Winter Model Discussion 18Z 19/1/13 onwards.

[TEITS]

Rather than some who are saying the models are wrong and so and so will happen without any back up whatsoever. Im going to post a chart from the 18Z at +36 and illustrate why the outlook is poor and why it has gone so wrong.

Look below and you will see two lobes of PV which I have highlighted A & B.

Now many were hoping or I should say predicting that A would weaken and B would back SW into Scandi. Look at the chart below at +144 from the 18Z GFS.

If this is right at +144 then the forecast was completely wrong because A is moving E and B is moving N!

The ECM is predicting exactly the same.

This is why the models are consistently predicting mild SW/W,lys because PV A is moving E and isn't weakening. The only way we could see our cold spell remain is if the models are completely wrong with regards to the amount of energy E the models are suggesting from PV A. The problem for us is we're running out of time because its very unlikely the GFS/ECM are wrong at this timeframe. However the only straw to clutch is the 06Z/18Z GFS did give us a glimmer of hope at +90 but for the moment thats all it remains a glimmer.

[Jason M]

Ensembles out to 192 and they are zonal on speed. No 13 is a great run, No 3 is promising but the rest are about as zonal as it gets.

Pressure looks like rising to our SE in response to the PV sat to our NW.

Will it change? hopefully - onwards to tommorow.

Jason

Edited January 21, 2013 by Jason M

[damianslaw]

The models all agree on a forceful Atlantic attack by thé weekend, however, given upstream signals couples simply by the fact that the pv Naturally weakens in february, im expecting à vert shortlived atlantic spell to end the month before à marked change to much colder conditions and this time with muchmm more robust northern blocking just my take on things

[igloo]

Wouldn't mind if we get a raging Bartlett next week, 2 week cold spell with snow is enough for me

be careful what you wish for we have seen bartlett setups lasting 3-4 weeks at a time in the 90s with huge amounts of rainfall not great for many.but with over a foot of snow lying and blowing a blizzard outside my house up here at the minute a welcome thaw would not be the end of the world

Edited January 21, 2013 by igloo

[M1JWR]

Did sombody say the magic words

bartlett/euro high

would be nice, as its the best way to melt all that snow with the minimum disruption

not a coldie i'm afraid, i work outdoors, for me snow is the worst, followed quickly by

mr jack frost, i remember 1982, no central heating then, we were all clammed around

a coal fire and an aga cooker, got down to -27, having said that i am no fan of shed loads

of rain either.

back to the models people.

[Timmytour]

SST's come under my level of expertise and with relation to SST and LRF, the atlantic SST profile has been screaming for height rises to our N and NW for this winter way before it started with a classic atlantic tripole. This led me to believe Greenland highs would be common this winter but this has been proven incorrect so far and shows there are plenty of variables needed to have something like that although once this canadian vortex gets out the way, I think we have a lot better chance. In regards to the strat being one of many factors, very true however i have always believed SST anomalies have been inportant for LRF but not so much anymore, i think the stratosphere, although one of many factors, is the biggest overriding factor we have and has proven this the last couple of weeks. It delivered a hemispheric change and without it, i felt we would have been stuck with the mild weather early jan for a while, maybe the rest of the winter. Sorry for a bit off topic guys and i agree with you Dave with you simply commenting on a poor NWP output at the moment for the future. However, im not going to make too many comments for a few days at least because i believe we will see height rises appear to our NW on ensembles in particular and GFS ops in the coming week or two but a poor poor output currently but the mild spell may be needed for a future cold spell to develop

Well we certainly had a mild spell before this current cold one. What puzzles me a little though is that the models were showing the cold spell to come in FI and indeed it seemed to be developing, before the SSW was actually supposed to have impacted, was it not? So I'm not sure the cold spell is directly attributable to it...it might have helped, but i believe we can have cold spells without it.

I believe anything that messes up the PV however has to give us a chance of benefitting from the fallout.... but its only chances and not certainty. And indeed if we are caught in the upstream of what can then move up to the Arctic, then we can get springlike rather than arctic weather. Would i be right in thinking that's what happened in the latter part of Feb 09 when, similar in some ways to recently, GP was posting up in a cold early Feb spell about the winter getting more severe in the second half.

i have a high regard for what he does, but i think he has an understandable excitement and enthusiasm at times for mistaking the opportunities that arise from it for the certainty of more severe cold spell following a cold spell. it's like being the underdog and then winning a corner. Sometimes i feel that too many fans want too many players commited forward for it, but I'm one of those who, while is hoping that we do score from it, is nonetheless wary of spring scoring on the counter attack

Edited January 21, 2013 by Timmytour

[Downburst]

No doubt you can read the output. People are perhaps upset that whilst commenting on the output you often make reference to GP and co. and the output not currently showing their thoughts.

