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

[Jason M]

What is also odd is no other 18Z ensemble member shows anything like the control run. So the fact the 12/18Z are identical is even more strange.Like you say I don't think I have seen this before.

Rather more predictable however is the chart 4 days later

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=384&mode=0&carte=0

GEFS have been better today and Ian's comments give hope, but it would be a brave man that bets against a UK or euro blocking high. High odds on a poorly aligned a secure ridge? Things can change but thus far there has been pretty much a zero indication of a genuine HLB setting up this winter. This seems to go against what many are saying on here, but there has been some sort of background signal that's preventing this, even where at face value the pattern seems to encourage it. In terms of learning, it's this that may be the main thing that's taken out of this winter.

That said, good to see improvement today and Fegies comments are welcome.

Edit wouldn't it be great though if we could squeeze a good easterly :-)

Edited January 23, 2015 by Jason M

[Weather Boy]

What is also odd is no other 18Z ensemble member shows anything like the control run. So the fact the 12/18Z are identical is even more strange.Like you say I don't think I have seen this before.

But eventually after huge numbers of runs it is sure to happen eventually.

The lack of ensemble support suggests it's coincidental

[Interitus]

GFS 18Z Looks positively freezing in greenland -40 uppers !-10 uppers into Scotland also and large part of UK under -6....trend continues!

 

They aren't really -40 uppers - most of Greenland's surface is above the 850mb level, a large proportion is above the average 700mb level.

At Summit station at 3202 metres the average pressure was around 644mb yesterday.

[TEITS]

GEM is interesting this morning as we see upstream its more amplified with the AZH ridging N with a potential LP tracking SE, followed by a potential rise in pressure to our N.

 

http://modeles.meteociel.fr/modeles/gem/runs/2015012300/gemnh-0-240.png?00

 

I also note alot of scatter remains around the 29th on the GEFS ensembles with these bringing much colder temps earlier than the GFS OP/GEFS control.

 

http://max.nwstatic.co.uk/ensimages/ens.20150122/18/t850Cambridgeshire.png

 

Keenly await the ECM.

[winterof79]

Sinking trough alert at 180z 

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=180

 

 

You would only need a cap gun to finish off the vortex and create the x- polar flow of sorts.Leaving the Canadian side to fend for itself

http://modeles.meteociel.fr/modeles/gens/run/gensnh-0-1-240.png

Edited January 23, 2015 by winterof79

[Polar Maritime]

The Northerly model'd for the turn of the Month looks more amplified this morning on both the GFS & ECMWF.

 

Edited January 23, 2015 by Polar Maritime

[Great Plum]

Sinking trough alert at 180z

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=180!

You would only need a cap gun to finish off the vortex and create the x- polar flow

http://modeles.meteociel.fr/modeles/gens/run/gensnh-0-1-240.png

Yes, by 240hrs, it's so close to a cross polar flow... Of course, as soon as it hits low res at 252hrs, the GFS flattens the ridge! Edited January 23, 2015 by Great Plum

[Polar Maritime]

ECMWF shows a much colder Northerly flow this morning.

 

[Captain Shortwave]

So the models are still keen on a 24 hour northerly of sorts to end January, the ECM and GEM do think there could be more to this potentially.

ECM

Sends a low south east through the UK with a deeper northerly following.

 

GEM

Potential for weak heights to form to our north again.

Still scope for something interesting to happen during week 2, no guarantees about this though.

Edited January 23, 2015 by Captain shortwave

[bluearmy]

Agree about cohen's blogs. I preferred if when he was more enigmatic and less like us!

And captain, I think a reload looks quite likely and if we get lucky with the track of the day 10/11 system, it could just be a cold and wintry 5/7 days.

