Model Output Discussion 1200 hrs 15/11/14

[ANYWEATHER]

Why has it gone totally bonkers? at day 6 it has support from the UKMO, GEM and JMA. If anything the GFS is the odd one out...

Gfs is not the odd one out at all. Its been consistent with its output over the last few days, Ecm is a pile of rubbish at the moment and leading folks up the garden path to the Phantom beast from the east.....    

[Eugene]

Gfs is not the odd one out at all. Its been consistent with its output over the last few days, Ecm is a pile of rubbish at the moment and leading folks up the garden path to the Phantom beast from the east.....    

 

 

Excellent post from Barry95 above with many good points, yes i agree GFS is the most consistent run and when it shows decent blocking charts in the next few days you will have to agree with it.

[MR EXTREMES]

Gfs is not the odd one out at all. Its been consistent with its output over the last few days, Ecm is a pile of rubbish at the moment and leading folks up the garden path to the Phantom beast from the east.....    

yes indeed the ecm has been up and down like a pair of pants with noro virus.

 

and infact id be inclined to suggest its been the worst model by far but we will see although it is worth taking note up to 144hrs on the ecm.

its love for heights has been in serious question for years.

 

although i see no route to the freezer i do see a route to cooler more seasonal temps after the warm surge from the south.

after this cooling of and at times rather wet windy and cooler, the east though does look pretty dry with less precip making it to far east.

 

another thing is its extremely difficult to get a easterly with enough cold to produce the 09/10 and 80s type winters.

but then there has not been a decent greenland block for some years now this in my mind is not showing on the model outputs also with the larger segment of the pv over around greenland and canadian area then i cant for the life of me see where any cold is going to come from other than west or northwest as the models are showing.

 

its getting painful to watch and it could well be that the stratosphere is not going down easy, and that the vortex fight back may have just been a little later than recent years there for this could well end up being a dud winter.

 

i do really feel that the models to watch are the gfs and gfs para and the ukmo even the jma can be ok i think im done with ecm wild goose chases. 

[Skyraker]

Yep sorry folks, ECM not playing ball tonight after a little teeze around 144, at 192 Azores high encroaching, December 1st will be mild and calm if this verifies.

t192 has as much chance of verifying as a semolina of the pope.

Edited November 22, 2014 by Polar Maritime
To remove personal remark.

[MR EXTREMES]

the only model to have the jet going far south is the gem all the rest have us direct inline 

[nick sussex]

I won't drone on too much about yet another shortwave drama but theres a clear correlation this evening with the pattern over the ne USA and those outputs which have more colder potential.

 

The uncertainty centres on whether shortwaves phase or remain separate and this effects how the PV behaves near Greenland, the ECM doesn't shear enough energy nw on phasing and you get the energy piling ne.

 

Timing issues, where the phase point is are all important in this type of set up.

 

GIven these comments from NCEP we really need to see cross model agreement on the upstream pattern at T120hrs before having a good idea of what the outlook is.

 

 MEANWHILE THE COMBINATION OF UPSTREAM ISSUES MAY MAKE IT
DIFFICULT TO RESOLVE DETAILS OF WAVINESS OFF THE EAST
COAST/SUPPORTING MID LVL SHRTWV WED-THU UNTIL PERHAPS THE SHORT
RANGE TIME FRAME

 

Full discussion here:

 

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

[Dancerwithwings]

Gfs is not the odd one out at all. Its been consistent with its output over the last few days, Ecm is a pile of rubbish at the moment and leading folks up the garden path to the Phantom beast from the east.....    

The garden path! that ECM ain't the only one at times... This time last week comes to mind when they both & GFS P sent us that Phantom thingy you was on about

 

[IDO]

Why has it gone totally bonkers? at day 6 it has support from the UKMO, GEM and JMA. If anything the GFS is the odd one out...

 

GEM blows up lows all the time and its run has a deep LP system that blows WAA to over amplify the Scandi high in the 12z. That means that heights are always bias on the GEM as you can see from it's bias verification:

 

 

If you look at the GEM mean it is clear again the GEM op is an outlier: 

 

Compare the above GEM mean to the GFS mean and we see where the pattern is going again: 

 

To me the stalemate will continue, and it is how far to the east the Atlantic will go before the energy goes over the top (after D10). The Azores is continuing to send heights to reinforce the sceuro block/euro block and is a recurring theme. Another upper level low may sink SSE after D7 and what happens to this may be interesting but this is the slow boat to China and patience is needed if this is our only hope from tropospheric drivers. As others have said we are going nowhere fast and its a case of waiting for stratospheric developments to reboot the NH profile, as we know from last winter that patterns can become entrenched, so that is our best chance in the medium term IMO.

