Model Discussion - 16th January

[winterof79]

Sticking with METO at present,

Here is my starting point lets get low heights moving s/e showers becoming increasingly wintry on sat into sun

http://www.wetterzentrale.de/pics/Rukm1201.gif

They may well be wrong too of course.

Edited January 17, 2012 by winterof79

[rich1]

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

another mild op run it appears. On the face on it, not bad, I guess for cold lovers there is a better chance of something decent emerging than last month. Though getting the feeling this winter is going to be a bit like watching Liverpool in the last 3 seasons. Flashes of hope but ultimate and perhaps slightly inevitable disappointment. After 3 pretty good winters, this one we might have copped a dud. It happens sometimes. To much HP to the south, either European, Bartlettish or Azores. I suppose though that in previous mild years there seemed no inclination for the highs to move, am not sure that has been the case this year as such, however time and again something seems to come along [the jet etc] to throttle it before it can get going

still a bit of time left of course but the models seem to be in tease mode a bit, even though there has been a break in the zonal pattern recently, it hasnt been allowed to fully reset. Just a bit out of luck this season I reckon. Not exactly a write off post, more a feeling of which way the wind could be blowing for us at this time. Still, who knows, could be more flip flopping on the way

[IDO]

The elephant in the room looks full of himself. It is now clear this cold spell is nothing but normal Jan fare and transitional at that. I have been saying for a while that the last three weeks of Feb are our best shot at cold but now I believe that this winter is probably over. The Strat warming has been too slow and in the wrong place. The next warming will have to be quicker otherwise it will be into March before it effects us. The HP remains our dominant feature and there is no sign from the models that it is going anywhere apart from shuffling around a bit. The best it will offer is cool zonality for a few weeks maybe. The South will therefore be facing very staid winter weather. Some may say the weather will suddenly flip but the nearest we have had this scenario is from the models. You cannot build into them the rigid rut this part of the world is stuck in. Another winter ECM may have been right with its cold runs but this year the combined force of HP and a strong jet stream has kicked any changes into the bin.

Hoping to be proved wrong, but expecting not to.

AH

[mulzy]

Let's face it folks, the cold spell is being downgraded all the time, and the trend continues with ECM 0z (fairly zonal January fare).

UKMO 120 gives us a straw to cluth onto I guess, but generally most of the other operational outputs pointing to a more zonal picture (albeit cool zonality at times) and a + NAO.

.

Edited January 17, 2012 by mulzy

[mountain shadow]

Cold/cool zonal sums up the models this morning, pretty much in line with the met monthly forecast. Whilst the PV departs from Greenland we still do not see sufficient height rises in that area to stop the jet barrelling through.

Certainly a much reduced probability of a prolonged cold and snowy period before month end, unless you live in Scotland which may see a decent bit.

[wolvesfan]

Morning all,

Models not good this morning as they downgrade our predicted cold snap,ECM the first to lead the way yesterday and GFS following.Needless to say though that's all they have done downgraded the cold for this weekend,there's still potential going forward although the recent strat warming hasn't been kind to us as yet.This morning's GFS run also one of the mildest of the ensemble members.GFS ensemble mean still running below the long term mean.

[nick sussex]

Unfortunately just when you don't want the models to agree they all follow the same trend with just too much energy being ejected eastwards to allow anything more than PM incursions.

The UKMO is probably the best of a bad bunch but even that would likely end up at the same point re the jet. Normal winter fare and probably passable if the rest of the winter hadn't been so poor,

Although we lose the PV from Greenland which was a reaction to the previous strat warming theres just not enough amplification in the pattern to take advantage of it, thats clearly shown in the ECM between 120 and 144hrs, where theres an opening but the door shuts as the jet just rolls east.

ECM 144hrs:

Maybe some of the ensembles amplify that ne USA low a bit more, I'm sending an emergency team of straw clutchers to ECM central to find out more!!!

ECM 120hrs:

Edited January 17, 2012 by nick sussex

[Frosty.]

There is good news and bad news from the 00z models this morning, the good news is the jet is favourably tilted more towards nw/se for most of the time so it allows bursts of polar maritime air to sweep southeast across the uk, such as friday, the bad news is we also get sectors of milder air washing the colder air away such as saturday into sunday, mainly for the south and sw of the uk and ireland, the northern half of scotland probably remains in the Pm airflow from thursday until early next week. The Gfs 00z really attemps to pull in some very wintry weather to the uk but it fails because of the constant presence of the large high over spain and france which occasionally pushes further north, the far north of the uk is favoured on the 00z for cold zonal conditions for much of the time but further south it's more of a mix of cool zonal and mild. Next week there is a chance of a much colder few days with a possible Northerly, the gfs shows all the ingredients for a cold spell with a stronger greenland high and a ridge extending southeast plus a deep scandi trough but that high to the south/sw of the BI is a real pain.