Look you need a wide range of analysis. Believe me it is helpful in the long run. Think of it as another member in a run. And nothing is certain, not even this years fav, SSW. We might be back to compelling arguments for sea surface anomalies or snow cover, or the recently dropped ENSO certainties.

[matty lfc]

Have long range forecasts become the emperors new clothes?

All the super computers,the uni degrees etc,breaking down every single model run with fancy reasons for this and that when the truth of the matter is that we cant predict the weather in this country beyond 120 hours. Anything over that is guesswork,granted some educated, but guesswork nevertheless.

It doesn't matter if it's GP,the meto or a newbie like me.At that range we'll be right some of the time and miles out most of the time.

[london-snow]

Seems my post upset a few but im merely commenting on what the models are showing. I really don't see how im having a dig at GP, CH but simply suggesting that the current model output does not suggest anything other than a spell of mild SW,lys. I realise the output could change in FI but you don't need to be an expert to realise this.

Someone asked how can I have such faith in the model output over recent events. Well the answer is broadly speaking the models are now singing the same tune which cannot be said in recent days. We are also seeing a change to a more mobile pattern which the models generally handle much better.

Overall very disappointing output and synoptically speaking its been a disappointing winter overall. We did very well with regards to snowfall these past 8 days considering we didn't exactly have mega blocking and it proves you don't always need it. However the GH remains elusive and the NAO simply refuses to go into negative values.

I feel that your disappointed thus far this winter because you are expecting a 2010 every winter which won't happen every year.

I make you right regarding you are only stating on what is currently being shown in the models & that is for milder weather to push in over the weekend.

However i feel the following points should be made -

1 ~

We have no confidence on what the models show after the initial breakdown to milder weather it could be breif or it could stick around.

2 ~

The fact that our own lrf guys with great records has punted for a cold feb months ago & are still very confident to this day fills me with confidence.

3 ~

OP'S,Ensembles,NAO, will not reflect the correct output in 2 weeks out when i feel something is afoot cold weather wise.

4 ~

It can take up to a month from a ssw to filter into & effect our weather patterns.

5~

I feel that the likes of op runs and ensembles do not handle or factor in the affects of a ssw event straight away and is always behind the 8 ball.

I have always put you down as a guy who is always a glass half full however going by your previous comments you have drunk the pub dry on this one.

Time will tell & i will be more than happy to say sorry if you are correct but i feel that there is a lot more cold weather to come early feb.

[A.J]

Well, moving much closer in, the hi-res modelling have been progging some interesting weather for the largely ignored south west of England, and they haven't disappointed, currently heavysnow, lightning, thunder, hail, sleet & the odd kitchen sink being thrown in for good measure. both specialist hi-res models the NAE & NMM as well as the GFS & ECM infer an interesting next 24-36 hours or so for us

[SnowBallz]

Have long range forecasts become the emperors new clothes?

All the super computers,the uni degrees etc,breaking down every single model run with fancy reasons for this and that when the truth of the matter is that we cant predict the weather in this country beyond 120 hours. Anything over that is guesswork,granted some educated, but guesswork nevertheless.

It doesn't matter if it's GP,the meto or a newbie like me.At that range we'll be right some of the time and miles out most of the time.

The irony being, 20yrs ago, there would've been a similar person pontificating that 'the truth of the matter is that we cant predict the weather in this country beyond 24 hours. Anything over that is guesswork,granted some educated, but guesswork nevertheless.'

You obviously take it for granted that there is an ability to forecast the weather out to 120hrs. It's those exact supercomputers and university degrees - whom you refer to so flippantly - which has given us that capability. If you take a phenomenon like Sudden Stratospheric Warming, potentially that's a new frontier in atmospheric understanding; one which could further extend the range of our confidence in a forecast. If you're really into meteorology, then that's exciting stuff.

Ensemble analysis, higher resolution layering, feedback cycling, and more and more powerful supercomputing resource IS the future of NWP. It's because it has to be. Every year there are hundreds, if not thousands, of experiments conducted by either universities or research institutions into various aspects of the weather and/or climate. It's the nuggets from those experiments; the little gems of knowledge or a relationship, that can help to refine what are inherently volatile algorithms.

