Model Output Discussion 18th Nov.2013-12z onwards.

[Man With Beard]

ECM T168 conjures up an easterly

[Barry12]

 

 

 

Potential

Edited November 19, 2013 by Barry95

[I remember Atlantic 252]

its a yucky easterly at 192, mild uppers, will bean drizzle for the south, would rather the high centred over the south

[gottolovethisweather]

Very end of GFS shows the next area of high pressure waiting in the wings, with low pressure anchored over Greenland

 

 

 

The one crumb of comfort for those seeking colder weather is it would be turning cooler once more

 

 

 

Gav, when is it actually going to warm up? The reason I ask is because I haven't caught up with all the various posts in here and I didn't think the Atlamtic was likely to get a look in so I cannot see anything above average until the start of December, perhaps.

 

Anyway, I best have a strong coffee and wade through the past 100 posts or so.

Edited November 19, 2013 by gottolovethisweather

[nick sussex]

The ECM joins the GFS in sending a shortwave se, however theres not enough amplification upstream so too much energy spills east rather than ne. Whilst we see these willing to send some energy se then there is still a smallish chance of a little more interest, the key really is that low in the eastern USA, the more amplified this is the better.

 

What we've seen over the last few days is the models flattening the pattern out, have we reached the end of this? On current trends you'd think the formhorse is they continue to flatten further in which case the se shortwave doesn't verify. If theres been a little over reaction by the models then we could squeeze just a bit more interest.

 

I think it could still feel pretty cold in the UK if theres a slack continental flow so frost and fog could make it feel festive but you can't sustain low heights over the northern Med without some changes to the current FI trend.

[Severe Siberian icy blast]

The ECM joins the GFS in sending a shortwave se, however theres not enough amplification upstream so too much energy spills east rather than ne. Whilst we see these willing to send some energy se then there is still a smallish chance of a little more interest, the key really is that low in the eastern USA, the more amplified this is the better. What we've seen over the last few days is the models flattening the pattern out, have we reached the end of this? On current trends you'd think the formhorse is they continue to flatten further in which case the se shortwave doesn't verify. If theres been a little over reaction by the models then we could squeeze just a bit more interest. I think it could still feel pretty cold in the UK if theres a slack continental flow so frost and fog could make it feel festive but you can't sustain low heights over the northern Med without some changes to the current FI trend.

I think realistically we need to give up the chase on this one nick, the ships sailed I think regarding the easterly . Let's see what happens in about 8 days from now regarding the wave 2 activity and the splitting of the vortex. . . Plenty more potential as we go through December , but as for the easterly next wk , it's just not gonna happen.

[radiohead]

We are an absolute world away now from type of output we were looking at only a couple of days ago. But as much of a blow as this is to those who were anticipating the those charts it also serves as a reminder of how quickly things can change...

[Purga]

Nothing worse than a mild easterly, such a waste.

 

 

 

marginally better than the atrocious UKMO

 

Let's see if we get a zonal reset and have another crack at things in a few weeks time.

[Ian Brown]

We are an absolute world away now from type of output we were looking at only a couple of days ago. But as much of a blow as this is to those who were anticipating the those charts it also serves as a reminder of how quickly things can change...

 

Thats because that output was at T200 plus and is always liable to wild swings ! 

[IDO]

I think realistically we need to give up the chase on this one nick, the ships sailed I think regarding the easterly . Let's see what happens in about 8 days from now regarding the wave 2 activity and the splitting of the vortex. . . Plenty more potential as we go through December , but as for the easterly next wk , it's just not gonna happen.

Yes GFS and ECM not only downgrading the synoptics run to run, but also watering down the uppers, to nearer average.The trend is also to sink the MLB (T240):GFS mean: ECM OP: All in all rather average late Autumn weather.Now to see if we can avoid the dreaded 3-4 week zonal fest that December can bring. Edited November 19, 2013 by i'm dreaming of...

[Catacol]

Is the 12z ECM today the new upgraded model?

[joggs]

Yes imo,certainly from a coldies view the search for major cold is over for the next week or so but still an intruiging pattern if you look at the whole nh!.Even though the gfs was a step or two behind at times it called the correct solution 1st this time.But plenty of frost and clear days to enjoy so could be a hell of a lot worse.

