Model Output Discussion 1st January 2014-06z onwards.

[Richie V]

I hear the gfs is having a serious referb in April, mabe it will gain some more respect in here if they trim the output range to 180+ max

I'm sure Nick will say something when he's available, but I'm sure the answer will be yes, especially if it went as far out as the GFS, wisely the programmers restricted it to 240hrs and that’s still stretching it IMO.

[kumquat]

I think we should have full runs of each of the the perturbations come out at a 10 minute delay in real time so that we could "amplify" the effect of how the forum mood changes as each perturbation run comes and goes. You could have mini ensembles for each pert (dig into the nitty gritty of the pressure and "energy" equation iterations performed by each) at 5 minute intervals following each pert run. These could be gone over with a fine tooth comb.

 

Looking at the "phasing" of Pressure, temp, GPE and KE of each individual iteration of each individual equation per pert would be a veritable feast of model watching at its finest.

 

And the spaghetti plots would be super awesome!

 

Happy hunting guys and gals.

[Mucka]

Good morning everybody GFS 00z trickling out as I write (about 126h).

As a continuation from my post last night discussing how the GFS appeared to be slowly moving in the right direction I can say that "trend" is continuing this morning with slightly lower pressure to the South, slightly stronger ridge with the pattern a trifle further West. These are quite small changes run to run but if I compare this mornings 00z to yesterdays you can see how they add up so let's hope its a trend that continues across the output.

 

Todays GFS 00z 132h/yesterdays 00z same time.

 

Edited January 5, 2014 by Mucka

[The Eagle]

Yes incremental improvement. Not there yet but a small step in the right direction. Crucial time in between 120 and 136 and the ridge building north. The stronger the better but we still don't have the energy underneath in to the continent.

[Mucka]

MetO not so good with the ridge being shunted East.

 

 

But GEM turns out chilly and very blocked though it is a slow burner and snow chances would be pretty slim. Still it's about establishing a block at this stage and the details will sort themselves out.

 

 

A great deal more blocking in GFS ensembles out to day 10 through various evolutions so we may have to be patient but cold may well be on the way for the second half of Jan if not a little sooner.

 

Final chart from me this morning.

We have gone all winter thus far without a sign of HLB so I had to laugh at this chart. The Synoptic is amazing.

 

 

Graphs for SE

 

http://www.meteociel.fr/cartes_obs/gens_display.php?x=287&y=122&run=0&runpara=0&type=0&ext=1

http://www.meteociel.fr/cartes_obs/gens_display.php?x=287&y=122&run=0&runpara=0&type=3&ext=1

Edited January 5, 2014 by Mucka

[Blizzardof82]

Still looking for pressure to drop in Europe, which to my untrained eye remains the problem.

Where would we go from here?

[The Eagle]

That's a very good chart. The jet stream has to make inroads in to the continent and every sign of it happening there. Pressure and heights are decreasing in that chart so an undercut is probable there. But it is cuckoo land range.

Edited January 5, 2014 by The Eagle

[Great Plum]

Chionomaniac said to keep an eye on the ensembles... The 0z GFS ensembles show a cooling trend...

http://www.wetterzentrale.de/pics/MT8_London_ens.png

Many runs after the 15th below -5...

As for the ECM, I'm just pleased to see Scandanavia with a cold plunge in the semi reliable...

http://www.wetterzentrale.de/pics/Recm1441.gif

Details for the location of the high pressures will be sorted out later... At this stage, a cooling (and drier) trend is probably the best to expect... Don't expect snowmaggedon yet!

[winterof79]

The way the ECM has been behaving, I accept

But seriously, we have to temper our expectations. Really frustrates me when the GFS is routinely panned.

As ever, its over to the morning runs now. More fun & games.

If you had seen the amount of times GFS runs have progged a return to our default zonal in low res, even in some of our splendid winters.

It does it this morning once more.Changes are afoot and it will be great to watch them unravel.

http://www.meteociel.fr/modeles/ecmwf/runs/2014010500/ECM0-168.GIF?05-12

http://www.meteociel.fr/ukmo/runs/2014010500/UW144-7.GIF?05-06 most welcome

Some of us have posted charts from archives to show just how sudden the change from raging zonality can occur.

