General Model Output Discussion

[Guest North Sea Snow Convection]

Actually after having a closer look they aren't that different from last night really, still air frosts saturday and monday night, by the sounds of some posts i thought we were in for a mega warm up or something.

Not bad outlook at all really with HP building again over us early next week, who knows what might transpire from there at this range

Definitely the end of the current long cold spell after the snow in the next 24 hrs. As you say, hopefully we will get HP building over us next week to keep things reasonably seasonal. Certainly would settle for that rather than a breakdown to atlantic wind and rain. A return to the hideous weather of Nov/early Dec doesn't bear thinking about.

The block to the east is still depicted by ECM and GEM, especially, to perhaps try and influence things in the further outlook. There is little doubt however that its suggested placing has slipped just a little further south so whilst a return to continental conditions looks quite possible, I think the chances of a properly cold reload have reduced.

Should this not reload happen, then it might well be the case that the most intense cold weather of the winter is now about to pass by. Not meaning to say by any means that we won't see any more snow before the days really draw out towards Spring, but I think the window of opportunity for another more sustained and deeper cold spell is starting to fade increasingly quickly away with signals for Feb suggesting we might see a different last third of winter.

[Methuselah]

Could not agree more re your comments as regards model output as regards trends. I am sure many that visit this thread only want to see cold and then if it does not show start throwing the toys out the pram. lol

However, to my untrained eye looking at the models it is clear the jet will remain far to our south, leaving us on the cold side the jet, so temperature are not likely to be that mild, giving a chance for much more snow than we have become used to - even if it is snow then a thaw rota. However, with the AO looking to stay on the negative side, and the solar conditons I would give a high chance that February will be very cold. Don't forget that synoptics can change at very short notice, almost out the blue, and so a reload could be possible at short notice. Personally though I will be glad of a thaw, even if temporary to clear the roads and to see a bit of green for a change; many folk have on the high ground been trapped in their homes for more than a week. And peeps like me that suffer from chest problems are forced to in the main stay indoors. In the short term it does look at though the far SW may reach double digits by the weekend, hopefully us here on the high ground will at least reach high single figures....I expect the cold will return next week though.

Absolutely agree, DL. The whole synopsis reminds me of the 1960s - when a mild spell would last for maybe 2 weeks; and mild meant 8C - and not 16!

[TEITS]

And with perturbations like these which shows what could transpire i am astonished hardly anybody is positive today, this has support from some other members too including control and the ECM ensembles.

Seems its only me and you.

I agree with some of the posters that based on the model output the chance of a reload has decreased. However how many times so far this winter have the models progged a spell of milder weather which has failed on two occasions. I remember a Joe B forecast just after xmas saying "ignore any model that suggests a cold spell, the return of winter won't be until mid Jan". Well look at how this turned out!

At the moment I remain positive and open minded. You simply cannot ignore a Siberian HP of 1060mbs and how this may influence our weather.

As for Feb being mild and to be honest im really baffled by such statements. The month of Feb has always been the winter month when blocking is more frequent. The signals may suggest a mild month but didn't the signals suggest another cold spell wouldn't occur until mid Jan according to Joe B!

[Stu_London]

I think it is fair to say that we are now at the last knockings of what could be described as severe weather and despite a bit of tooing and froing on the operational output, it has to be said the ensembles on GFS had this nailed a good week ago (actually we are a day ahead of schedule)

However, unless there is a significant pattern change in the NH, then our weather conditions remain vulnerable to an attack from the east and I can see this being for some considerable time yet. This of course, does not guarantee a return to severe conditions, but does leave it a possibility.

Edited January 12, 2010 by Stu_London

[Snowly does it]

The pattern, to my eye, looks something like the following

Rest of this week - cold by day, cool by night, some snow chances as described, the higher up, the better.

Friday into Saturday - the irresistable force of the Atlantic meets the immovable object of the Scandi/Russian HP and we end up squeezed between the two for a day or so and a little milder (perhaps a little above average for a day or so)

Then, like squeezing a spot (eeew), it gives and HP ridges up from the Azores and leaves us under HP influence on the outer limits of the now descending Siberian HP cell (already at 1050 and growing) - this ridge has been progged consistently now.

From here we end up either at the far end of a cold train and rather cold to cold, getting colder or the HP slips alignment N-S and we end up mild looking longingly 100 miles to our East for the cold.

Worth bearing in mind is the trouble the Atlantic is having shifting the 1025 Scandi HP - reinforcements are on the way for the Scandi, are they for the Atlantic?

[Guest North Sea Snow Convection]

I think in terms of trying to be positive or appearing to be negative it is really all down to the changes that are occuring that people like JH and GP are discussing.