[nick sussex]

The garden path! that ECM ain't the only one at times... This time last week comes to mind when they both & GFS P sent us that Phantom thingy you was on about

 

But that's well into FI, the ECM has been useless between T168 and T240hrs. I hate to rip into it as I've often been one of its biggest fans but I'm fast losing faith in it. especially from that timeframe.

 

Of course at that range you expect some volatility but its also how its ensembles are jumping all over the place. Overall it clings to first place on the T144hrs verification but after that its now losing all credibility.

[Polar Maritime]

I've deleted a few off topic posts, Please continue with Model Discussion only.

 

Thanks, PM. 

[fergieweather]

The current situation is a well-known scenario wherein we are seeing - and will *continue to see* - marked/dramatic variance both inter-run and inter-model. THIS NEEDS EMPHASISING before any wild goose-chase assessments looking into next 5-15 days.

Cherry-picking certain runs or models as the 'favoured' solution is a wholly pointless exercise at this juncture, as exemplified by the very muted pointers towards medium range flow diagnostics emerging earlier today from DECIDER (looking ahead into early December).

The sort of wild swings characterising EC-DET (for sake of just one example), may be frustrating but are to be wholly expected in this finely-balanced saga; moreover they are not indicative of some fundamental model failure/bias (as some purport)... instead, they offer an exemplar of the difficult prognostic exercise facing medium range forecasters.

There remains, at time of writing, NO clear/definitive signal towards calling the west-v-east outcome into at least next 10-15 days and I'd urge folks to sit tight on this (perhaps confusing) period of NWP to-&-fro, which may continue for some time yet. Add some of the possible background hemispheric drivers described well by Tamara and others, and the complexity moving ahead - and caution needed interpreting daily model output - should be very apparent.

[ANYWEATHER]

The current situation is a well-known scenario wherein we are seeing - and will *continue to see* - marked/dramatic variance both inter-run and inter-model. THIS NEEDS EMPHASISING before any wild goose-chase assessments looking into next 5-15 days.

Cherry-picking certain runs or models as the 'favoured' solution is a wholly pointless exercise at this juncture, as exemplified by the very muted pointers towards medium range flow diagnostics emerging earlier today from DECIDER (looking ahead into early December).

The sort of wild swings characterising EC-DET (for sake of just one example), may be frustrating but are to be wholly expected in this finely-balanced saga; moreover they are not indicative of some fundamental model failure/bias (as some purport)... instead, they offer an exemplar of the difficult prognostic exercise facing medium range forecasters.

There remains, at time of writing, NO clear/definitive signal towards calling the west-v-east outcome into at least next 10-15 days and I'd urge folks to sit tight on this (perhaps confusing) period of NWP to-&-fro, which may continue for some time yet. Add some of the possible background hemispheric drivers described well by Tamara and others, and the complexity moving ahead - and caution needed interpreting daily model output - should be very apparent.

Ian, Ecm as been a Flank of late, Gfs positive in its Output

[knocker]

The anomalies tonight

 

The NOAA 6-10 has the Canadian trough SE into the UK, Scandinavian HP orientated west/east and the quite strong Azores HP pushing up from the south tightening the Atlantic flow. No great amplification N. America and a weak trough east Pacific.

 

The GEFS is not dissimilar to this with perhaps less emphasis on the Azores HP. The ECM has the Canadian trough orientated more north south with a general area of low pressure into the eastern Pacific and the Scandinavian HP orientated more NW connecting via the pole to the Pacific HP. This allows the Azores HP to ridge further west in connecting with the Scandinavian HP

 

The lack of agreement obviously creates much doubt on the veracity of any surface analysis so powder has to kept dry at this stage and maintain a waiting game The extended run of the ECM at T300 it's back to the Canadian trough SE scenario which the NOAA 8-14 supports.

 

So essentially not a great deal of change unless the the ECM idea of retrogressing the trough takes hold which doesn't seem very likely.

Edited November 22, 2014 by knocker

[Nick F]

MJO generally forecast to be weak, but slowly heading through phase 4 into phase 5, with a December anomaly weighting here showing continued support for heights to our NE:

Conclusion? Stalemate and more stalemate. I'm not seeing a renewed strong westerly pattern as Gibby suggested earlier - instead we are marooned between a trough and a block for a while yet. However for me the long term signs do not point to a significant renewal of atlantic energy. But we need to watch and wait for a little longer and see out this lull. What will follow is still up for grabs.

Add in signs of El Nino developing, which often favours a colder drier northern Europe and warmer wetter southern Europe during the winter, certainly plenty to be optimistic about for the winter months ahead. Australian Bureau of Meteorology El Nino update last week upgraded from a watch to an alert with at least a 70% chance of El Nino occurring, something I'm sure Chino and Lorenzo will be factoring in their winter forecast.

