General Model Output Discussion

[TEITS]

Another excellent run so far from the ECM.

However the perfect run in F.I would be to see a splitting of the PV with the HP moving to Greenland allowing another surge of bitter temps on the E flank.

Now im being greedy.

I will add that is seems amazing its only the 6th Jan!!

[Jason H]

Superb T168 chart. Low undercutting, up the channel she goes. The winter of 2009/10 goes on.

[snowmadchrisuk]

I'm scared chris!! i never want it to end!

168~+ is better than I thought it'd be.

It will end at some point , but there will likely be other cold snaps in Feb. This is already going to go down as one of the coldest winters in recent history . ECM and UKMO look pretty much the same to me at +144 and with the Scandi block and the Southerly jet I see no reason why that low won't keep to the South for the time being , it is when the Scandi block starts to weeken that we will then be looking at game over.

[Nath]

If that 168 came offv london would stop totally LOL

[cyclonic happiness]

azores high is sending a ridge up at 192, maybe another omega block for later in the month?

http://www.meteociel.fr/modeles/ecmwf.php?ech=192&mode=1&map=0

[AtlanticFlamethrower]

By T168-192 the cold uppers have gone so I'm guessing that the snow will be due to surface cold - even at the coasts.

Edited January 6, 2010 by AtlanticFlamethrower

[snowingtequila]

We could be finally beginning to see the models settling on the beginning of the end. More agreement to settle the High somewhere over Scandi which leads to an Atlantic attack.

Obviously this could lead to some serious snowfall but from past experience from these set-ups, in terms of the Atlantic coming back in, if the first one doesn't get you the second one probably will.

if the high does settle down in Scandi I think we may have a few days of some serious snowfall but then a breakdown, I would want to see a high develop near iceland to prevent this, maybe a ridge from the azores high? don't know of this is really likely. If not I think the end is coming into view even if it only temporary

[cyclonic happiness]

We could be finally beginning to see the models settling on the beginning of the end. More agreement to settle the High somewhere over Scandi which leads to an Atlantic attack.

Obviously this could lead to some serious snowfall but from past experience from these set-ups, in terms of the Atlantic coming back in, if the first one doesn't get you the second one probably will.

But then the azores high pumps our scandi high back up and re-inforces the block, so...cold all the way with a snow event in the middle, no mild breakdown from the ECM

http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=1&map=0

[Snowyowl9]

I hope you all get plenty of snow in the south/SE,more than enough here now.

http://www.wzkarten.de/pics/Recm1681.gif

A few dry very cold days now and severe frosts,then saturday onwards looks like more snow showers from the east.

http://www.wzkarten.de/pics/brack2.gif

Just want some wind to blow the snow off the roof a foot of snow now is getting heavy.

[Cecil Hogmanay Melchett]

We could be finally beginning to see the models settling on the beginning of the end. More agreement to settle the High somewhere over Scandi which leads to an Atlantic attack.

Obviously this could lead to some serious snowfall but from past experience from these set-ups, in terms of the Atlantic coming back in, if the first one doesn't get you the second one probably will.

Yes we are seeing signs that the Atlantic wants to smash the block.ECM pulls a rabbit out of the hat with the azores ridge.

we'll see.

[PubliusEnigma]

But then the azores high pumps our scandi high back up and re-inforces the block, so...cold all the way with a snow event in the middle, no mild breakdown from the ECM

http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=1&map=0

GFS seems pretty much determined to bring in the breakdown from T168 10 days out it looks like deck chairs in the garden weather if its to be believed ! . How accurate was the gfs with the breakdown over christmas when the last cold spell ended ?

[MR EXTREMES]

We could be finally beginning to see the models settling on the beginning of the end. More agreement to settle the High somewhere over Scandi which leads to an Atlantic attack.

Obviously this could lead to some serious snowfall but from past experience from these set-ups, in terms of the Atlantic coming back in, if the first one doesn't get you the second one probably will.

absolutely ian does indeed.

id be pretty sure now the breakdown for cold is coming next week infact im very sure ecm is wanting to hold on to the cold,

gh going on holiday and scandi block weakening perhapes a short snow spell for the south maybe 24/36 hours for the rest of the uk.

ecm has little support from other models and all models now picking up on mild breakdown in one form or another.

but still seen nothing like this since the 80s im happy.

[TEITS]

We could be finally beginning to see the models settling on the beginning of the end. More agreement to settle the High somewhere over Scandi which leads to an Atlantic attack.

Obviously this could lead to some serious snowfall but from past experience from these set-ups, in terms of the Atlantic coming back in, if the first one doesn't get you the second one probably will.

Strongly disagree.

First of all lets forget about recent experience because it means nothing all after our recent spell/weather pattern. Now if we look back at the classic winter synoptics of the olden days the 12Z ECM is showing similiar patterns. If the block remains strong like the ECM shows then subsequent low pressure systems track underneath. However the other option which isn't currently shown, but could be in future output, is with the LP systems tracking underneath there is the possibility of the HP moving back to Greenland. This was a common occurence during 1963 and especially 1947.

I see no sign of a breakdown in this cold spell. We need to forget about the our recent winters because this winter has proved the christmas pudding phase was nonsense.

P.S Not having a go at you by the way mate.

Edited January 6, 2010 by THE EYE IN THE SKY

[Bobby]

ECM goes for a channel low with major snow I would wager for southern Britain for early/mid next week.

