Model Output Discussion - 8th December Onwards

[Mucka]

Hum! Pretty awful gfs0z with the Atlantic really taking over,when we eventually see the deep low disipate we then see another strong jet streak hurtling across the Atlantic which squashes any hope of a mid atlantic ridge ,something that bih high to the NE needs to ridge westwards.

ukmo 0z also looks fires up the Atlantic.

Better make the most of the next 3 or 4 days of seasonal weather,im not expecting much in the way of snow when the breakdown arrives and youd be hard pressed to see any prospect of snow this side of christmas for the majority now.

potential for Dec is rapidly disappearing thanks to that god damn atalntic.

Other than the very obvious signal for a more amplified pattern to the West, and possible Atlantic ridge around 168 across the output?

Little in the models to suggest we are heading for a zonal rut despite the reports from Ian on the Mets musings being for such a scenario.

Edited December 10, 2012 by Mucka

[iowpompeylee]

Fair play to ian fergusson.hes been saying this would happen for the last day or two.a lot of wet weather to come..backed up this morning...

[IDO]

The pub run as per Saturday night keeps to its ranking. Yesterday Saturday's was downgraded through the day; today GFS 0z just got it over with quickly. The ensembles are nearly 100% sure of a quick breakdown Thur/Fri in London area:

http://cdn.nwstatic..../t850London.png

The 850s go to positive and the mean hits 2c. By the end of FI it's back to -2.5c. So in the short run a return to average temps is followed by a steady return to pre-cold snap ranges. Plenty of short-lived milder interludes by members at times (in FI), a typical cool/cold zonal profile from these.

The Op has low after low pushing in on an active westerly jet stream after T240, once the fight between the block is won by the Atlantic. Some PM excursions especially to the north. The Atlantic doesn't allow, on this run, any upstream amplification to succeed (notably at T168) and we are sent into default mode. Mean surface temps suggest around average in week two for the south, cooler further north:

http://wxmaps.org/pix/temp4.html

The GFS mean offers a little hope at the end of FI with the Siberian high heading back west but very slowly and pushes colder uppers closer to the UK. Otherwise it is pretty quasi-zonal (with slowing down of the flow at points) :

http://modeles.meteo...h-0-1-240.png?0

So 4/5 days of cold and a quick breakdown from the Midlands south. LP's sit over us for another 5/6 days as there is the fight between the zonal flow and the block. Rain being the headline for the Midlands south. On this occasion the westerlies win and the last 4/5 days of FI bring four further LP systems through. No mild other than in the flow as Azores High ridges temporarily, so feeling cool at best. It's the 4/5 battle we hope that can swing it back for a colder outlook but the high to the NE needs some help upstream.

Edited December 10, 2012 by i'm dreaming of...

[snow drift]

Hum! Pretty awful gfs0z with the Atlantic really taking over,when we eventually see the deep low disipate we then see another strong jet streak hurtling across the Atlantic which squashes any hope of a mid atlantic ridge ,something that bih high to the NE needs to ridge westwards.

ukmo 0z also looks fires up the Atlantic.

Better make the most of the next 3 or 4 days of seasonal weather,im not expecting much in the way of snow when the breakdown arrives and youd be hard pressed to see any prospect of snow this side of christmas for the majority now.

potential for Dec is rapidly disappearing thanks to that god damn atalntic.

This is 5 days before Christmas. The latest period should teach us that things change quickly. I understand the temptation after dissapointment to then write off the next few weeks.

Edited December 10, 2012 by snow drift

[winterof79]

The block is going to stay put for the foreseable

http://www.meteociel.fr/...&map=1&archive=0

Which can only be a good thing so early.

http://www.meteociel.fr/...&map=1&archive=0 it may have a march this way at some point.Battle ground close to our shores.

[MR EXTREMES]

as i said lastnight consistent model runs and i mean every single model has dartboard low over the uk no mild but average and as was mentioned by nick l hold on to your hats up north very cold sustained cold and lots of snow and blizzard conditions.

i suspect around mid month to set up a cold block over the uk no white christmas but could be some intresting surface cold.

but europe is cold to our north is cold so jan id expect the next rollercoaster to start but still optimistic for jan feb.

