Model output discussion 25th Jan onwards

[winterof79]

absolutely tetis i been watching with great interest and there is clear signs showing your ideas.

i still fancy mid feb and march to be cooler than average if not colder.

Usually, when the operational run goes off on one,be it a cold or mild outlier,it is eratic and only one run before it goes scuttling back into the pack.

The last few op runs have trended colder steadily and not erratically,the control has trended with it today

http://cdn.nwstatic.co.uk/ensimages/ens.20140206/00/t850West~Yorkshire.png

http://cdn.nwstatic.co.uk/ensimages/ens.20140206/00/prmslWest~Yorkshire.png

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

Edited February 6, 2014 by winterof79

[winterof79]

According to the Meto fax charts its a kitchen sink job this weekend with a parcel of 528dam running across the South on Sunday

http://www.weathercharts.net/noaa_ukmo_prognosis/PPVL89.gif?31415

Unusual to see the 510dam line marching toward Ireland too

http://www.weathercharts.net/noaa_ukmo_prognosis/PPVO89.gif?31415

[Summer Sun]

GFS 00z precipitation charts show another wet week coming up especially in the south, south west most of wales and the north west with another 40 to 85mm of rain possible in these parts

 

 

However we have a glimmer of hope from the 14th to 22nd with rainfall easing for most, the wettest places looks to be the far south west, all of Ireland and western Scotland seeing the heaviest rain though its not much more than 30mm its certainly an improving picture for somerset this morning longer term

 

[Troubleatmill]

ECM 850's loo

 

Karl,im not saying its not relevant but there is another thread for indepth analysis of the storm situation.

I posted about the 0z runs being Atlantic driven with a small window of opportunity next week for something more wintry in the north,which is what the ecm/ukmo runs show.

 

Depends where you mean the North? ECM 850's look ok for snow prety much anywhere away from the sea facing west coasts, although marginal at lower levels . certainly your location would see snow, with -7 850's and strong westerly flow 

Edited February 6, 2014 by Nicholas B

[MR EXTREMES]

heights lowering into europe but rising in eastern europe azores retreating south its heading towards a different set up few more days and we should see more direct route to cooler colder setup mid feb or last week of feb.

 

gfs

[Frosty.]

heights lowering into europe but rising in eastern europe azores retreating south its heading towards a different set up few more days and we should see more direct route to cooler colder setup mid feb or last week of feb.

 

gfs

I will be amazed, not to mention, gutted, if we don't manage to get a spell of colder zonality during the next few weeks, I have said this before but then ultimately the models have shot me down but I think we are going to see a more wintry flavour to the weather for the second ½ of february and into early march at least.

[winterof79]

I will be amazed, not to mention, gutted, if we don't manage to get a spell of colder zonality during the next few weeks, I have said this before but then ultimately the models have shot me down but I think we are going to see a more wintry flavour to the weather for the second ½ of february and into early march at least.

It will be interesting to see wether or not it is on the colder side of the ensembles again and indeed if some other members follow it if the run continues to trend colder.Edit.Yet again the run trends cold toward the end.All is still to play for on the 6th February. Edited February 6, 2014 by winterof79

[Troubleatmill]

I will be amazed, not to mention, gutted, if we don't manage to get a spell of colder zonality during the next few weeks, I have said this before but then ultimately the models have shot me down but I think we are going to see a more wintry flavour to the weather for the second ½ of february and into early march at least.

 

Think the ensembles will go on to show just that Frosty, 06z GFS the same as the 00z in showing this happening, Believe the ECM will also start to show this its later reaches too soon

[MPG]

Not seen this much consistancy for a while...

 

[Weather Boy]

Not seen this much consistancy for a while...

 

 

True, but worth pointing out that the pressure rise is from a ridiculously low base not much over 970Mb, so it would be astounding if the ensembles didn't call as one for a rise to some extent and at some stage.  Therefore, query whether much can be read into these ensembles.

