Model Output Discussion; into 2015

[martthefart]

hi all popped in to say hello great site keep up the good work

[IDO]

It will be interesting to see if it tallies with my general thoughts from the current output.  I am thinking JMA are close to the mark:

 

Edited December 27, 2014 by Nick L
Deleted quote removed

[Nick L]

Can we all just act like adults? Please? Posts are going to keep disappearing and if you can't abide by the forum guidelines you may find your posting liberties restricted.

 

Back to the models.

[Long haul to mild]

I'm going to break with tradition in this thread and actually post a chart to try and provoke some model discussion!

Now I know this is deep FI, but it would only need a monster low like this to get a little nudge Southwards into undercut territory and we are into some very interesting winter weather!

Despite the recent model runs, I certainly don't buy into some of the posts declaring that we are set for weeks of zonality; it strikes me that some of those declarations are aimed to wind people up, especially as they very rarely come with any charts to back up their proclamations!

[IDO]

 

The 8-10 day means are unusual. You would expect them to be the other way round!

 

Edited December 27, 2014 by i'm dreaming of...

[Long haul to mild]

The 8-10 day means are unusual. You would expect them to be the other way round!

test8.gif

This is one of the reasons I don't necessarily see the doom and gloom that some others have been predicting for the first half of January.

We can usually expect the GFS to be the most zonal, and although that mean chart is hardly full of blocking, the operationals have been occasionally playing around with shallow highs to the N of the UK. As both TEITS and bluearmy both mentioned in the earlier thread, this can lead to some cold conditions if other cards fall for us.

Edited December 27, 2014 by Long haul to mild

[Captain Shortwave]

The 8-10 day means are unusual. You would expect them to be the other way round!

 

test8.gif

The Euros have been consistently the more Atlantic progressive of the models. The UKMO/ECM are probably the most mobile at day 6.

Looking at the GFS anomaly, we still have low heights to our south and a neutral surface pressure north of this. Could we possibly get a wedge of heights to build to our north east and bring cold in from the east. Given the upstream pattern this looks like being the only feasible way of delivering something more significant than transient polar maritime incursions.

[nick sussex]

For those that have been reading the strat thread and the suggestions re the PV then its going to be difficult to develop any meaningful block.

 

Although we do see some splitting of the PV one chunk is expected to set up in ne Canada which will fire up the jet and send low pressure into the UK.

 

At the moment the possible uncertainty is really what the angle of the jet will be into the UK which of course makes a big difference to temperatures and snow chances.

 

If you look at the mean zonal winds from last nights ECM a case can be made for some high pressure cell towards the pole:

 

 

You can see there some reversal of the zonal flow towards the polar region, this will act to force the jet southwards as pressure builds there so a full on zonal mild attack seems unlikely at present, more average/colder interludes.

 

A feature that I alluded to on the last thread was whether we might see some interaction with low pressure developing over the USA and phasing with that PV chunk, this can help pull some of this further nw and can help develop more dig south of the jet near the UK, although we don't have a strong block over Greenland the pressure rises near the pole could possibly help disrupt  the troughing with a possible shortwave ejecting and heading se.

 

 

Cold hopes for the UK will increase and decrease relative to how far east the PV chunk sets up, so further west better, further east less so, and of course the amplitude of the pattern upstream which will effect shortwave/PV interaction.

 

Essentially from a cold perspective you're trying to squeeze out the best from a pattern where although there are some positives you don't really have all the pieces of the puzzle fitting together.

 

 

 

 

 

 

[Cheshire Freeze]

I actually think there's too much false optimism in this thread at the minute. I took two days off model watching over Christmas and upon checking the models yesterday evening I was genuinely shocked at how poor the outlook being advertised is.

 

First day of 2015...

 

 

That's as poor of a chart as you could wish to see in the heart of winter.

 

As long as we see HP keep up its residence to the S of the UK we'll keep seeing charts of this ilk...with perhaps short lived pm incursions for the N. We need a whole scale pattern change and we need it soon if we're to see anything like a 'cold hearted winter'. Posting charts at 300+ hours out showing pm incursions is fruitless.

Edited December 27, 2014 by CreweCold

[Carlrg]

A Couple of FI charts to keep your chins up. 

