Model Output Discussion

[Lewis]

Its not further south Lewis and in fact the high is at a slightly better angle on the 12z then the 06z, however the end result will stil lbe the same as the upper fetch isn't enough and the air probably will be overall a little too stable after Thursday for most.

Also past 144hrs there isn't enough of a trigger to really drag down any decent northerrly either so may get stuck in a broadly anti-cyclonic flow till it totally transfers into a west based feature...remaining cold though as long as it hangs nearby.

It is further south, like TEITS said by about 30 miles.

To some people that's nothing, but in modeling terms it's a lot.

[Eugene]

Nice steady pattern out to this weekend, with high confidence i can tell people they can go out and enjoy the weather this weekend instead of hiding away indoors from Heavy Rain, well until the weekend of February 27th/28th that is

http://www.wetterzentrale.de/pics/Rtavn13817.png

Harsh frosts likely at night away from the cloudier southeast.

Nowhere near to a atlantic breakdown and that at T+144 hrs the limit of what to believe really.

http://www.wetterzentrale.de/pics/Rtavn1441.png - Slower retrogression should help prolong the cold spell.

[TEITS]

It has nothing to do with SE/EA bias.

People really need to chill out and stop biting, i'm discussing the model output. Some member are just clutching to a lost cause, learn when to let go, otherwise it will get the better of you.

Nothing to do with biting.

When I posted my model summary a few days ago I suggested E Anglia/SE look most favoured. This led to some members including yourself saying I was being biased to the SE. The reason at the time why I said this wasn't because I was being biased but just referring to what the model output suggested. Now the UKMO 12Z/GFS 12Z continue to hint at snow showers for E Anglia and particularly Kent. I admit the snow showers won't be as widespread as I intially hoped for. However the main areas still look likely to see some snowfall.

Have to say some members are disappointed not because of the moel output but because their expectations were too high in the first place!

Edited February 8, 2010 by THE EYE IN THE SKY

[Duane S.]

Lets see what the ECM shows.

I would appreciate this post staying as it is relevant to the model thread. It isn't about people biting when they see a downgrade at all Lewis, it's when they see a poster (and it's often you) misleading others as a result of their own hysteria.

The high pressure isn't trending south at all. Its angle on the 12z is better than the 06z if you want to be pedantic and believe every GFS model every 6 hours. The recent issue has been that the HP will be too close for most for anything decent bar the SE for a few days before we get into the unknown and potential increases for everyone.

EDIT: Ah, you beat me to it with your comment about the improved angle of the HP cell on the 12z, Kold Weather

Edited February 8, 2010 by Coast

[Yeti]

There you go;

Really I don't see what the big issue is at the moment - this was always going to be more of an event for SE/E Anglia as soon as it appeared within the more reliable timeframe and I don't see much output to change that?

Easterlies rarely affect the whole of the UK - in fact they are usually severest in the SE - and people were warned of this a few days ago but as usual, many seemed intent on ramping it up: blizzard this, Feb 86 that. There has been a SLIGHT shunt Swards but this is almost always the case with the models, and often they readjust (upgrade) later on to reach a halfway house. Besides, the difference this will actually make at the surface, as TEITS says, is really very small indeed. Snow showers could still crop up in most areas with more and more the further S and E you go.

It still looks an exciting week for many, and even if it doesn't snow, at least it will be relatively settled, cold and sunny.

http://www.wetterzentrale.de/pics/Rtavn961.png

Doesn't seem a bad chart to me considering we were looking at raging SW'lies just a week ago!

[cheshire snow]

Complete novice at looking at the models,so please be gentle,but to my untrained eye it looks like the HP is moving more

NE,hense giving a more easterly flow come weekend instaed of the proged Northerly

C.S

[yamkin]

Very disappointing 12z in the short term from GFS and UKM

Where does it all go wrong?

UKM at 42 hours looks good, all we needed was a trough to dig west and we would of got something.

As it is for my location, a few days ago we were definately getting the -10c sub pool not its about 100/150 miles to the south.

It will be interesting what the ECM 12Z shows later on. What is more important will be the MetO's LRF outlook tomorrow afternoon. The MetO have been spot on with this current cold period using their human input when the models seemed to be having difficulties.

[kold weather]

Yep still looks nice and cold for a while to come yet and thats the key thing, looks like a fairly stable pattern as well looking at the 12z GFS run. Daytime temps rise a little once we lose the easterly airflow and we get into an anticyclonic northerly type of airflow until we eventually see the -ve NAO turn more west-based and we hopefully we more of a pure northerly, though of course that has its own real risks...

