Model Output Discussion

[kent]

The charts from my learning eye do not suggest a return to colder weather outside of FI. As for some people around the forums comparing this winter to 62-63 is laughable. Being 65 years of age I can remember driving around in tunnels of snow. A lot of the pavements disappeared simply because there was no where else for the snow ploughs to put the snow. And I am referring to my own location in Poole Dorset where until now Ive seen the sum total of 1cm of snow. So from my own particular point of view this winter so far has been colder and snowier as of late but certainly not memorable.

[MR EXTREMES]

if you take into consideration the chaos theory and the order theory then its certain cold will be back before winters end.

the models are messy they where like this in november i got agree with gp that the likely hood of febuary being warmer is very high indeed.

but as some have suggested there is ssw event neg ao,

but positive nao so its 50/50 now.

and i could well be wrong thinking end of jan being the turning point for cold to come back,

nino is the likely cause to the shift from cold to milder.

but still been a cracking winter im very happy and perhapes winter is over posts might be valid now.

but always a chance of arctic stuff as depressions pass over and when they come they will be very cold and possibly very snowy.

infact now i would like a cold blast from the north rather than the east.

its clear that all the models are going for the alantic domination and i really think the block to the east will be blasted away.

perhapes a blast of winter end of feb.

Edited January 15, 2010 by badboy657

[stewfox]

Morning CC, I think your post sums up, exactly why we get days like yesterday, full of people getting the nark with one another. The models have really not been back and forth with anything; in fact I would suggest that they have been very consistent with the general pattern. Yes a few runs have tried to establish a meaningful easterly, but the general trend has been for an initial Atlantic incursion, followed by a brief period of influence by the Siberian high and then a return to a normal UK westerly based regime. I would say about an 80/20 split in favour of that evolution, I do often wonder if some members are looking at model runs in an alternative universe from the one I live in.

I have to agree here.

Charts 'struggling' and ebbing and flowing is a bit of a wishful thinking for cold rampers.

Reference to the Siberian High seems to suggest its 'a new phenomena this winter'.

I guess one thing we do have is that cold pool intensifying in the next few days to our East e.g. -6c max fore cast for Berlin next Wednesday.

The 'battle ground' however if there is one isn't over the uk, I don't think you can say the models are 'struggling' to bring that colder air 200/300 miles further west. There not suggesting at present it will be bought west ?.

Of course further runs could change that.

[Timmytour]

The charts from my learning eye do not suggest a return to colder weather outside of FI. As for some people around the forums comparing this winter to 62-63 is laughable. Being 65 years of age I can remember driving around in tunnels of snow. A lot of the pavements disappeared simply because there was no where else for the snow ploughs to put the snow. And I am referring to my own location in Poole Dorset where until now Ive seen the sum total of 1cm of snow. So from my own particular point of view this winter so far has been colder and snowier as of late but certainly not memorable.

A lot to agree with here. What makes this winter memorable for me is the comparison with so many recent winters. Only last year i was reminiscing about how the lakes i see on my train into work used to freeze over regularly but I couldn't remember seeing them do so for a long time. Until this year!

Actually I wouldn't compare this winter so much with 1962/63 as with 1961/62. I've a feeling, that I appreciate might emanate from hope alone, that the cycle of mild winters has passed. I think preceding 1962 there was a run of a number of months which had above average temperatures so trends can come to a bit of an abrupt end, which I hope is a fate the trend for milder winters will meet.

What's fascinating to me is to wonder what everybody on here would have been saying 50 years ago in the lead up to 1962/3. If we are destined to have one of those winters only every 50 years, won't it be great if it is next year and won't all the stuff and analysis on this website now will be invaluable to those looking forward to another one in fifty years time!

[lorenzo]

Am a novice here so be kind.

Looking at the Atlantic charging itself up with low after low over the next 7 days, the point that interests me is +132 on GFS.

The Jetstream is really kicking in and barrelling any cold over Iceland and East Greenland back to source, no sign of any blocking there.

