Model output discussion - 1st December onwards

[johnholmes]

1 hour ago, Nouska said:

You are right to say that the weather can do unexpected turnarounds but there is usually some factor to precede this.

In the case of '73, a strong SSW in February of that year. '65 had a Canadian warming in December and '66 saw a February SSW also. Both winters were QBO east with strong El Nino - this winter, there are few mitigating circumstances to view as yet - hopes will lie far above our heads!

Links.  http://ggweather.com/enso/oni.htm

            http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

But what everyone has to remember is that, at the time, no forecaster had any understanding of this and certainly nothing was available for the bench forecaster other than surface and upper air observations from a fairly limited area. The data you quote Nouska has only become available many years later.

[legritter]

Models do seem to point to very mild air across our tiny island right out to christmas ,but beyond that things could change ,i,m hoping perhaps if the polar vortex does become a monster that it Squares off with our patch of the northern Hemisphere .

I,m sure that somewhere along the road temperatures will correct themselves ,but very interesting weather all the same .

I seem to have lost a few posts and cocked up posting so my apologies if i,m causing Mayhem .

Good posts on our first rate forum ,cheers all .

[Captain Shortwave]

Very little change so far on the 12z outputs.

Week 1 - High pressure over Europe having a reasonable amount of influence in the south, low pressure bringing wind and rain at times to northern and western areas. The north is slightly above average to mild, the south is mild or very mild throughout.

Again Thursday and Saturday show the mildest weather, the difference today is the emphasis that Saturday could now go even higher than Thursday now.

Saturdays very mild weather is pretty much UK wide as opposed to Thursday where a cold front will be pushing through during the day.

 

Week 2 - This period doesn't look as mild, but looks potentially stormy with well below average heights sitting close to the north of the UK with bands of rain and strong winds throughout, there is the risk of secondary systems that could produce damaging winds.

GFS

GEM

There is a chance that the gas pedal might be released somewhat in regards to the jet stream and hence we could see calmer and chillier conditions develop around the Christmas period. But this is a long way away in terms of forecasting at least.

At the end of week 1 we look likely to be sitting around 5C above average in regards to the CET, so even a cooler zonal period like the ones shown above would put us on a probable course for the mildest December on record, whilst it isn't a statistic most of us would have wanted, it is exceptional none the less with some daily CET records likely to be broken in the coming days and always the chance in lucky spots that the all time daily maximum could be put under threat.

 

Whilst we shouldn't dwell too much on how likely things are to verify, it is hard to ignore the consistency of the output, so much so that maybe we should potentially mark the 23rd as a day where we could see a significant wind event for example.

Edited December 14, 2015 by Captain Shortwave

[wishfulwinter]

26 minutes ago, nick sussex said:

Hi GP nice to see you posting again. Although NCEP haven't produced their new summary yet, the  models have updated. Theres a big divergence between the ECM, the ECM monthly and the GEFS bias corrected:

ECM:

ECM monthly:

GEFS BC:

 The GEFS seem reluctant to progress the signal with it hanging around phase 4.

PS Just to add for any newcomers to the thread, the MJO is strongest  the further away from that inner circle . If it goes into the circle its basically irrelevant in terms of any impacts on the NH pattern.

 

Aaaah! So that's what meant by circle of death?? Won't even begin to explain what I thought. No wonder I could never make "my interpretations" add up to the same as everybody else's! 

[nick sussex]

19 minutes ago, wishfulwinter said:

Aaaah! So that's what meant by circle of death?? Won't even begin to explain what I thought. No wonder I could never make "my interpretations" add up to the same as everybody else's!

Yes the infamous COD. The actual ECM monthly forecast really goes against what you'd expect to see with a strong El Nino. If you saw GP's post re that November episode this does give a glimmer of hope. But its really whether we can get to phase 7 or whether the signal heads into the COD. There are no definites with the MJO even if we get to a favourable phase, other variables can mute out the response but at this point we need something to disrupt the stuck pattern.

If my memories correct that December 2014 cold snap came about with a high amplitude phase 6, but of course the other teleconnections were different at that point.

I'll add this link which I think is excellent if anyone wants to learn more about the MJO:

https://www.climate.gov/news-features/blogs/enso/what-mjo-and-why-do-we-care

I particularly like the way the author describes the ENSO( El Nino, La Nina) versus the MJO:

Imagine ENSO as a person riding a stationary exercise bike in the middle of a stage all day long. His unchanging location is associated with the persistent changes in tropical rainfall and winds that we have previously described as being linked to ENSO. Now imagine another bike rider entering the stage on the left and pedaling slowly across the stage, passing the stationary bike (ENSO), and exiting the stage at the right. This bike rider we will call the MJO and he/she may cross the stage from left to right several times during the show.