[mountain shadow]

A much slower retrogression leads to a far better northerly down the line..

Not to be sniffed at.

http://charts.netweather.tv/gfsimages/gfs.20100208/12/240/h500slp.png

Sorry but have to agree with Lewis. He has a good point and thats how he sees the models and what he thinks will happen. If the ECM shows the same I think Lewis will have his trend.

Agree with him or not, we want a slower retrogression.....

http://charts.netweather.tv/gfsimages/gfs.20100208/12/288/hgt500-1000.png

[Climate Man]

Whilst there is some concern over the use of the term, the latest GFS suggests a slight upgrade - perhaps not for snow but at least for cold and longevity of the cold spell. Better placement of HP and towards FI a slight drift to the East will make for some interest.

[weather eater]

I think the use of terms such as 'upgrades' and 'downgrades' is unhelpful on a model discussion thread. It appears to me that models just change, which means some area will 'upgrade' and some will 'downgrade' depending on how the models change. There have of course been many changes in the models over the last ten days viz-a-viz a cold spell and things have changed further over the last 48 hours, particularly with regard to a full-blown long- lasting easterly. If you look back at last week, many were posting charts for later this week showing an easterly from western Russia to mid-Atlantic, with a double HP over Scandinavia and Greenland, which obviously raises expectations. This may of course still happen, but does not seem that likely.

I think some of the more experienced (and dare I say older) contributors should be more aware than there are many younger posters on here (not me unfortunately) that might read more into the post than you are meaning and therefore when a lot of FI charts showing deep cold at +240 are posted, you have to accept a certain degree of disppointment when these disappear, as there is excitement when the post is originally made. (And no TEITS, I am not aiming this comment specifically at you.)

And for what it's worth, I think TEITS' summary for this week looks pretty realistic to me.

Yep have said before that the words upgrade and downgrade should be banned from the model thread. If we look back to last week when the models were predicting mild SWlys for this week then surely we have seen a massive upgrade, thus demonstrating how poorly used these two words are, especially given the amount of posts that feature the word downgrade to describe one or two recent runs, plus of course it shows the foolishness of trusting projections for a week ahead whether they show mild or cold unfortunately the ultra optimists and the ultra pessimists can’t seem to stop themselves from doing this. While we are at it lets get rid of the phrase, if this run verifies, as projections several days ahead really never do, except in a very broad sense, this word also gives a false message to less experienced members by inferring that climate modelling is just really a case of adding two and two together to make four, instead of two plus any other random number you can think of, thus making 3, 4, 5, 6, 7, etc. Perhaps we should change the title of the thread to, Model Output Discussion a study in Chaos Theory as that would be more apt.

In terms of the models I think there’s much to be happy with, a cold week ahead, mainly dry for most with HP close by. There after retrogression to Greenland still looks the odds on favorite, thus introducing a more northerly regime, as usual a prognosis subject to revision as the models continue getting to grips with the evolution.

[Tom D]

Charts still looking good today, GFS currently showing a less strong easterly flow but there's still time between now and then which is important - ECM/UKMO still showing some potential snow/wind for EA and SE, maybe E Midlands and south coast too. It is looking cold and dry for much of the rest of the country however cold will become embedded and with cold comes snow.

Interestingly a trend picked up in the last couple of GFS beyond +192 is the northerly the ECM was showing a couple of days ago, so some longevity in this spell. It's looking increasingly likely that after an anti-cyclonic spell across most of the country we look to the north once more.

The bickering between members on here in unnecessary; take a look back at the winter so far and take a look at the charts on every model and you're bickering over nothing.

[TEITS]

Whilst there is some concern over the use of the term, the latest GFS suggests a slight upgrade - perhaps not for snow but at least for cold and longevity of the cold spell. Better placement of HP and towards FI a slight drift to the East will make for some interest.

Yes im very pleased with the overall trend of the 12Z.

I remain unconvinced of a W based NAO. I do think this will eventually happen but not until we have seen some fun and games from the N.

As I said back on Saturday, there is the potential for week 2 to be more wintry than week 1. However alot of uncertainity with the details as you would expect.

[NorthantsSnow]

Bring on the northerly in week 2. Better chance of significant snow from this little lot.

http://charts.netweather.tv/gfsimages/gfs.20100208/12/276/h850t850eu.png

[nick sussex]

ok ok guys, i won't post.. simple

Suppose to be a model thread, i post what i see, that's all i have ever done.

Some of you need to take your glass'es off, they seem to be steamed up slightly.

