Winter Model Discussion - The Hunt For Cold - 12th Dec

[bluearmy]

please lets not start examining stewarts posts from last week. 'he's not the messiah, he's a very naughty boy'! the models changed and so to did the solution. a few hundred miles north which is a nats globally but very relevant for nw europe. anyway, the gfs op as it hits low res is almost laughable. the atlantic trough drives east before it receives a boost from the shortwave behind the ridging. even in this low res mess, my thoughts from this morning re the tumbling vortex are evident. still a long shot but almost becoming plausible (though remaining v unlikely).

[Buriedundersnow]

his posts related to when the pv moves to siberia which it is in the process of doing so realistically his thoughts still stand till after then till we see if it is hit or miss and with getting upgrades in that part of the model we should keep our eyes on there.

[Paul]

Ok, can we keep it to the model output now please, going back over old posts for crumbs of cold comfort isn't relevant in this thread.

[Frosty.]

As phil said, the siberian high won't last much longer, if anyone looked at the gefs 6z mean I posted earlier, it shows the russian high disappearing off the charts by T+384 hours. What does this mean for the uk?..well it means it is going to become much milder, almost springlike for parts of the south and southwest with temps of 12c but a bit cooler for northern britain and the scottish mountains may hold on to a wet slushy snow cover. There is a chance of cooler cyclonic weather further into FI but only cold enough for snow on northern hills and mountains, also, very little in the way of frost after tonight.

[snow drift]

T144 Look at the differences to NW. UKMO has not been great at this range but looks a little more interesting than GFS.

Edited December 12, 2012 by snow drift

[Panayiotis]

As phil said, the siberian high won't last much longer, if anyone looked at the gefs 6z mean I posted earlier, it shows the russian high disappearing off the charts by T+384 hours. What does this mean for the uk?..well it means it is going to become much milder, almost springlike for parts of the south and southwest with temps of 12c but a bit cooler for northern britain and the scottish mountains may hold on to a wet slushy snow cover. There is a chance of cooler cyclonic weather further into FI but only cold enough for snow on northern hills and mountains, also, very little in the way of frost after tonight.

I agree the Russian high will disappear over the coming week(s) but stating that it will be gone at 384hrs isnt really accurate because we never know what will happen in Fi, for all we know, it may be back! Edited December 12, 2012 by panayiotis

[snow drift]

I agree the Russian high will disappear over the coming week(s) but stating that it will be gone at 384hrs isnt really accurate because we never know what will happen in Fi for all we know, it may be back!

He stated that it was gone from the charts on GFS at t384.

[Weathizard]

Think although we may have to suffer for a while why the Siberian high finally pulls back, in the long run and going into January I think its much better, don't get me wrong I love siberian blocks, the shear strength of it and size is something to behold and quite rare indeed, however for cold on our shores I think we are better off letting the Atlantic steam through and use all its energy and take the chance when it comes to ridge high pressure into Greenland/Svaalbard. I'm more positive than i was this morning anyway because really in the broad scheme of things its only the weather and we can't control it so let's just see what it throws up, and we are only 12 days into winter proper.

What will be will be!

[Buriedundersnow]

T144 Look at the differences to NW. UKMO has not been great at this range but looks a little more interesting than GFS.

hopefully they upgrades can keep coming as if we get a greenland high form if part of the pv is predicted to come this way might this force it towards us like in winter 10/11

oooops just noticed one of them is the UKMO lol thought they were both GFS just different runs lol

Edited December 12, 2012 by Buriedundersnow

[Panayiotis]

He stated that it was gone from the charts on GFS at t384.

Ye I understood what he was saying but at 384hrs we dont really know what is going to happen.

[Matty M]

192hr GFS EPS Mean shows us stuck in a rut.

Notables include Development of Iberian/Southern Europe High. Low pressure to our west.

Notable is a lack of amplification in the flow to our west which is necessary to enhance Northern latitude blocking.

It looks a strong pattern and models have been rock solid of late in the medium term. 7-10 days in this set up would appear likely.

[Frosty.]

I agree the Russian high will disappear over the coming week(s) but stating that it will be gone at 384hrs isnt really accurate because we never know what will happen in Fi, for all we know, it may be back!

If it does come back, I hope it gets a bit closer next time, the mean is a very good guide though and it shows the high getting further and further away. We will now have to look west or southwest because that is where our weather will be coming from in the next few weeks, mild or very mild at times but sometimes cooler and cyclonic, but no sign of cold after tomorrow.

[nick sussex]

T144 Look at the differences to NW. UKMO has not been great at this range but looks a little more interesting than GFS.

Yes subtle but important differences between the GFS/UKMO a bit more energy going se in the latter with the Azores high flatter.

The UKMO looks to be developing a shortwave on the southern flank of the trough. The GFS not to mince my words is a horror show for cold lovers!

I'd be inclined to put the GFS 12hrs as an outlier solution given the rest of the output so far this evening, especially as its showed poor continuity upstream over recent days.

Edited December 12, 2012 by nick sussex

[Frosty.]

Normally there would be nearly 700 viewing the 12z aftermath, just shows how the models have flopped with the cold outlook and now showing average to mild instead, it looks locked in until christmas or beyond to be honest.

[The Eagle]

I really don't think we are as far away as some are suggesting. We will maintain a generous area of high pressure over western Russia into eastern Europe for the forseeable future. The jet stream is not playing ball right now but just as this week's "event" evaporated very quickly last week the same can just as easily happen again the other way around. These charts will change a lot over the next few days I think.

Look at this chart. This is 120hrs. This is really not that bad. It's not far away from what we want to see at all.

Edited December 12, 2012 by The Eagle

[Panayiotis]

If it does come back, I hope it gets a bit closer next time, the mean is a very good guide though and it shows the high getting further and further away. We will now have to look west or southwest because that is where our weather will be coming from in the next few weeks, mild or very mild at times but sometimes cooler and cyclonic, but no sign of cold after tomorrow.

Yes I agree that we will have weather from the W/SW but i dont agree that it will be for the next few weeks, but for the next few days/week, this is a chart for next week, if the low to the east of America moves south it will be able to move the pressure more into Greenland and therefore we will be in more colder conditions.

http://cdn.nwstatic.co.uk/gfsimages/gfs.20121212/12/165/h500slp.png

[Dean E]

It seems to me past +162, the GFS has gone default once again. Something its famous for doing when its having trouble in the longer term...

Jet stream not so much amplified compared to recent days, but from the 500hpa, that troublesome Low centered in the Atlantic is still there with a rather impressive Azores High.

All seems pretty default from the GFS in the Medium to long term for now. A clear sign its having trouble.

SM

Edited December 12, 2012 by SnowMania

[Buriedundersnow]

i dont get this place evryone was saying how we need a greenland high for extended cold and now the gfs is showing height rises around greenland and with further upgrades a link to scandi and now nobody wants know

[Kentish Snowman in Yorks]

I fail to see how we will have to look west or south west for our weather for the next few weeks when only last week T72 was being described as FI.

Yes we may have a week or so of 'zonal' type conditions to come but there is enough interest in the charts at present to make any medium term weather prediction very brave indeed.

[nick sussex]

GEFS spreads:

Decent cluster of solutions taking energy se, the GFS operational takes this ne.

The mean value can look quite skewed in this set up, the GEFS is basically split with where to take the energy.

If the ECM continues its trend from this morning then expect it to say no to the GFS horror show, thats not to say we're going to see some great output but certainly better than what the GFS dished up!

[Timmytour]

The GFS 12z is bringing us a mild and blowy Christmas Day. But let's not forget just over a week ago..... in a shorter time-frame.... it was giving us narnia for this friday coming.

I know I keep saying it, and i know all the signs seem to point against it, but I think a dramatic shift in the models is coming with the East more influential than shown in recent runs ( though not to the degree shown a week ago)

The 18z may be the pub run, but to me it's the first one to bring in a run that becomes a trend. I really think this evening's one is going to be the one that turns the tide. This is 1979 all over again with reports of the Easterly's demise being greatly exaggerated

Edited December 12, 2012 by Timmytour

[mulzy]

THe GFS Operational is a horror show and the GEFS ensembles are not great (albeit the usual wide scatter does occur in FI). Another concern is the PV potentially slipping back towards Greenland.

http://modeles.meteo...21-1-360.png?12

Disappointing output.

Edited December 12, 2012 by mulzy

[East_England_Stormchaser91]

I reckon january will have better opportunities for cold tbh. Remember, most substantial snowfalls have came well into january and february in the past. December is normally a wet and windy month anyway and when the jet is generally most active too. Let's have some patience folks, stuff could materialise pretty soon I reckon. It only takes one slight change in pattern to change everything !

[Kentish Snowman in Yorks]

The GFS 12z is bringing us a mild and blowy Christmas Day. But let's not forget just over a week ago..... in a shorter time-frame.... it was giving us narnia for this friday coming.

I know I keep saying it, and i know all the signs seem to point against it, but I think a dramatic shift in the models is coming with the East more influential than shown in recent runs ( though not to the degree shown a week ago)

The 18z may be the pub run, but to me it's the first one to bring in a run that becomes a trend. I really think this evening's one is going to be the one that turns the tide. This is 1979 all over again with reports of the Easterly's demise being greatly exaggerated

That's the spirit! The troops will be rallied now!

Azores High...Icelandic Low...Gulf Stream...Zonal Express...your boys are going to take one hell of a beating!

Now i'm just off to go and find a straw to clutch...

[Isolated Frost]

Stormy and wet- especially in Scotland and Northern Ireland- with temps close to the seasonal average, and the chance of wintriness in sub-516 air in the highland peaks for Saturday evening.