General Model Output Discussion

[TEITS]

Only just got round to looking at the models and bloody hell some are a peach. During yesterdays output there was the hint of the ultimate block developing and this is even more so on tonights ECM.

You may wonder what im referring to when I say the ultimate block. Well this is an extremely rare set up and has only been seen on a few occasions. What im referring to is the link between the Greenland HP and the Siberian HP. At first I thought beyond the S,ly tracking LP would be a spell of N/NE,lys courtesey of the Greenland HP. However im now beginning to wonder whether a monster from the E is going to appear!

Back to this LP and I see the UKMO is being a pain although to be honest beyond +144 the synoptics look fantastic. The main problem with the UKMO is it would delay the cold arriving. Looking at the models around +96 to +120 and there is good agreement that a SW will split off the main LP and track E. However I still think some of the models have this too far N. I would put the N limit of the precip being around Lincs although I wouldn't be surprised if this is pushed further S.

Looking forward to the 18Z.

[Snowaddict]

It doesn't get much better than the latest updated De Bilt Ensembles...

Control Run is a little less cold for a time into FI but this correlates with a significant snowfall before temperatures drop well back thereafter..

Just look at that Ensemble Mean:

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

[Glacier Point]

Happy Christmas !

Not sure about any easterly event. Both GFS and GEM H5 mean height anomalies days 11-15 depict height rises across Greenland to Siberia, but the strength of the projected height anomaly across Greenland is massive and should ensure a more northerly flow dropping a trough into Scandinavia.

http://raleighwx.easternuswx.com/models/gfsensemble/12zENS11-15day500mbHeightAnomalyNH.gif

http://raleighwx.easternuswx.com/models/cmcensemble/12zCMCENS11-15day500mbHeightAnomalyNH.gif

We look to be heading into January with the Global Wind Oscillation centred around phase 7 which corresponds to the mean ridge centred towards the location projected by GFS and GEM ensemble means. For a sustained period, the GWO will alternate the focus of this ridge backwards and forwards across the North Atlantic from Iceland to the Canadian Arctic.

[TEITS]

Happy Christmas !

Not sure about any easterly event. Both GFS and GEM H5 mean height anomalies days 11-15 depict height rises across Greenland to Siberia, but the strength of the projected height anomaly across Greenland is massive and should ensure a more northerly flow dropping a trough into Scandinavia.

You know what im like GP, obsessed with E,lys.

I see the updated AO ensembles go off the scale once again!

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

[AtlanticFlamethrower]

Can anyone tell me the reason the snow doesn't appear to make it to my area? Is it due to the 850's or is it just unfavourable location in such a setup?

Slough is too far inland from many points - North/South/East/West for showers to be a consistent snow giver.

That's like my region - it's too far south for Northerly and North Easterly showers which burn out over Suffolk and North Essex. Obviously too far East for Westerlies. You don't really get southerly showers. My region is only favourable for ESE showers and when that happens it needs to be cold enough for the snow to settle, which often it is not. Being inland you have the advantage over where I live in colder temps but disadvantage of less showery PPN.

We both need to look out for frontal PPN that sweeps across the country, and we need it cold enough so that PPN falls as snow. You can't miss frontal snow except by bad luck which could affect any region. Frontal snow could come from the North or from the South - the latter in battleground scenarios where maritime low pressure crashes into embedded continental cold spilling over NW Europe.

Edited December 25, 2009 by AtlanticFlamethrower

[Cloud 10]

gfs 18z +72 ukmo+72

Big difference between the gfs and ukmo at +72,the 18z looks to be another cracker (touch wood)

Edited December 25, 2009 by Cloud 10

[Costa Del Fal]

Not sure about the Tues/Wed/Thurs event for here on the 18z. Still takes it a bit too far North imo.

Edited December 25, 2009 by Blizzards

[AtlanticFlamethrower]

koldweather said yesterday the models could be dodgy today because they will not be using all their data. 18z is a dodgy run at the best of times, right?

[Costa Del Fal]

koldweather said yesterday the models could be dodgy today because they will not be using all their data. 18z is a dodgy run at the best of times, right?

Indeed, todays runs should certainly be taken as a pinch of salt!

[SMU]

Lets hope so- as the 18z is identical to the UKMO 12z-

Model watching over for me today- back tomorrow with a fresh set of runs..

Steve

[Geordiesnow]

Not sure about the Tues/Wed/Thurs event for here on the 18z. Still takes it a bit too far North imo.

Yep, it takes the milder air further northwards still, no doubt we might have a few toys in the pram posts coming up.

Rule out the UKMO at your peril! It goes to show what a few miles differences can make too our weather.

[peterf]

Indeed, todays runs should certainly be taken as a pinch of salt!

aye everyone is having a lazy day lol.

[Costa Del Fal]

Yep, it takes the milder air further northwards still, no doubt we might have a few toys in the pram posts coming up.

Rule out the UKMO at your peril! It goes to show what a few miles differences can make too our weather.

Yep the 18z is even worse. I shall see what its like over the next few days.

[J10]

Not sure about the Tues/Wed/Thurs event for here on the 18z. Still takes it a bit too far North imo.

GFS seems further north compared to the 12Hz run.

[Stu_London]

18z means next week event is a scotland only event.

General pattern in tact however with everyone get a shot of cold afterwards.

[swfc]

gfs heading towards ukmo in the early part of this run.Very confusing runs today :whistling:Still looks good tho for up here.

Edited December 25, 2009 by swfc

[bluearmy]

Lets hope so- as the 18z is identical to the UKMO 12z-

Model watching over for me today- back tomorrow with a fresh set of runs..

Steve

bet ya sneak back for a look at the FAXES .........................

[Costa Del Fal]

GFS seems further north compared to the 12Hz run.

I hope this doesnt become a trend as this would have been quite an event. I wonder if this will continue or will the charts revert back to runs like the 6z.

[rbw]

Yes, definately not looking good for England and Wales, but I must admit I would rather that than miss the snow by 3 miles as I did over the last week !

R

[Geordiesnow]

I think the 18Z will get there eventually regarding the cold but i still prefer if it has the low that bit further south like the ecm and previous GFS runs have been showing.

Be interesting where the op runs fits in with the ensembles and it does show how it can all change in one run. Which is why i am not too worried as of yet.

[Barb]

18z is totally different to previous GFS runs. Everything is like 250 miles further North, pretty big jump in 6 hours. Will be interesting to see ensembles.

[rbw]

Starts to look more interesting by 31st but that's too far away and I worry that there might be warm sectors in there

R

[SMU]

Id actually take the 18z anyway- inline with the UKMo means warmer to start with- but better potential with the Easterlies later- ( I think I mentioned that earlier..)

Ah well- what will be will be...

Not interested in the fax charts now- just because they are modified to suit a model doesnt mean to say they are right- wait for the T24 + 36 fax...

ngt

Steve

Edited December 25, 2009 by Steve Murr

[Hammer]

Xmas and Boxing Day model runs will be all over place. Talk about great timing for this cold spell. Let's see who calls it right Sunday night.

[swfc]

Struggling to understand some posts again tonight.???.Greenland high virtually nailed on,jet going south and a very cold outlook.What people are looking for or expecting is beyond me.Its one run again.