[chiller]

So after this cold "blip" peaking this Weds/Thurs none of the main 3 show anything of particular note for cold fans If I'm interpreting this right So much promise last week but hey ho its still VERY early in the season and we have at least seen some of the white stuff already! I'm sure it will be all change again in a couple of days.

[TEITS]

So nobody is going to mention the ECM then??

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

SE,lys ahead of the front instead of SW,lys and much better than the UKMO output.

Beyond and the +168 onwards is loaded with potential.

http://www.wetterzentrale.de/pics/Recm1681.gif

Pretty much what some of the GFS Ops have suggested i.e block to our E slowly backing W with the Atlantic LP weakening.

[Nick F]

So, the usual reality check of the 00z suite following the euphoria of the 18z 'pub' run.

Although it looks like we will remain under the influence a cyclonic flow of the trough near the UK for a bit, H500 anomaly charts clearly indicate +ve height anomalies to our north - which suggests the PFJ will remain suppressed, which at least opens up the opportunity for the Atlantic troughs to disrupt eventually and for high latitude blocking to develop.

[Ian Brown]

The block is going to stay put for the foreseable

http://www.meteociel...map=1&archive=0

Which can only be a good thing so early.

http://www.meteociel...map=1&archive=0 it may have a march this way at some point.Battle ground close to our shores.

Both the ECM and the GFS keep the block out to East to day 10, we then see the ECM try to build heights to the West and North West , so plenty of potential in those charts. Obviously the GFS then fires up the Atlantic which is always a possibility going that far ahead.

[winterof79]

So nobody is going to mention the ECM then??

http://www.wetterzen...ics/Recm961.gif

SE,lys ahead of the front instead of SW,lys and much better than the UKMO output.

Beyond and the +168 onwards is loaded with potential.

http://www.wetterzen...cs/Recm1681.gif

Pretty much what some of the GFS Ops have suggested i.e block to our E slowly backing W with the Atlantic LP weakening.

My post #752 referred to the model

[TEITS]

My post #752 referred to the model

Oops sorry.

What I like about the ECM is if this output had gone out further then im 99% sure the +276/+300 charts would show an impressive E,ly. Now im sure members are tired of looking into F.I for cold spells but an E,ly could develop sooner if we see undercutting.

[Tom Montalbano]

Some pretty good agreement now between ECM/GFS/UKMO for end of week/ next weekend.

http://cdn.nwstatic..../ecm500.120.png

http://cdn.nwstatic....120/h500slp.png

http://cdn.nwstatic..../00/met.120.png

ECM a little further south with that complex area of low pressure strung out across the UK and west into the Atlantic.

Hints from the models that go out that far, that the Russian High will try to push back west again, in just over a weeks time.

Meanwhile, flooding looking likely to become a major problem for some again, by the weekend.

Regards,

Tom.

Edited December 10, 2012 by TomSE20

[IDO]

Oops sorry.

What I like about the ECM is if this output had gone out further then im 99% sure the +276/+300 charts would show an impressive E,ly. Now im sure members are tired of looking into F.I for cold spells but an E,ly could develop sooner if we see undercutting.

If the GFS has a habit of defaulting to zonal in FI then it's probably fair to say, that lately, ECM tends to bring in an Easterly at T240. Especially about a week ago. Not falling for that one again. The Atlantic has scuppered our easterly and transitional snowfall when blocking was excellent, it will likely do the same in 5-10 days when blocking is not as strong. No done deal but I think very cold weather will struggle in the medium term.

[Severe Siberian icy blast]

So, the usual reality check of the 00z suite following the euphoria of the 18z 'pub' run.

Although it looks like we will remain under the influence a cyclonic flow of the trough near the UK for a bit, H500 anomaly charts clearly indicate +ve height anomalies to our north - which suggests the PFJ will remain suppressed, which at least opens up the opportunity for the Atlantic troughs to disrupt eventually and for high latitude blocking to develop.

Means absolutely nothing though to be honest does it? It's been favourable for a long time , if its not a piece of the split vortex setting up shop over greenlands giving us too much energy , it's a short wave that prevents the high pressure from the west joining with the high over scandi that in turn prevents us from having an easterly.

We haven't even got an easterly of any kind now to look forward to , not even a sniff. If it wasn't for this low pressure down the noth sea whipping in the cold air on its northern flank we wouldn't have any cold air to grab these next few days.