[Troubleatmill]

Next Tuesday beginning to look intersting snow wise for many, will change to and fro from area to area, but currently dew points, 850-1000, wet bulb and 850 temps looking good for large areas:

Edited February 6, 2014 by Nicholas B

[nick sussex]

I think some of the hopes in here re a pattern change are a bit premature, even with those ensembles showing higher pressure towards Iceland, even with some increase in pressure there it could still be some relatively weakish low heights that remain which means perhaps a slacker trough.

 

The mid Atantic ridge could set up but for how long and once the PV has reformed will the energy just flatten the whole pattern again?It could be that the next PV will be weaker over the Canadian sector so this might allow for better trough disruption if theres some blocking near the UK but the ECM ensembles are resolute in not bringing anything much colder to western Europe:

 

 

A poor set of ensembles, its only the GEFS which has something a little more interesting but we've yet to see anything showing up operational wise in the higher resolution.

 

Even in the GEFS colder solutions are still in the minority, I've yet to see a clear signal to develop any decent cold pooling that the UK could tap into.

 

I don't want to sound like a misery here but I don't really see anything to be excited about in the outputs, bar some marginal snow perhaps but there is no sign yet of a major change that could bring temps down sufficiently to bring some decent snow and temps that can sustain this.

 

 

 

 

 

[Paul]

Yes karl,underwhelming from a cold perspective.

There is a thread for the storms flooding etc i was commenting on the ongoing Atlantic dominated 0z charts.

 

For the final time, this thread is for discussing the models, not just cold, everything. If people want to focus on cold that's fine if it's model related, if people want to focus on the here and now that's fine as long as it's model related, and if people want to look at deep fi, that's fine too so long as it's model related. So hopefully you get the jist - model discussion is fine in this thread regardless of the slant, so please can we put an end to this apparent need to tell people what they should and shouldn't be posting about. 

[Troubleatmill]

I think some of the hopes in here re a pattern change are a bit premature, even with those ensembles showing higher pressure towards Iceland, even with some increase in pressure there it could still be some relatively weakish low heights that remain which means perhaps a slacker trough.

 

The mid Atantic ridge could set up but for how long and once the PV has reformed will the energy just flatten the whole pattern again?It could be that the next PV will be weaker over the Canadian sector so this might allow for better trough disruption if theres some blocking near the UK but the ECM ensembles are resolute in not bringing anything much colder to western Europe:

 

060200.png

 

A poor set of ensembles, its only the GEFS which has something a little more interesting but we've yet to see anything showing up operational wise in the higher resolution.

 

Even in the GEFS colder solutions are still in the minority, I've yet to see a clear signal to develop any decent cold pooling that the UK could tap into.

 

I don't want to sound like a misery here but I don't really see anything to be excited about in the outputs, bar some marginal snow perhaps but there is no sign yet of a major change that could bring temps down sufficiently to bring some decent snow and temps that can sustain this.

 

You are probably right Nick, as far as proper cold (thinking cold dry air) there is little in the forecastable future in high res that can be showed, GEFS is beginning to show a change further out wouldnt you agree though? normal caveats apply obviously, but we have to look somewhere,even if its just for an end to this constant atlantic battering, im still a bit more optimistic than a couple of days ago where we could go right out to T384 on all ensembles and all we saw was a continuation 

Edited February 6, 2014 by Nicholas B

[Mucka]

There are really three areas of interest to follow in the MO though some of that interset may depend on your specific location.

The first is the most obvious and most pressing and that is the storminess through the weekend and through the first part of next week as things stand. It won't be particularly settled thereafter and there will be plenty of chance for more rain and strong winds to develop though we should start to see the main chunk of Canadian PV losing steam and move away East by then with a somewhat slacker jet beginning to develop.

It is good to see ECM a little less PV centric this morning but it is still quite progressive and unusual to see it ramping up the Atlantic more than GFS or at least it used to be.

Was it not upgraded recently? I have noticed the Op seems to be one of the most progressive runs within the ensemble suite and often among the "milder" runs more often than not these days. Regardless ECM ensembles are uninspiring for coldies and GFS 06z set is little better.

