Model Output Discussion - 5th December - 11th December

[Tigers]

Reading the majority of this evenings posts you don`t have to be a genius to guess their location, there is life north of the Watford gap you know

One set of runs, tomorrow will be different again no doubt it was only around a week or so ago nothing even remotely cold was showing in the models

When will people learn

[jpwild]

What are the models saying for Manchester city centre and for higher area such as Edale and Buxton? What's the risk of snow?

[johnholmes]

Reading the majority of this evenings posts you don`t have to be a genius to guess their location, there is life north of the Watford gap you know

One set of runs, tomorrow will be different again no doubt it was only around a week or so ago nothing even remotely cold was showing in the models

When will people learn

never!

[BLAST FROM THE PAST]

Like it or not the stratospheric signal would provide reasonably strong support for an evolution akin to the GFS 06z. I get the feeling we've been pretty 'lucky' with the current cold snap and indeed we are fortunate to have the one forecast for later this week.

The stratosphere has been at record or near record levels of cold for a while now and it seems inevitable that we revert to such a pattern as illustrated on this mornings run eventually. This is particularly significant taking into account the usual lag time for the effects of the stratosphere to be felt in the lower levels of the troposphere.

[shedhead]

Do Pm incursions ever amount to anything in ilchester? it still looks like a second cold swipe for the northeast of the uk after a less cold interlude on thursday morning, friday looks bitterly cold with snow showers in the far north of the uk.

Yes PL if course they do. We've had some massive snow showers here in a W, infact anything between 260-290 deg can give some beauties off the Bristol Channel. Yes Friday will be bitterly cold in the far north of the UK according to the latest GFS, but it will also be bitterly cold in the Faroes and Reykavic, both being about as equally relevent to 80% of the population. I'm not being IMBY for the sake of it, but most of us don't give a chuff if Kirkwall and Thurso are in whiteout conditions, we want to see everyone getting a taste of the action and that looks very unlikely as things stand.

Edited December 5, 2011 by shedhead

[BLAST FROM THE PAST]

Like it or not the stratospheric signal would provide reasonably strong support for an evolution akin to the GFS 06z. I get the feeling we've been pretty 'lucky' with the current cold snap and indeed we are fortunate to have the one forecast for later this week.

The stratosphere has been at record or near record levels of cold for a while now and it seems inevitable that we revert to such a pattern as illustrated on this mornings run eventually. This is particularly significant taking into account the usual lag time for the effects of the stratosphere to be felt in the lower levels of the troposphere.

Like it or not KK unless the models get more consistent and support for that evolution then I think its unlikely to happen. 12z says no. There's no 'luck' involved is there? and with the stratos at near record cold then why aren't in there now. How much lag does the stratos want, stratos has been cold for sometime now....? What is the lag time and can you show it?

This current set up is a lot cooler/colder than many thought. I was involved in discussions with the mild v cool or cold set up. Conditions are definitely 'colder' and in and out of average and cold category with more to come BUT no prolonged digging in of cold IMO. The 'kitchen sink' scenario for Dec remains. 3rd week remains as best shot for wider spread wintry conditions IMO.

BFTP

Edited December 5, 2011 by BLAST FROM THE PAST

[iceaxe]

bor fest. Friday into Saturdays cold seems to last only hours now. Then zonal all the way. This IS the theme.

Well what a suprise predicted it would only last 12 hours or less two days ago . I did think the models were over cooking how far south the cold would stretch.Used loads of old data from previous similar set ups to produce my own predictions along with the models.seems theres been one or two one word post that are not model related.

[chionomaniac]

Like it or not KK unless the models get more consistent and support for that evolution then I think its unlikely to happen. 12z says no. There's no 'luck' involved is there? and with the stratos at near record cold then why aren't in there now. How much lag does the stratos want, stratos has been cold for sometime now....? What is the lag time and can you show it?

BFTP

Remember all, that it is not necessarily cold that a warmer stratosphere would bring, but an increased chance of high latitude blocks. The reverse is true as well. A cold stratosphere reduces the chance of high latitude blocks, but not necessarily cold, as the current spell for more northern areas shows.