Also the regrouped polar vortex for the first time this winter does seem to suggest something of a proper return towards its oft seem home near Greenland, and the -NAO signal is going. Yes, we have a very large cold pressure area to our east and that is going to be a buffer indeed towards the progress of atlantic weather. However, as Mr Joe Floori has suggested, the best chance for a further cold reload is more likely to be reserved for more central parts of europe and it could well be that we will remain on the periphery of the block. Without a -NAO to encourage undercut, as we have seen so far this winter, and with the jetstream moving north we look to lose the strong retrogressive forcing we have seen so far this winter that has backed the cold west.

The positive zonal winds are starting to make their presence felt due to the cold stratosphere of late, and whilst an interesting warming is taking place atm, this is not going to have any influence on proceedings for a couple of weeks or more yet and we have to take into account GP's suggestions that the atmsophere is likely to become more nina like which will not encourage the southerly jet pattern seen so far this winter. We know from last winter that despite a colassal MMW event, that due to the nina conditions present we were unable to benefit from the full effects of the vortex split (even though we did have the early Feb cold spell for a time)

With these factors in mind, I am not so sure that a full on reload this time is quite as assured as it has been so far this winter. We may only see the fringe benefits of that huge NE'ern block with the very coldest air held back into central europe, western Russia and Scandinavia.

Edited January 12, 2010 by North Sea Snow Convection

[Stu_London]

I think in terms of trying to be positive or appearing to be negative it is really all down to the changes that are occuring that people like JH and GP are discussing.

Also the regrouped polar vortex for the first time this winter does seem to suggest something of a proper return towards its oft seem home near Greenland, and the -NAO signal is going. Yes, we have a very large cold pressure area to our east and that is going to be a buffer indeed towards the progress of atlantic weather. However, as Mr Joe Floori has suggested, the best chance for a further cold reload is more likely to be reserved for more central parts of europe and it could well be that we will remain on the periphery of the block. Without a -NAO to encourage undercut, as we have seen so far this winter, and with the jetstream moving north we look to lose the strong retrogressive forcing we have seen so far this winter that has backed the cold west.

The positive zonal winds are starting to make their presence felt due to the cold stratosphere of late, and whilst an interesting warming is taking place atm, this is not going to have any influence on proceedings for a couple of weeks or more yet and we have to take into account GP's suggestions that the atmsophere is likely to become more nina like which will not encourage the southerly jet pattern seen so far this winter. We know from last winter that despite a colassal MMW event, that due to the nina conditions present we were unable to benefit from the full effects of the vortex split (even though we did have the early Feb cold spell for a time)

With these factors in mind, I am not so sure that a full on reload this time is quite as assured as it has been so far this winter. We may only see the fringe benefits of that huge NE'ern block with the very coldest air held back into central europe, western Russia and Scandinavia.

A good assessment there Tamara and the 06z evolution demonstrates your worst case scenario very effectively.

[Snowly does it]

Ensembles currently support the 'tightrope' with a 50/50ish split after the weekend for another cold spell or a mild spell with the further East you are the lower the mean ensemble members - which again hints at where we need to look over the next few days.

All eyes NE and beckon the oncoming Arctic (or shoo it away if you have had enough cold)

[ANYWEATHER]

Another factor to consider especially this Winter is that the gfs has tried several times to bring back the Atlantic in full swing and we all know what has happened. That ginourmous high pressure will influence our weather sooner or later, but will it deliver bitter cold or as the 06z demostrates a nearmiss scenario of deep Winter....? Im still thinking this

[TEITS]

Keep an eye on that mean around the 20th to see if a dip occurs as other members follow suit.

Dip in the mean around the 20th is already occuring.

http://charts.netweather.tv/ensimages/ens.20100112/06/t850Cambridgeshire.png

Watch how more members will follow this in subsequent runs.

Whilst some think this is the end im convinced the next cold spell is on its way. I will explain why im convinced later on and some will be amazed at what im using as a forecast. Let me put it this way i've used this method since I was 10yrs old and so far has never failed me!

[sandstorm2]

Dip in the mean around the 20th is already occuring.

http://charts.netweather.tv/ensimages/ens.20100112/06/t850Cambridgeshire.png

Watch how more members will follow this in subsequent runs.

Whilst some think this is the end im convinced the next cold spell is on its way. I will explain why im convinced later on and some will be amazed at what im using as a forecast. Let me put it this way i've used this method since I was 10yrs old and so far has never failed me!

Well thats fascinating TEITS and I can't wait to hear your explanation.

Yesterday I was convinced that the mild atlantic would win but I have had a change of mind this morning after seeing the size of that high coming out of Siberia, wasn't it GP who said that the model performance would dip, that is what is now happening.