 

ECM ensembles.

 

 

Even so if and when the jet slackens around mid month there will be a window of opportunity for a more amplified pattern but this window has already been shunted back a little and although GFS Op's have been consistent in bringing in increasingly cool/cold conditions from mid month it is very difficult to have any faith in them at this point.

This phase though is now coming into range of ECM so we will get a better idea over the next couple of days if we have a genuine chance of a pattern change.

It is rather typical of this Winter though that we need to look so far ahead just for the hope of something better even though I have been fairly positive about the possibility thus far. All the same that would be a second area of interest.

 

The third, the cold Westerly that looks likely to set up next week, is a little more location dependent. If you are in the SW or SE then there is likely little of interest other than watching the rainfall totals stack up but more Northern and Western areas could see snow falling at least for a time to low levels - probably 11th through to the 13th offering the best opportunities but any snow is very unlikely to settle except across high ground and in a normal Winter it wouldn't be a big deal. Still, if conditions fall right it could still offer some wintry surprises while by the same token it may be a damp squib.

 

Plenty going on in Model Output land for members to get their teeth into whatever their particular interest, concern or flavour of weather.

Edited February 6, 2014 by Mucka

[Tamara]

 

 

However, I would be very wary of taking such a change of hemispheric upper feature re-arrangment as any definitive signal for any cold(er) spell for us in the UK anytime in the foreseeable future.

 

We need to see evidence in stratospheric modelling that not only might ongoing wave activity affect more wholesalely changes in patterns upstream, and move this burden of a vortex far enough away from its downstream influences, but that zonal westerly winds are going to slow down (at least) below 20 m/s - because we already know from experiences of the middle part of January with the attempted trough disruption and failure to lose the upper low to the NW, that this level is likely to be insufficient to permit blocking at any favourably higher latitude or encourage sufficiently far enough westwards those heights now shunted far east into the Siberian/Asian continent.  Clearly, with the recent/current ramping up of all this turbo energy coming from upstream, we have also lost the decent cold pool that had encroached just the other side of the North Sea in the last week or so.

 

On the basis of predicted zonal energy calculations as suggested, the possible retrograde of the Pacific pattern instead supports a developing NW/SE split perhaps into the second half of February as the worst of the present/upcoming cylogenetic jet streak subsides and adjusts northwards and westwards, but with still too much upper westerly flow to encourage any significant rise in heights to our north, even with the upper trough easing a little further away from our immediate vicinity.

 

I think that stratospheric progress is now being made for the longer term to change the weather pattern finally to a more blocked one, after all these dreadful months, but this remains well beyond our MOD discussion radar, and in my opinion quite conceivably also the radar of the winter season itself with lag time issues also to take into account here

Previous post highlighted for continuity

 

In terms of proper winter snow and cold weather opportunities this winter is now surely destined as close to a complete write-off. The evidence out there is all to compelling to see with a continuing failure of stratospheric activity to benefit our part of the NH in this respect, and in complete contrast. we see the continuing bitter conditions from Northern Canada dictating our appalling fortunes downstream. Game set and match to the deep upper atlantic trough for winter 13/14.

 

There is little hope of any meaningful atlantic amplification occuring whilst the vortex occupies Canada in the way it continues to, and the signs are that the next upcoming actiivity on the vortex simply serves to benefit the Canadian sector once more, so one doesn't have to be a genius to work out what that means for us in the UK  The pattern will stay flat in our sector with further low pressure systems tracking towards us much in the way they have since mid December.

 

The 'best' that can be said is that the pattern *should* eventually become 'less extreme' as signals continue to indicate the Pacific pattern retrograding somewhat in the much longer term with the result that the extreme temperature gradients fuelling the jet stream will be mitigated, even though energy will still be available to keep the pattern too flat for amplification to bring cold incursions. However none of this is going to happen soon enough, and we stare bleakly out at another 7 to 10 days at least with no let up in this alarmingly stormy pattern - this really is not the outlook any of us (most especially in the south west) wants to hear

 

Approaching Springtime seasonal wavelengths shortening, and accompanying seasonal final warming out of the vortex looks to me to be the only definitive way out of this destructive, and then afterwards plain unsettled and changeable, pattern. Moderation of these extremes should be the biggest priority to look out for anyway in these torrid circumstances - and besides, expectations of any late glimpse of official seasonal winter weather have all but gone. Certainly in my opinion anyway.