And the current phase and outlook is as would be expected from current stratospheric conditions.

Edited December 5, 2011 by chionomaniac

[Iceaxecrampon]

12z GFS is very different to 6z

Really big differences at short timeframes.

Agreed.

Friday the 9th is back on again - a real model rollercoaster....

Sunday 18th.... :blink:

Although ppn is rain?

[shedhead]

BFTP, even if we remain in the current pattern, there is absolutely no sign of proper cold. If you take the full 192hrs of the higher res part of the run, the whole country only remains in -5c Hpa air for 2 hours in the early hours of Friday and come tomorrow morning I expect that will have been whittled away by about ermmm 2hrs...

Nothing wrong with being +ive, but there's a time and a place for it and like last Jan/Feb this is neither of those from what I can see.

Edited December 5, 2011 by shedhead

[BLAST FROM THE PAST]

BFTP, even if we remain in the current pattern, there is absolutely no sign of proper cold. If you take the full 192hrs of the higher res part of the run, the whole country only remains in -5c Hpa air for 2 hours in the early hours of Friday and come tomorrow morning I expect that will have been whittled away by about ermmm 2hrs...

Nothing wrong with being +ive, but there's a time and a place for it and like last Jan/Feb this is neither of those from what I can see.

And no sign of above average constant mild SW'lies as you have been saying we will have and should be in. I absolutely agree there is no sign of prolonged cold, absolutely agree but coming and going of cold shots...yes.

BFTP

Remember all, that it is not necessarily cold that a warmer stratosphere would bring, but an increased chance of high latitude blocks. The reverse is true as well. A cold stratosphere reduces the chance of high latitude blocks, but not necessarily cold, as the current spell for more northern areas shows.

And the current phase and outlook is as would be expected from current stratospheric conditions.

C

Can you clarify. Wouldn't a more SW/NE axis be expected as a general rule? We do get what we get now BUT not very often with such a cold stratos and is not the prevalent set up.

BFTP

Edited December 5, 2011 by BLAST FROM THE PAST

[Mark Neal.]

The BBC Weather forecaster Chris Fawkes has hinted at the possibility of the Polar Low getting close to us, he tweeted this on twitter. Polar low looks on track to visit shetland tomorrow morning. Will it be blizzards or cold rain?

Have the models been showing the polar low to hit the shetlands or has it been a quick turn of event?

[Zakos]

Like it or not KK unless the models get more consistent and support for that evolution then I think its unlikely to happen. 12z says no. There's no 'luck' involved and with the stratos at near record cold then 'funny' how we aren't in there now. How much lag does one want, stratos has been cold for sometime....maybe until it shows the 'wanted' set up? What is the lag time and can you show it?

BFTP

Great post BFTP. I am a fan of your posts.

As you say, wasn't the pattern supposed to be flat now?

Wasn't there supposed to be no snow before New years?

People are right in saying it wont be as bad as last year. But, why are people comparing this december to the coldest on record? I dont see the logic in that. I agree with those that say there is no prolonged cold spell in sight.

BUT, how long is "in sight"? Mark Vogan I believe is on to something. He doesnt say that we will be thrown into the freezer come the 15th. He states a gradual change to colder conditions, eventually becoming very wintry.

There is no point in comparing this winter to last. It was an extreme event. Compare this winter to the two winters before last year, and I cant see how we can not see similar conditions, although probably not serious cold until at least after Christmas.

Edited December 5, 2011 by Zakos

[shedhead]

And no sign of above average constant mild SW'lies. I agree there is no sign of prolonged cold, absolutely agree but coming and going of cold shots...yes.

BFTP

Well I conceded the other day that I was surprised just how cold it's been and currently is for many, but I don't honestly see this trend continuing. I think the next 24hrs will see the bottom of the cold, (but lets keep things in perspective if you consider this a cold shot what the hell did you call this time last year?), chilly yes on Friday, then gradually milder from there but never becoming full on mild.