After so much promise a wk ago we now have what looks like a sustained period of southwesterlies and severe flooding to look forward to. The facts are we can all the northern blocking in the world but it means nothing unless we can tap into cold air, if we don't it means we would be facing a very wet winter likely with troughing sat over us.

Absolute joke this has been , chasing shadows and getting sucked in to what?

Edited December 10, 2012 by Severe Siberian icy blast

[MR EXTREMES]

i just cant buy the fi output it would be foolish to be drawn into more dissapointment although i agree and forgot to mention that blocking is holding firm with a dissapating low pressure system i dont think a further shift west from that block is likely.

but i cant say it wont happen just at this moment in time its unlikely.

all this said i noticed this short cold spell when modelled went from deep fi and happened alot quicker than fi predictions so anything is possible but im on the fence.

[snow drift]

Oops sorry.

What I like about the ECM is if this output had gone out further then im 99% sure the +276/+300 charts would show an impressive E,ly. Now im sure members are tired of looking into F.I for cold spells but an E,ly could develop sooner if we see undercutting.

Want to know what a battle hardened poster looks like.^^^^^^^^ Love your optimism. For one, I would not count out anything. As IB said the other day some of the FI charts are Bizarre. The height rises to the NW did make me look but the recent disappointments had me saying “gone in 24hrsâ€. Totally illogical but not unreasonable.

[MR EXTREMES]

Means absolutely nothing though to be honest does it? It's been favourable for a long time , if its not a piece of the split vortex setting up shop over greenlands giving us too much energy , it's a short wave that prevents the high pressure from the west joining with the high over scandi that in turn prevents us from having an easterly.

We haven't even got an easterly of any kind now to look forward to , not even a sniff. If it wasn't for this low pressure down the noth sea whipping in the cold air on its northern flank we wouldn't have any cold air to grab these next few days.

After so much promise a wk ago we now have what looks like a sustained period of southwesterlies and severe flooding to look forward to. The facts are we can all the northern blocking in the world but it means nothing unless we can tap into cold air, if we don't it means we would be facing a very wet winter likely with troughing sat over us.

Absolute joke this has been , chasing shadows and getting sucked in to what?

to be honest i understand your dissapointment even i said last week game on just goes to show how things change the weather will do what it wishes.

but there is a possibilty that it could happen i think jan but this winter does have a similar setup to 2009/2010 but perhaps a little later on.

and theres no sw flow,

westerly flow average to slightly below in temps on all models to easterly to our north so its very close and there could be suprises depending on low heights moving southeast.

frustrating i know but very intresting.

[Timmytour]

The GFS is like a random spirograph after T160 in its recent outputs.

One FI message it does seem consistent with though is the fall of heights to our North East

In the meantime, i think the West Country is in some danger of losing the "s" from its name!

And what was once portrayed as a chilly wintery day not so long ago for the UK by the GFS, the saturday before Christmas (or after the world has ended if you like!) is now shaping up to be a day with temps approaching double figures and this...

[Frosty.]

According to the gfs and ecm 00z we will be entering a very unsettled pattern after midweek, wet and windy at times with low pressure (s) in control for the next couple of weeks including christmas, nothing mild as such, temps mainly either just below or rather below average with some snow for the scottish hills and mountains. Very cold air never far away to the northeast and the northwest, the atlantic does look very fired up on both models this morning but the first half of this week is the relative calm before the storm with widespread frosts and some freezing fog, then towards midweek winds pick up from a SEly direction and rain begins to push north and east, briefly turning to snow as it hits the cold air then back to rain again, perhaps a longer spell of snow for the hills of northern england, n.ireland and scotland but followed by less cold air and heavy rain, becoming very windy after midweek, gale force ESEly for scotland becoming lighter and more variable for a time. Interestingly we retain surface cold despite losing the cold uppers, so rather cold/near average and unsettled, wet and windy sums up the outlook this morning.

Edited December 10, 2012 by Frosty039

[nick sussex]

So the Russian high continues to tease this morning.

The problem is to get that to retrogress sufficiently from its expected location is going to be a long haul, I think it could help extend some forcing to deliver something as a low is forced se but to a full blown easterly type scenario is just very difficult to see.