 

A lot of uncertainty about this, but such moderation should come by the last third of the month, in the form perhaps of lows tracking further north and maybe pressure rising to our south. But there is no sign at all of any end to the westerlies in the greater sense for some to come yet. 

 

Edit: I was obviously speaking in terms of probabilities of any significantly cold weather. It seems clear to me that any variant options with a Canadian vortex in place, which might certainly be possible in some circumstances, are limited in the overall current NH circumstances, and those that have dictated the winter, and unlikely to come to much at all - especially when set against the overriding continuing significance of so much severe weather threat

 

There remains a concerning amount of uncertainty wrt to wind strength and storm track for possible rapid cyclogenesis in the low next week circa 11th Feb. The London ECM ensembles illustrate this clearly enough

 

http://www.weathercast.co.uk/meteo/eps/ensemble-ff-london.gif

 

Also, the Ensemble maps at day 5 show a few of the extreme solutions hinted at by last night's ECM 12z - although there is a wide variety of other more preferable solutions. Member 34 is surely the scariest...

 

Edited February 6, 2014 by Tamara תָּמָר

[Troubleatmill]

Previous post highlighted for continuity

 

In terms of proper winter snow and cold weather opportunities this winter is now surely destined as close to a complete write-off. The evidence out there is all to compelling to see with a continuing failure of stratospheric activity to benefit our part of the NH in this respect, and in complete contrast. we see the continuing bitter conditions from Northern Canada dictating our appalling fortunes downstream. Game set and match to the deep upper atlantic trough for winter 13/14.

 

There is no hope whatsoever of any atlantic amplification occuring whilst the vortex occupies Canada in the way it continues to, and the signs are that the next upcoming actiivity on the vortex simply serves to benefit the Canadian sector once more, so one doesn't have to be a genius to work out what that means for us in the UK  The pattern will stay flat in our sector with further low pressure systems tracking towards us much in the way they have since mid December.

 

The 'best' that can be said is that the pattern *should* eventually become 'less extreme' as signals continue to indicate the Pacific pattern retrograding somewhat in the much longer term with the result that the extreme temperature gradients fuelling the jet stream will be mitigated, even though energy will still be available to keep the pattern too flat for amplification to bring cold incursions. However none of this is going to happen soon enough, and we stare bleakly out at another 7 to 10 days at least with no let up in this alarmingly stormy pattern - this really is not the outlook any of us (most especially in the south west) wants to hear

 

Approaching Springtime seasonal wavelengths shortening, and accompanying seasonal final warming out of the vortex looks to me to be the only definitive way out of this destructive, and then afterwards plain unsettled and changeable, pattern. Moderation of these extremes should be the biggest priority to look out for anyway in these torrid circumstances - and besides, expectations of any late glimpse of official seasonal winter weather have all but gone. Certainly in my opinion anyway.

 

A lot of uncertainty about this, but such moderation should come by the last third of the month, in the form perhaps of lows tracking further north and maybe pressure rising to our south. But there is no sign at all of any end to the westerlies in the greater sense for some to come yet. 

 

Hi Tamara, great post. Didnt many say however that the uk can still get cold with a strong PV over Canada? 

 

I will be proven wrong on the 12z ensembles, but for now i look at the 06z ensembles and do see hope

Edited February 6, 2014 by Nicholas B

[Jason M]

Odds on that Tamara is correct IMO, with the slight proviso of maybe replacing 'no hope' with 'slight hope'.