[The Eagle]

 

 

ECM at 144. I challenge anyone to rule out the Atlantic LP being 400 miles west with a little more of the core jet stream to our south. We are really close.
 

 

Loads of possibility there. Plenty of time for it to change in our favour.

Edited January 5, 2014 by The Eagle

[bluearmy]

A very good example on the op 00z gfs of the affect of the sudden drop in resolution at T192 on the models ability to handle a blocking situation which is evolving at that point. You can see it creating the resistance to the trough in the frames leading up to T192 and then at T204/T216, whoosh, the trough fires though.

tf the model says consistent through its next few runs (and it doesn't have an outlandish solution at that point so it could well do), will be interesting to see where that trough disruption sits in 12/18 hours time.

As far as the ECM is concerned, arctic highs over eastern scandi and Eastern Europe at day 10 with associated p/v type uppers. could be some fun ens members to view on the de bilt graph later. should we see a run brings that air in our direction, just remember that once it gets within T168 on the models, , it will nearly always develop a shortwave to halt its direct path and deflect it. Air that cold doesn't like passing freely across warm seas without creating a dynamic to slow itself. I'm sure JH could give you the physics behind it but I'm just giving you too many years of seeing it modelled and watching the distress in places like this! not to say it can't happen as we have illustrations where we have taken a direct hit. Just to say there are far more where we've missed out because of a shortwave development. (I know it works when frigid Canadian air hits the nw Atlantic - if the earth rotated the other way then the momentum would take care of our particular problem).

As for gem, well it just shows whats feasible as the wall to our ne begins to exert itself against the strong jet. Small changes early on can have big ramifications at the moment.

Mucka, didn't mind the ukmo this morning. Good day 6 chart going forward with developing scandi ridge, with vortex to its north east, and the flow kicking south to our west.

Edited January 5, 2014 by bluearmy

[Radiating Dendrite]

Something is certainly going to change..... But the ECM and GFS still have energy going NE and not SE. Hopefully this will start to change on later output.

I am still a little sceptical because the PV seems completely anchored to the south of Greenland which is not a good place for getting cold in the UK. Heights may develop to our East, but we may be too far West to see any benefit - a large high to the east and a trough to our West and us in no man's land could be a possible outcome?

[KTtom]

Something is certainly going to change..... But the ECM and GFS still have energy going NE and not SE. Hopefully this will start to change on later output.I am still a little sceptical because the PV seems completely anchored to the south of Greenland which is not a good place for getting cold in the UK. Heights may develop to our East, but we may be too far West to see any benefit - a large high to the east and a trough to our West and us in no man's land could be a possible outcome?

 

No mans land can actually be an exiting place to be in situations like that if you like your snow....isn't this the exact situation refereed to  in the N-W winter forecasts?

[Frosty.]

Well I have come in for a lot of ridicule for being so positive but that's only because I feel there has been a lot to be positive about on the models. It's only January 5th and there continues to be lots to be positive about, there is way too much negative energy on here, some call it realism but I call it pure glass empty negativity. There is growing support spread throughout the GEFS 00z perturbations alone for a very wintry pattern to emerge, some from as early as T+144 hours across scotland and then gradually spreading south to all areas, we have height rises to the north west, blocking atlantic highs, blocking scandi high's, scandi troughs and a belt of high pressure across the pole. There is a lot of wintry options from mid month onwards with southerly tracking jets & reloads galore. I continue to believe there are strong signs of a proper blast of winter in the not too distant future with severe frosts and snow.

[weather eater]

Not much to add this morning as the operational’s ECM, GFS and UKMO pretty much support the post I made last night, Atlantic slowly putting the brakes on, MLB for a while followed by a possible return of the Atlantic, although to be fair only the GFS goes that far out so confidence must remain low on that for the time being, my confidence for sustainable HLB that would really get the forum buzzing is also low, some hints of it in the ECM run and a little in the GFS but I have little faith in it amounting too much. Even if we don’t see the return of the Atlantic, MLB seems more likely to me, frankly any drying up of the pattern would suit me.

