Model Output Discussion

[weather eater]

Hope is fine of course, if you have this opinion then I cant fault it.

I have however this week seen references to 1981 and 1982 - so basically I've developed a little cynicism along the way but I get what you mean - In my virtually short lifetime though winter often goes through a few patterns, rather than continues the same throughout.

I would expect during December a milder pattern to take hold - obviously I may be wrong but it's a good bet based on previous years (although we havent, other than last year, really seen a cold start to winter).

We'll see anyhow.

I just hope people dont get disappointed

Oh I’m sure plenty of people will be disappointed, I have hope but no expectations so I wont be one of those. I also rather wish people would save the references for past glory years until we actually see something, if nothing else its bound to be the kiss of death to any cold spell developing.

[DAVID SNOW]

There is the potential for some very mild weather into the second week of the month as we could well see deep troughing in the Atlantic allied to a pressure rise over Europe, putting us in SSW/Southerlies.

Potential, could. Now, would you please answer my question

[bluearmy]

bbc forecasting snow and 1c on friday! take a look your self!

no the beeb are not - the computer generated rubbish is. if you want to look at a half decent attempt at an automated forecast (and its still not very reliable), i sugget the meto website. sorry to sound a bit angry but if we have to get thru this winter with the beeb 5 dayer being posted there wont be many people left on here come march. now i feel better

[Weather-history]

Very much so Reef, they are nothing to get excited about even if they materialise. The North Sea is still warm at this time of year and Europe is also warm. Sliders, southerly tracking lows etc... wouldn't have any air cold air to run into.

At this time of year, if we are are wanting cold and snow then we should be looking to northerlies - and that is not what the models are showing. I think part of it as that the christmas pudding has conditioned people to expect the usual synoptics, which IMO could very quickly materialise out of this model confusion, that anything different provides a lot of undue excitement.

The problem is the lack of cold pooling over Europe. November 1993 and December 1995 prove you can get a cold easterly early in the season, if there is a cold source available and it can be tapped. And the North Sea wasn't exactly chilly back in early December 1995, not after that hot summer and warm autumn.

Edited November 29, 2009 by Mr_Data

[snowlover2009]

yeah most likely in the christmas pudding, been tragic really not seen a sub zero temp yet, still autumn I know but, got northerly wind now and my temp is 5.1°C, would have been less before 2000?

it is not a proper artic northerly. you do know that.

[SP1986]

it never will be an ARTIC northerly, maybe an ARCTIC northerly

I'm not sure an polar northerly would deliver much in the way of cold right now - certainly not as cold as now, due to the fact it would have a sea track.

[chionomaniac]

It's astonishing really Mark, it's nearly Dec and most places are yet to see a ground frost.

Chiono, I accept that the sort of set-up that has been conducive to establishing a deep PV is not in place, but the Nino driven pattern can override all other factors and I would expect January to feature a dominant Polar Vortex.

I am glad that you agree that the current stratospheric profile is not conducive to establishing a deep PV. I agree with you that there is a big risk that El Nino may override all other factors. I expect the strat PV to increase in January but not exceed 30m/s.

[bluearmy]

despite most of us to wanting ian to be wrong, there is more chance of what he describes verifying than the winter wonderland that was the 12z parallel. however, i do think he is failing to take everything that is currently on the table into account. nevertheless, his choice is the 'form horse' and to take issue too much will probably bring you a 'bloody nose' early in the season.

decent anomlies on offer from the NAEFS 12z but not quite right for us. (by the way, a warm north sea is just fab if we could get some deep cold advected westwards). GP's last update still looks pretty good after a couple of days on the 'merry go round'.

[Weather-history]

yeah most likely in the christmas pudding, been tragic really not seen a sub zero temp yet, still autumn I know but, got northerly wind now and my temp is 5.1°C, would have been less before 2000?

I think you probably will have come Tuesday morning.

Incidentally, Oxford didn't record an air frost until January 1954

[Cecil Hogmanay Melchett]

despite most of us to wanting ian to be wrong, there is more chance of what he describes verifying than the winter wonderland that was the 12z parallel. however, i do think he is failing to take everything that is currently on the table into account. nevertheless, his choice is the 'form horse' and to take issue too much will probably bring you a 'bloody nose' early in the season.

decent anomlies on offer from the NAEFS 12z but not quite right for us. (by the way, a warm north sea is just fab if we could get some deep cold advected westwards). GP's last update still looks pretty good after a couple of days on the 'merry go round'.

Any sign of the ecm ens Blue army?

[West is Best]

I'm still not sure recent mild has any real relevance. Some of the deepest winters of the pre-christmas pudding have been preceded by mild autumns, and even very mild spells in early winter. I think Monday night should give a nice frost for many.

I also do feel it necessary to point out that last winter in this part of Devon was the snowiest for 20 years and the snowiest I've seen in Britain since the mid 1980's. And that didn't come off northerlies. The key was a southerly PFJ, with a marked meridional pattern.

Plenty of potential for cold out there. And indeed for mild!

Edited November 29, 2009 by West is Best

[DAVID SNOW]

It's astonishing really Mark, it's nearly Dec and most places are yet to see a ground frost.

Chiono, I accept that the sort of set-up that has been conducive to establishing a deep PV is not in place, but the Nino driven pattern can override all other factors and I would expect January to feature a dominant Polar Vortex.

Indeed december will soon be here,so will you please answer my question that you think THIS december will be the warmist in your modern ..............?

