mcweather

January 18, 2015

With yet another putting off of the proposed Atlantic insurgence towards the end of the week. One can't help but get just the inkling of a feeling that the bigger picture mentioned by the likes of Chiono and Tamara may just be starting to be heard as a stronger signal above the chaos of Atmospheric white noise in the current modelling.

I would not be at all surprised if we start seeing some 1947esque synoptics popping up in FI over the coming week of model watching.

To me this week has all the hallmarks of a minor skirmish prior to a much bigger event.

January 18, 2015

got a feeling, think theres a reasonable chance of a freeze developing.

not that i want one...

Crikey Mushy if you carry on like this we'll have to call you Murrshymanrob.

I think you may well be right though. So many people have got caught up in trying to tell us who will get snow from the synoptics shown on various runs in the past few days and presumably because this is the first chance of real winter weather since March 2013 they have taken their eyes off the bigger picture.

That picture is one that suggests that the upcoming week could merely be round one, a preliminary skirmish in what may turn out to be a much longer affair. Suggestions from both Chiono and Tamarra that the overall atmospheric patterns both strat and trop related are falling into place for a far more significant cold spell down the line.

Todays forecast for the week ahead posted up on the bbc about 20 minutes ago was very indicative of the uncertainty at the MET OFFICE about a return of the Atlantic beyond next weekend.

January 16, 2015

Hi mcweather, - did you know that the EC32 has a verification page where we can look back at the previous forecasts?

Have a look; it does much better than you give credit for. Maybe interpretation is the issue in some of the bad press it gets.

http://old.ecmwf.int/products/forecasts/d/charts/mofc/verification/anomaly/anom_grp/vanomaly!temperature!Europe!mofc!2!anomaly!20150105!/

Thanks Gael will take a look.

January 16, 2015

Indeed. No worries...I was just curious! It goes without saying we don't slavishly follow EC Monthly as 'gospel'. Always critically scrutinised alongside GloSea5.

Quite so Ian. It will be interesting to see how things pan out after the current colder spell of weather, I really thinks at the moment anything beyond seven days has to be taken with a large pinch of salt rather like you suggested the other night regarding a quick Atlantic return.

January 16, 2015

Here is the SLP anomaly forecast for current period, from EC Monthly prognosis of the 29-12-14 run. It continued the theme of cyclonicity to NW/N. There was never a compelling signal for strong heights over Greenland, certainly not in any of the runs I recall (I saw each since winter began). Where did you see that?

Hi Ian It was in a tweet from a fellow professional meteorologist!

Still all water under the bridge now.

January 16, 2015

People were asking about the EC32 - WSI blog has put up a graphic for the next 4 weeks.

http://www.wsi.com/blog/energy/less-cold-europe-at-the-end-of-january-early-february/

Ah yes the The ECM 32 dayer the same model that had an extreme high pressure anomaly over Greenland for January back in late December.

The words Chocolate and fireguard spring to mind.

With the polar vortex being bounced and stretched around in all sorts of different ways, I think that this winter is one where anything beyond about 7 days really is fantasy forecasting.

January 15, 2015

Latest from Fergie in Model thread;

A mixed bag of EC clusters.... any pronouncements of a secure and swift return to 'mild' conditions need to be taken with pinch of salt. Meanwhile, nearer-term focus needs to be on the late Sat-Sun high WBPT plume curving atop the low running off down into Biscay. *Could* get interesting on N flank of this feature, but wide spread in PPN envelope (e.g. MOGREPS has this anywhere from N France to S Midlands!!)..

January 15, 2015

A mixed bag of EC clusters.... any pronouncements of a secure and swift return to 'mild' conditions need to be taken with pinch of salt. Meanwhile, nearer-term focus needs to be on the late Sat-Sun high WBPT plume curving atop the low running off down into Biscay. *Could* get interesting on N flank of this feature, but wide spread in PPN envelope (e.g. MOGREPS has this anywhere from N France to S Midlands!!)....

I always find in these situations with a wide spread its best to take the middle ground solution, so that'll be the south coast of England then.

Crikey that's where I live. LOL

January 10, 2015

Here's the latest tweet from someone who obviously spends a great deal of time looking at the models, quite of lot of which we don't have access too.

Ian Fergusson @fergieweather Â· 2h 2 hours ago

W COUNTRY CONT'D...with temperatures generally below average & occasional N'ly bias to winds. Frost/ice/some snow possible into 6-15d period

January 10, 2015

Most recent tweet from Fergie

Ian Fergusson @fergieweather Â· 2h 2 hours ago

W COUNTRY CONT'D...with temperatures generally below average & occasional N'ly bias to winds. Frost/ice/some snow possible into 6-15d period

January 8, 2015

but frosty the met office have been bang on this winter. Think until they come on board we should remain cautious of the charts.