It's really not about being 'fancy' either. Meteorology is a very, very, very complex field of science with an almost unimaginable level of complexity. But, where we - as scientists - to approach that complexity with such a defeatist attitude, then we wouldn't be able to have that confidence in 120hr computer-generated forecasts. There's an education to be had, for anyone who is willing enough to take the time and effort to understand the weather, more that it being just some random pretty pictures.

[Barry12]

The irony being, 20yrs ago, there would've been a similar person pontificating that 'the truth of the matter is that we cant predict the weather in this country beyond 24 hours. Anything over that is guesswork,granted some educated, but guesswork nevertheless.'

You obviously take it for granted that there is an ability to forecast the weather out to 120hrs. It's those exact supercomputers and university degrees - whom you refer to so flippantly - which has given us that capability. If you take a phenomenon like Sudden Stratospheric Warming, potentially that's a new frontier in atmospheric understanding; one which could further extend the range of our confidence in a forecast. If you're really into meteorology, then that's exciting stuff.

Ensemble analysis, higher resolution layering, feedback cycling, and more and more powerful supercomputing resource IS the future of NWP. It's because it has to be. Every year there are hundreds, if not thousands, of experiments conducted by either universities or research institutions into various aspects of the weather and/or climate. It's the nuggets from those experiments; the little gems of knowledge or a relationship, that can help to refine what are inherently volatile algorithms.

It's really not about being 'fancy' either. Meteorology is a very, very, very complex field of science with an almost unimaginable level of complexity. But, where we - as scientists - to approach that complexity with such a defeatist attitude, then we wouldn't be able to have that confidence in 120hr computer-generated forecasts. There's an education to be had, for anyone who is willing enough to take the time and effort to understand the weather, more that it being just some random pretty pictures.

Do you have any qualifications in Science/Meteorology?

...Best leave it to the people who know what there talking about and not adding big words to try and sound clever

Edited January 22, 2013 by Barry95

[Nigerian Prince]

So it will be turning mild and unsettled at the weekend,according to the models, and according to must people on here today, from what they can see, its a done deal, the reality is that the mild spell at the weekend is not a done deal,. well not yet, as the forecaster on BBC as just said, there is just a suggestion, it might turn milder at the weekend, history allways suggest, that very cold air, once in place, is much harder to displace than most of the models suggest. LETS SEE WHAT THE MODELS WILL THROW AT US LATER ...............

[Winter Monsoon]

Do you have any qualifications in Science/Meteorology?

...Best leave it to the people who know what there talking about and not adding big words to try and sound clever

WTF!!??? Do you realise how derogatory that post sounds? do YOU have qualifications??? Best leave those derogatory (or sexist??) remarks for the playground....TROLL

Completely uncalled for

Edited January 22, 2013 by Winter Monsoon

[ABCD]

Do you have any qualifications in Science/Meteorology?

...Best leave it to the people who know what there talking about and not adding big words to try and sound clever

I'm sure if you ask her nicely enough she'll explain to you what all those big words mean, Barry.

[mike Meehan]

The irony being, 20yrs ago, there would've been a similar person pontificating that 'the truth of the matter is that we cant predict the weather in this country beyond 24 hours. Anything over that is guesswork,granted some educated, but guesswork nevertheless.'

You obviously take it for granted that there is an ability to forecast the weather out to 120hrs. It's those exact supercomputers and university degrees - whom you refer to so flippantly - which has given us that capability. If you take a phenomenon like Sudden Stratospheric Warming, potentially that's a new frontier in atmospheric understanding; one which could further extend the range of our confidence in a forecast. If you're really into meteorology, then that's exciting stuff.

Ensemble analysis, higher resolution layering, feedback cycling, and more and more powerful supercomputing resource IS the future of NWP. It's because it has to be. Every year there are hundreds, if not thousands, of experiments conducted by either universities or research institutions into various aspects of the weather and/or climate. It's the nuggets from those experiments; the little gems of knowledge or a relationship, that can help to refine what are inherently volatile algorithms.

It's really not about being 'fancy' either. Meteorology is a very, very, very complex field of science with an almost unimaginable level of complexity. But, where we - as scientists - to approach that complexity with such a defeatist attitude, then we wouldn't be able to have that confidence in 120hr computer-generated forecasts. There's an education to be had, for anyone who is willing enough to take the time and effort to understand the weather, more that it being just some random pretty pictures.

I agree with you inasmuch as since 1963 when I left the Met Office, there have been enormous strides made in research and computer programs, so much so that a lot of the terminology used today is somewhat akin to a foreign language to me today.

