General Model Output Discussion

[Avain]

its the Standard Atmospheric Pressure for the whole world which ( ICAO) (International Civil Aviation Organisation) use.

1013.2mb

Thanks John, and Also Village Plank for your help. I did wonder if the chart referred to a division between the two pressure types but wondered why it was not on the 1000mb line as the natural/average sea level pressure, I am very well acquainted with the use of the 1013mb or 2992 inches in the USA as the standard altimeter setting above the transition level for various nations, so it is interesting to see it marked on the chart.

[TEITS]

The op was one of the 3 coldest members for T144-168hrs and the mean and conrtol pretty close for milder weekend,a short colder 2-3days next week then returning to almost average.

Yes but have you noticed the OPs continue to be the coldest. In these circumstances its usually the ensembles that follow the operationals rather than the other way round.

[billy]

Im not actually surprised by the ECM tonight. I would be amazed if the models suggested an E,ly at +168 which works its way down to +0. This has never happened since I started following the models and never will do.

This synoptic pattern that we're currently seeing has often been a forecasting nightmare and this was the case back in the 1980's/90s. One of the biggest headaches is just a relatively small shift in the W extent of the Siberian HP can mean the difference between bitter cold and snow showers or mild S,lys.

Even if all models suggested an E,ly at +144 I would still be wary of the model output. Since I joined this forum the E,ly has caused many ups and downs on here. Remember Dec 05 when the models were progging an E,ly but then changed their mind for 48hrs and then of all of a sudden the E,ly returned in the model output.

The Met O outlook could change to very cold, snow showers at a flick of a switch. Thankfully though I have my sign that is suggesting the bitterly cold E,lys are on their way.

Hi Eye, how confident are you that your secret sign is going to be right ? Come on give us a clue . Is it the Fieldfares , LOL . Regards Billy

[Ben_Cambs]

It's the sort of situation where minor changes result in massive differences for the UK. I would imagine that there will be plenty of cold options in the ECM emsembles.

However, unless we get the jet to undercut or back off considerably, then any Easterly will be a fairly short 'end of the line' affair anyway.

The other thing is that as we have seen with some recent winters, it doesn't matter how big the High to the NE is, if the jet doesn't play ball then there is no cold for the UK.

Yes, thats the one thing I'm worried about, if the block is marginally too far East, then we could easily be in mild and wet Southwesterlies. The models will throw out all kinds of situations over the next few days IMO. By the way, when do the ECM ensembles come out?

Edited January 13, 2010 by Snowman0697

[phil nw.]

Yes but have you noticed the OPs continue to be the coldest. In these circumstances its usually the ensembles that follow the operationals rather than the other way round.

I havent studied the behaviour pattern of the op.v ens.wrt a possible Easterly Dave so i can`t comment on your last sentence.

Believe me i love the proper winter cold even at my age but I just say what i see

http://charts.netwea...arwickshire.png

Maybe a brief return to cold next week,briefly,then warmer again.

Edited January 13, 2010 by phil n.warks.

[Ben_Cambs]

I think these might be the updated ECM ensembles, correct me if Im wrong....

Edited January 13, 2010 by Snowman0697

[gottolovethisweather]

Im not actually surprised by the ECM tonight. I would be amazed if the models suggested an E,ly at +168 which works its way down to +0. This has never happened since I started following the models and never will do.

This synoptic pattern that we're currently seeing has often been a forecasting nightmare and this was the case back in the 1980's/90s. One of the biggest headaches is just a relatively small shift in the W extent of the Siberian HP can mean the difference between bitter cold and snow showers or mild S,lys.

Thankfully though I have my sign that is suggesting the bitterly cold E,lys are on their way.

Agreed, is it true that models use the interpreation of the 'here and now' to indicate and generate forecasts down the line, if I'm right with that in mind all models will be better equipped to deal with winter blasts from the east in future. Especially as we have had 2 winters in a row differing much from the recent modern winters.

I think your sign is the split jet being hinted at the charts come Sunday allowing a subesequent easterly to build or maybe it's the fact I have had 26 different bird species in my suburban garden in Newbury. Of course then there are unusual number of bitterns about the country.

Ok, back to the models, put us out of our misery TEITS.

Sorry about the slightly OT post earlier GMG

STORMBOY

[nick sussex]

Agreed, is it true that models use the interpreation of the 'here and now' to indicate and generate forecasts down the line, if I'm right with that in mind all models will be better equipped to deal with winter blasts from the east in future. Especially as we have had 2 winters in a row differing much from the recent modern winters.

I think your sign is the split jet being hinted at the charts come Sunday allowing a subesequent easterly to build or maybe it's the fact I have had 26 different bird species in my suburban garden in Newbury. Of course then there are unusual number of bitterns about the country.

Ok, back to the models, put us out of our misery TEITS.

Sorry about the slightly OT post earlier GMG

STORMBOY

Yes spill the beans Dave and stop doing a Jordan by trying to court all this publicity! It better be good!

New ECM ensembles, the operational one of the warmest runs for days 8-10, quite a few colder members.

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

Edited January 13, 2010 by nick sussex

[TEITS]

Maybe a brief return to cold next week,briefly,then warmer again.

Or even cold next week, then briefly milder before turning colder again.

Have to say im finding the model output fasinating at the moment. I love watching these battles between the E & W.

[PB22]

ECM ensembles for Holland show the operational to be one of the warmest runs, along with the control:

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

[phil nw.]

I think these might be the updated ECM ensembles, correct me if Im wrong....

They have date 12/01/2010.

Still waiting but anytime now.