If we keep the same broad pattern into March as Tamara suggests that leads us into other problems because whilst the pattern will inevitably relax at some point, if the trough is sitting over us with the stronger solar input that late Feb early March brings that will result in massive convection and consequently some huge thunderstorms. So wind may become less of an issue but rainfall totals could ramp up considerably. Similar I guess April - June 2012.

A one hour storm can easily drop as much rain as the system coming over us today.

[bluearmy]

the uk can get cold with a deep p/v over canada. one with the axis that this one continues to occupy and with its extended upper trough into the north atlantic does, however preclude any decent atlantic ridging. however, even with the p/v as it is, it is feasible to have a strong arctic ridge dropped into greenland which could deflect the jet far enough south for the uk to sit north of the pfj. it is also feasible for a scandi block to sit far enough west to bring easterlies. these scenarios require other factors to sit right and that quite plainly has not occured thus far this winter. simple statement that a means b cannot happen are not generally true in the complex dynamics ot the atmosphere. if you want to speak in probabilities, then quite clearly a strong canadian p/v is not going to increasee the chances of cold for the uk.

Edited February 6, 2014 by bluearmy

[Troubleatmill]

the uk can get cold with a deep p/v over canada. one with the axis that this one continues to occupy and with its extended upper trough into the north atlantic does, however preculde any decent atlantic ridging. however, even with the p/v as it is, it is feasible to have a strong arctic ridge dropped into greenland which could deflect the jet far enough south for the uk to sit north of the pfj. it is also feasible for a scandi block to sit far enough west to bring easterlies. these scenarios require other factors to sit right and that quite plainly has not occured thus far this winter. simple statement that a means b cannot happen are not generally true in the complex dynamics ot the atmosphere. if you want to speak in probabilities, then quite clearly a strong canadian p/v is not going to increasee the chances of cold for the uk.

Something similar to what some of the ensembles are starting to show then BA.agree that there is zero chance as we stand as we are part of a huge system that extends all the way to mid Canada, a fair amount of ensembles show a more split set up T 216 onward with well seperated pressure systems which could can will or wont create a cold set up, hope is there though for an hour and a half anyhow Edited February 6, 2014 by Nicholas B

[Hotspur62]

Not what coldies wanted to hear but I think Tamara's post will probably   be spot on which pretty much writes off February in terms of a cold spell in UK. That still leaves first 15 days of March for many of UK to get maybe their first snowfall of Winter 13/14 lol.!!.All models seem fairly consistent with continuation of the pattern we have had now for 8 weeks with more rain and pretty much average temps(although in the rain it will feel cool).The PV has certainly been the main driver for our winter this year unfortunately!!

[johnholmes]

the uk can get cold with a deep p/v over canada. one with the axis that this one continues to occupy and with its extended upper trough into the north atlantic does, however preculde any decent atlantic ridging. however, even with the p/v as it is, it is feasible to have a strong arctic ridge dropped into greenland which could deflect the jet far enough south for the uk to sit north of the pfj. it is also feasible for a scandi block to sit far enough west to bring easterlies. these scenarios require other factors to sit right and that quite plainly has not occured thus far this winter. simple statement that a means b cannot happen are not generally true in the complex dynamics ot the atmosphere. if you want to speak in probabilities, then quite clearly a strong canadian p/v is not going to increasee the chances of cold for the uk.

 

what a sensible and constructive post on the probabilities in the current upper air situation

[johnholmes]

lutions hinted at by last night's ECM 12z - although there is a wide variety of other more preferable solutions. Member 34 is surely the scariest...

 

 

 

nothing wrong with your post Tamara, a sensible and logical look at various outputs, but PLEASE can you just link to your post with date and time rather than either all the last one or great junks of it please.

Not only you others too please?

thanks

[Tamara]

what a sensible and constructive post on the probabilities in the current upper air situation

Just seen your next post. Heavily edited already John, believe it or not

Edited February 6, 2014 by Tamara תָּמָר

[johnholmes]

Not seen this much consistancy for a while...

 

 

very true-perhaps a hint of some kind of pattern change but nothing in the anomaly charts yet, not that they are infallible at times