But all these positive indicators from ENSO, Eurasian snow cover and tropospheric wave impacts on the strat aren't going to change things overnight, so we may have to endure the edge of the Atlantic troughing to and fro influence over the next few weeks at least, but blocking will never be far away to the east looking at extended ens, so we will have to live with its to and fro influence too. Despite some calls to get rid of the block, it may turn to our advantage (coldwise) if upstream pattern changes or we have a SSW - which there's a high chance of this winter.

Edited November 22, 2014 by Nick F

[johnholmes]

 

MJO generally forecast to be weak, but slowly heading through phase 4 into phase 5, with a December anomaly weighting here showing continued support for heights to our NE:

? the last one I saw showed it in 3 and predicted to remain in 3?

MJO generally forecast to be weak, but slowly heading through phase 4 into phase 5, with a December anomaly weighting here showing continued support for heights to our NE:

[stewfox]

Ian, Ecm as been a Flank of late, Gfs positive in its Output

 

Could you post the statistics that back that up ?

[karyo]

Disappointing 18z with the Azores high not doing us any favours at 144 hours as it takes the jet further north and sends it over the block!

[swfc]

Not a great pub run pushing the jet north ete.Could i just ask you guys a question?Keep hearing comments that fi is generally about 5 days .

 

 

 

 

.Why are people pinning there hopes on strat conditions,mjo,enso ete when they are generally forecast weeks away?Are they not way in fi and subject to the big changes just as the model output is.Thanks in advance

Edited November 22, 2014 by swfc

[knocker]

MJO generally forecast to be weak, but slowly heading through phase 4 into phase 5, with a December anomaly weighting here showing continued support for heights to our NE:

? the last one I saw showed it in 3 and predicted to remain in 3?

MJO generally forecast to be weak, but slowly heading through phase 4 into phase 5, with a December anomaly weighting here showing continued support for heights to our NE:

 

Last I saw

[Cloud 10]

MJO forecast a bit confusing between different models,so use with caution!

 

gefs..  ecm..

[johnholmes]

MJO forecast a bit confusing between different models,so use with caution!

 

gefs..NCPE_phase_21m_small.gif  ecm..ECMF_phase_51m_small.gif

 

yes indeed, I should have made it clear in my post that I never use anything but the GFS output, not that it is any more accurate simply that using one all the time makes for less confusion to me!

[nick sussex]

Given both GFS's 18hrs and the ECM I think the UKMO solution is looking very unlikely, whilst both the ECM and UKMO might look similar at T144hrs there is a small but critical difference over in the ne USA which means the ECM will not be able to develop the more favourable trough disruption at T168hrs.

 

The divergence begins within T120hrs and so its very unlikely that with an extra 6hrs worth of data that both the GFS and GFS P have called the pattern incorrectly.This is in relation to shortwave phasing and timing issues.

 

I hope I'm proven wrong in the morning but the evidence suggests that the UKMO, GEM and JMA are barking up the wrong tree. The UKMO is generally known for being the dream killer in here as its often the one that harpoons an easterly by refusing to come on board, I've yet to see it pull out a colder solution against the other major models at the T144hrs timeframe that verified.

 

The GEM regardless of its upgrade and the JMA are basically cat litter and not to be trusted, the performance of the UKMO has been dismal over the last week, we saw from it Scandi high, a refusal to develop shortwave energy to the ne etc etc.

 

The ECM which I have criticized frequently over the last few weeks may have been all over the place at T168hrs onwards but sadly in this case is likely to be right at the key T120hrs timeframe.

 

The models may all still have the pattern too far east but even allowing for that the PV over ne Canada is just sending across too much energy to realistically see the high backing west at this stage , it may happen later.

 

Much talk of jam tomorrow which is understandable as there are better background signals this winter and we're not yet even into December but I think I speak for many when I say we're bored and we want jam now!

Edited November 22, 2014 by nick sussex

[Polar Maritime]

An interesting run from the GFSP,  Another more potent reload of Pm air showing, With snow chances over much of the UK and a bitter N/W wind for the start of Winter. Fingers crossed! 

 

Edited November 22, 2014 by Polar Maritime

[Weather Boy]

Not a great pub run pushing the jet north ete.Could i just ask you guys a question?Keep hearing comments that fi is generally about 5 days .

 

 

 

 

.Why are people pinning there hopes on strat conditions,mjo,enso ete when they are generally forecast weeks away?Are they not way in fi and subject to the big changes just as the model output is.Thanks in advance

As I understand it, strat forecasts are much more reliable than trop forecasts and therefore FI is much further ahead.

Hope that clears that up,for you

[karyo]

An interesting run from the GFSP,  Another more potent reload of Pm air showing, With snow chances over much of the UK and a bitter N/W wind for the start of Winter. Fingers crossed! 

 

Polar, there's nothing good about this chart. The gfs has the tendency to overdo the coldness of the uppers at this range when the wind comes from the west/northwest which we also saw last winter.