Model Output Discussion - Stormy Period Inbound...

[bluearmy]

I think there are several sets of 'energy' to get through before we get to where we want to be.

I think this high to our ne on some ops and ens is much too soon in the overall evolution.

I think there could be some fun and games (some windy, some wet, some white) on the way to week 3 and beyond.

I think that this outlook, though made over quite a few days of watching could go by the wayside if another driver takes over and derails it. It's that kind of season!

[joggs]

No matter how you paint it up,just standard jan fayre in my eyes(the pattern)esp the latest mo update and no hlb to be seen,its always 10+ days out(cold)and with nothing untoward hap in the strat......

Edited January 7, 2015 by Paul

[Frosty.]

No matter how you paint it up,just standard jan fayre in my eyes(the pattern)esp the latest mo update and no hlb to be seen,its always 10+ days out(cold)and with nothing untoward hap in the strat......

Well it's a cold weekend ahead with showers turning to snow further north and very stormy in Scotland with 90 mph gusts so not really standard fayre in my opinion.

[Kentspur]

Keep the faith fella- last snowy month we had down here was March 2013! And I like many others haven't seen a flake since,and as captain shortwave has just shown all the models are hinting at a change in around 10 days- where as before it was just the GFS in Fi.

The ensembles seem to be taking a downward trend from then too- something to keep an eye on. As Tamara and others have stated with the el nino type winter we were always going to have a better chance of cold and snow in the final 1/3 of winter- i.e February/ early March.

Let's hope the models start to get interesting and the all important Met office come on board in the weeks ahead

No matter how you paint it up,just standard jan fayre in my eyes(the pattern)esp the latest mo update and no hlb to be seen,its always 10+ days out(cold)and with nothing untoward hap in the strat......

Edited January 7, 2015 by Kentspur

[nick sussex]

In a bizarre twist this mornings ECM now looks the most amplified over the eastern USA after having been very reluctant before.

 

The obituaries for the MJO may have been prematurely written, overall theres at least some agreement which at least gives us something to work from.

 

At the moment though it might be we enter a pattern of alternating colder/milder but with the colder a bit more potent towards the second half of the month.

 

It's still hard to make a case for an extended cold spell at this time but hopefully that might come  later on.

Edited January 7, 2015 by nick sussex

[IDO]

The first system is early Friday morning and high winds Birmingham North but the strongest gales are mainly in Scotland's NW>N>NE:

 

 

The second system is again early Saturday morning, moving east through the day and clearing the east by early afternoon. This maybe does not have the very high (100mph) gusts of the first storm but is UK wide:

 

 

 

It remains gusty with intermittent stormy conditions for the following week. With PM flows within that period chances of wintry showers to the usual suspects. Not really seeing any frontal snow at the moment:

 

GFS snow totals next 7 days highlight this: 

 

Further on remains fluid with the GEFS still playing around with the heights arriving from the US after D8. Not expecting a resolution on that till the weekend. The op and C play with a wedge of heights squeezing to the NE on this run. However this will likely change by the 06z:

 

 

 

A good spot from the GEFS from around D16; timing issues as you would expect, but the break down of the zonal flow well sign posted. Obviously as we know, even at D10, ECM has terrible trouble with height rises, so the chopping and changing of how those heights interact is only to be expected from the GFS/GEFS from the D16 countdown.

 

CFS MJO continues on its consistent theme of getting us through phase 7 and now hints at trying to go through phase 8:

 

 

Both the AO and NAO becoming less positive as the move through the next ten days but no clear signal that there will be a move to a negative state.

 

As others have said a bit of everything in the next two weeks though no sign of anything sustained wintry wise.

Edited January 7, 2015 by i'm dreaming of...

[MR EXTREMES]

I think there are several sets of 'energy' to get through before we get to where we want to be.

I think this high to our ne on some ops and ens is much too soon in the overall evolution.

I think there could be some fun and games (some windy, some wet, some white) on the way to week 3 and beyond.

I think that this outlook, though made over quite a few days of watching could go by the wayside if another driver takes over and derails it. It's that kind of season!

Wow for a few days the gfs has toyed and gefs and now the ec and gem change is being sniffed at !!!!!