[fergieweather]

Latest Exeter thoughts from modelling into 6+ days are:

- NW broad flow expected to remain first few days of Feb: high to west, trough to E

- Changeable conditions remain but with chance of quieter wx in south

- Signs of anticyclonic influence becoming more prominent later into Feb (combined GloSea5/EC Monthly signal) and NW flow diminishing

- However, this shift in pattern may not manifest as a very blocked scenario per se. Still v uncertain

- Weak signals for MJO to enter Phase 6 early Feb

- Weak signals for -ve NAO circa 10 days into Feb on

- SSW signal remains below climatological norm, but within this overall muted signal, GloSea5 shows an increased warming fraction next month. This being closely monitored.

[EML Network]

I would have loved to have seen the next frame from the ECM as this system dived south East...

 

 

The cold pool over to our East would be waiting in the wings to flood in and if this run came to pass the way it's shown the next frame would be snow heaven for many ..and probably the frame after that too

 

 

I really hope that the ECM is on to something with this run, im my opinion it's the best run of the Winter so far for the evolution and the likelyhood of an extended cold run. 

 

Will await to see the ECM Ensembles with interest today, I think Feb is going to be anything but mild looking at how things are panning out, winter proper is just around the corner folks, it might be a slow gradual cooling down before we get there, but that's how a like it, get the cold in first and then let the fun and games begin

[Frosty.]

Great to see the Ecm sticking to its guns with the wintry blast which looks like it would reload further on, looks like our first arctic blast of the winter is on the way. :-)

[BLAST FROM THE PAST]

Awesome ECM this morning

 

t192

 

 

 

 

 

 

t216, reload coming with cold air already entrenched

 

 

 

 

 

 

 

and t240

 

 

 

 

 

This is what I've been banging on about and why I said the other day I'm issuing severe weather alert/watch/ and I'm ALL in.  GFS not too shabby either.  Remember, general theme and timing more or less ok with that.  Also that Atlantic block would probably give way [ok with that]...reloads down the line?...I think so...I'm quite interested in FI as I think very impactual weather lies ahead...

 

 

TEITS, this illustrates what I meant/tried to explain the other day, it isn't the same as we had before this winter but also shows no true HLB to maintain pattern....trough is not to our NW so its a colder pattern

 

BFTP

Edited January 23, 2015 by BLAST FROM THE PAST

[IDO]

It is hard to disagree with Dr Cohen re the trop vortex over Baffin Bay, a consistent Winter Killer for the UK. It highlights that even SSW's can be detrimental to our winter if the re-shuffle is mis-aligned. 

 

The D12 GEFS show an array of solutions and it is very difficult to pick the bones from these. Certainly around D7-10 we have the stalling of the Atlantic sector with heights building and the energy diverting into the Euro trough. The potential for at least a few days of cold air, initially at D6 PM then Arctic., though timing issues reign within the GEFS. Still about a 25% cluster that keeps a cold pool over the UK by D12, so a potentially a similar cold period in length to the current one, though different synoptics. The other members are more mobile. Early days on longevity but transient looks more probable from current output.

 

The main picture from this amplified flow may be the stormy conditions, as the trough to our east digs south. Variations on how this materialises but all models keen:

 

EC:  GFS:  GEM: 

 

Looks another fluid period of model watching as they come to grips with this more meridional cycle. Good potential for at least the north for some more interesting weather late next week, and the possibility for the snow starved south to maybe get some of the white stuff.

 

In the interim we have six days of changeable weather with dry interspersed with frontal precipitation, with temps averaging out to a seasonal level.

 

 

 

 

 

 

[ANYWEATHER]

Morning everyone! Well reading the output this morning one thing comes to mind, exciting charts , and never a dull moment! The see/saw, yo/yo temperatures are predicted for about another  week and then all eyes to the west with regards amplification out in mid-Atlantic, and a broad scale low pressure system developing over Scandinavia, which leaves the uk  in a turbulent north/northwest flow, bring wintry conditions for many. A long way off at the moment, but the trend is there! Interesting times ahead.

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY FRIDAY JANUARY 23RD 2015.

NEXT UPDATE SATURDAY JANUARY 24TH 2015 08:00

THE CURRENT GENERAL SITUATION A couple of cold fronts will move SE across the UK through today and tonight followed by a cold NW flow ahead of a ridge of High pressure tomorrow.

