Model Output Discussions 12z 30/11/16

[ITSY]

Ensembles aren't exactly encouraging. Bets on the first WIO post? It is December 1st after all....

[Frosty.]

2 minutes ago, Geordiesnow said:

No not old frosty please, its actually refreshing he is analysing the output we are actually seeing and not being a fantasist when it comes to snow opportunites by posting snowy set ups in GFS FI.

 

I post all year round so I'm not a fantasist, and when there are cold and snow opportunities I'm hardly alone in ramping it up!

Anyway, still some frosts and fog in the reliable but then it looks like becoming milder, at least for a time.

[Polar Maritime]

OK, Only Model Discussion from here on in please, Anything else otherwise will go missing.There are other threads for general chat or Winter.

Thanks, Please continue.

Edited December 1, 2016 by Polar Maritime

[Summer Sun]

Good agreement on the ens for things to get milder next week a slight delay to the 850's falling compared to the 00z and 06z - 06z it was the 12th now it's around the 15th

12z

06z

Edited December 1, 2016 by Summer Sun

[NO LONGER POSTING]

Fear not dear cold lovers. This is the UK we are one of the hardest if not hardest countries on our latitude to get cold weather. 

Give it time... If by March the Atlantic or westerly regime is still here then you can say winter is over lol

It was evident that it wasn't going to be an easy trip to get cold (snow)  this side of the new year. BUT the GFS loves a mild ramp it's sods law though that the EMC gets better agreement with the GFS when warmer weather is on the cards. 

This is why I hate long term and longer outlook model watching it's success rate is less then what. . 10-20%?

We can't predict weather sometimes 24hrs in advance let alone the whole of winter! ! !  

You wouldn't let a computer predict the lottery results,  so don't let it con you into predicting the weather =) 

[swfc]

looking threw the12z the split on the nhp is evident but the western section of the split pv takes it out.tbh id prefer a bit of a good old blow from the nw instead of this lazy stagnating high. it could still evolve over the next few days along with a better push from the pacific but if i was a betting man id say doubtfull.

[nick sussex]

Not much excitement from the 12hrs runs so far. There are though huge differences upstream between the GFS and UKMO at T144hrs, also a different handling of the Aleutian Low and Pacific Ridge.

GFS                                                            UKMO

 

The evolution of the UKMO could be different downstream because its more amplified towards the east Pacific, the UKMO has a shortwave coming up from near Mexico, these often develop quickly as they get an injection of much colder air heading south from Arctic Canada, if we get an amplified shortwave moving east this would help to sharpen up the downstream low, at the same time as that amplifies it will help pull that chunk of the PV in northern Greenland westwards. The positive heights from the Pacific side could then nose through the gap and with some trough disruption off that low to the west we might be able to see a different path forward.

 

At this point further to my afternoon post re the Miracle that hasn't bitten the dust yet but we haven't made any progress this evening.

I would have had a complete meltdown this evening given the lack of progress towards anything wintry but will wait to see what happens with that shortwave energy at T144hrs near Iceland.

The UKMO may well develop a better upstream pattern between T144 and T168hrs which could help sharpen up that low to the west, we'll see later when we get the T168hrs Atlantic view output.

PS. NCEP think the GFS is maybe too progressive with the USA pattern, they do expect to see a re-amplification over the USA next week.

Looking further out into later next week medium range solutions
continue to show a general re-amplification of the flow across the
lower 48 as a pronounced early-season arctic surge pushes southward
into the Rockies and northern high plains. This will eventually set
the stage for cyclogenesis across the central plains which will
track northeastward over time. Rather significant differences remain
however on where this will occur with the operational GFS remaining
on the more progressive side of the guidance.

 

 

Edited December 1, 2016 by nick sussex

[chris55]

We need to place some faith in "what might be" post 120/144. It's far enough out to be open to debate, and if we could get the energy heading south east rather than north east from the stalled Atlantic system then we would be in business regarding a colder start to the month.

If it plays out with the energy riding over the top as modelled then a milder period is on the cards.

here is the main point of interest.

 

 

[weatherguy]

Incredible NH synoptics.  Incredibly infuriating to end up with the mild stuff from this. 

[NO LONGER POSTING]

Pffft I thought it was gonna be mild but when it looks like this. . . 

[nick sussex]

4 minutes ago, weatherguy said:

Incredible NH synoptics.  Incredibly infuriating to end up with the mild stuff from this.