There are some tasty looking cold charts, the Gem 00z T+240 was a highlight, but again, mainly for the north.

Edited January 17, 2012 by Frosty039

[shedhead]

The overnight runs continue to put any sustained cold spell on increasingly shaky ground, at least this side of months end, but at least we should see occasional short lived Pm shots bringing some snow to favoured northern area. Difficult to pick any standout charts this morning, but once again the UKMO 120-144hr show some promise, albeit short lived and a long way from proper cold. My overall assessment is the 'jam tomorrow' senario that we've seen for over a fortnight continues, the only problem being now we're officially in the 2nd half of Winter we are starting to run out of tomorrow's...

Edited January 17, 2012 by shedhead

[nick sussex]

Ok my team of Strawclutchers are reporting back!

The ECM ensemble maps don't offer that much excitement, but there are still a few better options, still some uncertainty with how far that troughing digs into Europe, a cluster do bring a stronger PM flow in:

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2012011700!!/

The ECM operational output upto 168hrs is better than that Freddie Kruger special we were all subjected to last night, perhaps it over reacted to the upstream signal to flatten the pattern out.

Theres probably just enough time to salvage a decent PM incursion,but for the timebeing thats really the best I can see within 168hrs.

[UV-RAY]

Looks very much like January will go out as how December started, I have too say something is amiss with either the models or teleconnections. For all the favourable synoptics in our favour, we just can't get any decent height rises to our North.

[TEITS]

still some uncertainty with how far that troughing digs into Europe, a cluster do bring a stronger PM flow in:

Indeed and the UKMO is really the only model that is keen to send the LP SE. Infact compared to last nights 12Z its probably better in this regard because the HP to our NE ridges slightly further W. The UKMO is fairly similiar to some of the GEFS ensembles I have seen these past few days.

Overall im disappointed with the model output and would love to see the models backtrack and return to showing LP diving SE into Europe rather than tracking E. Still not ruling this out happening.

[Jason M]

Different day same ...........

Azures high to the SW, fairly non descript outlook as said elsewhere this morning.

Still some very good ensembles, although looking through the parallel ensembles they didnt look as good to me (albeit i had a quick scan through). In reality the ensembles are probably little use in this scenario as the opps with the higher resolution must be picking up a signal that cant be seen by many of the ensembles.

A week ago, we could say with high confidence that there would be nothing overly cold in 10 days, with a bit more uncertainty around that's maybe narrowed down to perhaps 7 days, so we are looking out to the 24/25th Jan as an earliest (albeit unlikely IMO) date.

Not sure what the CET is running at this month, but if Feb carries on like this we could challenge some of our milder winters i'd have thought. 88/89 would take some beating though.

Jason

[BLAST FROM THE PAST]

Yes the tilt to a NW/SE flow has somewhat flattened. The ridge is not allowed to build up northward behind it as another LP places itself over southern tip of Greenland. Its interesting to see how the models are handling this scnario ahead of us [which hasn't happened yet] and also the point that GP suggests that the AZH is going to get a huge yank westward soon. Either the signal is diluted by another influence or the timing is not there yet, but suffice to say although 00z not as bad as the evening runs, when compared to yesterday we see a backward step overall. What will be right? UKMO holds firm on the trough digging SE into Europe more than any other and that is a straw to clutch to for now and it is only Jan 16th and the way the models have changed their outlook over recent days / week I'm not at all convinced the pattern is set correctly, though sustained deep cold doesn't look round the corner yet.

BFTP

[geoffw]

is everyone forgetting GP tech post?! the models are struggling because there is a huge atmospheric change occuring

[Radiating Dendrite]

is everyone forgetting GP tech post?! the models are struggling because there is a huge atmospheric change occuring

That may be, but the pattern may change to something just as benign as what we currently have.

An atmospheric change does not equal cold for the UK.

[john mac]

UKMO 96-

http://www.wetterzen...cs/Rukm961.html

UKMO 120-

http://www.wetterzen...s/Rukm1201.html

GFS 96/120/144/168/-

Theres a day difference mate

[Gibby]

I don't know why people on here and elsewhere over the last few weeks have got there hopes for cold up on the back of charts that have never got into the reliable time frame. It's easy to forget that the periods beyond 96hrs-120hrs are about as far as weather can be reliably forecast even in 2012 and all charts thereafter should be used for trend setting and not necessarily for what they show. Yes there has been some occasional eye candy for cold entrepreneurs to enjoy and discuss but in all the time since Christmas have any of the models ensembles shown a 'trend' that would indicate deep cold for the UK and in all honesty to date they have been spot on right. This mornings FI output continue to show more of the same when taken as a trend so expect more of the same for the next two weeks. My lessons of studying UK weather is not to get hung up on charts beyond 96hrs and you won't get disappointed when things don't turn out the way things are shown.