SS2

[Yozzer]

LOL, you probably made the same comments before the reload in early Jan, i find it strange people dismiss or forget the cold charts from last night but suddenly believe the runs this morning, more flips to come me thinks

Sorry Eugene, but I thought this was a discussion of the models, not of what isn't there, otherwise maybe you should be posting on a 'guess the synoptics' thread!. There is no real evidence, If there is, show it rather than mock.

And to set the record straight, no I didn't...

[snowingtequila]

What do you mean by the "Block is too far south"? The block of high pressure is to the east and northeast of the uk! How much that influences us in the days ahead is still open to question?

I meant the high pressure is too far south, which I think it is, the models seem to show it slipping SE unless I have read them wrong (which is highly likely) Although I see signs of the atlantic becomg more dominant as we go on by the models I have looked at I have not looked at the Ensembles and my own view of a likely weather pattern from experience would suggest that we could be cold and damp as we are now for a long time. I remember this once before I am not sure when but it involved 2 or 3 weeks of cold damp air just above freezing with odd attacks from the SW and some clearer weather from the east from time to time. The hills around me had constant snow cover whilst lower areas had a raw thawing feeling. My concern from the models is the positioning of the polar vortex and the run of low pressure systems running to Iceland, I am heartened that people disagree with me here and look forward to more evidence of the block moving west again!

[impster]

Whilst some think this is the end im convinced the next cold spell is on its way. I will explain why im convinced later on and some will be amazed at what im using as a forecast. Let me put it this way i've used this method since I was 10yrs old and so far has never failed me!

It's not seaweed is it????!!

[Rollo]

Dip in the mean around the 20th is already occuring.

http://charts.netweather.tv/ensimages/ens.20100112/06/t850Cambridgeshire.png

Watch how more members will follow this in subsequent runs.

Whilst some think this is the end im convinced the next cold spell is on its way. I will explain why im convinced later on and some will be amazed at what im using as a forecast. Let me put it this way i've used this method since I was 10yrs old and so far has never failed me!

I hear what you say TEITS but that vortex predicted over Greenland worries me, however whilst not having any particular scientific knowledge to go by my instincts aided by a good memory of previous battles lead me to think that you could well be right,as only time will tell I wish your forecast good luck.

[mushymanrob]

When a model 'sees' a cold-spell in FI, it's being a trendsetter; but, when the very same model 'sees' anything milder coming, it's being over progressive...

exactly! the mid breakdown first suggested by the gfs was recomended ignore it, bin it, but in reality it first picked out this slow move towards milder weather.

At the moment I remain positive and open minded. You simply cannot ignore a Siberian HP of 1060mbs and how this may influence our weather.

As for Feb being mild and to be honest im really baffled by such statements. The month of Feb has always been the winter month when blocking is more frequent. The signals may suggest a mild month but didn't the signals suggest another cold spell wouldn't occur until mid Jan according to Joe B!

i agree, as long as theres a scandi-siberian high theres always a chance of another freeze.

february can be a beautifully mild month though... 1982 springs to mind ... just after a 'new year' cold spell..

the 06z is great for those of us who prefer milder weather, the 'best' run for some time and could be a pre-cursor to GP's suggestion that february MIGHT be very warm!

[TEITS]

It's not seaweed is it????!!

No.

The 06Z ensembles on the continent are interesting.

http://www.wetterzentrale.de/pics/MT8_De_Bilt_ens.png

http://www.wetterzentrale.de/pics/MT8_Berlin_ens.png

So synoptically speaking not alot of support for the 06Z. As you can see the suggestion from those ensembles in locations such as Holland, Germany could see a return of cold E,lys. So the question is will this E,ly come to the UK or will the PV prevent it? Well you know my answer!

The Met O outlook speaks of wintry showers, frosts and even says "the transition to less cold weather is uncertain".

[ANYWEATHER]

Sorry Eugene, but I thought this was a discussion of the models, not of what isn't there, otherwise maybe you should be posting on a 'guess the synoptics' thread!. There is no real evidence, If there is, show it rather than mock.

And to set the record straight, no I didn't...

Well, ok this may happen ,perhaps not, but all models develop a very intense high pressure over Western Russia and extending west towards Scandinavia and further west towards the UK. It cant be ignored and the mighty Atlantic will put up a fight and if you follow the models day by day you will see that somewhat milder weather the weekend, but even that is still open to question as to how mild. With such a cold and intense high pressure out to the east its very likely to affect the uk ,just look back at the history books and this will testify. Ok its not 100% certain but I think another very cold setup is likely from this setup, If I was a betting man I know which I would back!!