Although looking like the recent cold event ATM as in pattern but the air from nw North is colder than coming from the North East at the moment.

My fingers are crossed.

As a more El Niño type pattern enriches itself then the back end of winter!,

as tamara and Nick f suggest for a couple days now I think it will evolve better this time even so it's gonna be chilly at time any milder air looking brief.

We seem to be getting more displaced heights showing.

Which suprises me as I had more confidence in a Scandinavia ridge but the weather will do what it wants lol

[Nick F]

The obituaries for the MJO may have been prematurely written, overall theres at least some agreement which at least gives us something to work from.

At the moment though it might be we enter a pattern of alternating colder/milder but with the colder a bit more potent towards the second half of the month.

It's still hard to make a case for an extended cold spell at this time but hopefully that might come later on.

Yes, there is still a glimmer of hope for an extended cold spell in the last half of winter. If it wasn't for GFS/CFS still sticking with MJO 7 and perhaps 8 later this month, I would have thrown the towel in. We may have to wait until right to the end of Jan or early Feb for a favourable change driven by MJO 7/8, given several days lag.

Also, quite a few GEFS members as well as the op indicate a volatile trop polar vortex later on this month, prone to splitting into lobes that amplify the upper flow - manifested by 6-7 members throwing a ridge north or NE in the Atlantic which could lead to some northerlies or even northeasterlies.

Before then, the PV re-organises after its current split, bringing some stormy weather. But if we see more wave prpagation this month, driven by the easterly QBO and more Nino-ish pattern developing again - as some models hint at, I think the PV will weaken again, without any SSW.

Edited January 7, 2015 by Nick F

[nick sussex]

Thanks Nick F.

 

Yes the will it won't it MJO saga continues. the ECM spreads show some interest in developing high pressure to the nw of the UK at day ten which does seem too soon perhaps for a more longer term change.

 

 

The mean 850's at day ten are -4 covering the whole UK which is pretty good at that range, given some of the ensembles will likely be flatter then there must be also be some nice looking ECM ensembles for day ten to get to that mean value.

Edited January 7, 2015 by nick sussex

[johnholmes]

my take for 6-15 days from close scrutiny of anomaly charts and looking at further out signals including MJO from GFS (the only one I use)

Wed 7jan

Ec-gfs

Both have about ‘lost’ the ridge/cut off/+ve they showed for 2 days; each has deep low/trough/-ve areas ne America-atlantic-uk n Europe,

Each seems to redevelop separate centre ne Canada , fairly meridional over n America on both, deep cold not showing for uk nor was noaa last evening; idea of slacker flow by 8-14 days on noaa with –ve heights ne of uk and some sign of ridging on 1 or more of outputs Greenland/sptzbergen area is not clear and only slight anyway. This takes us into mid January with little sign of marked trough e of uk into near Europe and ridging to w or nw!

signal from MJO I do not see (on gfs) as suggesting a marked change in 500mb pattern so far.

add

Just looked at the GFS MJO and it has a reasonable predicted orbit to take it into 6 (no help from deep cold) and then perhaps into 7 at a reasonable orbit, which could help towards late January perhaps?

tentative signs only as yet.

Edited January 7, 2015 by johnholmes

[knocker]

The extended mean anomalies still showing a marked difference between the GEFS and EPS at T360. The GEFS can be seen below but the EPS has a weak Alaskan ridge and weakish build up of heights NE North America but a far more extensive trough Greenland into NW Europe down to the Med. Albeit quite weak.

 

Surface wise to my simple mind this doesn't portend any cold incursions anytime soon and basically has an HP zonal Atlantic flow with LP to the NW and east with the ECM given a tad more prominence to the latter.

Charts courtesy weatherbell

 

[mushymanrob]

Well it's a cold weekend ahead with showers turning to snow further north and very stormy in Scotland with 90 mph gusts so not really standard fayre in my opinion.

 

id have though snow showers further north was pretty much standard fayre for the uk in january. its not going to be that cold this weekend, just chilly... as i type carol kirkwood has temps of 12c for saturday north of the cold front straggling southeast uk...