However having said that I do wonder whether at times too much reliance is being put on the computer models, which at the end of the day are only as good as the information put in, albeit that the latest forecasts have been quite accurate in the short term and under favourable conditions can be fairly accurate up to 5 days ahead.

At this stage of the evolution of meteorology there still has to be a fairly large human imput to interpret the different signals correctly and this is where the experience and if I dare say it, the intuition of the forecaster also comes into play together with a willingness to look out of the window and see what is actually happening.

To illustrate what I mean, the forecaster who correctly forecasted a weather window for the D Day landings in 1944 is not lost on me and at that time he would have had nothing like the information what is available today, nor the other wartime forecasters who had to use their experience to determine the weather conditions over Germany with the only possible source of information, apart from that which had already passed by and that of returning aircrews who very often had their first priority of trying to remain alive, with perhaps the odd agent, if he thought about it.

But as I suggested in an earlier post, improvements are likely as a result of the continuing research, though human experience, knowlege and expertise is still vital in making an accurate forecast.

[full_frontal_occlusion]

There is only one way to treat people who post derogatory remarks in the hope of provoking a response.

Ignore them.

I can't help but think there is a smidgen of jealousy in some peoples post's.

Who was it once said 'science is 1% inspiration, 99% perspiration?'

Meteorology has a long way to go, but thank goodness there are people prepared to dedicate their lives to pushing forward the boundaries of knowledge.

And to do it in such a public way takes courage and confidence.

Long may they continue.

ffO.

[shotski]

Wow, I wasn't expecting that overnight from the GFS 18z and 00z.

We end up with a Euro high scenario at +192 on both runs ? cant wait to

see what the more senior members make of it as I'm at a loss to be honest

[snowblues]

Wow, I wasn't expecting that overnight from the GFS 18z and 00z.

We end up with a Euro high scenario at +192 on both runs ? cant wait to

see what the more senior members make of it as I'm at a loss to be honest

I was thinking maybe a bit of atrend there too,even at T120 the atlantic held a little with some advection pushing north ito Iceland.A little trend.Maybe? Edited January 22, 2013 by snowblues

[Ryan Dutch Weatherman]

I see at the LT strong blockings from de controlle 00z GFS ens the 00z GFS debt, operationeel.

Wateffer will happen end of the months SW for Britain or the Euro High , it will be short lifted.

Cold spells will occure in the month of februari als in begin march i think.

The block wile be restored , but the pattern wil be different this time , i think more directly from the north rather than easters or NNE.

Time will time , but i am very confident in this solution.

[shotski]

I was thinking maybe a bit of atrend there too,even at T120 the atlantic held a little with some advection pushing north ito Iceland.A little trend.Maybe?

To be honest I'm 50/50 at the moment if this is a good or bad development.

All we would need is for some energy to undercut the Euro High and we could

be game on big time, but that wont happen.................will it ?

[Weather-history]

The stratosphere is one piece of a jigsaw amongst many. However some of these pieces are bigger than others i.e SSTs. I just feel the Stratosphere isn't as big as some believe on here. I generally have a negative view of LRFs whoever produces them because in my opinion we cannot fit all these pieces together to complete the puzzle.

I think the stratosphere should be looked at this way, it's like if you are daft enough to smoke. You increase your chances of getting cancer etc from smoking but it is not guaranteed you will get these problems. Same with a favourable stratosphere.

[IDO]

Not much change today apart that the pattern has been pushed north with the AH now ridging over the UK and joining the high to our east. This keeps the zonal flow to our north:

ECM at T240: GFS:

GFS at T384 has the AH ridging again. However the PV over W Greenland looks like it may topple that one again:

So a trend towards height rising from the south which is good as we are not getting much help for HLB from the pole.

Support for this pressure rise to be as far north only fledgling at the moment: so the maintenance of the lower temps a bit of an outlier at the moment (D8-10).

Too early to know where that HP will be in situ close to the UK. A transient period of less cold still the likely scenario after the breakdown this weekend.

Edited January 22, 2013 by i'm dreaming of...

[shaky]

Saturday is looking very interesting for a snow breakdown from both the gfs and ecmwf!!

[Tom D]

Just a quick one. Encouraging signs on the GEFS regarding the wider synoptic pattern. Low confidence at the moment.

What I see is a (low confidence) trend to high pressure building over Reykjavik and low pressure in Scandinavia (a reversal of the present pattern).

Which gives us this kind of set-up.