[zubzero]

Fantasy land is about 72h atm http://www.meteociel.fr/modeles/ecmwf/runs/2013111912/ECH1-72.GIF?19-0

 

All models struggle with blocking, And IMO thats a great chart for cold @ 72h  and not 144+ in lala land 

 

Once the northerly has passed through and high pressure takes over it is any ones guess what will happen next week.

[Summer Sun]

ECM showing less cold air coming in as early as Sunday now continued signal for high pressure to dominate our weather for a while once it moves in on either Friday or Saturday

 

 

Edited November 19, 2013 by Summer Sun

[bradymk]

Is the 12z ECM today the new upgraded model?

I believe its the ensembles that are being upgraded

[JK1]

ECM showing less cold air coming in as early as Sunday now continued signal for high pressure to dominate our weather for a while once it moves in on either Friday or Saturday

 

 

would that be mildish or cold high pressure? I get confused with these charts sometimes

Edited November 19, 2013 by JK1

[nick sussex]

I think realistically we need to give up the chase on this one nick, the ships sailed I think regarding the easterly . Let's see what happens in about 8 days from now regarding the wave 2 activity and the splitting of the vortex. . . Plenty more potential as we go through December , but as for the easterly next wk , it's just not gonna happen.

Yes I think you're right re the ship but theres not much else to discuss in the nearer timeframe!!! And anyway I've already done one of my paint jobs which the thread will now be subjected to!

 

Circled red is that amplification heading out of the eastern USA, the more amplified this low is  so more oval, or elongated rather than football shaped the better, this downstream will add  a bit more forcing on the shortwave circled black to head se rather than east or ne. The orange circle indicates some weakish pressure rise adding a little more forcing on the shortwave, the green triangle I call the sharpness so we want to see a more defined gap between the low and SW, so rather than lets say an arc more that triangle shape.

 

 

Another thing to add re that low the problems we see with both the ECM and GFS even though they just about manage to eject the shortwave is that theres not enough shearing of energy ne off the low as it heads east, this then spills over the top stopping the high getting further north. Theres not a lot of time to salvage some more interest as the key synoptics are within T144hrs but also bear in mind that the models were wrong re the jet within 120hrs. I'd give it till tomorrow to see if theres one final twist and then if not its likely to be high pressure over the UK.

 

Still could be frosty and on the cold side and certainly best to concentrate on the nearer term especially after seeing that last frame of the ECM!

[Summer Sun]

I believe its the ensembles that are being upgraded

 

yes and the ec32 which we don't have access too

[Summer Sun]

would that be mildish or cold high pressure? I get confused with these charts sometimes

 

Probably still cool at first but gradually becoming less cold all will depend on the wind direction as well temperatures for tonight's ECM will be available around 8pm so we'll get a better idea then

[AWD]

Remember when we have high pressure in situ at this time of year the 850hpa temps become much less active when trying to determine temperature forecasts.

Inversions/surface cold can often mitigate the 850hpa modelling and thus what may appear to be a less cold airmass or even milder airmass may appear less so at the surface. We do live at the surface and not 1500ft in the sky remember!

That's not necessarily specific to any forecast modelling tonight, just a general observation!

Edited November 19, 2013 by AWD

[ANYWEATHER]

Lol, in all respect its not the first time the gfs has got it right in all fairness!!  Anyway both gfs and ecm out to t+144 both show high pressure over the Uk, cutting off anything really cold entering the Uk. But on the positive note some nice late Autumn weather to be had, with shallow Anticyclonic cold conducive to forming frost and fog, some of this fog may well be hard to clear in some places and its likely to be freezing fog in places, which may give some "ice" days in one or two places! So perhaps not the ideal situation many coldies want, it will at least be a seasonal start for the weather conditions at this time of year,,,,,

[Severe Siberian icy blast]

Yes I think you're right re the ship but theres not much else to discuss in the nearer timeframe!!! And anyway I've already done one of my paint jobs which the thread will now be subjected to!

 

Circled red is that amplification heading out of the eastern USA, the more amplified this low is  so more oval, or elongated rather than football shaped the better, this downstream will add  a bit more forcing on the shortwave circled black to head se rather than east or ne. The orange circle indicates some weakish pressure rise adding a little more forcing on the shortwave, the green triangle I call the sharpness so we want to see a more defined gap between the low and SW, so rather than lets say an arc more that triangle shape.