I would agree that we could see the block holding and lows sliding underneath, I believe GlacierPoint also stated this was likely during Mid Month. So I think this ECM run is plausible.

Edited January 6, 2010 by Barb-

[Tom D]

This is an... odd looking chart

Edited January 6, 2010 by Tommyd1258

[Cheshire Freeze]

The thing that is stopping the retrogression from occuring is the Polar vortex reorganising itself and intensifying. This has the effect of tightening gradients and pulling the jet further north. We need the PV to be weaker or disorganise itself before we can think of retrogression IMO. This could still happen, but the way I see it at the moment is 40/60 favouring an Atlantic skirmish; maybe 50/50 if i'm feeling generous.

[MR EXTREMES]

Strongly disagree.

First of all lets forget about recent experience because it means nothing all after our recent spell/weather pattern. Now if we look back at the classic winter synoptics of the olden days the 12Z ECM is showing similiar patterns. If the block remains strong like the ECM shows then subsequent low pressure systems track underneath. However the other option which isn't currently shown, but could be in future output, is with the LP systems tracking underneath there is the possibility of the HP moving back to Greenland. This was a common occurence during 1963 and especially 1947.

I see no sign of a breakdown in this cold spell. We need to forget about the our recent winters because this winter has proved the christmas pudding phase was nonsense.

P.S Not having a go at you by the way mate.

ecm is really the only model that is trying to hold on to the cold,

and i agree its not been the norm type of winter with last winter to being fairly full of blocking to but unless all models agree on something similar to each other then id back a breakdown.

i also noticed alot of post regarding this weekend easterly being a downgrade this does not seem likely from what im seeing,

very confused though bbc south weather and meto warning of possibliy more prolonged snow on sunday here in the south,

i dont understand how?

:lol:

[Thundery wintry showers]

We could be finally beginning to see the models settling on the beginning of the end. More agreement to settle the High somewhere over Scandi which leads to an Atlantic attack.

Obviously this could lead to some serious snowfall but from past experience from these set-ups, in terms of the Atlantic coming back in, if the first one doesn't get you the second one probably will.

I agree, but it's also worth mentioning that if the jet stays well south then any Atlantic return could end up being temporary, or struggling to penetrate beyond the south before cold air sinks back down again, as happened repeatedly during the winter of 1978/79, and also occurred as recently as this December just gone (Atlantic return for Boxing Day).

Alternatively of course the Atlantic could power the block away and bring in westerlies- but it does raise the question, is this impending possible breakdown (out at T+240 for starters!) likely to be the end of the cold spell or just a temporary milder interlude? It needs to get a lot closer to the reliable timeframe before we can be sure.

[cooling climate]

Once again cracking charts in the fairly reliable time frame out to t144. I say 144 because they are all

(the big three) finally singing from the same hymn sheet.

A fantastic weeks weather to come for winter weather lovers and even though I should be getting use

to them by now I still find myself staring at the synoptics charts half disbelieving what I am seeing.

[Duncan McAlister]

Would the uppers at +168 support snow or would it be more sleety/rainy at this stage?

[swilliam]

But then the azores high pumps our scandi high back up and re-inforces the block, so...cold all the way with a snow event in the middle, no mild breakdown from the ECM

http://www.meteociel...40&mode=1&map=0

Indeed and it is remarkable (synoptically) how similar the ECM240 chart is to the UKMO60.

It is like the block goes off for a wander round the N.Atlantic/Scandi region and then comes back to where it was.

[Wayneywoo]

If GP is correct then the ECM is the most likely but even then not quite right?

Quote, "What this means is that the sub-tropical jet is going to become re-charged leaving little flow to the north allowing a re-emergence of the blocking structures between Greenland and Iceland around 12-14th January."

This copied from the In Depth / Technical Thread.

Interesting times!

[bluearmy]

ecm is really the only model that is trying to hold on to the cold,

and i agree its not been the norm type of winter with last winter to being fairly full of blocking to but unless all models agree on something similar to each other then id back a breakdown.

i also noticed alot of post regarding this weekend easterly being a downgrade this does not seem likely from what im seeing,

very confused though bbc south weather and meto warning of possibliy more prolonged snow on sunday here in the south,

i dont understand how?

sorry badboy - which other model looks like it gets rid of the cold? UKMO and GEM T144 runs from 12z look similar to ecm. GEM 00z which runs to T240 wasnt convincing in removing the cold - its D10 chart would still be cold. only GFS goes to T240 more than once a day as per ECM so i presume you are talking about ECM v GFS. i think you'll be in a monrity on here if you're backing GFS low resolution against ecm.

[Altostratus]

A good run from the ECM. A nice settled spell of weather after the deep snow cover would help to get some very low minima. The channel low shown at 144-192hrs will undoubtdely bring milder air into the mix. It will certainly be marginal for snow in the south. It is a risk worth taking however - historically, the heaviest snowfalls have come from similar situations in the past. It is far from an ideal channel low, but if it brought snow I don't think anyone would care.

Edited January 6, 2010 by Altostratus

[MR EXTREMES]

ECM goes for a channel low with major snow I would wager for southern Britain for early/mid next week.

I would agree that we could see the block holding and lows sliding underneath, I believe GlacierPoint also stated this was likely during Mid Month. So I think this ECM run is plausible.

i crewecold hit the nail on the head,

the pv is looking like ruining the party,

and i think gp will most likely would agree that snow event mid month is likely.

but most likely agree also the turning point from our current cold,

progressing to a mild febuary.