Model Output Discussion - Into November 2019

[Ali1977]

Not bad, HP positioned well in NW Russia, cold air heading under that towards the U.K, and decent over Greenland . But a little tricky to decipher near the U.K. to my amateur eye!! 

[swfc]

6 minutes ago, northwestsnow said:

The low in the North sea is a real pain..

Looks ok at 168 hrs?

[booferking]

5 minutes ago, northwestsnow said:

The low in the North sea is a real pain..

We all know what happens after this chart 3 lows come together and explode

[knocker]

The ecm Su > Tues

[booferking]

Just now, swfc said:

Looks ok at 168 hrs?

Watch all 3 lows come together boom.

[swfc]

8 minutes ago, booferking said:

Watch all 3 lows come together boom.

Yep !!! Ah well on to the next one .better heights tho towards Greenland tho than the 6zand then it vanished

Edited November 12, 2019 by swfc

[nick sussex]

Quite an unusual scenario .

One low moving north as another shortwave moves se between day 6 and 7 . This interaction  and pivot isn’t really what we want to see but before it unravels there could be some snow for higher elevations in the north .

Overall it looks very messy and complicated . At the moment we have a chef as in some good background signals with some high quality ingredients making a very average looking meal .

 

[Catacol]

7 hours ago, IDO said:

You could not get a worse D12 chart if we sat down and plotted the GFS 06z ourselves:

Taking into account what comes before we can suggest that the current setup is simply too far gone to be useful for cold or dry weather for the UK. An awful setup with no potential for the foreseeable. The GFS seems to now have settled on this option, the worst case scenario!

I must be the only one then that looks at these chart and walks off satisfied. Anyone hunting wall to wall snow in November needs to read their history.

The pressure differential between Greenland and Scandy on those charts is pretty good for vortex disruption when combined with the Aleutian low in the North Pacific. November is nothing but a setup month - no low ground product in terms of snow is realistic. In addition the pattern is effectively blocked, and people need to realise that a block creates a more meridional flow that promotes warm flows from the south as well as cold flows from the north. The fact that the Scandy anomaly helps pull warm air up over the UK is part of life in this part of the world at this time of the year. The pattern is not one of raging zonality, the strat/trop disconnect remains in place at least for now, and vortex stress looks likely.

Winter doesn’t start for 3 more weeks, and realistically doesn’t really kick in until mid December which is 5 more weeks. If you need to cheer yourself up in the search for snow try reading up about the Feb 18 reversal that led to that beastly spell. The Atlantic preconditions are not dissimilar and while every patten is unique we are certainly in with a chance of a cold outbreak this season. Just don’t expect it in November and don’t expect it to last all winter. 1963 was unique and a year I don’t think we will see repeated for as long as the world continues to warm.

[Methuselah]

At least the 12Z operational run is on the warm side of the bunch...Thank you, God. For very small mercies!

   

   

Desperate times call for desperate measures!

[Ali1977]

5 minutes ago, Ed Stone said:

At least the 12Z operational run is on the warm side of the bunch...Thank you, God. For very small mercies!

   

   

Desperate times call for desperate measures!

Best set for a while with plenty cold ones in that lot. Looking at the pressure graph FI is in around 5 days.

[Frosty.]

Some wintry GEFS 12z perturbations, more than the 6z..the mean also looks slightly colder than earlier and that wasn't too shabby either!!..broadly speaking, high pressure to the NE and low pressure to the SW.. more signs of an early taste of winter than usual across the models again today!!

[Jordan S]

Gem shows a more blocked scenario towards Greenland and Scandinavia next week with the jet stream continuing to be south compared to what you typically expect although slightly milder next week according to the Gem..

The Gem continues the wet signal upto 10 days the accumulated rainfall depicts a northwest southeast split quite well but pretty unusually the south and east wetter than the Northwest.. 

Edited November 12, 2019 by jordan smith

[knocker]

1 hour ago, Catacol said:

I must be the only one then that looks at these chart and walks off satisfied. Anyone hunting wall to wall snow in November needs to read their history.

 

But in theory this thread is not about hunting wall to wall snow or arctic plunges in November, or any other time come to that, but simply discussion of the model output, irrespective of people's inclinations.

Edited November 12, 2019 by Blessed Weather
Unnecessary comment removed.

[knocker]

Little constructive to add to previous comments regarding the ext mean EPS anomaly. Still a squeeze across the Arctic courtesy of the anomalous vortex lobe and Euro ridge, albeit the latter has slightly adjusted it's orientation. That adjustment ensures that the energy running east beneath the trough is a tad further south before it diverges over the UK courtesy of the ridge  Ergo systems will tend to track south east before running out of momentum leading to a tricky surface analysis with temps around average

[booferking]

ECM op & mean like for like to day 6 850s wise but that's where they diverge..

[Mr Frost]

It is usually up here (West of Scotland) getting constant rain/wind at this time of year - quite a strange last month and a half. (October was 0.8 C below the 1981-2010 average, rainfall was 87% of the average and sunshine was 118% of the average)

Feels like it has been cold and mainly dry here since the second last week of October. 
Lovely today again with the mountains in the distance covered in snow. (Snow is going nowhere above 700 meters for at least another week and maybe beyond)

The lack of Autumn gales/severe gales has been quite remarkable! 

Latest ECM keeps it chilly and more of the same.