However it appears this is in turn fuelling the Scandi High and at that timescale on GFS pushes the high west towards our east coast - an avenue for cold to return 20/01 18:00.

In particular am wondering about the duel lows shown at this point on the chart. What chances are there of these merging and throwing the models again into chaos? Would this in effect burn the atlantic out and allow Greenland to re strengthen?

[jy]

Just a quick question reference the models.On our own website yesterday Mr.Fish said on his weekly update that a return to cold from the east from Wednesday was expected.

In fairness,he cannot have the luxury of changing what he said,as the models then chop and change,but of interest to me,as its our forum and site,what model would he have used to make his forecast.

Not being contentious here,just trying to get a picture of how it works.

[winterof79]

I'm reading a lot of posts talking about a battleground, I can't see there being a battle, more a skirmish which the mild will win although tomorrow there could be some rain turning to snow in the east before turning back to rain again with next week less cold / milder everywhere.

Strange that most on here are calling milder everywhere.If the METO can not call it,in their latest update,and the beeb and mr Fish talking about colder next week,how can some say with conviction that mild will win next week.Its ludicrous,because actually you cannot.All that is being displayed here is a guesstimation.The band wagon rolls and most go for a ride,as they did before this cold spell,calling mild and that they can not see any cold.Some signs of the atlantic again and they fix the bandwagon,that crashed and burned and they are off again.I am sticking with the pros they have more knowledge.The siberian high may not win,but it will give a good account of itself i think.

Edit:That was not aimed at you Frosty.Just the milder everywhere bit

[igloo]

Just a quick question reference the models.On our own website yesterday Mr.Fish said on his weekly update that a return to cold from the east from Wednesday was expected.

In fairness,he cannot have the luxury of changing what he said,as the models then chop and change,but of interest to me,as its our forum and site,what model would he have used to make his forecast.

Not being contentious here,just trying to get a picture of how it works.

to be honest the Mr.Fish forecast i think his weekly forecast was made a few days ago before these latest runs came out well filmed a few days ago anyway but back to todays models the euro models really havent changed that much since yesterdays runs a bit more progressive with the atlantic yes but not drastic change the one model you have to laugh at is the GFS how it can drastically change each run in a space of every 6 hours is beyond me.

well its odds on that next week looks mild wet and windy

[karyo]

Interesting post from Brickfielder on the Technical model discussion thread! He is looking west, for the next cold spell, not east!

He is expecting the Russian high to sink southwards, allowing the vortex to move east and a block to form over the Atlantic.

It means at least a week-long Atlantic dominated weather before something interesting happens!

Karyo

[PB22]

I touched on this earlier, but I strongly suspect the main concerns next week will be more associated with flooding than anything else. With a thaw of lying snow, and the wet months at the end of last year, the ground is saturated and cannot take much more rain. Therefore to see the projected rainfall spikes on the ensembles is rather worrying to say the least:

http://www.wzkarten.de/pics/MT8_London_ens.png

http://www.wzkarten.de/pics/MT8_Manchester_ens.png

http://www.wzkarten.de/pics/MT8_Aberdeen_ens.png

http://www.wzkarten.de/pics/MT8_Dublin_ens.png

We're fast heading from wondering if next week will be wet, windy and dominated by the Atlantic to just how wet, windy and Atlantic dominated it will be.

[bluearmy]

slowly but surely, realism seems to be settling over this thread. there really is no indication of the russian high exerting its influence over us re deep cold apart from hopecasting. now hopecasting will be right every now and again but i think a few are hanging onto this block by their fingernails, desperate to pull it in our direction. doesnt look like its coming, looking at all available output. i see BF has, like GP, seen the same indicators that the trough may get to our east by the back end of Jan.

[sandstorm2]

Just looked at the most recent models and it is very difficult to come to any sort of conclusion, but with the way the atlantic and the jet are looking it would be very difficult to go against less cold weather affecting the UK next week.