[Ventnor Viking]

Afternoon all, have just observed the latest operational runs for the week:

 

Monday to Wednesday:

 

 days look to be clear and fine with cirus clouds aplenty and looks to be frosty for all overnight, except the far southwest, with some of the frost reluctant to lift the further north and east you are and of course over the high ground where there is also a possibility of some freezing fog. There is a risk of quite severe frosts making conditions quite treacherous on the roads. 

 

Temps during the day can be expected between 2-5c widely and 7-9c in the far south west. Over night temps will drop off very quickly and will see temps fall between -1c to - 4c widely and would expect to see locally a -5-7c in the country side away from coasts and the further north and east you are.

 

The Far north west of Scotland may see the odd shower, wintry over the higher ground, however these will be light and isolated. Where showers do form here and clears it will be come very icy.  

 

Thursday and Friday:

 

as the Atlantic try's to push back in you can expect to see temps try to rise widely 4-8c during the day with fronts trying to push in any precipitation will be mainly light and patchy as it comes through. in any clearer spells at night its will be expected 1-3c. One thing to note is that that as the Atlantic does try to push in the air behind is still cool to cold so expect to see wintry precipitation over high ground to the north and north west.

 

The position of the high is key to temps and moisture which will effect our temps and cloud cover drastically. Im very reluctant to put any confidence in forecast beyond 5 days.

[Tamara]

The upstream pattern has followed predictions through the second half of December very well up to the current Atlantic amplification.

 

The predicted pattern from here has been to teleconnect the Atlantic ridge to Scandinavia. This ridge instead is toppling into Europe ahead of renewed energy upstream.

 

Hein-sight is one thing obviously, but the upcoming evolution I think is finally giving us a measure of the difference to prospects that the interruption to Siberian -AO feedback during December has made.

 

Massive snow cover build over Eurasia in October, and continued momentum of the imprinting of the feedbacks during November extended through December, as reasoned was possible, highly likely might have meant that our Atlantic amplified ridge would have indeed been destined for Scandinavia, to meet a robust Siberian High.

 

Such a set-up much better equipped even to deal with an unfavourable vortex split with too much energy left in the Atlantic - as the the present set-up leaves us to deal with (All this, rather than the reality of a retreating European ridge)

 

Equally reasonable to see how our cold hearted winter may have timely started from the beginning of 2015 instead of looking for hopes of changes by mid January. The change of pattern over Asia during December is just one point of discussion - the hope is of course that by winters end there will be no need to revisit it at all.

 

We continue to see tendency in AAM being -ve. This underpins the model suggestions for the jet stream to be southward displaced (and therefore no mild pattern advertised) Average to, at times, slighly below average more especially in the north is the way ahead for the foreseeable future. In perspective at least, this is a better version of the start of Jan 2014 for sure.

 

In addition, the GWO continues to look set to orbit back from Phase 3 into Phase 2. On this basis we can expect further possible amplification potential in the Atlantic coming from upstream to provide better 'below average' conditions from time to time. This overall scenario looks set for the forseeable future certainly.

 

The subject of -AAM tendency though leads us to another problem with the winter pattern conundrum - as to getting to a holy grail HLB pattern our side of the pole this winter.

 

Such Nina-like atmospheric tendency is working against the underlying Nino ocean signal in the Pacific. The latter of which would teleconnect us properly to Eurasian feedback and the missing squeeze we need on the vortex our side of the pole. We have already seen the MJO fail to overwrite the atmospheric signal once in December - and fresh convection fire instead back in the Indian Ocean.

 

For sure, GWO led wave 2 activity (Phase 1/2 amplification) ensures that splitting potential continues beyond the indicated vortex split in the 8/10 day period. This in on top of continued wave 1 activity as the Pacific ridge (-EPO) continues to show poleward tendency.

 

However, as much as our -AAM regime may be preventing any full blown mild pattern setting in, and GWO phasing 1/2 supports some colder more amplified incursions, the Nina like atmospheric state is also overriding and hampering taking advantage of a more favourable ENSO signal that teleconnects us to fast tracking Siberian feedbacks in tandem with a -QBO that would also assist fast tracking of propagating any negative zonal wind anomalies within the stratosphere created as a result of stratospheric warming.

