has been wrong & along with it Cohens forecast, (  & of course mine + NW & the idiot Madden who forecasts the same thing every winter )

 

A very muted signal for Northern blocking which may improve into Feb, although its not the favourite as it stands...

S

Steve

I wouldn't put any money on HLB....but ironically I wouldn't be surprised to see some beauty come Spring

 

BFTP 

[JoeShmoe]

I know for my own part that the last thing I have done is put any window dressing on anything. Continually trying to provide evidential suggestions as to what has happened and why. As disappointing as it is has been however (from a MOD thread pov) so far, I think it is pointless any of us moaning about it in my honest opinion.

 

Its a fine balance on here between 'flying the flag' for colder weather and being objective at the same time. Its not all about 'will it snow' (as much as we might want it to) its trying to learn why it doesn't happen sometimes as much as knowing and learning what does make it snow in the UK - at least within the context of this thread anyway which generally has a bias towards looking for it.

 

On that balanced basis, evaluation of the 'background factors' has a very good place - if one wants to try and also learn something along the way while waiting for preferred weather type

 

I'm not personally going to give up trying to learn about any of these drivers just because they don't make it snow in any given winter

 

Maybe this isnt the time and place but each winter i see a lot of folks putting a lot of store in Teleconnections and background signals and every year the weather continues to be a chaos system in which even incredible amounts of super computing power cant forecast accurately past 5 days. I know as 4 or 5 years ago i was trying to do the same and learn from events but to me its a fool's game, like trying to back horses, because there are no repeating signals, pattern matches, call it what you will. 

 

All we can really do is look at trends in the long term models, play the short game and hope computing power evolves to better long range prediction over time ....

 

People like Steve and Ian and IDO do a grand job trying to make sense of it all within these ranges but OPI, AAM, MJO, SST's etc .. too many variables ... when a butterfly flaps it's wings ....

[BLAST FROM THE PAST]

I know for my own part that the last thing I have done is put any window dressing on anything. Continually trying to provide evidential suggestions as to what has happened and why. As disappointing as it is has been however (from a MOD thread pov) so far, I think it is pointless any of us moaning about it in my honest opinion.

 

Its a fine balance on here between 'flying the flag' for colder weather and being objective at the same time. Its not all about 'will it snow' (as much as we might want it to) its trying to learn why it doesn't happen sometimes as much as knowing and learning what does make it snow in the UK - at least within the context of this thread anyway which generally has a bias towards looking for it.

 

On that balanced basis, evaluation of the 'background factors' has a very good place - if one wants to try and also learn something along the way while waiting for preferred weather type

 

I'm not personally going to give up trying to learn about any of these drivers just because they don't make it snow in any given winter

Tamara

I think Steve is saying that even with all the explanations none have come to fruition...been a tough winter

 

BFTP

Edited January 23, 2015 by BLAST FROM THE PAST

[Ali1977]

Anything beyond next weekend is way out in FI, even next weekends set up will change although a colder flow looks promising.

Personnally I feel we could be set for a real cold spell from next weekend, reloads from the North with eventually enough of a ridge into Greenland to form a block.....

[Mucka]

I think the upcoming Atlantic blocking will be a toppling ridge BUT it is not so clear cut thereafter and I think we should start to see trough disruption to our NW showing its hand again around day 10. This is something the models struggle to pick up in low res and it is just about creeping into ECM time-frame albeit deep FI this evening.

Something similar to the spell we have just had only more potent and longer lasting looks on the cards to me now but it won't be from the Atlantic ridge pushing WAA to Greenland and getting a cut off high IMO. We will have to wait a little longer for low pressure to disrupt S/SE over or just West of the UK and get some heights built to the NE first. From there we may have better conditions than previously to get something more sustained.

I expect a toppler to end the month with a messy transition to a MLB to our N/NE and cold spell to develop around middle of first week of Feb.

All the above based on previous patterns this winter, current output and expected conditions early Feb,

It may be it takes more than one bite and we have to wait for the 2nd week but the pattern of NW/SE tilted jet and deep European trough will open the door to height rises to the NE as low pressure begins to disrupt to our NW giving WAA toward Iceland/Scandinavia.

 

Won't be posting very often but look out for signs of  low pressure disrupting being modelled around day 10 Feb 2nd(ish) over the next few days

Edited January 23, 2015 by Mucka

[Frank Trough]

Steve

I wouldn't put any money on HLB....but ironically I wouldn't be surprised to see some beauty come Spring

 

BFTP 

 

Isn't HLB generally more common in spring than winter anyway? It should never be that much of a surprise. Nobody should be expecting spring 2013 to be repeated any time soon, though......at least statistically!