[TEITS]

I don't know why people on here and elsewhere over the last few weeks have got there hopes for cold up on the back of charts that have never got into the reliable time frame. It's easy to forget that the periods beyond 96hrs-120hrs are about as far as weather can be reliably forecast even in 2012 and all charts thereafter should be used for trend setting and not necessarily for what they show.

You must of missed a few model runs then because over the past few days some of the excellent charts have been shown in the reliable timeframe i.e LP sinking SE with a NE,ly as the LP pushes S. The uncertainity of these last few days has been whether we see a trough dig SE into Europe or as todays output suggests LPs tracking E instead. The models have never really shown deep cold affecting the UK but at times the model output has been cold enough for snow events.

[Gibby]

You must of missed a few model runs then because over the past few days some of the excellent charts have been shown in the reliable timeframe i.e LP sinking SE with a NE,ly as the LP pushes S. The uncertainity of these last few days has been whether we see a trough dig SE into Europe or as todays output suggests LPs tracking E instead. The models have never really shown deep cold affecting the UK but at times the model output has been cold enough for snow events.

I haven't missed any runs to my knowledge. The most wintry charts I've seen of late were shown by ECM some 3-4 days ago when as you say Low pressure dived down SE over the UK to a position to our South and SE and that was at T216 and t240hrs at the time.

[Paul]

As Geoff says, would recommend a read of this:

I'd also say, all this jumping about of the models, and fairly large divergence in the ensembles is often (in my experience) indicative of a (significant?) pattern change in the offing.

[wolvesfan]

I don't know why people on here and elsewhere over the last few weeks have got there hopes for cold up on the back of charts that have never got into the reliable time frame. It's easy to forget that the periods beyond 96hrs-120hrs are about as far as weather can be reliably forecast even in 2012 and all charts thereafter should be used for trend setting and not necessarily for what they show. Yes there has been some occasional eye candy for cold entrepreneurs to enjoy and discuss but in all the time since Christmas have any of the models ensembles shown a 'trend' that would indicate deep cold for the UK and in all honesty to date they have been spot on right. This mornings FI output continue to show more of the same when taken as a trend so expect more of the same for the next two weeks. My lessons of studying UK weather is not to get hung up on charts beyond 96hrs and you won't get disappointed when things don't turn out the way things are shown.

I personally think the models recently have shown lots of potential for cold lovers to get exited about,more importantly though it's the background signals that have made for better viewing,we've seen a big warming to the stratosphere and a -ve AO develop along with the NAO become more favourable.

I'm no expert but IMO the potential is still there,we need to let the atmospheric transition evolve and see where we stand.

[Bristawl Si]

I haven't missed any runs to my knowledge. The most wintry charts I've seen of late were shown by ECM some 3-4 days ago when as you say Low pressure dived down SE over the UK to a position to our South and SE and that was at T216 and t240hrs at the time.

I think a number of us have been pinning our hopes on the likes of GP's Winter forecast, his regular updates and Chino's updates on strat warming which seemed to be quite +ve towards a change over the last couple of weeks' posting, for a change towards end of Jan.

Add this to some more +ve runs from a couple of the models over this last few days and that's where the raised hopes came from.

Edited January 17, 2012 by Bristle boy

[TEITS]

I haven't missed any runs to my knowledge. The most wintry charts I've seen of late were shown by ECM some 3-4 days ago when as you say Low pressure dived down SE over the UK to a position to our South and SE and that was at T216 and t240hrs at the time.

Sunday night the 18Z GFS/GEFS ensembles suggested the cold N/NE,ly and the mean dropped to -8C. Over the past few days the NOGAPS has shown this and the UKMO continues to suggest a trough digging SE into Europe.

The only consistent thing about the model output has been the inconsistency.

Just add I don't like this term "hopecasting". If a member comments on a wintry run then this isn't hopecasting but merely discussing the model output at the time!

Edited January 17, 2012 by THE EYE IN THE SKY

[Zakos]

I'd also say, all this jumping about of the models, and fairly large divergence in the ensembles is often (in my experience) indicative of a (significant?) pattern change in the offing.

. Yes paul, I thought this was case, and I am glad someone of your experience also thinks this.