[SnowObsessor90]

And no sign of above average constant mild SW'lies. I agree there is no sign of prolonged cold, absolutely agree but coming and going of cold shots...yes.

I'd be happy with that if it meant there was a possibility for a little more than just hail for this neck of the woods in the NW otherwise it's just another big fat meh for me,

Edited December 5, 2011 by Anonymous21

[Bobby]

As expected the GFS has jumped on board with the other models. Unanimous agreement now on unsettled zonal weather for the forseeable future. Not mild but not cold either. Looks like this pattern will take a lot to shift...

[SMU]

http://www.meteociel.fr/modeles/ecmwf/run/ECH1-120.GIF?05-0

Im still in the game for non Zonal...

S

[BLAST FROM THE PAST]

Well I conceded the other day that I was surprised just how cold it's been and currently is for many, but I don't honestly see this trend continuing. I think the next 24hrs will see the bottom of the cold, (but lets keep things in perspective if you consider this a cold shot what the hell did you call this time last year?), chilly yes on Friday, then gradually milder from there but never becoming full on mild.

I said last year to expect extreme cold and record cold for parts. Ok.....lets agree on chilly conditions? No concessions needed and this post of yours is nice and clear.

ECM 12z could be interesting....chucking a storm or two at us

BFTP

Edited December 5, 2011 by BLAST FROM THE PAST

[Summer Sun]

Just as other models go mild-ish ECM produces this tonight

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

http://www.wetterzen...cs/Recm1201.gif - Potentially heavy snow for the Midland northwards.

http://www.wetterzen...cs/Recm1441.gif

Cold fans don't give up hope the models are very up and down at the moment.

Edited December 5, 2011 by Gavin D

[Matty M]

The ECM trying its best to turn things around in a unimaginable fashion

Would be snow for many as a low moves through B&I at 120hrs

[Grimsby Snow Lover]

Just following the latest ECM 12z run. Does this chart show the PV moving west away from Greenland? Thanks in advance GSL

http://www.wetterzen...cs/Recm1441.gif

Edited December 5, 2011 by Grimsby Snow Lover

[Geordiesnow]

As expected the GFS has jumped on board with the other models. Unanimous agreement now on unsettled zonal weather for the forseeable future. Not mild but not cold either. Looks like this pattern will take a lot to shift...

The -10hpa albeit briefly flirts with Scotland for Friday, if that is not cold air then I don't know what is sadly!

This afternoon runs have really made this low pressure for Thursday deeper than what it was originally meant to be so with cold uppers on Friday there will be a certain windchill and blizzards is most likely for higher parts of Scotland but even lower levels could see blizzards conditions thanks to that deep low.

Still a small amount of time left for things to not be so dramatic but it is certainly one to keep an eye on I feel imo.

[phil nw.]

Colder zonality from ECM and UKMO out to T144 and the Azores High kept at bay with troughing into Europe.

With GFS showing a less colder prospect nothing is settled beyond the weekend that`s for sure.

Edited December 5, 2011 by phil n.warks.

[NorthernRab]

As expected the GFS has jumped on board with the other models. Unanimous agreement now on unsettled zonal weather for the forseeable future. Not mild but not cold either. Looks like this pattern will take a lot to shift...

The number of times I've heard this on the model thread is staggering. To any learners it's worth reminding them that as an island at our latitude on the edge of a continent between the warm oceans and the cold north, where air masses constantly struggle for control, it really doesn't take a lot to change the weather pattern in the UK.

Edited December 5, 2011 by NorthernRab

[chionomaniac]

C

Can you clarify. Wouldn't a more SW/NE axis be expected as a general rule? We do get what we get now BUT not very often with such a cold stratos and is not the prevalent set up.

BFTP

I don't know if one could expect a general rule but I suspect not. The axis of flow would depend upon the position of the PV and other non stratospheric influences. So the cold stratosphere could lead to a stronger polar vortex but not the orientation of flow.