Edited December 14, 2015 by nick sussex

[Ravelin]

Clutching at straws somewhat, very short straws, the GFS 12Z looks slightly better to my eyes than the last few runs. Nothing majorly cold but what cold there is maybe pushing slightly further south.

Oh and on the Xmas snow watch...accumulated snow out at t240.

GFS has been reasonably consistent for at least some snow on the Scottish hills on the run up to the Xmas period.

[Ali1977]

Ok so no SSW happening as far as we can see on the GFS, do the longer range models have the ability to see strat temps out to a month ahead? IE - will they pick up , and potentially amend their ideas based on this event happening. I have a feeling we may get some SSW but may get it at the very end of Winter, not early Jan when the UK will potentially benifit the most!!

[bobbydog]

3 minutes ago, Ali1977 said:

Ok so no SSW happening as far as we can see on the GFS, do the longer range models have the ability to see strat temps out to a month ahead? IE - will they pick up , and potentially amend their ideas based on this event happening. I have a feeling we may get some SSW but may get it at the very end of Winter, not early Jan when the UK will potentially benifit the most!!

i suppose if we could see it coming a month away, it wouldn't be called a 'sudden' stratospheric warming...

[feb1991blizzard]

5 minutes ago, bobbydog said:

i suppose if we could see it coming a month away, it wouldn't be called a 'sudden' stratospheric warming...

Sudden means its a dramatic warming inside a few days, it doesn't mean it isn't predicted, The 2013 event was seen coming on the strat thread and by Met Office forecasters.

[Ali1977]

9 minutes ago, feb1991blizzard said:

Sudden means its a dramatic warming inside a few days, it doesn't mean it isn't predicted, The 2013 event was seen coming on the strat thread and by Met Office forecasters.

Cheers Feb, that's what I was getting at...can they see it coming!!

[knocker]

35 minutes ago, Ravelin said:

Clutching at straws somewhat, very short straws, the GFS 12Z looks slightly better to my eyes than the last few runs. Nothing majorly cold but what cold there is maybe pushing slightly further south.

Oh and on the Xmas snow watch...accumulated snow out at t240.

GFS has been reasonably consistent for at least some snow on the Scottish hills on the run up to the Xmas period.

Yes that's to do with these two features which could bring a fair bit of snow to the N of Scotland and some some winds around the borders. But rather a long way off to rely on any detail. And the jet stream in all it's glory.

Edited December 14, 2015 by knocker

[bobbydog]

10 minutes ago, feb1991blizzard said:

Sudden means its a dramatic warming inside a few days, it doesn't mean it isn't predicted, The 2013 event was seen coming on the strat thread and by Met Office forecasters.

but a trigger for a warming event is difficult to predict 4 weeks ahead therefore an SSW is relatively speaking, quite sudden.

[MR EXTREMES]

Be very interesting to see if the El Niño weakening and perhaps a warming event in the strat and how sudden the effects on the mjo could be!.

although I still feel the magnitude of our current Nino event is just to much for hlb to establish itself.

but my question would be can a wreaking Nino weaken and establish a modki Nino ?

also does a weakening Nino help with better strat forcing ?

although we seemed to have had few years of a more La Niña like atmospheric dynamics and this seems to have fuelled the polar vortex into a more dominant feature since the epic winter of 09/10 slowly gaining strength as each year has passed of coarse El Niño is really showing its hand this winter.

but overall it looks like the long range models especially the ukmo have performed exceptionally well.

 

even if it supports knockers daffodils fetish.

but there really is little to be excited about if sledges are on the Santa list.

although miracles do happen sometimes.

[Ali1977]

Isn't the EC32 out tonight, let's hope it has some good news!!

[feb1991blizzard]

1 minute ago, bobbydog said:

but a trigger for a warming event is difficult to predict 4 weeks ahead therefore an SSW is relatively speaking, quite sudden.

This discussion probably better in the Strat thread itself where it will get seen by the Strat experts but If you go back and read previous strat threads though, I remember chiono posting in mid Nov 2011 that he expected an SSW in Late Jan 2012 on his signature, ok it didn't quite meet the threashold but its what was responsible for that cold spell in early Feb 2012 and what Stewart was banking on when he did his winter forecast that year.

[gottolovethisweather]

51 minutes ago, Ravelin said:

Clutching at straws somewhat, very short straws, the GFS 12Z looks slightly better to my eyes than the last few runs. Nothing majorly cold but what cold there is maybe pushing slightly further south.