 

The missing link our side of the pole is that we are playing catch up with Siberian feedbacks to bring about the missing wave activity which would break the cycle of vortex destabilisation favouring the Pacific side rather than 'our side' of the pole.

 

In this process, we can see how we are are getting stuck with the Canadian lobe of the vortex, despite a weak and predicted splitting of the vortex - and the consequential downstream energy prevents HLB developing favourably our side of the pole. Most especially exacerbated by the breakdown of Siberian -AO feedbacks.

 

Benefits of any tanking -AO look set to be destined stateside before Europe. Judah Cohen is taking some unfortunate criticism already on the basis of the unforeseen derailing of feedback progress, but I think his latest blog update is balanced correctly in terms of the present situation.

 

This post is simply meant to help re-set expectations realistically - not to be overly and uneccessarily negative in any way. Much can change through January of course - and further on especially as wave lengths change  

Edited December 27, 2014 by Tamara תָּמָר

[Cheese Rice]

I actually think there's too much false optimism in this thread at the minute. I took two days off model watching over Christmas and upon checking the models yesterday evening I was genuinely shocked at how poor the outlook being advertised is.

 

First day of 2015...

 

 

That's as poor of a chart as you could wish to see in the heart of winter.

 

As long as we see HP keep up its residence to the S of the UK we'll keep seeing charts of this ilk...with perhaps short lived pm incursions for the N. We need a whole scale pattern change and we need it soon if we're to see anything like a 'cold hearted winter'. Posting charts at 300+ hours out showing pm incursions is fruitless.

You've cherry picked one chart at the transitional phase between the next Pm incursion and suggested that is the dominant pattern. How is the transitional phase the dominant pattern?

Literally the next few slides show the PM incursions.

We will eventually be entering a pattern similar to the start of December.

Only this time the colder SST will aid wintry potential.

[IDO]

The Euros have been consistently the more Atlantic progressive of the models. The UKMO/ECM are probably the most mobile at day 6.

Looking at the GFS anomaly, we still have low heights to our south and a neutral surface pressure north of this. Could we possibly get a wedge of heights to build to our north east and bring cold in from the east. Given the upstream pattern this looks like being the only feasible way of delivering something more significant than transient polar maritime incursions.

 

Yes the D7 chart where a wedge of HP develops to the UK's west is the sympathetic reaction to the Alaskan Ridge amplifying the upstream as the trough digs into the US:

 

 

Usually you would expect a more pronounced Atlantic ridge, even if was a toppler. However we find at that time the Canadian PV lobe is just too strong to allow anything significant. Yesterday GEM tried to make more of it, but we are running out of time now for that to verify:

 

[Long haul to mild]

I actually think there's too much false optimism in this thread at the minute. I took two days off model watching over Christmas and upon checking the models yesterday evening I was genuinely shocked at how poor the outlook being advertised is.

 

First day of 2015...

 

 

That's as poor of a chart as you could wish to see in the heart of winter.

 

As long as we see HP keep up its residence to the S of the UK we'll keep seeing charts of this ilk...with perhaps short lived pm incursions for the N. We need a whole scale pattern change and we need it soon if we're to see anything like a 'cold hearted winter'. Posting charts at 300+ hours out showing pm incursions is fruitless.

It's certainly hard to find much joy in the outputs at present, hence the frequent dipping into FI to find crumbs of comfort. Maybe we are looking for a pot of gold when there really isn't one at the moment.

However, on the other hand, some of the "winter's over" posts that have been clogging up this thread of late are pathetic in the extreme. The weather frequently makes fools of those who try to proclaim so far ahead and I for one will be pleased to see these merchants of schadenfreude silenced with a good cold spell that appears from nowhere about 7-8 days out, as so often happens in this country.

If we don't have some optimism, we will turn into these "glass completely smashed" types and this thread would be a grim place indeed!

[CanadaAl]

I may well be slightly over pretentious in saying this but considering the models didn't pick up this drop low until Tuesday, it shows me that this Atlantic onslaught may be over done. I realize the deep cold going into the states is concerning but I've already noticed this pacific high responsible is starting to wane and shift further north with each run (precursor to a greeny/scandi link up, who knows?) . I'm only amateur at chart reading so if my analysis is wrong please let me know

Edited December 27, 2014 by CanadaAl

[snow mad]

You've cherry picked one chart at the transitional phase between the next Pm incursion and suggested that is the dominant pattern. How is the transitional phase the dominant pattern?