[Iceni]

Hi Eye, how confident are you that your secret sign is going to be right ? Come on give us a clue . Is it the Fieldfares , LOL . Regards Billy

Oi! that's my secret sign… find your own

[TEITS]

ECM ensembles for Holland show the operational to be one of the warmest runs, along with the control:

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

Wow that mean has dropped since the 0Z. Far fewer warmer runs compared to the 0Z.

http://www.knmi.nl/exp/pluim/vijftiendaagse/Data/15DAAGSE_06260_NWT.png

Only slight concern is the way the control follows the OP.

[phil nw.]

ECM ensembles for Holland show the operational to be one of the warmest runs, along with the control:

http://www.knmi.nl/e...M_06260_NWT.png

Mmm it runs pretty close to the mean until day 6 though Paul and even then there are a number of milder runs.

As it`s Holland as you know it may be different for us if the block remains too far East.

Let`s see what the ext.Ens. for London look like when they come out.

Edited January 13, 2010 by phil n.warks.

[Tim Bland]

In the more immediate term then is little discussion on Saturday. Fax charts suggest a possible snow even for the east (high ground at this stage) but would take much variation to make it more widespread?

http://www.wzkarten3.de/pics/brack3.gif

[bluearmy]

excellent 10 day ens. the question is - do we bin the 12z op on the back of these or is the development on this shortwave the type of thing the lower res ens wont pick up?? the 00z is eagerly awaited

nick - the meto have picked up on the possibilities re the T72 se wind ahead of the fronts. however, i think we will be the wrong side with temps +2 or +3c in the se plus the annoying fact that uppers are likely to be above 0c!!

Edited January 13, 2010 by bluearmy

[PB22]

The extended ECM ensembles have trended colder for Holland tonight:

http://www.weerplaza...im.asp?r=midden

I wonder what the London ones will show later?

Edited January 13, 2010 by Paul B

[LomondSnowstorm]

Wow that mean has dropped since the 0Z. Far fewer warmer runs compared to the 0Z.

http://www.knmi.nl/e...E_06260_NWT.png

Only slight concern is the way the control follows the OP.

Encouraging ensembles in general, and I think it's fair to say that it would be quite unusual if we didn't have at least a slight blip from the models - remember the ECM's 24 hour haywire period before the cold spell began in mid-December last year. Even then that was noted as being a fairly wobble-free model build up.

As long as your 'secret' is still there (please tell us!!) and the other models support this evolution I'm not too worried.

LS

[sandstorm2]

Certainly the anticyclone is not as intense on the 1200 run but still produces an easterly for a couple of days, the ECM looks like it is backing off from its cold runs tonight, but then I am falling into the trap of comparing the 0600 with the 1200. I will give the trend a couple of days to settle down before making a judgement on what is going to happen next week.

SS2

[weather eater]

Agreed, is it true that models use the interpreation of the 'here and now' to indicate and generate forecasts down the line, if I'm right with that in mind all models will be better equipped to deal with winter blasts from the east in future. Especially as we have had 2 winters in a row differing much from the recent modern winters.

STORMBOY

The Models are not learning programs they do not pattern match in any way, then are not programmed for the even larger teapot and they will not change to reflect how future winters pan out. They are programmed to simulate the climate and use numerical data to do this, air temperatures, sea temperatures, solar effects, etc. I'm sure you can find details on NW or elsewhere on the Internet.

[Candice]

On this image of Sundays UKMO chart

What is the significance of the black line that separates the blue isobars from the orange?

1013 is the delimiter between high and low pressure - I think

Edited January 13, 2010 by Candice

[MR EXTREMES]

The Models are not learning programs they do not pattern match in any way, then are not programmed for the even larger teapot and they will not change to reflect how future winters pan out. They are programmed to simulate the climate and use numerical data to do this, air temperatures, sea temperatures, solar effects, etc. I'm sure you can find details on NW or elsewhere on the Internet.

also remember its climate at the current time thats being programmed for what may happen in the near future,

so there for it could be that past influence are programmed aswell,

models id of thought are always lerning new trends all the time.

i will say im not convinced by a easterly its to messy but to see the ecm show that massive low pressure bashing into the eastern high,

i know who i would back the low pressure it seem the jet wants to party aswell.

if any cold come i think last week of january we need a shift in pv and southerly tracking jet and a nice sww event so end of jan early feb if nothing takes grip then i think the philip eden theory could well be correct

[sandstorm2]

I am amazed tonight at the number of members that are debating the models from +144 onwards, now I know that the model discussion is to discuss the variation in the models but these charts very rarely verify.

SS2

[snowingtequila]

also remember its climate at the current time thats being programmed for what may happen in the near future,

so there for it could be that past influence are programmed aswell,

models id of thought are always lerning new trends all the time.

i will say im not convinced by a easterly its to messy but to see the ecm show that massive low pressure bashing into the eastern high,

i know who i would back the low pressure it seem the jet wants to party aswell.

if any cold come i think last week of january we need a shift in pv and southerly tracking jet and a nice sww event so end of jan early feb if nothing takes grip then i think the philip eden theory could well be correct

No from my understanding they are numerical programmes that do not learn trends etc. I am sure they must be explained properly on this site somewhere

[Snowyowl9]

In the more immediate term then is little discussion on Saturday. Fax charts suggest a possible snow even for the east (high ground at this stage) but would take much variation to make it more widespread?

http://www.wzkarten3.de/pics/brack3.gif

There was some snow shown on the graphics for the east/west will be milder heavy rain saturday 9c was shown at the highest west.

I`m saying this because there needs to be a thaw here now ease things off,as that cold to the east

is not far away and could very easy come back with a scandi of that magnitude.

More likely hang onto the colder continental dryer air further east

that would be good for the CET to keep it low.

HP comes back in.

http://www.wzkarten3.de/pics/brack4.gif

Edited January 13, 2010 by Snowyowl9