[phil nw.]

That may well apply to you Ian, but as far as I have seen the vast majority on here are basing their expectations on the what the models are actually showing and what the teleconnections may have to offer alongside this. I believe UK troughing giving wet but average temps, as suggested by GP, is the most likely outcome over the coming weeks but that there still remains the possiblity that a colder burst may be possible - and more so than a Bartlett.

Ian, if the stratosphere was running a lot colder than average, I am sure that you would have mentioned how this would be bringing us strong polar vortex 'christmas pudding' synoptics. It isn't, so, if you base a lot of your christmas pudding theory on this being so, and it isn't, then surely you should mention this. But you don't - why is this?

c

Hi C,

I was about to post asking IB the same thing.

I am no expert on telecons. but i do get the idea from yours and GP`s helpfull postings why the Vortex is weaker than average.

I wonder IB are you being mischevious in ignoring these signals?

Do you not take thse into account?

It`s apparent that there`s little energy going North in the jet and the Vortex is not modelled over Greenland in the foreseeable,in fact it`s fragmented and continually trying to rebuild in different places.

http://www.meteociel...&mode=0&carte=1

http://www.meteociel...72&mode=1&map=1

and

http://www.meteociel...72&mode=1&map=1

http://www.meteociel...carte=1&runpara=

In a normal season,when by now the vortex is showing dark blue/purple to our North West i could accept your prognosis but why now do you favour

the Mild S.Westerly north of the PJF pattern.

Please explain.

Quick edit,

Ian i see you replied to C`s post whilst i was typing.

So what are you suggesting for December as it seems your blowtorch is now on hold until January?

Edited November 29, 2009 by phil n.warks.

[bluearmy]

Any sign of the ecm ens Blue army?

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

nowt special ...........................yet

[Cecil Hogmanay Melchett]

I cant answer for Ian but i suspect he expects the PV to gain in strength as we head through Dec into Jan,

probably aided and abetted by the El Nino.A continuation of the ststus quo for the next 10 days at a guess.

[SP1986]

I'm still not sure recent mild has any real relevance. Some of the deepest winters of the pre-modern era have been preceded by mild autumns, and even very mild spells in early winter. I think Monday night should give a nice frost for many.

I also do feel it necessary to point out that last winter in this part of Devon was the snowiest for 20 years and the snowiest I've seen in Britain since the mid 1980's. And that didn't come off northerlies. The key was a southerly PFJ, with a marked meridional pattern.

Plenty of potential for cold out there. And indeed for mild!

Whilst the outcome may not have any connection to a mild Autumn, the milder Autumn which may lead to milder sea surface temperatures, may well at least delay the onset of a colder pattern.

Mind you you're essentially correct, no pattern of anytime has any direct relevance on another, whether it be cold-mild, or mild-cold.

[phil nw.]

I cant answer for Ian but i suspect he expects the PV to gain in strength as we head through Dec into Jan,

probably aided and abetted by the El Nino.A continuation of the ststus quo for the next 10 days at a guess.

Yes i know what he expects the PV to strengthen but i wish he would post the pointers.

[nick sussex]

The gfs looks like continuing on its merry way here, big differences here from very early on against the general model guidance, it seems very persistent with its view of things, will it be a humiliating climbdown tomorrow or will it redeem its reputation by being a trend setter?

Personally this looks like yet another gfs run for the shredder, the gfs has been known to persist with wrong synoptics for several runs till almost within T-96hrs and then backtrack,I just can't believe every other model is wrong and the gfs right here, anyway I'm sure we'll know by tomorrow.

Edited November 29, 2009 by nick sussex

[phil nw.]

The gfs looks like continuing on its merry way here, big differences here from very early on against the general model guidance, it seems very persistent with its view of things, will it be a humiliating climbdown tomorrow or will it redeem its reputation by being a trend setter?

Yes Nick very uusual pattern for the end of November,here at t120

http://www.wetterzen...s/Rtavn1201.png

A weak Vortex and jet way South,little energy going North.

Where can this go?

This can`t be right surely?

Edited November 29, 2009 by phil n.warks.

[nick sussex]

Yes Nick very uusual pattern for the end of November,here at t120

http://www.wetterzen...s/Rtavn1201.png

A weak Vortex and jet way South,little energy going North.

Where can this go?

This can`t be right surely?

No it's garbage with a capital G! This is one of those typical gfs runs which lose their way early on and look clueless.

[butler_son]

Yes Nick very uusual pattern for the end of November,here at t120

http://www.wetterzen...s/Rtavn1201.png

A weak Vortex and jet way South,little energy going North.

Where can this go?

This can`t be right surely?

Tut tut, looks like the GFS has been drinking on a school night looking at that. It'll be going into work with a nasty hangover...

[bluearmy]

No it's garbage with a capital G! This is one of those typical gfs runs which lose their way early on and look clueless.

wonder how early the parallel will diverge ??

[nick sussex]

wonder how early the parallel will diverge ??

T-6 hrs!

I will personally go to Lourdes tomorrow and join the church if this run verifies! that's how sure i am that its a total pile of nonsense.

[Cecil Hogmanay Melchett]

lOOK AT THE COLD building up north in FI.

If we get the right synoptics we'll get a proper freeze with all that to tap into.

[reef]

A few one liners and off-topic posts have been removed. Please try to avoid this as it clutters the thread and makes it difficult for people to understand whats happening.

Thanks