I think we're going to need some help from the Azores high to be forced west and north because of more amplification upstream.

So whilst everyone maybe looking east its really the eastern seaboard of the USA to the west that will determine whether this just turns into a stalemate or not.

I think the route back to cold will probably come from pressure rises to the nw and you could still with that get some easterly cut back on the southern flank but as for a proper easterly like the one that imploded last week I think its unlikely.

Anyway I would be very happy to be proved totally wrong as no one would probably care as they would be out enjoying the snow!!!

[Dampdorset82]

Means absolutely nothing though to be honest does it? It's been favourable for a long time , if its not a piece of the split vortex setting up shop over greenlands giving us too much energy , it's a short wave that prevents the high pressure from the west joining with the high over scandi that in turn prevents us from having an easterly.

We haven't even got an easterly of any kind now to look forward to , not even a sniff. If it wasn't for this low pressure down the noth sea whipping in the cold air on its northern flank we wouldn't have any cold air to grab these next few days.

After so much promise a wk ago we now have what looks like a sustained period of southwesterlies and severe flooding to look forward to. The facts are we can all the northern blocking in the world but it means nothing unless we can tap into cold air, if we don't it means we would be facing a very wet winter likely with troughing sat over us.

Absolute joke this has been , chasing shadows and getting sucked in to what?

Sucked into the most interesting chart evolution in my life time. If its snow your after your really in the wrong country. Im sorry but I cant understand the moans the science behind the changes are great.

[mulzy]

Oh dear - charts have taken a turn for the worse this morning. Probably what we all feared. Block to the East, trough over the UK looks likely now till Xmas at least. Worryingly there are signs of pressure rising from the south too.

[Nick F]

Means absolutely nothing though to be honest does it? It's been favourable for a long time , if its not a piece of the split vortex setting up shop over greenlands giving us too much energy , it's a short wave that prevents the high pressure from the west joining with the high over scandi that in turn prevents us from having an easterly.

We haven't even got an easterly of any kind now to look forward to , not even a sniff. If it wasn't for this low pressure down the noth sea whipping in the cold air on its northern flank we wouldn't have any cold air to grab these next few days.

After so much promise a wk ago we now have what looks like a sustained period of southwesterlies and severe flooding to look forward to. The facts are we can all the northern blocking in the world but it means nothing unless we can tap into cold air, if we don't it means we would be facing a very wet winter likely with troughing sat over us.

Absolute joke this has been , chasing shadows and getting sucked in to what?

I share your frustration, but I'm trying to look on the brighter side.

The pattern could be worse though, we could have a strong vortex over Greenland and a bg far Bartlett over Europe with seemingly never ending mild dross. What we do have is a pattern of an increasingly southerly tracking jet with +ve heights to our north and a strong Russian block which could back west and increase the heights to our north when the Atlantic trough eventually weakens and fills.

Remember much of central and northern Europe has benefited from the current pattern with regards to cold and snow ecently , but unfortunatley with us being on the margins at mercy of the Atlantic jet.

Edited December 10, 2012 by Nick F

[nick sussex]

Means absolutely nothing though to be honest does it? It's been favourable for a long time , if its not a piece of the split vortex setting up shop over greenlands giving us too much energy , it's a short wave that prevents the high pressure from the west joining with the high over scandi that in turn prevents us from having an easterly.

We haven't even got an easterly of any kind now to look forward to , not even a sniff. If it wasn't for this low pressure down the noth sea whipping in the cold air on its northern flank we wouldn't have any cold air to grab these next few days.

After so much promise a wk ago we now have what looks like a sustained period of southwesterlies and severe flooding to look forward to. The facts are we can all the northern blocking in the world but it means nothing unless we can tap into cold air, if we don't it means we would be facing a very wet winter likely with troughing sat over us.

Absolute joke this has been , chasing shadows and getting sucked in to what?

Shaun if its any comfort even the UKMO got this wrong. Indeed the easterly was shown at T 120hrs and then the culmination of the shortwave in the USA not running ne and yet more shortwave activity to the north tipped the balance, one of those could have been overcome at least to keep the cold longer but both happening was the end.

Anyway personally easterlies are beginning to try my patience and a sentiment probably echoed by many in here.

Edited December 10, 2012 by nick sussex