 

my take for 6-15 days from close scrutiny of anomaly charts and looking at further out signals including MJO from GFS (the only one I use)

Wed 7jan

Ec-gfs

Both have about ‘lost’ the ridge/cut off/+ve they showed for 2 days; each has deep low/trough/-ve areas ne America-atlantic-uk n Europe,

Each seems to redevelop separate centre ne Canada , fairly meridional over n America on both, deep cold not showing for uk nor was noaa last evening; idea of slacker flow by 8-14 days on noaa with –ve heights ne of uk and some sign of ridging on 1 or more of outputs Greenland/sptzbergen area is not clear and only slight anyway. This takes us into mid January with little sign of marked trough e of uk into near Europe and ridging to w or nw!

signal from MJO I do not see (on gfs) as suggesting a marked change in 500mb pattern so far.

 

yep, the noaa charts prove likely to be correct over gfs fi again... no surprises there really.

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY WEDNESDAY JANUARY 7TH 2015.

NEXT UPDATE THURSDAY JANUARY 8TH 2015 08:00

THE CURRENT GENERAL SITUATION A strong and mild SW flow is developing across the UK as a cold front moves SE across the UK later today and more slowly across Southern England tonight.

MODELS-2 WEEK HEADLINE Rather changeable and often windy or even stormy and sometimes mild with rain at times. Some drier interludes likely too with slight frosts at night.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows a very strong Jet Stream being maintained across the UK or just to the North in the short to mid term before it steadily weakens later as the result of a weakening vortex to the North of the UK.

GFS OPERATIONAL The GFS operational continues to look very zonal, sometimes mild and wet, sometimes cooler and more showery but never particularly cold but nearly always very windy from a Westerly point. Later in the run though Low pressure slips SE down across the UK and on into Europe interrupting the zonal pattern with rain and strong winds giving way to colder and frostier weather for a time with some wintry showers possible before milder SW winds, first affecting the NW start their inevitable trek SE across the UK towards the final frames of the run.

THE GFS PARALLEL RUN The Parallel run is as yesterday more reluctant to show any meaningful rise of pressure from the West late in the run and while the run briefly weakens the zonal Westerly weather conditions late in the run changeable weather under a Westerly regime remain the favourite weather type likely two weeks from now though probably less windy at least at times.

THE GFS CONTROL The GFS control run leans towards rather colder conditions later in Week 2 as this run shows a wet, windy and mobile period for all during Week 1 before a build of pressure filling a gap between Low pressure systems transforms the weatehr to a colder and more blocked pattern with frost developing by night with some wintry showers likely across Eastern parts as winds turn Easterly late in the period.

THE GFS CLUSTERS The GFS Clusters show little change in the theme of an Atlantic dominated pattern with the only slice of colder air delivered by a 15% group who think we could end up in a colder and polar maritime NW in 14 days time with deep Low pressure over Scandinavia

UKMO UKMO shows a strong and direct Westerly blast developing over the next 6 days with spells of mild and always very windy weather with rain alternating with colder and more showery weather, still with gales and wintry showers over the hills.

THE FAX CHARTS The Fax Charts shows a very volatile and active Atlantic flow as deep depressions cross quickly East between Scotland and Iceland with all areas seeing broad mild sectors with rain at times heaviest on Northern and Western hills  mixed with colder polar maritime Westerly winds, equally strong with showers, wintry on hills across the North.

GEM GEM today shows a continuation of the cyclonic pattern of weather over the UK with spells of strong winds and heavy rain alternating with colder periods with showers, wintry on hills. The Low pressure areas do show signs of digging deeper into the UK later sending colder uppers down over the South too at times heightening the risk of wintry showers on hills at times here too.

NAVGEM NAVGEM reflects no end to the Westerly flow either with often mild, wet and windy conditions holding sway over the UK with short and colder periods with showers in between.