Literally the next few slides show the PM incursions.

We will eventually be entering a pattern similar to the start of December.

Only this time the colder SST will aid wintry potential.

problem being that PM incursions are pretty rubbish for most! We are just looking for min 3 day proper cold to get some sledging in but at the moment there is nothing on the horizon and anything that looks good just gets blown away very quickly. I agree with Crewe there has been way to much optimism and hope casting sorry but that's the truth

[Cheshire Freeze]

You've cherry picked one chart at the transitional phase between the next Pm incursion and suggested that is the dominant pattern. How is the transitional phase the dominant pattern?

Literally the next few slides show the PM incursions.

We will eventually be entering a pattern similar to the start of December.

Only this time the colder SST will aid wintry potential.

 

 

Dress it up all you like. Polar maritime shots (temporary ones at that) will be no good for the majority....obviously if you live in the Pennines, Dales, Scotland etc you may be OK. The was not cherry picked for any other reason than it's 5 days out (edge of reliable) and the first day of January. Anything after that is less likely to happen (even these mythical pm incursions). What I can't see however is any sign of a pattern flip!

[SMU]

Afternoon All-

Well for me the next week of outputs is key, if we are going to start making a run at a notable January which is sub 2.5c then things like the arctic high development really need to show a strong influence over our weather, it is great having these signs build over the pole, however if they stay over the other side of the hemisphere without conjoining with ridges from the atlantic or scandi then they are irrelevant.

 

All eyes on the atlantic ridging at around 168-192 & the arctic high movement.  Its already stronger at 72 on the 12z GFS.....

 

S

[swfc]

Well looking outside here with5-6 inch of snow the atlantic reving up seems miles away!anyway lets hope the projected wnw winds bring something wintry.also tamaras post as ever does show the way hopefully.uto

Edited December 27, 2014 by swfc

[Banbury]

I actually think there's too much false optimism in this thread at the minute. I took two days off model watching over Christmas and upon checking the models yesterday evening I was genuinely shocked at how poor the outlook being advertised is.

 

First day of 2015...

 

 

That's as poor of a chart as you could wish to see in the heart of winter.

 

As long as we see HP keep up its residence to the S of the UK we'll keep seeing charts of this ilk...with perhaps short lived pm incursions for the N. We need a whole scale pattern change and we need it soon if we're to see anything like a 'cold hearted winter'. Posting charts at 300+ hours out showing pm incursions is fruitless.

That is laughable really have a look at charts from yesteryear you will always find ones  that suggest constant zonality only for something to appear a few weeks later, have a look at charts from early January 1991 , strong W/NWly winds, no one ever saw what was around the corner in February.

 

So you comment of we need something soon.....................isn't exactly correct......................is it.

[Cloud 10]

Worth pointing out that there is a substantial warming of the stratosphere (not a SSW) ongoing at the moment and is set to continue for a good while yet.

 

Just posting it here because people often say that these charts are always in FI but never verify.

 

[SMU]

*HIGH POTENTIAL*

 

Lets hope it manifests past day 6-

http://www.meteociel.fr/ukmo/runs/2014122712/UN144-21.GIF?27-17

[Cheese Rice]

Dress it up all you like. Polar maritime shots (temporary ones at that) will be no good for the majority....obviously if you live in the Pennines, Dales, Scotland etc you may be OK. The was not cherry picked for any other reason than it's 5 days out (edge of reliable) and the first day of January. Anything after that is less likely to happen (even these mythical pm incursions). What I can't see however is any sign of a pattern flip!

Regardless of whether a PM incursion is fruitful or not the chart you posted was indicative of mild south westerlies, fronts straddling western parts of the uk. If you've decided not to take into account the output past five days then your point regarding a poor start to winter stands but to ignore output T144 onwards doesn't make sense.

[Eskimo]

Why are some people disheartened? If the GFS is to be believed in fi (of course if you are deranged) then it shows low pressure systems gradually tracking more and more south with a chance of snow across the Midlands northwards.