Have to accept what the more knowledgeable members are saying too and that is to look at the models more subjectively and give a more honest commentary on their output.

SS2

PS can't wait for that sign TEITS.

[Frosty.]

Strange that most on here are calling milder everywhere.If the METO can not call it,in their latest update,and the beeb and mr Fish talking about colder next week,how can some say with conviction that mild will win next week.Its ludicrous,because actually you cannot.All that is being displayed here is a guesstimation.The band wagon rolls and most go for a ride,as they did before this cold spell,calling mild and that they can not see any cold.Some signs of the atlantic again and they fix the bandwagon,that crashed and burned and they are off again.I am sticking with the pros they have more knowledge.The siberian high may not win,but it will give a good account of itself i think.

Edit:That was not aimed at you Frosty.Just the milder everywhere bit

that's ok, i'm just saying the argument for much colder weather is losing credibility by the hour, it may well become rather cold in the east again after tuesday but snow looks mostly limited to hills in the north and it will be milder in many western areas and before then it looks less cold / milder everywhere with a rapid thaw leading to local flooding. Quite a wet outlook is shown by the latest models but no sign of any significant cold, wintry weather sadly.

Edited January 15, 2010 by Frosty039

[johnholmes]

It wasn't so much that the high pressure to the east collapsed around christmas 1962, more that it gradually formed a link with the Greenland high and eventually established itself there immediately after christmas. It then went on to develop further and form a broad band of high pressure stretching from Greenland to Scandinvia, this forced the jet a long way south of its usual position.

The major difference between then and now is that, currently, the Siberian high is further east than was the high pressure in 1962 and is unable to drift westward due to the increasing power of the jet which is running directly at it rather than under it.

If the current Siberian high was to collapse the jet would have an unrestricted flow right into western Russia and we would be back in a situation similar to the horrors of recent winters.

exactly as it was TM

Morning CC, I think your post sums up, exactly why we get days like yesterday, full of people getting the nark with one another. The models have really not been back and forth with anything; in fact I would suggest that they have been very consistent with the general pattern. Yes a few runs have tried to establish a meaningful easterly, but the general trend has been for an initial Atlantic incursion, followed by a brief period of influence by the Siberian high and then a return to a normal UK westerly based regime. I would say about an 80/20 split in favour of that evolution, I do often wonder if some members are looking at model runs in an alternative universe from the one I live in.

TEITS is right to suggest that this evolution is not set in stone, we have, after all, seen rock solid looking projections fall over at short range before. However, I doubt that if he turns out to be wrong, that those who have suggested that the Atlantic will most likely win out, will receive quite so many posts suggesting that they are in fact forecasting geniuses, in the way that Dave has done. Don't get me wrong I'm not knocking TEITS he's a great bloke and he has a good handle on the models, explains why he thinks the models will play out in a certain way. What has been nauseating over the last couple of days is the copious all praise to TEITS the weather forecasting guru posts. Its always nice to have a post commented on in a positive way, but there re many on NW who are just as good at analysing the models, but who get little praise just because they are less partisan about cold and easterlies. While I don't see any need for members commenting on the models to always be completely objective, I do think objective comments on those posts are a far better read, than an endless sea of posts praising XXXX while making no observations of their own.

The second paragraph is not a comment on any of your posts CC its just something I feel needs saying.

I totally agree with the above-some of you may notice I've taken out some of the more direct comments as I prefer to leave those things off the forum, but yes first class post.

[sandstorm2]

GFS 1200 out to +96 and it is bringing in a continental infleunce again, continues to confound.

SS2

[Thundery wintry showers]

Looking over the current model outputs as well as the teleconnections, I don't think this coming week will be particularly mobile or windy due to the strength of the blocking to the east, but it may produce some slow moving areas of rain which present a risk of flooding (though not on anything like the scale of March 1947).