ECM ECM this morning shows little consequential change to a well worn pattern of a strong Westerly flow being maintained across the UK. The variability in how this affects the UK day to day will continue to be common with rainy mild weather alternating with colder and brighter interludes with showers.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart shows a very slow shift East of the Low pressure belt to the North of the UK with time. As the central core of pressure slips more towards Scandinavia there will be a greater impact from the colder and more showery conditions behind cold fronts for Southern areas too later in the period probaly seeing snowfall down to modest levels in the North at times and hills more generally further South. This does look the only shift though in an otherwise still very unsettled and mobile pattern powered by High pressure to the SW and an over active Jet flow.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend this morning remains largely usettled and windy with spells of rain at times and short colder spells with showers. Yesterday's hints of more High pressure likely to be in the mix during Week 2 are still hinted at within the GFS pack but hold no cross model support as yet.

MY THOUGHTS Not a lot of change this morning I'm afraid with the Atlantic holding control of the weather across the UK the most likely option we end up being at still two weeks from now. GFS does offer an olive branch on the shape of a pattern change later through week 2 from both it's operational and control runs but in all honestly they look a little isolated in the grand scheme of things shown elsewhere. They achieve this change by sending Low pressure SE across the UK and SE Europe allowing pressure to build across the UK and Northern Europe later and dare I say it setting up an Easterly by Day 15 on the Control Run. However, that's where the story ends as all other outputs show a variation of a theme of very windy and turbulent weather with rain at times and severe gales or storm force winds especially over the North in the coming week with no doubt some structural damage and news worthy headlines. There is still opportunities for colder and showery weather to throw down the odd wintry fall here and there again between the storms largely in the North but all in all there will be little or no seriously cold and wintry weather on a Nationwide scale through the next two week's if this morning's output verifies and although the Jet stream is expected to decrease somewhat later in the period the axis and vortex will remain more or less in situ continuing the theme of Westerly winds and rain at times the most lilely place we find ourselves two weeks from now.

[Frosty.]

GFS 00z op run shows a slight delay in the cold air plunging SE on Saturday compared to 18z but Scotland turns bitterly cold with lots of snow showers piling into exposed north western areas.

Edited January 7, 2015 by Frosty.

[Polar Maritime]

Yes Frosty lot's of cold sharp Pm blast over the coming days, With plenty of Snow showers around and strong N/W winds/gales. Quite a Wintry outlook.. Adding on the wind-chill it will feel bitter/raw, Very seasonal charts.

 

Edited January 7, 2015 by Polar Maritime

[Polar Maritime]

Some severe Gales Force winds to come for the N/W on Friday to keep an eye on. Could get very tricky, With Gust 90/110mph.. 

 

Edited January 7, 2015 by Polar Maritime

[Mucka]

The weak signal for potential pattern change has not strengthened over the last couple of days and is barely registering now so any ridge looks likely temporary, at least at first attempt.

However the pattern also looks likely to remain more amplified last 3rd of Jan so potential for a colder more blocked pattern to set up later still.

Story of the Winter so far has been any blocking signals being overridden and that looks like continuing for the foreseeable but not a done deal as yet and of course this will have no bearing on Februaries weather.

 

This mornings output. (00z)

 

GFS and GFSp have a bit of a love in with the Azores high, generally maintaining high pressure South of the UK until low pressure attempts to dig into Europe in around 10 days time. GFS offers some home of a toppling ridge keeping the pattern amplified while GFSp flattens the pattern in the most mundane way possible (horrible run)

GFS also wants the Azores high to play spoiler all the way out to mid month with low pressure running further North than ECM and UKMO and shallower troughs limiting any potential transient wintriness.

 

ECM is much better up to mid month with colder air digging further South and generally maintains a colder flow through mid month with the PV shifting east in a more organised fashion rather than dividing energy and giving a more SW/NE tilt the flow as in below's comparison. Sods law this Winter that GFS will be right and we will get the milder wetter and windier regime of GFS than the colder more showery ECM.

If ECM is right however there could be good fall of snow for Northerners at some point and good dumps of snow for the hills.

 

Edited January 7, 2015 by Mucka

[legritter]

morning all ,looks like gfs both are our friends still this morning .very interesting 240hr chart from ecm today ,but as we all know at this range subject to big changes the next time it updates .my big straw taken from the models today would be the fair possibility of good 850 mb temperatures becoming more widespread in our kneck of the woods and low pressure much further south and eventually to our east .so not a bad day so far ,we just need a good throw of the dice ,but i will only be happy when ECM and UK Met hint more like the GFS .so we have some very lively weather hitting the UK ,and a great interest on where the gfs low of next week tracks ,could be dropped totally ,or it could slip further south but at this range there are many options ,  

[Mucka]

GFS 06z and GFS 06zP small steps toward the Euros out to the mid term so hopefully that continue into this afternoons output.

In that regard disagree with above post, GFS is not our friend at all out to mid month, Euros better for transient snow chances.

As far as after mid month and FI, GFSp was awful this morning with very brief cold air incursions right the way out to T384. Granted the T384 chart might be okay going forward but...

GFS 00z Op doesn't get any cold air over the UK at all in FI so not sure how that is friendly coldies either?

I guess if it is general synoptic terms then the diving low scenario offers some hope but this mornings GFS do not deliver and ain't no friend of mine.  :smiliz46:

 

Hoping for better on the 06z

 

Edit.

 

GFS 06z Op and GFS 06zP both better for snow chances in run up to mid month

 

 

Of course these charts will change run to run but they highlight the possibility of a snowfall in the run up to mid month even if it will likely be a temporary fall.

 

GFSp even throws in something I mentioned a couple of days ago as an unlikely possibility, a secondary low running along the base of the trough.

Now that would keep the Southerners out of bed! (50/1 any takers?)

 

Edited January 7, 2015 by Mucka

[Man With Beard]

Well imo the situation continues whereby we can't see the train coming but train-like noises can be heard in distance. The ECM mean and op, towards the end, leave open the possibility of a stronger NWly, and suggestions that the GFS had completely backtracked from its idea of North Atlantic height rises are overstated - while perhaps the original signal was too pronounced, some sort of signal remains for a height rise towards the tip of Greenland leading to at least a temporary northerly flow - the latest GFS(P) is an example:

uppers conducive to snow pretty much everywhere:

 

But until we see something like this inside T144, it remains a noise which might not be a train at all. A few more days needed yet.

[Mucka]

Well imo the situation continues whereby we can't see the train coming but train-like noises can be heard in distance. The ECM mean and op, towards the end, leave open the possibility of a stronger NWly, and suggestions that the GFS had completely backtracked from its idea of North Atlantic height rises are overstated - while perhaps the original signal was too pronounced, some sort of signal remains for a height rise towards the tip of Greenland leading to at least a temporary northerly flow - the latest GFS(P) is an example:

uppers conducive to snow pretty much everywhere:

 

But until we see something like this inside T144, it remains a noise which might not be a train at all. A few more days needed yet.

 

Yes agree with that, a noise but muffled.

 

I think some form of Atlantic ridge is likely but the signal for it to usher in a pattern change, particularly to a cold, blocked regime has remained very muted. Still time for that to change but all the output points toward a toppler. Of course GFSp 06z is a toppler but would still at least bring the best spell of winter thus far to many. If there is to be a pattern change it looks as though we will need another attempt at blocking either from the ridge toppling into Scandi and favourable block setting up there (possible but I see very little support for that at this stage) or by another attempt to build an Atlantic ridge which IMO there is a little more support for.

Overall though any blocking setting up in January looks tenuous at this stage but by no means can it be discounted and at least there are some signs.

 

ECM London ensembles.

 

 

I think they are colder than last nights going off memory. Looks generally below average after mid month anyway.

[bluearmy]

The extended mean anomalies still showing a marked difference between the GEFS and EPS at T360. The GEFS can be seen below but the EPS has a weak Alaskan ridge and weakish build up of heights NE North America but a far more extensive trough Greenland into NW Europe down to the Med. Albeit quite weak.

 

Surface wise to my simple mind this doesn't portend any cold incursions anytime soon and basically has an HP zonal Atlantic flow with LP to the NW and east with the ECM given a tad more prominence to the latter.

Charts courtesy weatherbell

Knocker - I would say that the main difference with ecm extended is the euro troughing. Whilst that signal remains, we have a chance of a fairly seasonal outlook. However, the euro heights have proved more resilient than forecast more than once this winter so we wait to see this trough get into the pre day 10 timeframe where the higher resolution ens will pick it up.

[Summer Sun]

Snow for the south later next week? GFS P says YES

 

Before we get to the south its NW Scotland where the totals mount up quickly early next week

 

 

Now the south joins in

 

 

GFS gives the south up-to 2 inches of snow by the end of next week whilst parts of western Scotland could be pushing 12 inches (1ft) of snow by the end of next week

 

[Tamara]

Analysis of AAM tendency and GWO pattern for Nov/Dec and Jan (to date), tells us the story of how the winter has been driven so far.

 

 

A cyclical winter Nina type atmospheric signal of +NAO courtesy of sub tropical ridging to mid latitudes - and totally inhibitive of amplified MJO cycling beyond the dateline. This, despite a weak El Nino oceanic signal which if in harmony with the atmosphere would teleconnect us to the Siberian SIA feedbacks that were expected to be much more prolific in determining the winter pattern, and would also have given us a much more amplified Atlantic pattern under a winter-time +AAM atmospheric state.

 

However, much as discussed yesterday evening, this is only the story of the first half of this winter.

 

Those tentative tell-tale forecasted signs of rising AAM (the green line) , signalling a breakthrough response of the GWO being forced out of negative tendency phases 1,2 and 3 into positive tendency Phase 5 are very important, should they verify, in terms of how a changing atmospheric response to better mirror the background Nino state might impact the NH weather patterns and begin to break us away from the flatter +NAO signal to something colder and more amplified.

 

Discussion was provided yesterday evening, as to how this might evolve the upstream pattern under such a changing signal.

 

It might take us to much later in the month and towards February, but it is a start. Anyway, best not get hung up on precise timing - the most important thing right now is that this trend is maintained.

 

Should this be the case, than we should not worry unduly about the MJO forecasts.

 

Atmospheric state in better harmony and jive with the oceanic El Nino signal will, in time, do the rest here...

 

Such as the case was in winter 04/05 under a weak El Nino, when cyclical patterns provided a Christmas toppler and snow to northern and western parts, followed by strong zonality through the first half of January (familiar so far ?) and then better amplification in the second half of January (which gave a NE'rly and snow showers IMBY  ) 

 

Ever improving amplification sequences and weakening vorticity over Greenland and Canada thereafter led to the fully blocked pattern during the second half of February and into the first days of March 05.

 

There is certainly a case for something similar to be possible this season.

 

Expectations for winter 14/15 have been higher than this obviously - but we have to manage them in terms of the reality of what has happened, and where we are instead

 

Its still very much a case of the trend needing to be our friend here, before we can buy a new sledge....and then think of waxing it.

 

One final bit of perspective though - Winter 04/05 did feature an SSW - but it arrived late (in Spring) on 16 March.....a week or two after any late season snow had melted....

 

....Eyes on the stratosphere anyway, to assess the magnitude of Asian MT tropospheric wave break which will occur with any entry of GWO into Phase 5. This would provide a forward extra momentum to the atmospheric forcing of its own to benefit our sector of the NH as we head towards and into February...

.

Edited January 7, 2015 by Tamara תָּמָר

[IDO]

The storms for the end of the week look like verifying as damaging and extreme:

 

 

 

Apart from the storms Friday and Saturday, we have another one around a week tomorrow. The GEFS are relatively confident of this though timing, track and intensity issues:

 

 

Temps for the next week look no worse than average for the south:

 

The D8-10 mean anomalies show the differences between GFS and ECM. The heights in the US are more amplified on the ECM than the GFS and conversely this makes the ECM more zonal. The GFS having less energy allows greater potential for phasing the height builds in the Atlantic between the PV flow:

 

 

NOAA show low confidence re 8-14 day anomalies so it is difficult to know which way it will go; maybe towards the middle. GEM wasn't showing any height rises over the last 5 days re the signal the GEFS picked up, however yesterday their members moved in that direction and again they continue the theme. Looking through their ENS and they are as spread as to a solution as the GEFS.

 

The only main signal from the GEFS showing any sort of continuity from D10 is that the flow moves towards PM>TM so I would expect a more seasonal feel to the weather.