Hi Terrier. I can see where you're coming from with this. The met office are rightly cautious because they have a national reputation to protect and one that will be mercilessly torn apart by a meteorologically illiterate media.

However this caution also plays against them because in the years that I have been following the weather on the internet. There hasn't been a single cold or snowy outbreak that they have eventually mentioned in their medium term outlook that wasn't blindingly obvious to experienced model watchers on this forum and TWO well before it ever made it into print on the Met office website.

By the way this is not a dig at the met office for whom I have the utmost respect.

January 8, 2015

Not sure what to make of the gfs and ECM at moment. Yes some colder pm shots. But just seen tweet from Ian ferguson saying westerly pattern to dominate till end of jan now. With any cold signal been tenuous.

Actually terrier the tweet says, late January not the end of January and seeing as the 20th January could be classed as late January it actually fits in quite well with what the ecm and gfs are trending towards.

January 5, 2015

I

Is that a snow event for southern England on the 12z GFS P that I can see?

January 4, 2015

The GFS model has certainly shown up some interesting wintry possibilities ( and that is all they are at the moment, possibilities) in FI over the last few days. It will be interesting if

a, It keeps displaying these possibilties

b, Brings them inside the 240 range

c, if it manages to get to point b then will the ECM start displaying such possibilties?

Getting a half decent cold spell to the UK is always like pulling teeth. So I think its a case of coldies having to keep everything crossed.

January 3, 2015

Although we're seeing some better outputs today we should bear in mind that we're talking of changes starting to occur around the T240hrs timeframe.

At this point theres no way of determining whether this will involve a northerly toppler type scenario or cold spell.

The first step is to displace the Azores high and get the jet track more nw/se. We need to see this constantly modelled and survive to the T168hrs timeframe.

Looking at the ECM ensembles they do show a colder cluster developing from around day 11 but at this time don't show an Arctic sourced northerly more a colder type PM flow which of course is better than whats currently on offer but really after such a long wait what we want to see is something that delivers UK wide.

That may still happen and a trend to amplify the pattern might be given some further help if the MJO can actually survive and remain strong.

So today some cause for optimism but really no more than that and certainly nothing warranting a trip to the sledge shop.

Indeed Nick hopefully signs of a significant change but simply eye candy and nothing more at present.

After many years of GFS let downs and Those ECM''s I'm sticking with my new Mantra this winter.

''You can scream and shout your happiness about ECM AND GFS

but it simply will not happen until the UKMET say yes.''

January 2, 2015

If we have a pattern change to negative AO say last week of Jan and lasting through Feb will people be quite so ready to write off the OPI theory.

I would be more inclined to let the rest of the winter pan first before making any decisions as to it's viability or lack thereof.

I can just imagine if the OPI had been presented back in autumn 1946 and a first half of january 47 being mild after a brief bit of cold around Christmas 1946 and people queuing up to call it a busted flush. they wouldn't have looked so clever come March 47.

Just musing to myself...................................................

January 1, 2015

Happy new year to members of the forum coldies /mildies and inbetweenies.

For now fast moving interchangeable mildish and coldish periods are showing on the models

Hopefully the rest of winter will have something to keep everyone happy, and I do think that will be the case. The first half January is very often a stormy period anyway so best just for those seeking widespread cold and snow away from northern hills to sit back and let it blow itself out. There are some back ground signals that hint a somehwat more wintry pattern later in the month and feb could bring anything. That's the wonder of this subject that we are all so wrapped up in.

So just relax and enjoy it we can't change it no matter what the models show.

December 31, 2014

I think that it is worth pointing out that the latest forecast zonal conditions are completely different to last years. Then we saw a displaced polar vortex to the NA sector, leaving us in the prime position for zonality. This year we have seen the vortex split a number of times and it is forecast to do so again in the coming days. The problem being this time is that the split is unfavourable for the UK, leaving a flattened section of one of the daughter vortices in the worst position possible - across the southern aspect of Greenland.

The vortex is not (forecast to) split strongly enough to allow the jet stream to be prevented from crossing the Atlantic - it is poorly positioned for an Atlantic block - but well positioned for a Scandi block as the following 100hPa chart shows:

viewimage.png

Further up the height of the stratosphere a warming is forecast to effect the Greenland daughter vortex but yet again it has not been modeled strong enough to fully knock both daughters out and so we are left with the situation where a weak tropospheric vortex can reform to our NW. We can see the vortex that we want 'knocked out' on the 30hPa chart.

viewimage-1.png

However, the modeling of any stratospheric split and subsequent warmings are not easy for the models to perform - the dynamics of the whole stratosphere interacting with the troposphere have been modeled inconsistently this winter - sometimes well and sometimes not so well. We have seen the disruption to the stratosphere that we would expect in an El Nino eQBO year, but have yet to reep the rewards. However with such uncertaintity with the strat that is still 'ripe' for further disruption, we should not rule out a sudden change in tropospheric synoptics. It wouldn't take that much of a change in what is forecast stratospherically to produce this.