[nick sussex]

Hi Nick, do you think we would see awful flip flopping in later timeframes as per gfs if the ecm ran 4 times per day?

Yes especially if it was extended to the same length as the GFS, it does depend though to a degree on whether the ECM would have the same drop off in terms of resolution in the latter stages.

 

I don't understand why NOAA just don't bring the GFS into T240hrs and keep the resolution the same without the drop off, personally I think its  a bit to do with the American designers psyche, its the only global model which takes its operational out that far, I think you know what I mean!

 

 They've had years of having to use more of the ECM in their outlooks but the penny still hasn't dropped!

[bluearmy]

stonking ecm ens run if blocking scandi ridges are your thing.  the atlantic jet looks split aswell. cant find much wrong with the trend there. one thing that was concerning me re this scandi ridge was the low mean thicknesses on the ens. struggling to get to 530.  all becomes clear now as we see that rather than our standard blocking ridges, thrown up from our latitude,  this is an arctic ridge with associated low thicknesses. (like the one from '62/63 - did i just post that? shame on me!). it also means that 500mb spreads on the esn mean chart will  be difficult to read up there although the 850's are the way to go now and this morning they show the coldest air against the mean, sinking into se europe.

[Captain Shortwave]

Hmm only seen the mean charts from the ECM ens, but there must be some interesting runs in there.

You can see the 850s drop out to the east as that cold pool over western Russia tries to head westwards with even the UK cooling off.

[tinybill]

morning  all i think i found our winter!!  it start  Jan 21 !!  i know it wont happen and if the express see it  its will be the next  ice age!!!  till then its looks like rain till then stay dry if you can

Edited January 5, 2014 by tinybill

[nick sussex]

Hmm only seen the mean charts from the ECM ens, but there must be some interesting runs in there.

You can see the 850s drop out to the east as that cold pool over western Russia tries to head westwards with even the UK cooling off.

Thats a huge improvement on yesterday, I think this is all down to the mid Atlantic jet and how much dig south we see, if we get enough we'll see a shortwave head through the UK allowing the ridge back over the top.

[shedhead]

 

Not much to add this morning as the operational’s ECM, GFS and UKMO pretty much support the post I made last night, Atlantic slowly putting the brakes on, MLB for a while followed by a possible return of the Atlantic, although to be fair only the GFS goes that far out so confidence must remain low on that for the time being, my confidence for sustainable HLB that would really get the forum buzzing is also low, some hints of it in the ECM run and a little in the GFS but I have little faith in it amounting too much. Even if we don’t see the return of the Atlantic, MLB seems more likely to me, frankly any drying up of the pattern would suit me.

 

Very much agree WE, clearly changes in the overall hemispheric pattern are afoot and no doubt much of Europe will eventually turn colder...but to be fair it could hardly turn any milder! Exactly how the wider changes will impact our small island as we move into the 2nd half of Jan remains to be seen, but simple assuming it will become cold seems a tad premature at this stage imo, with a range of other potential options still on the table. However in the shorter term the only real trend that matters as far as I'm concerned is the drying trend. If I wanted to live by the coast I'd move 20 miles N to the coast, I don't particularly like it moving here with me...

Edited January 5, 2014 by shedhead

[Gibby]

Good morning everyone. Here is this morning's account of the midnight outputs of the NWP for toeday Sunday January 5th 2013 taken from http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

 

All models shows another very deep depression crossing slowly ENE across the Atlantic to reach an area to the North of Scotland as a filling feature by Wednesday of this week. The next 72 hours will be characterized by a spell of rain crossing East today to be followed by a couple of days of blustery and heavy showers, especially near Southern and Western coasts but some drier spells in the more sheltered East. Winds will be strong to gale force SWl'y but should subside towards midweek with temperatures holding well up to average of not a little above in the South. Soon after midweek all areas will become quieter with light winds but with slow moving troughs caught up in the slack flow over the South which could give rise to further copious rainfall, not helpful at all to the current flooding situation.