 

 

there seems to be affair bit of doom around at present but this there are some fairly interesting and "wintry" charts about which aren't right in the far reaches of FI:

 

 

admittedly it's not a countrywide snow event but it'll be seasonal. I'd rather that was at t+ 192 than this: 

[Frosty.]

Impressive Ecm 00z ensemble mean with increasingly disturbed, colder and wintry charts at the end of Jan and into early Feb. The expert view on things is the same as yesterday, no downgrade. The idea remains for high pressure to be displaced further west with a vigorous trough diving SE through scandinavia with the UK experiencing its first strong blast from the Arctic, it's the type of pattern which could reload with multiple shots of arctic air through the last third of this winter..I hope :-)

[Woollymummy]

This winter, I think the jetstream has been more meridional than last year, hasn't it? In that sense, maybe some of the OPI and Cohen predictions were not completely wrong......the weather presenters certainly seem to show more of one and less of the other this year :-)

Edited January 23, 2015 by Woollymummy

[BlueHedgehog074]

Just a fairly quick red line summary of the models today.

 

The models continue with a mixture of milder, rainy, spells alternating between cooler Polar Maritime North-Westerly flows with wintry showers to the North and North-West. Some places will avoid the showers at times, particularly towards the South or South-East. And with High Pressure quite close to Southern UK at times, this area would see the least in the way of unsettled conditions. But, further North, it will tend to be a lot more cooler and more disturbed. What is perhaps worth mentioning is that models like the GFS do also show some milder 850 hpa temperatures spilling over the top of the Azores High into some of the North-Westerly flows next week (especially across South-Western areas), so this could translate to some cloudy periods at times.

 

It then seems evident towards the end of next week that a much colder North-Westerly, Northerly, or North-Easterly spell could develop and perhaps bring some wintry surprises to numerous parts of the UK. This possible developing colder shot from the North seems to be in response to an area of very low 500mb thicknesses transferring East towards Scandinavia from our North-West. This should help aid a trough of Low Pressure to establish over Europe and force the cold and snow fans' nemesis - the Azores High   - to pull back to our West and try to hold up advancing Atlantic Lows. As some mentioned the other day, the further South Low Pressure can dig into Europe and also the further South Low Pressure towards Eastern North America can dig, the more likely the High Pressure in the mid Atlantic (Azores High) can become sufficiently squeezed up North and provide the Greenland/Canadian Vortex a good battering. This then resulting in blocking occurring to the North or North-West. But it could always be possible the amplified ridge of High Pressure in the Atlantic gets knocked North-Eastwards into Scandinavia, which could then force Lows in the Atlantic to take a much more Southerly path through the UK. 

 

Would probably say, for now, that the possible cold shot some models show for later next week, would seem like a toppler affair. However, I suppose as longs the Azores High can become locked away to our West and keep allowing room for Lows to drop to our East, then renewed amplification over the Atlantic is possible with further cold shots from the North - just like what happens on the GEM and ECMWF runs towards the end. There is also all those other aspects which I imagine have probably already been covered by others, like Tamara, (e.g: amplified ridging upstream, the MJO/North Atlantic Oscillation /Arctic Oscillation, Stratospheric Warming events to help wipeout/move/split the Vortex pieces, etc).

[Gael_Force]

Maybe this isnt the time and place but each winter i see a lot of folks putting a lot of store in Teleconnections and background signals and every year the weather continues to be a chaos system in which even incredible amounts of super computing power cant forecast accurately past 5 days. I know as 4 or 5 years ago i was trying to do the same and learn from events but to me its a fool's game, like trying to back horses, because there are no repeating signals, pattern matches, call it what you will. 

 

All we can really do is look at trends in the long term models, play the short game and hope computing power evolves to better long range prediction over time ....

 

People like Steve and Ian and IDO do a grand job trying to make sense of it all within these ranges but OPI, AAM, MJO, SST's etc .. too many variables ... when a butterfly flaps it's wings ....

 

As I posted the other night, these teleconnectors are like the symbols on a fruit machine's barrels - the permutations are infinite and if super computing power struggles it's not likely that individual brains will be more successful. That said, it should never stop one trying to learn more about our atmosphere's complexities.