 

ECH1-120.gif

 

Another thing to add re that low the problems we see with both the ECM and GFS even though they just about manage to eject the shortwave is that theres not enough shearing of energy ne off the low as it heads east, this then spills over the top stopping the high getting further north. Theres not a lot of time to salvage some more interest as the key synoptics are within T144hrs but also bear in mind that the models were wrong re the jet within 120hrs. I'd give it till tomorrow to see if theres one final twist and then if not its likely to be high pressure over the UK.

 

Still could be frosty and on the cold side and certainly best to concentrate on the nearer term especially after seeing that last frame of the ECM!

Lol I think between your obsession with "short waves" , Steve's obsession with the gfs failings , frosty's obsession with extreme weather charts , and 700 other peoples (including me) obsession with snow we have the ingredients to be so much more than weather enthusiasts on a weather forum !!! Of course I'm a super hero by night . . . Not sure about anybody else though?!!!!

[Summer Sun]

Latest from Gibby on the 12z models

 

All models show a deepening depression slipping SE down the North Sea then South across to Southern Europe on Thursday. Fronts associated with it will sweep SE across the UK tonight and tomorrow with rain for all and snow on the highest ground for a time. The cold front could be quite active with hail and squally winds ahead of a change to cold and bright weather with scattered showers, wintry in the North. Unsettled conditions then clear the South on Thursday with High pressure building quickly down over the UK from the NW where it then sits for the reliable future with dry, crisp days but with cold, frosty nights and the possibility of fog too, freezing in places.

 

GFS then shows High pressure meandering around in the vicinity of the British Isles until nearer the end of the run when Low pressure half-heartedly tries to give a semi-breakdown in conditions with some rain at times then. Temperatures overall will be on the cold side of average at the surface, often due to frost, mist and fog. Things may warm up a little late in the run as milder Atlantic winds show occasional success at moving into the UK from the West

 

.UKMO tonight shows High pressure over the South-western half of the UK with a slack Westerly flow developing over the North. Most areas will stay cold and dry with sunshine by day with frost and fog problems night and morning. The far North may see cloudier weather moving in off the Atlantic later restricting frosts and fog by night and raising daytime temperatures a little too.

 

GEM tonight also shows High pressure settling down near to SW parts of the UK through the latter end of the run. With Westerly winds rounding the Northern flank of the High there would be an infill of cloud from off the Atlantic first across the North and later the South too so after a cold and frosty start the weather would become milder but cloudier day and night but the threat of Anticyclonic gloom becomes a real possibility should this run evolve.

 

NAVGEM once more holds High pressure further to the North over Scotland or the Northern North Sea. The net result of this would be to keep the weather cold for all with a stronger Easterly flow over the South. This would make things feel very cold here with some sunshine at times but though frosty overnight fog would be less of a problem. Northern areas on the other hand would see plenty in the way of frost and fog as skies stay clear and winds stay light.

 

ECM tonight completes a very High pressure dominated set of model runs tonight as High pressure refuses to leave our shores gradually migrating to the East and SW but maintaining a ridge with it's axis West to east over the UK. As a result quiet weather will persist with frost and fog night and morning, slow to clear in places. Daytime temperatures may nudge up a degree or two later if fog clears and frosts become less harsh, especially towards the North as the Atlantic becomes poised to end the fine spell on Day 10.

 

The GFS Ensembles tonight show a lot of High pressure over the first 10 days though the NW may see some milder and more unsettled conditions next week. Later in the run the chances of this unsettled weather spreading to all areas increases with WNW winds likely to bring rain or sleet at times with snow on hills possible late in the period.

 

The Jet Stream is flowing directly South near the British Isles at the moment before it ridges High over the Atlantic setting up a blocked pattern and a High pressure over the UK by the weekend. Longer term there is a hint that it may change trajectory to allow a WNW to ESE flow across the North Atlantic and down over the UK.

 

In Summary the weather will be fine and dry for much of the period with High pressure remaining in close proximity to the UK. All models with the exception of NAVGEM do show a more Southerly axis to the High pressure belt tonight with a trend even further South late in the outputs as the Atlantic becomes more threatening and likely to invade our shores again later in the runs.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

[Gavin Hannah]

 

Differences in the output at t.96

 

And at t.120

 

Really difficult to see where the weather is heading this weekend.  HP seems to be the theme for the coming week and weekend but ECM and GFS not agreeing which direction to it's going.  The LP over Siberia will have a huge bearing on what happens here.

[cooling climate]

Tendency of relative AAM has increased dramatically now I am no expert when it

comes to GWO and GLAAM but I would not be surprised to see a big switch in the

model output over the next couple of days.