I think if we had the normal PV stuck over Greenland and jet on steroids then it would be less frustrating because in that case you know the NH pattern is really against cold. However we seem to be in this situation where the outputs should be delivering much better synoptics and we're getting zip. The chart you posted highlights this well, somehow with the main PV in Siberia, a negative AO the other chunks of the PV well to the nw you'd expect the bit in the middle to not be so underwhelming.

[marksiwnc]

2 minutes ago, nick sussex said:

I think if we had the normal PV stuck over Greenland and jet on steroids then it would be less frustrating because in that case you know the NH pattern is really against cold. However we seem to be in this situation where the outputs should be delivering much better synoptics and we're getting zip. The chart you posted highlights this well, somehow with the main PV in Siberia, a negative AO the other chunks of the PV well to the nw you'd expect the bit in the middle to not be so underwhelming.

Still about 10 days away I think so a lot can change.  Remember what's been said today.  it may change round again soon as models struggle with quite different scenarios to what we are used too.. 

[blizzard81]

3 minutes ago, nick sussex said:

I think if we had the normal PV stuck over Greenland and jet on steroids then it would be less frustrating because in that case you know the NH pattern is really against cold. However we seem to be in this situation where the outputs should be delivering much better synoptics and we're getting zip. The chart you posted highlights this well, somehow with the main PV in Siberia, a negative AO the other chunks of the PV well to the nw you'd expect the bit in the middle to not be so underwhelming.

There is another way of looking at this. That chart is 9 days away. It would only take a few tweeks for the UK to benefit in a huge way Not given up on this one - yet!

[SMU]

The JMA tonight looks about the worst possible chart you could see if you were enjoying this settled frosty & cold weather.

horrific.

[Frosty.]

Looking at the GEFS 12z mean, high pressure does slowly sink s / se into mainland europe but throughout the next few weeks, at least a ridge is maintained across the s / sw which is where the best of the weather would continue to be, bar occasional interruptions but the north on the other hand becomes more changeable / unsettled but still with some fine weather at times. As for temperatures, still some chilly days and cold nights this weekend and early next week with frost and fog but then gradually becoming milder as the high slips away and winds become broadly southwesterly pumping air up from the azores although it does become cooler later with more north atlantic influence.

Edited December 1, 2016 by Frosty.

[nick sussex]

2 minutes ago, blizzard81 said:

There is another way of looking at this. That chart is 9 days away. It would only take a few tweeks for the UK to benefit in a huge way Not given up on this one - yet!

True but our recent tweek history has all been going the wrong way! lol Take for example that parcel of low heights which runs nw meets up with the troughing within the T144hrs range.

[blizzard81]

3 minutes ago, Greenland1080 said:

Even though seems to be a lot of deflation tonight, with most models showing +NAO , ECM delayed, Ec46 delayed, wavering of the models and model fatigue setting in on the 1st December....even the latest CFS has gone awol im still optimistic of a change mid month.........The daddy is the carnival model from Brazil still showing the way......Come on coldies...We deserve a White Xmas period for once to warm the cockles and have a very festive seasonal Christmas

 

Now if that was the ecm, it would capture my attention I see this model is the new navgem for this winter lol.

[blizzard81]

3 minutes ago, nick sussex said:

True but our recent tweek history has all been going the wrong way! lol Take for example that parcel of low heights which runs nw meets up with the troughing within the T144hrs range.

Couldn't agree more lol. It does seem the winter gods are against us - again! At 9 days out though, plenty of time for more positive tweeks to come

[Summer Sun]

ECMWF Weekly Model won't be delayed tonight

[blizzard81]

Just now, Summer Sun said:

ECMWF Weekly Model won't be delayed tonight

Is that the ecm 46?

[Nouska]

55 minutes ago, weatherguy said:

Incredible NH synoptics.  Incredibly infuriating to end up with the mild stuff from this. 

Yes, it's not very often you see such charts before a SSW has done a job on the vortex. I suppose 2010 was a recent example but very different higher up in the stratosphere.

2010 = split from wave breaking - (I presume?)  

I think it was Ed who said the jet will not cross a split - it didn't.

Now = Canadian warming                                        

You can see why modelling is showing a dipole anomaly, cross polar, split but it is not angled correctly to benefit us ... (yet) and there is no split to stop the Atlantic jet.

Edited December 1, 2016 by Nouska

[Summer Sun]

Just now, blizzard81 said:

Is that the ecm 46?

Not sure I get confused with all these different seasonal models

 

[Nick L]

The EC 12z op is now arriving.

[feb1991blizzard]

Steady as she goes at T0.

[johncam]

been a long term lurker, quick question to our more learned posters, why do you believe the extended ECM will be correct but no one seems to believe the short term models will be correct?

Just asking? :-)