The continental high may well ridge far west enough between Sunday and Tuesday/Wednesday to bring a quieter spell to much of central, eastern and southern Britain with temperatures staying a little below normal and even giving some sunshine- something which has been at a premium for most since the very sunny first third of January. The models have now almost completely removed potential for any meaningful easterly now, so I think the chance of us getting one is down to 10% at most.

It's looking more and more likely that the Atlantic will come crashing through "properly" late next week after the aforementioned quieter spell.

[johnholmes]

Edit: I will add that any battleground situation is still possible in the coming week before the trough to the west slowly migrates to the east but I think that ultimately the Siberian High will lose - the 100 hPa forecasts also suggest this.

the whole post is totally realistic-first class summation of what is the most likely happening, apart from the Atlantic deciding to put a spanner in the works. On balance I would say its 70/30 to some kind of pressure build to the north west end of this month or more probably into February.

[nick sussex]

As I alluded to earlier the cut off low was important, on the gfs 06hrs run this headed nw and became absorbed by the main Atlantic trough which reduced the ridging westwards, here this doesn't happen and so we see colder surface air pulled nw into the UK.

These small changes on a global scale make a big difference, chance now for some snow as the fronts try and push eastwards.And now because of this the ridge is further west with low pressure to the south, this forces some disruption to the trough with another shortwave heading se'wards.

This is a very good example of such a small feature much earlier causing a massive domino effect. It's the gfs so i'm not going to overplay this but certainly adds to the interest for next week.

Edited January 15, 2010 by nick sussex

[Bobby]

Potential snow next Wednesday

[igloo]

it looks like the block wants another battle with the atlantic just like last nights 18z i state my point as earlier how can it drastically change every 6 hours with this model is beyond belief

[TEITS]

Earlier on today I said if the models trend towards an E,ly then this won't occur until its within the +96 timeframe. Until then all we can do is look and see which way this battle is going because this will shift E & W over many runs. The reason why I say +96 is with good reason and this is due to many years of following such battles. For starters the models will always underestimate the extent of blocking and it isn't until +96 that this becomes evident. Also at the current timeframe the models will be reluctant to show SW tracking underneath the HP.

What I said above last night is already beginning to show its hand.

http://www.wetterzentrale.de/pics/Rtavn901.png

Considering this is the 12Z which is by far the most likely run to blast any blocking away.

I will add im not promising bitterly cold upper temps with snow showers but we might be able to pull enough colder air in to bring a few snow events. I wonder if those who were so confident of a mild week next week are so confident after seeing the 12Z!

[Eugene]

I would say model accuracy is very low past a certain point at the moment with such a monster siberian high hanging around, too much counting their eggs before the chickens have hatched going on in here, its quite offputting to read.

[len]

AAt T160 now, and this more favourable for cold run, looks as if the Vortex could be split by the rising heights between the GIN sea & Baffin

[nick sussex]

The ukmo does what the gfs 06hrs run did and doesn't look great but then pulls out an interesting 120hrs output!

[Shiny_Bottom_1]

What I said above last night is already beginning to show its hand.

http://www.wetterzentrale.de/pics/Rtavn901.png

Considering this is the 12Z which is by far the most likely run to blast any blocking away.

I will add im not promising bitterly cold upper temps with snow showers but we might be able to pull enough colder air in to bring a few snow events. I wonder if those who were so confident of a mild week next week are so confident after seeing the 12Z!

But there are many many people on here Dave who let go of the 12z bar on the monkey frame, and then jump to swinging on the 06z.

There needs to be consistancy by people when reading the models and claiming which is the most reliable.

I will agree the colder air is further west on this run (compared to yesterdays 12z at T+114), but if we want to talk about reliability, then we should wait for the UKMO which has proven recently (from a post yesterday) as the most reliable in this sort of time frame.

I would also prefer to wait for the ensembles to see the agreement...it might be there, but it might not. The GFS Op run is one of dozens from just the GFS and ECM.

Edited January 15, 2010 by Shiny_Bottom_1