 

GFS makes less of this feature gradually drying things up after Thursday as High pressure glides east over France. A Southerly breeze develops in it's wake and it isn't long before low pressure once more develops close to the West, moving North-East and renewing rain events to all areas in blustery winds. This format retains it's place then for the remainder of the run with strong winds again shown later with just brief drier spells under transient ridges over the South. Temperatures look like holding largely close to average.

 

UKMO this morning closes on Saturday with High pressure to the SE and light winds over the UK and a light SW flow over the North. A front looks like being straddled across Southern Britain in light winds meaning a slow moving area of rain could lie close by with largely cloudy skies while the North has the best chance of seeing somewhat brighter conditions.

 

GEM is the driest model run this morning with events later in the week showing a steady drying up process with all frontal activity removed by the weekend as High pressure develops over Scandinavia. This migrates slowly South and West late in the run to be positioned close to NE Britain by Day 10. The weather would turn cold and frosty with some sunny spells but a cold and raw SE wind would likely develop over many areas though it would likely stay largely dry.

 

NAVGEM shows slack pressure late in the week and over the weekend over the South with slow moving troughs again running the risk of creating wet conditions over the South before the pattern looks like becoming a little more changeable and mobile again from the West following next weekend.

 

ECM today also shows slack pressure towards the end of the run and with upper troughs caught up in the slack airflow it looks unlikely to be guaranteed dry with the South most at risk of some prolonged rain while the North sees the best chance of brighter conditions with a little more wind pushing troughs through rather quicker.

 

The ECM 10 Day Mean Chart today is better news for cold fans as it now supports in a bigger way High pressure over Scandinavia and a slack Southerly feed the most likely bias over the UK. Low pressure has a much weaker bias to towards the NW this morning. With a continental feed injected over the UK there I would think be good support from the members of it's ensembles for very much colder conditions to arrive after next weekend.

 

http://www.wetterzentrale.de/pics/Reem2401.gif

 

The GFS Ensembles do show a dip this morning below average in Week 2 with some unsettled and mobile weather still thrown into the mix by some members. There are rather more members though approaching the -10C value later in the run with a wider spread from all the members averaging a bias towards the cold end of the range.

 

The Jet Stream Forecast shows the lengthy spell of West to East movement over the Atlantic and Southern Britain coming to an end later next week. The flow looks like disrupting late this week and particularly at the European end appears to be forced to lower latitudes indicating the possibility of High pressure over Northern European latitudes.

 

In Summary there is a change in the weather on the way although changes involving the cessation of rainfall may have to be more patient. From the middle of the week gales will be a thing of the past but some stubborn slow moving troughs could keep things potentially wet at times in the South until the weekend. From thereon we have a split with GFS and NAVGEM going the way of returning unsettled and windy conditions with yet more rain in the second week while UKMO and ECM operational shows a High pressure to the SE with an Atlantic drift over the NW where some rain would become likely again later. The more interesting slant this morning is shown by the ensembles which especially from ECM show their greatest indicator yet of pressure becoming High to the East and NE and throwing much colder weather our way as a result. The margin for error is very fine though and we need to see more cross model support before shouting from the rooftops. Nevertheless, it looks like at last the Atlantic may be running out of steam for a time so all areas look almost guaranteed of becoming rather drier and certainly much less windy and with the natural risk of cold weather occurring from Europe increasing later in the Winter it is from these predicted weaker Atlantic synoptics that cold spells can develop quite quickly should things fall into place correctly.

[The Eagle]

 

Even at 240 the ECM ensemble mean is very promising. I suspect far more colder ens runs in there than previously. Much more than the 12z.

[nick sussex]

I've found this great new way of looking at the ECM De Bilt ensembles, this shows the maximums and the percentage of the ensembles going for a particular temperature range:

 

 

The link is here, you can also look at mins and snowfall predicted for that region:

 

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.php?run=00

Edited January 5, 2014 by nick sussex

[Cecil Hogmanay Melchett]

I think it is fair to say any potential change in regime is likely to be a very slow burner(if we get a meaningful change at all that is).

I mentioned the other day the cold is coming for central and Eastern Europe and the ECM 0z bears that out perfectly as the Arctic air sweeps south and east.

In summery,im not convinced of a meaningful change anytime soon...