MODELS-2 WEEK HEADLINE Changeable with rain at times but some drier spells too. Less cold. Turning more generally unsettled and very cold again later with snow in places, especially over the North and East.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows the flow across the UK currently moving back South sharply over Europe in a weeks time setting up the UK and NW Europe very much on the cold side of the flow then positioned to the SW of the UK moving SE.

GFS OPERATIONAL The GFS operational today shows progressively windier and changeable conditions as we move through next week. All areas will see spells of cold and bright conditions mixed with milder and cloudier spells with rain at times. Later in the week and more especially next weekend will see a more significant dip into strong and cold NW then North winds as Low pressure sinks South over Europe bringing wintry showers of sllet and snow to all areas for a time before at the very end of the period the winds steadily back West again renewing the changeable Westerly pattern of before.

THE GFS CONTROL The GFS control run is broadly similar to the operational in terms of sequence extending the cold period somewhat longer with perhaps more extensive snow or snow showers almost anywhere for a while before the milder Westerly winds resume late in the run with rain and windy weather at times.

THE GFS CLUSTERS The GFS Clusters today show NW winds the likely position we find ourselves in both in 10 and 14 days time. The positioning of governing Low pressure driving this feed is crucial with many clusters supporting some very cold and wintry weather on a Northerly for a while mid term while the trend on the later period clusters support a less robust and milder West flow with some rain at times to end the period.

UKMO UKMO this morning shows a strengthening and increasingly chilly and unsettled WNW flow developing through next week with a fairly dry and chilly start of the week under a ridge being replaced by cloud, wind and rain midweek and colder conditions filtering down on a strong WNW flow later in the week with precipitation turning wintry in the North later.

THE FAX CHARTS The Fax Charts show a series of cold fronts moving East and SE across the UK around High pressure to the SW over the next 5 days with alternating spells of rain and milder air mixed with short periods of colder and clearer conditions with some wintry showers in the NW and frost at night in places.

GEM GEM today also deepens the strong and cold WNW flow late next week and weekend as Low pressure slips SE across the North Sea and NW Europe with strong and cold NW or North winds and wintry weather for many late in the period.

NAVGEM NAVGEM follows the theme too with 5 or so days of modest conditions with some rain and brighter colder periods before more generally cold and unsettled weather arrive for all from the North late next week and weekend with some wintry weather for some especially the North.

ECM ECM this morning completes the set with a mix of alternating milder and chillier days through next week ahead of a dip into distinctly cold and wintry conditions powered by intense Low pressure over Europe feeding very cold NW and North winds and spells of snow showers or longer spells of snow later as further Low pressure feeds down into the cold air from the NW in 10 days time.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart today endorses the main output in promoting cold North winds across the UK in 10 days time in association with Low pressure over Scandinavia and High pressure to the SW.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS There is a strong trend today for at least a temporary track into very cold and unstable North or NW winds and some wintry weather for the UK in a week or so.

MY THOUGHTS Once again this morning we have to look North for our next impending spell of cold weather interest as the period of benign weather of the next 5-6 days changes to something of much more interest late next week. There will be 5-6 days of alternating periods of mild and damp weather between colder and brighter spells when frost at night may occur. Then later next week all output shows a sharp deepening of the trough over Europe developing into it's most powerful state this Winter so far. The net result for the UK will be to enhance and strengthen a WNW then NW r North flow driving ever colder weather South next weekend to turn all precipitation to sleet and snow in deeply unstable air. The period then looks like remaining cold with winds veering to North for a time with considerable snowfall for the North and East in particular with no doubt sharp night frosts. Then we have to look further into the distance to see what happens thereafter. Some output bring this sharp burst of Winter to a close quite quickly as a ridge from the West crosses the UK and backs winds to a milder Westerly with rain and wind at times while others including ECM look like sustaining cold rather longer as further pulses of cold Low pressure slips SE into the cold air across the UK later enhancing the risk of more extensive sleet and snow at times. It also shows a stronger build of pressure then over the Atlantic, insufficient at present but trending the right way. So all in all it looks like the cold fraternity will have every reason to be happy with the output this morning as cold weather has complete support from all models to arrive from the North next weekend with just the duration of such a spell open to doubt at the moment. I await further model runs in the coming days with interest.