Indeed Chiono. very much as the latter stages of todays 12z GFS para would suggest. let us hope this trend is our friend.

December 19, 2014

Great to see some genuine excitement in this thread based on more than our own interpretations of each model run. Ian F's interventions have certainly upped the ante somewhat.

This should come as no surprise reall . Retron over on TWO pointed out that last nights nights ECM control run would have brought snow to nearly all parts of the UK by day ten.

Also one of the BBC forecasts looking at next week and beyond raised the possibility of snow and strong winds to low levels in the far south. So eyebrows must really being raised over some of the possible outcomes at the met Office.

The models are becoming genuinely interesting at last.

December 15, 2014

This is a brilliant guide Steve.

Having worked outside most of my working life since 1976 I thin k I have been out and about in most of the levels on the guide.

Proud to say I have been witness to level 13 snow on the night of 18th/19th February 1978 down here in Dorset in the great Southwest Blizzard.

Another incident I remember vividly which would probably count as level 12 and that was the start of a Blizzard on sunday 13th December 1981 when I watched a vast curtain of white advance across Poole harbour from the Purbeck hills looking not unlike some of those amazing shots from the recent Buffalo lake effect storms, once it reached me at Broadstone it pelted down with 50p flakes that covered the ground and everything else in less than a minute.

December 10, 2014

Well as a young hand I find it totally incredible that anyone would wish for a repeat of the winter of 62-3. Reading this sort of comment I must admit I do have have serious concerns regarding the mental stability of some in this area, Still "Hope Springs Eternal"

Hi Knocker,

I'm not sure you took my post in the vein that it was intended, because nowhere in it did I say that I was wishing for another 62/3 or 47. Iwas just pointing out that those two exceptional winters did not start early in the season.

I know sometimes one can react to a post without reading it properly, Still hope springs eternal eh.

December 9, 2014

I know some posters find it difficult when nothing particularly easterly or snowy is showing in the models, and some of you are probably heartily sick of old hands like myself telling you that patience is the watchword but it is worth remembering that the winter of 63 didn't really get properly cold until 23rd Dec which at the moment is well beyond the reliable timeframe.

Also the snowiest winter of the last 200 years namely 1947 didn't get cold and snowy until the 21st January.

So just hang in there.

December 7, 2014

Thanks for this Barry You are however wrong on both counts you suggest :

1) I have explained in extended detail, as much as I am able, the progress of the patterns thus far from autumn (see first posts back in October in OPI thread and then continued on this MOD thread thereafter last month and into this). Many of these posts have had copied entries to illustrate continuity of thought so that progress can be checked and thereby form a very transparent check for accuracy. But most importantly of all (as far as I am concerned) for learning when mistakes are made - as they most certainly will be in a science as complicated and unpredictable when it comes to evaluating weather and weather patterns..........................................................

A superb and detailed post Tamara, not to say a great riposte to those who seem to throw their toys out of the pram because the charts don't show what they want to see..................... yet.

Yourself and other very experienced and knowledgable posters ( as opposed to chart commentators) have always pointed out that this winter was likely to be a slow burner which was unlikely to see a pattern change until mid to late December at the earliest. So why any one would want to comment that it hasn't happened yet or they cannot see it in the model output is as you say somewhat bewildering.

45 years of weather watching in the British winter has taught me one thing and that is that the watch word in the search for cold and snow from Northern Blocking is patience. Unfortunately we now live in a society governed by instant gratification where most things can be accessed at the touch of a button. The weather, thank heavens is not one of those things that we can have at the touch of a button which is what makes it so interesting.

December 5, 2014

Looks like the 12Z GFS is trying to bring us a polar low next weekend;

November 28, 2014

Major amplification on the ECM tonight with a connection opening to the arctic High. This would sure accelerate the feedback processes..if it happened

We know that ECM is prone to over amplification but this is exactly the type of evolution we are looking for further down the road to lead us to the important next step to a colder pattern - and with wave breaking feedbacks in the atlantic sector.

To illustrate this further, see how at day 10 (if we assume at face value the ECM operational verified) the heights are building again over Scandinavia.

Pattern re-cycle following the transfer of energy across the pole as modelled this week - and much as I mentioned in my post a day or two back

Its a case of if/when this happens. Very arguably not when ECM suggests here, but it does show the template for the way ahead as we go through December.