Oh and on the Xmas snow watch...accumulated snow out at t240.

GFS has been reasonably consistent for at least some snow on the Scottish hills on the run up to the Xmas period.

It provided us with something similar last Thursday/Friday if I recall, hence I never place too much faith in the wobbly weekend runs (as I like to call them) and luckily I am able to view charts during the week so can scrutinise them as I see fit. I think the period through 22nd to 24th as above is a timeframe of note for a good shout at some storminess and temporary snowfalls somewhere, as I alluded to on Friday and during other times beforehand. This 12z is possibly a rogue run but as the dates under discussion are coming ever nearer it is worthy of consideration. Perhaps, after viewing tonight's full suite I might attempt a Christmas weather probabilities type posting once again and see if much has changed.

 

Edited December 14, 2015 by gottolovethisweather

[Ali1977]

Well the strat thread seems very positive today for the coldies - maybe around Xmas the GFS may look a whole lot different!!

[bobbydog]

9 minutes ago, feb1991blizzard said:

This discussion probably better in the Strat thread itself where it will get seen by the Strat experts but If you go back and read previous strat threads though, I remember chiono posting in mid Nov 2011 that he expected an SSW in Late Jan 2012 on his signature, ok it didn't quite meet the threashold but its what was responsible for that cold spell in early Feb 2012 and what Stewart was banking on when he did his winter forecast that year.

i agree. the base conditions for an ssw are predictable. for example, an event is expected this january (but not guaranteed) WQBO and strong El Nino can lead to ssw mid to late winter. its the event itself which is difficult to predict.

Edited December 14, 2015 by bobbydog

[gottolovethisweather]

Not a lot of model output discussion going on in here but each to their own I guess. I'd like to suggest though, that for personal one to ones, why don't some of you kindly use a direct PM to other forum users. That way we don't fill up the thread with non-model output related discussions such as the post I'm making now. 

 

 

Edited December 14, 2015 by gottolovethisweather

[nick sussex]

2 minutes ago, emotional rollercoaster said:

Be very interesting to see if the El Niño weakening and perhaps a warming event in the strat and how sudden the effects on the mjo could be!.

although I still feel the magnitude of our current Nino event is just to much for hlb to establish itself.

but my question would be can a wreaking Nino weaken and establish a modki Nino ?

also does a weakening Nino help with better strat forcing ?

although we seemed to have had few years of a more La Niña like atmospheric dynamics and this seems to have fuelled the polar vortex into a more dominant feature since the epic winter of 09/10 slowly gaining strength as each year has passed of coarse El Niño is really showing its hand this winter.

but overall it looks like the long range models especially the ukmo have performed exceptionally well.

 

even if it supports knockers daffodils fetish.

but there really is little to be excited about if sledges are on the Santa list.

although miracles do happen sometimes.

The Modoki El Nino seems to have had a lot of press recently but its unlikely this El Nino will morph into that, the Modoki is specifically a central Pacific one. Although the El Nino is expected to weaken its coming from a very high level, of course any weakening is welcome.

[phil nw.]

Guys i understand the link but can we please discuss the Strat.in it's proper thread and stick to the usual discussions in here please.

Ta

[Captain Shortwave]

As the ECM comes out, just a heads up on post Christmas thoughts from the GEFs

This has been consistent for many runs now to rebuild the heights over Europe, given those anomalies are similar to those predicted this week it could mean a return to mild or very mild conditions to end the year and also suggests that perhaps more settled conditions could develop if the heights over Europe manage to push far enough north to take the jetstream north of the UK as suggested might happened by the Metoffice update.

[phil nw.]

Just  looking ahead a bit there does seem a trend to really squeeze the isobars across the UK between the ever deepening Greenland lows and the stubborn Euro slug.

Example at t168hrs supported by the ens shows the jet firing up as it eases south across the UK

this is becoming a concern for really stormy conditions with heavy rain and gales just as we approach the Christmas period.

 

[Ali1977]

As the METO have said, pressure building over the UK in FI, actually 7 or 8 are showing heights building over Scandinavia and NW Siberia.

[mb018538]

Looking mild right out for the next week, before some colder shots digging in behind the low pressure areas interspersed with the mildness again.

http://www.wetterzentrale.de/pics/Rmgfs120sum.gif

Rainfall totals out to 120 hours up to 50mm in the NW areas that don't need it, 10-20mm in the drier east. Could turn a lot wetter in the period after though as the jet intensifies and takes a more direct hit over the UK. Potentially worrying times in the NW once again, which is most sad.