[john mac]

Next weekend IMO o's the perfect set up fur a polar low to develop with the deeply unstable air in place that hubby refered to. Still a long way to go but signs are very promising from all models this morning.

[Captain Shortwave]

Solid trend from the ECM ensembles out to day 10 with the winds veering to a north/north westerly direction in week 2

 

I must agree with BA with the potential for the pattern to keep reloading as the Siberian lobe of the polar vortex remains dominant and aligned across northern Russia and into Scandinavia. Transient northerlies at the moment with the potential for something more substantial to crop up if the cards fall our way.

[nick sussex]

Morning all

 

Nice to see the outputs firming up on the Euro troughing, interestingly the GFS now keeps the main PV to the east compared to its earlier runs which wanted to bring this back west through Greenland.

 

Because of this theres a better chance to extend some ridging further north, the ECM has an eye catching low tracking se'wards on day ten which could be a big snow maker, a weaker feature would be preferable here.

 

The GEM is particularly interesting and could lead to a more sustained period of cold, overall good agreement across the models but too early to say how much amplification we can squeeze out of the Azores high.

[carinthian]

Next weekend IMO o's the perfect set up fur a polar low to develop with the deeply unstable air in place that hubby refered to. Still a long way to go but signs are very promising from all models this morning.

Hi John ,to get a real Polar Low you need very cold air in place. Example of this chart from February 1969 produced a classic Polar Low with deep snowfall and extremely low 850mb uppers of -15c over the British Isles. Remember it well with 2o inch fall of snow in Cheshire, started at 9am and finished at 6pm. Temp never got above -5C all day and that was at 75m asl. Funny enough the week before has a southerly with 15c max. Just goes to show how a turn about can happen so quickly. Interesting February coming up I think.

[Andrew snow hope]

For a newbie can someone explain what the models need to be showing for the South to get a descent snowfall and where the cold needs to come from for the best set up.

[chionomaniac]

For a newbie can someone explain what the models need to be showing for the South to get a descent snowfall and where the cold needs to come from for the best set up.

Here is a great guide on winter set ups from Ian (TWS) - It is worth reading first and then coming back if you have any further questions.

 

https://forum.netweather.tv/topic/56318-guide-to-uk-winter-setups/

 

Edit and this one is better from him for snow set ups

 

https://forum.netweather.tv/topic/20474-winter-snow-setups/

 

The learning area is a must for any newer member who is trying to learn the basics about the charts and models.

Edited January 23, 2015 by chionomaniac

[nick sussex]

The GFS 06hrs run has a different profile over the Pole this time and at this range hard to say what will land on the day itself.

 

Gone is the split PV and the GFS now seems to be going back to its earlier view! I think for a continuation of the cold this could still come if high pressure can develop and cut off near Iceland forcing a shortwave to edge se to the west of the UK, as you can see even with that different polar profile this still has a chance.

 

The lower resolution sends the energy over the top, you can see the difference in how the PV is ejected out of Canada between the 00hrs and 06hrs, the latter is more favourable because you would have a chance to throw a ridge ne.

Edited January 23, 2015 by nick sussex

[IDO]

The GFS 06hrs run has a different profile over the Pole this time and at this range hard to say what will land on the day itself.

 

Gone is the split PV and the GFS now seems to be going back to its earlier view! I think for a continuation of the cold this could still come if high pressure can develop and cut off near Iceland forcing a shortwave to edge se to the west of the UK, as you can see even with that different polar profile this still has a chance.

 

^^^ Yes on this run lots of snow in the North Sea. The pattern just a bit too far east: