Model Output Discussion - 30th November onwards

[Cheshire Freeze]

I spot -16 uppers creeping into northern Texas....

 

Yep, this really isn't a bad hemispheric pattern

 

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013120112/ECH1-240.GIF?01-0

 

So then, close but not quite- however working in the right direction- 

 

 

All in all satisfied with tonights outputs V prediction- PLENTY of time for that high to be further North rather like the UKMO projection.

 

S

[Snowman.]

I spot -16 uppers creeping into northern Texas....

 

AO must be dropping like a stone by that point.

[Gaz1985]

Perhaps Greece is a place coldies may want to go? 

 

 

Ends with the UK under mildish uppers, very cold across East and South East Europe.

 

[stodge]

indeed I agree very robust looking high and placement is very important as nick says there is low heights dropping into the alantic and at 240 ecm I could stand corrected by a scandi high.

 

but it does look to be going into south east Europe which is not an ideal location.

 

http://www.meteociel.fr/modeles/ecmwf/runs/2013120112/ECM1-240.GIF

 

Or perhaps not given the continuing LP over Greece and Turkey.

 

An excellent chart for cold fans in the SE with a continental drift setting in and a very real prospect of fog. Whither then the HP - into Scandinavia (perhaps, perhaps not ?). I suspect we could still see the centre over Denmark or North Germany were there a T +264 on this model. That would be sufficient (with the right orientation) to advect colder air into southern Britain

[shotski]

Fantastic t-240 chart from the 12z ECM tonight, full of potential, get in there  

[Jason M]

well I stand correct the ecm 240 as steve suggested is epic

There is huge uncertainty at the moment at day 5 and 6 and therefore there is no point getting hung up on the opps in isolation. Wait for the ensemble groupings.Overall the outputs are pretty decent tonight considering its 1st December. Edited December 1, 2013 by Jason M

[shedhead]

ECM pretty much franks the 48 day cold spell for most, perhaps 60hrs in the far NE and 36hrs in the SW. Thereafter I'd suggest pretty decent agreement, with HP over Europe developing firstly 'milder' S flow and eventually a mild SW'erly during the 2nd week of Dec. The danger now is the 48hr cold spell shortens even further across the next 4 to 6 runs, but as things stand all of us look set to feel the first cold blast of Winter on Friday, with some of the white stuff also possible in the north...at least for now.

 

With all this talk of cold it's easy to forget the main Scottish barbecue season starts on the 10th?

 

[Mucka]

This is how we want ECM to progress tomorrow.

 

[BLAST FROM THE PAST]

So Hot and sunny in summer, bitterly cold and snowy in winter....I want eastern Med and southern Italy climate please...

 

 

 

 

BFTP

[Ian Brown]

ECM pretty much franks the 48 day cold spell for most, perhaps 60hrs in the far NE and 36hrs in the SW. Thereafter I'd suggest pretty decent agreement, with HP over Europe developing firstly 'milder' S flow and eventually a mild SW'erly during the 2nd week of Dec. The danger now is the 48hr cold spell shortens even further across the next 4 to 6 runs, but as things stand all of us look set to feel the first cold blast of Winter on Friday, with some of the white stuff also possible in the north...at least for now.

 

With all this talk of cold it's easy to forget the main Scottish barbecue season starts on the 10th?

 

Yes essentially fits in with what Ian F said earlier of an essentially anti-cyclonic pattern with the Atlantic effecting the far NW at times, whether we can avoid some very mild weather on the whole will be dependent on the HP centre not slipping South.

So Hot and sunny in summer, bitterly cold and snowy in winter....I want eastern Med and southern Italy climate please...

 

 

 

 

BFTP

 

Yes, like some of the early 00s winters with potentially a lot of snow for Greece and Turkey.

[Iceaxecrampon]

Great chart this

In July 

Bin....

[Cheshire Freeze]

Remember-

 

•  Circular, monostrength PV= Raging +AO/NAO= poor set up for hopes of cold.

 

•  Distorted, stretched PV with amplified jet and ridges/WAA across the N hemisphere= neutral or Negative AO and potential -NAO at times.

 

I don't see any of the first option on offer this evening which has to be a plus.

Edited December 1, 2013 by CreweCold

[pip22]

What is the forecast for the NAO? Is it going to be a negative or a positive in the next few weeks?

[Catacol]

Away for a day - over 800 users online, and page upon page of skim reading required. You can always tell when winter is in full swing on NetW - come here in the summer and we barely get to a new page each day!

 

Fascinating watching this uncertain scandy evolution develop. I'm still in the camp that thinks it will not quite make it, but for those that saw my post of a day or so ago showing wave 1 warming slap bang over the uk, what we are now beginning to see is the models wrestle with this data. The warming at the top of the atmosphere will propagate downwards thus by day 9

 

 

Zonal winds at the moment are here - notice around 30m/s around 60N in the middle strat

 

 

dropping to around 20 m/s at the same latitude by day 9

 

 

Remember that the warming is in our sector of the NH, so this reduction of zonal winds is likely to be most exaggerated over the uk

 

Vortex impact? Some very interesting images today at day 9 once again. First at 100hPa - almost into the troposphere:

 

 

Notice how the main heart of the vortex has been shoved over to Canada but the centre of the vortex is elongated and under stress from the wave 1 energy highlighted before. This leads to this 24 hours later, once again at 100hPa

 

 

Not quite a vortex split, but a definite separation of sorts and as we have seen recently a marked meridional pattern. Higher up at 30 hPa in 10 days time, the same strat support for height rises in our part of the world:

 

 

Note here the warming is a little further to the east, but helping to drive zonal winds away from the scandy sector in the days following this image - or so I would guess.

 

Conclusion? Scandy height rises look on the cards following the cold shot coming - the evidence was there a day or so ago - but just how great that ridging will be is uncertain. However if energy at the heart of the vortex is separated at 100hPa as on that 10 day chart then chances increase all the time. Not enough to convince me yet, but enough for a definite loading of the dice towards that possible solution. One thing I dont think it will be is a return to zonal at all. Another period of uk high with stagnant dross is my best guess but I would put proper scandy height rises into second place with zonal atlantic very much third.

 

For all strat doubters note again that the energy that has kicked this off was a wave 1 warming forecast at 1hPa and propagating downwards. No disconnect here - once again,.

Edited December 1, 2013 by Catacol_Highlander

[Sweatyman]

Greece bathing in -8 to -10 uppers.happens all the time does my head in jammy sods

 

[SW Saltire]

Whether people on here admit it or not after a very brief colder spell thurs - sat we are looking at a period of 2weeks before any sustained cold may set up. Imo its a case of come back in two weeks to see if our prospects have improved.

Well, if you have been following the forum recently and not the express then this should have been obvious. Nobody has suggested HLB on this forum in the near future. Only recently have some knowledgeable members such as BA and Nick Sussex et all noticed the idea of a Scandi high gaining support. Therefore, we are doing quite well with regards tocold with a not that favourable a pattern at present. Cold northerly shots will keep the lions at bay while the larger picture is shaping up nicely with the continent forecast to cool significantly. The fact that the polar vortex is not dominating our weather at present is rather encouraging and has been a theme for the past 5 or so winters Edited December 1, 2013 by SW Saltire

[Paul]

At this rate there are going to be several people stopped from posting in here this evening... Please moderate yourselves before it comes to that - posts which have nothing to do with the models, point scoring, accusing people of trolling just because they have a different opinion to you, and posts designed to disrupt rather than add positively to the discussion are all the sorts of things that people need to stop themselves posting...

[Catacol]

... and as an extra. I dont like this GFS strat chart on Meteo so well - but it does go out much further. Right up to 384 we have a signal for continued warming over the Euro sector

 

 

 

If this comes off then it is possible the pattern may be supported by strat signals for a good 10 days or more. So a Scandy high evolution might be there for a while. That would be interesting.. wouldnt it? Mind you - bear in mind this is a GFS strat forecast at a million miles away - but strat forecasts are usually a bit more accurate than trop ones... and it only needs be a trend to keep the vortex buckled away from our sector to allow height rises to be maintained.

[Frosty.]

Ecm 12z op run is still looking very wintry later in the week with snow showers, N'ly gales and severe frosts, the ecm might be a bit quick killing the n'ly on saturday, it could be a 3 day Arctic blast, coldies should be happy with what the ecm is showing and what darren bett just showed on this evening's weather, areas exposed to the full force of this blast will have drifting snow. Nice end to the 12z with no sign of the atlantic coming back, indeed the blocking signal strengthens with a chance of european cold on the way as we go deeper into December...GOOD RUN.

[SW Saltire]

Away for a day - over 800 users online, and page upon page of skim reading required. You can always tell when winter is in full swing on NetW - come here in the summer and we barely get to a new

page each day!

 

Fascinating watching this uncertain scandy evolution develop. I'm still in the camp that thinks it will not quite

make it, but for those that

saw my post of a day or so ago showing wave 1 warming slap bang over the uk, what we are now beginning to see is the models wrestle with this

data. The warming at the top

of the atmosphere will propagate downwards thus by day 9

 

 

Zonal winds at the moment are here - notice around 30m/s around 60N in the middle strat

 

 

dropping to around 20 m/s at

the same latitude by day 9

 

 

Remember that the warming

is in our sector of the NH, so this reduction of zonal winds is likely to be most exaggerated over the uk

 

Vortex impact? Some very

interesting images today at

day 9 once again. First at 100hPa - almost into the troposphere:

 

http://users.met.fu-

berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf100f240.gif

Not quite a vortex split, but a

definite separation of sorts and as we have seen recently a marked meridional pattern. Higher up at 30 hPa in 10 days time, the same strat support for height rises

in our part of the world:

 

 

Note here the warming is a little further to the east, but helping to drive zonal winds away from the scandy sector in the days following this image - or so I would guess.

 

Conclusion? Scandy height rises look on the cards following the cold shot

coming - the evidence was

there a day or so ago - but just how great that ridging will be is uncertain. However if energy at the heart of the vortex is separated at 100hPa as on that 10 day

chart then chances increase all the time. Not enough to convince me yet, but enough for a definite loading of the dice towards that possible solution. One thing I dont think it will be is a return to

zonal at all. Another period of uk high with stagnant dross is my best guess but I would put proper scandy height rises into second place with zonal atlantic very much third.

 

For all strat doubters note again that the energy that has kicked this off was a wave 1 warming forecast at 1hPa and propagating downwards. No disconnect

here - once again,.

Fantastic post, very informative. It would lend itself to more drama in here as you point out that the effect of this warming will be exaggerated over the UK and thus, eye candy should start to appear on the NWP although this does not mean it will verify!

[Grimsby Snow Lover]

What is the forecast for the NAO? Is it going to be a negative or a positive in the next few weeks?

Going by this I would say there is 50-50 chance of it going negative or positive.On closer inspection perhaps more of a negative NAO as we head into the first full week of Decemberhttp://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif Edited December 1, 2013 by Grimsby Snow Lover

[Team Jo]

So! For those who don't believe in Santa/this week's northerly and wish to discuss, here's a good place to be: http://forum.netweather.tv/topic/76235-model-banter-moans-and-ramps/

 

 

For those that want to know if it will snow in the teaspoon in their back garden... here's a link to the regionals... http://forum.netweather.tv/forum/142-regional-discussions/

 

 

For all other keyboard warriors, I'd suggest you either sit on your hands or try and think before you type - this isn't somewhere that one-upmanship and personal insults are accepted. Just because the Models aren't showing you what you want, doesn't mean you can behave like a chump. And if you do, the you probably won't find your posts (or memberships) to this site sticking around.

 

Much Love!

 

Jo

[Catacol]

Fantastic post, very informative. It would lend itself to more drama in here as you point out that the effect of this warming will be exaggerated over the UK and thus, eye candy should start to appear on the NWP although this does not mean it will verify!

 

Yes - the models will toss up varied solutions I think over the coming days, but all pointing to height rises. I would emphasise though that even with zonal winds falling and warming helping drive the vortex away from uk/scandy sector we are still not anywhere close to the kind of strat conditions where zonal winds die right down and sometimes reverse - leading to all kinds of high lat blocking and easterly flow. The overall pattern would still suggest that it will be hard for a scandy ridge to evolve far enough north to bring a proper easterly to the UK... BUT this winter has been a very interesting one already - and its only 1 day old - and maybe... just maybe the constant ridging that has been evident over the aleutians and over the atlantic/uk is a sign of something this winter that might just give us something special early on.

 

Further on the optimistic side zonal winds will decrease naturally through Jan/Feb and if the blocking signal can be maintained then it will increasingly build further to the north. Plenty to look forward to even if we dont quite manage more than short lived blasts in December.

 

And the blast coming this next weekend is certainly looking like a special one! Another bit of evidence pointing to this winter being anything but ordinary. Perhaps winter 2013/14 will become known as the one where composite analgues didnt quite cut the mustard!

Edited December 1, 2013 by Catacol_Highlander

[Paul]

I think it's a brave person who forecasts anything with any confidence for this weekend, let alone beyond from a from run to run, across the models and between the ensemble suites there's such a range of possible solutions being shown. It's probably one of the most used phrases in here over the years, but it's a good one - more runs are needed...