Spitting your dummies out because i said the HP is further South and the colder air is all going into France, who was it that also posted this earlier. "Nick Sussex, as always spot on!", keep listening to him and you won't go wrong.

If you want me i'll be in the Yorkshire/lincs thread, or private message.

Unfortunately we seem to be seeing a recurring pattern with the models and easterlies, I've noticed this with looking at the ensembles for southern Europe, when the easterly was reinstated initially there wasn't much support for the main cold in these regions, however with time a cluster of colder members appear but the operational is reluctant to go with these, the models then already start retrogressing the pattern so the core of the high starts forming to the nw and the ridge to the east takes a back seat. This then takes the coldest air into Europe, although there is still some -10 air getting into the se. In previous winters the problem has been the jet roaring over the top and causing the coldest air to go into mainland Europe, this winter the problem for easterlies has been the continually evolving pattern to retrogression, so that the ridge to the east is already being squeezed out by the troughing in Scandi.

I still think theres a little more room for manouevre but IMO any main snow for areas away from the east and se is more likely to come from a northerly as the pattern retrogresses.

[Duane S.]

Whilst there is some concern over the use of the term, the latest GFS suggests a slight upgrade - perhaps not for snow but at least for cold and longevity of the cold spell. Better placement of HP and towards FI a slight drift to the East will make for some interest.

Absolutely. If we are going to look at each model and compare it with the last then this is indeed an upgrade. I'd rather see an improved synoptic setup than a poorer one with a fleeting chance of snow any day.

The danger is that the -NAO is too far west leaving us open for attack. I think that a retrogressing HP to the North West is most likely but I think maybe it won't be as west based as some are forecasting. I think the block may be held at bay in a more favourable area as opposed to scooting off towards Canada. The SSW/MMW could scupper or indeed massively improve things at relatively very short notice, so that needs to be watched above all else I would say.

Edited February 8, 2010 by s4lancia

[Lewis]

Only one dummy being spat as far as I can see!

Hi jam,

Far from it, i just find it upsetting that people disagree with the obvious sign, it's not about IMBY biasness, it's all about what the models are truely showing. Some people just don't know when to accept that the cold snow setup they was expecting is slowly turning into a drier affair, with frost's at night, with the odd snow shower about.

The GFS is showing a different evolution, it's cold throughout with re-load potential and height building to the North. I'm not dismissing that we are seeing a continous cold trend, cold and dry is fine for me, anything is better than a mild SW'erly coming off the Atlantic. I just think a lot of people need to relax, most people know I go run by run, i'm not one of these that see's a cold run and ramps it up and sticks with it, and refuse's to let it go like some on here.

The weather is my life, since a little kid i have loved the weather, model outputs, snow, thick fog, freezing fog, heavy rain, severe gales, water spouts, severe thunderstorms. I can't wake up in the morning without looking outside first, and looking at my weather station. I love the weather that much! some people are just interested in snow, and not other weather, some people prefer seasons to all seasons. I like every aspect of the weather, and one thing i would never do is lie to myself with regards what it's going to do, i take it run by run, day by day. People need to slow down.

TEITS for example a few days ago (and still is) was ramping up the cold easterly, it looked very good on the GFS back then, but instead he was posting charts way out in FI that showed something better. This is not realism to me. (but that's how TEITS works, and i'm fine with that)

Anyhow, when i post i post my thoughts like anyone else. If we all respect each others thoughts then we would not argue, i know that's near enough impossible, but it would be good to try.

Lewis

Edited February 8, 2010 by Storm Force Lewis

[Yeti]

Sorry but have to agree with Lewis. He has a good point and thats how he sees the models and what he thinks will happen. If the ECM shows the same I think Lewis will have his trend.

If the whole of the UK is sitting under the high on Thursday/Friday as Lewis seems to be suggesting then I will eat my hat. Sorry but this is really getting quite annoying, what "point" is actually being made here? That we're all in for a big disappointment if we don't listen to what he says? The only reason that anybody should be disappointed is if they took those tasty FI charts at face value a few days back. In fact I remember certain individuals were already talking about snow for most of the week in Yorkshire. FI is, and always will be, UNRELIABLE, especially wrt details such as where snow will fall! Honestly, if anyone is disappointed at that 12z they have themselves to blame!

The UKMO and ECM still have the high slightly further N anyway (and the 12z is marginally better than the 6z, so quite what this new "trend" is I've no idea). There's no reason to think that this is all going to be a flop -

http://www.wetterzentrale.de/pics/Rtavn961.png

http://www.wetterzentrale.de/pics/Rukm961.gif

http://www.wetterzentrale.de/pics/Recm961.gif

All in all an excellent selection of charts, with cold for all and snow for most places S of the Wash and even N of it at times.