[Weather-history]

Manchester 06z pressure ensembles suggest to me not a strong Atlantic dominance. The pressure mean is about 1020mb after peaking 1030mb from the 19th. Its not a suggestion of a return to a colder weather, the 2m temps suggest this but neither does it suggest the Atlantic dominating. If it was as I said before those pressure means would be lower.

http://www.wzkarten3.de/pics/MT2_Manchester_ens.png

Edited January 12, 2010 by Mr_Data

[Methuselah]

Dip in the mean around the 20th is already occuring.

http://charts.netweather.tv/ensimages/ens.20100112/06/t850Cambridgeshire.png

Watch how more members will follow this in subsequent runs.

Whilst some think this is the end im convinced the next cold spell is on its way. I will explain why im convinced later on and some will be amazed at what im using as a forecast. Let me put it this way i've used this method since I was 10yrs old and so far has never failed me!

Lol Dave...Watch-out no-one calls out the Old Bill!!! :rofl:

[Craigers]

No.

The 06Z ensembles on the continent are interesting.

http://www.wetterzentrale.de/pics/MT8_De_Bilt_ens.png

http://www.wetterzentrale.de/pics/MT8_Berlin_ens.png

So synoptically speaking not alot of support for the 06Z. As you can see the suggestion from those ensembles in locations such as Holland, Germany could see a return of cold E,lys. So the question is will this E,ly come to the UK or will the PV prevent it? Well you know my answer!

The Met O outlook speaks of wintry showers, frosts and even says "the transition to less cold weather is uncertain".

I've been on here since 2004 and TETIS always seems to spot the correct trend when it comes to easterlies! I totally agree with you that the next cold spell is coming back! I was amazed when people are saying February will be mild even though the SEA temperature will be very low this year and with the solid blocking usually at this time of the year! surely we could be seeing a development on the models for a perlonged cold spell coming from the east or north east? The ECM has been hinting this for past 3-4days!

[SP1986]

The sea temperature means very little though, it's a case of chicken and egg, how does one expect sea temperature to rise if there's no warmth.. the sea temperature only features in the right synoptic patterns.

I myself cannot share the enthusiasm and certainty than an easterly will occur, I instead suggest a slow laboured return to Atlantic westerlies. Of course of the Easterly idea goes wrong, we can always have a Bartlett?

[BLAST FROM THE PAST]

Manchester 06z pressure ensembles suggest to me not a strong Atlantic dominance. The pressure mean is about 1020mb after peaking 1030mb from the 19th. Its not a suggestion of a return to a colder weather, the 2m temps suggest this but neither does it suggest the Atlantic dominating. If it was as I said before those pressure means would be lower.

http://www.wzkarten3.de/pics/MT2_Manchester_ens.png

That suggests to me that the models will change quite near frame over the next 2 days to start to show the jet kicking south again. I'm not expecting a re-load of intense cold but cold conditions to re-assert from the weekend onwards [-5 uppers]. I fully expect the Atlantic to roar in last week of Jan too though, with period 25-31 to look out for, for strong Atlantic LP system/s. Yesterdays ECM was too much of a blip to be a blip.

Out of interest some talk on ACCU is of a pattern developing in the SW USA similar to that that occurred early Dec. Now bearing that in mind and how this winter has panned out so far and the timings...what may that say for very early Feb? One of the reasons why I'm holding fire at the moment, how the hemisphere reacts over the next 6-7 days will help me determine the longerterm outlook.

BFTP

Edited January 12, 2010 by BLAST FROM THE PAST

[mushymanrob]

I've been on here since 2004 and TETIS always seems to spot the correct trend when it comes to easterlies! I totally agree with you that the next cold spell is coming back! I was amazed when people are saying February will be mild even though the SEA temperature will be very low this year and with the solid blocking usually at this time of the year! surely we could be seeing a development on the models for a perlonged cold spell coming from the east or north east? The ECM has been hinting this for past 3-4days!

no ones said february WILL be mild... Glacier Point (who is very good at interpreting upstream developments) suggested that february MIGHT be a warm one, IF the 'upstream' signals translate into reality.

[chionomaniac]

Dip in the mean around the 20th is already occuring.

http://charts.netweather.tv/ensimages/ens.20100112/06/t850Cambridgeshire.png

Watch how more members will follow this in subsequent runs.

Whilst some think this is the end im convinced the next cold spell is on its way. I will explain why im convinced later on and some will be amazed at what im using as a forecast. Let me put it this way i've used this method since I was 10yrs old and so far has never failed me!

You haven't been scribbling on your wallpaper again have you Dave?!!!!

I do agree increasing support in the ensembles after each run is very encouraging.