[TEITS]

TEITS for example a few days ago (and still is) was ramping up the cold easterly, it looked very good on the GFS back then, but instead he was posting charts way out in FI that showed something better. This is not realism.

Lewis

Here are the UKMO upper temps.

-12C upper temps for E Anglia/SE for Wed from the 12Z GFS.

http://www.wetterzentrale.de/pics/Rmgfs542.gif

Your region might look dry but for E Anglia/SE the risk of snow showers continues. Im not ramping anything just pointing out what the models show.

Edited February 8, 2010 by grab my graupel

[mountain shadow]

The UK Met show far more of an easterly at T+96 than GFS. Who would you believe?

http://charts.netweather.tv/gfsimages/gfs.20100208/12/96/h500slp.png

GFS restricts snow to the far SE. Meto favours more eastern areas, maybe even Hull.

[Eugene]

We are in for a cold northeasterly mid week though with >-10C 850 hPa uppers moving into the southeast of england/east anglia just because it doesnt reach all of the UK doesnt mean TEITS shouldnt point it out.

Less cold air will always move in after an initial cold blast anyway, look at the history of the UK`s winter weather and even in historic winters like 1962/63 less cold air moves in, i think people have expecatations way too high for an island just off the atlantic jetstream, you will always get less cold air even with blocking cold patterns in the UK, learn to live with it or move to a continental climate.

[Lewis]

Fair enough but I will always take issue when I think somebody's post is misleading (and that's nothing to do with opinion) and that was the problem with your original post. It was obvious from how you wrote it that you were bitter about the outlook not being as good as it could have been and were implying that the models had been downgrade after downgrade. Very confusing if I was a newbie trying to understand the models.

Whereas if you are honest with yourself you would have to admit that where we are now is, yes, not as good as it maybe it COULD have been, but... pretty much what had been forecast. There is still time for plenyt to change.

And if you want to see how to put across a 'realistic' view properly, look no further than Nick Sussex who does it very well indeed.

That's fair enough

But whats mid leading about, the HP being further South with the colder air heading into the near continent (France).

Let's hope the ECM can come to the rescue, or put us out of our misory with regards such uncertainty.

Edited February 8, 2010 by Storm Force Lewis

[Tom D]

The UK Met show far more of an easterly at T+96 than GFS. Who would you believe?

http://charts.netweather.tv/gfsimages/gfs.20100208/12/96/h500slp.png

GFS restricts snow to the far SE. Meto favours more eastern areas, maybe even Hull.

From what I can see (given the GFS you posted is in 4s and the UKMO in 5s), those charts are virtually identical for the UK Each has a fairly slack ENE flow.

http://91.121.94.83/modeles/gfs/run/gfs-0-96.png?12 - meteociel GFS

- meteociel UKMO

Also, the advance warning the METO have out for Kent Thursday is obviously based off their precipitation chart. It is one of the strangest warnings I've ever seen, only covering the far SE 3 days ahead. They must not be expecting it to be much further in land, perhaps only just clipping Kent.

Edited February 8, 2010 by Tommyd1258

[kold weather]

Yes im very pleased with the overall trend of the 12Z.

I remain unconvinced of a W based NAO. I do think this will eventually happen but not until we have seen some fun and games from the N.

As I said back on Saturday, there is the potential for week 2 to be more wintry than week 1. However alot of uncertainity with the details as you would expect.

I'm not sure a west based -ve NAO is a bad thing really, esp because I'm not sure there will be enough of a trigger to drag the colder northerly airflow down until the upper high shifts further west towards western Greenland and we can finally drag down a upper low. Of course that is rather risky as well, as can be seen by the ECM if it ends up a little too far west based...

[TEITS]

Very pleased with the GEFS mean at +168.

http://91.121.94.83/modeles/gens/run/gens-21-1-168.png?12

The overall pattern is slightly further E than the 06Z mean which is what we want to see.

I will add that does not mean widespread blizzards. Just pointing out that beyond +144 we could start looking to our N rather than our E.

But whats mid leading about, the HP being further South with the colder air heading into the near continent (France).

Because the colder pool does arrive in E Anglia/SE as I illustrated with the charts from the UKMO/GFS.

All im saying is just because the colder upper temps don't arrive in your location doesn't mean this is the case of other parts of the UK. Im not trying to get into a fight with you but just trying to illustrate what the models do show.

Edited February 8, 2010 by THE EYE IN THE SKY