 

To be honest I would take the current pattern for all of Winter! (That would be selfish of me and miserable for lots of members on here though! So let’s hope it changes soon so folk can dry out/get a break from the flooding)

All the best and have a good night!

[Mike Poole]

So where are we today? It is November 12th, which comes as something of a surprise given the activity on here is more like January!  We have a tropospheric pattern that is prone to blocking, not as yet in positions to bring cold weather to the UK, pressure being exerted already on the stratospheric vortex, and seasonal models that refuse to play ball.  
Taking the seasonal models first, and I still haven't seen the latest GloSea5 - I will comment on it when the MO website updates because I want to see all the charts - but by all accounts it is as several previous months updates, which is OK by me.  I am working on the hypothesis that the seasonal models are failing to factor in the solar minimum properly, and are hence giving too little probability to a more amplified meridional jet, and if this hypothesis is correct one wouldn't expect a change this month, in fact some of the months that earlier versions of the seasonal models have made predictions for have now already happened and been shown to be wide of the mark - a bias has now been established, I think.  That's not to say that things couldn't all flip as we enter winter proper, they certainly could, and we can remember occasions when that has happened, but there are no real signs of it in the near term models at the moment.  The stratobserve NAM plot continues to indicate a trop strat disconnect, with a weakening strat vortex to boot, as far as we can see (that's based on GFS 0z:

Zonal winds:

All downhill now, to below 10 m/s on some ensemble members, so this is where it starts to get interesting.  But before we get there we have got the current outlook to deal with, GFS GEM and ECM at T168:

Sufficient uncertainty to be going on with there, an awful lot of rain, and GEM the best.  

So to sum up, some nasty weather to get through, at the moment there is promise of a cold start to winter, but the dice still have to fall right, and the most significant one in my view is the strat...so we will keep watching!

[Cleeve Hill]

 Here some interesting info for the Coldies. If this comes to fruition then no + NAO and a wintery spell coming. 

[bobbydog]

Well... after a busy year so far, I haven't been on here much and whilst I've not really been keeping up, I have been watching the CFS for general long-term trends, some of which have been spectacular for (northern hemisphere) winter. What's the general consensus? 

[Jordan S]

ECM for Thursday showing the rain to become very slow moving in similar areas that I showed in a earlier post this morning showing some sleet or snow to higher ground perhaps.. then pushing northwest into the flood effected regions before slowly fizzing out..

Then more rain is shown to push in from the southeast on Friday night into Saturday much like the Gfs shows.. 

 

[Mike Poole]

28 minutes ago, bobbydog said:

Well... after a busy year so far, I haven't been on here much and whilst I've not really been keeping up, I have been watching the CFS for general long-term trends, some of which have been spectacular for (northern hemisphere) winter. What's the general consensus? 

Hi bobbydog!  In a nutshell and shamelessly copied from a post I made recently in another thread:

• All long range models giving a highish probability of a mild winter.
• Low solar activity at solar minimum, which the models apparently don't deal well with, this should lead to a more meridional jet. 
• Big strat trop disconnect forecast to continue for the foreseeable.
• SSTs in Indian Ocean favourable for increased westerlies (as per MO Contingency Planners forecast and discussion in teleconnections thread).
• Possibility of an early SSW.
• Low arctic sea ice.  

Other than that, it's wet.

Edited November 12, 2019 by Mike Poole

[damianslaw]

21 hours ago, northwestsnow said:

 

More of the same for the foreseeable, we are in a bit of a stuck pattern at the moment, one full of trough domination stalling over the UK, with the azores high floundering far to our SW, and heights building to the NE, locking it into place. A cold unsettled outlook for everyone, lots more rain in places that don't want any more unfortunately. Cold and frosty in the north at times, with snow on higher ground throughout.

Into next week, the trough pattern doesn't look like changing anytime soon, but with heights setting up stall to our NE, and perhaps in time sinking south, we could end up with more of a southerly flow wrapped within low pressure/trough features, meaning something a but milder (only average though), with probably just more rain. If you like trough domination - then you will liking November 2019!

[Stonethecrows]

2 hours ago, Catacol said:

I must be the only one then that looks at these chart and walks off satisfied. Anyone hunting wall to wall snow in November needs to read their history.

The pressure differential between Greenland and Scandy on those charts is pretty good for vortex disruption when combined with the Aleutian low in the North Pacific. November is nothing but a setup month - no low ground product in terms of snow is realistic. In addition the pattern is effectively blocked, and people need to realise that a block creates a more meridional flow that promotes warm flows from the south as well as cold flows from the north. The fact that the Scandy anomaly helps pull warm air up over the UK is part of life in this part of the world at this time of the year. The pattern is not one of raging zonality, the strat/trop disconnect remains in place at least for now, and vortex stress looks likely.

Winter doesn’t start for 3 more weeks, and realistically doesn’t really kick in until mid December which is 5 more weeks. If you need to cheer yourself up in the search for snow try reading up about the Feb 18 reversal that led to that beastly spell. The Atlantic preconditions are not dissimilar and while every patten is unique we are certainly in with a chance of a cold outbreak this season. Just don’t expect it in November and don’t expect it to last all winter. 1963 was unique and a year I don’t think we will see repeated for as long as the world continues to warm.

The most sensible, realistic and on the money post that has been written on here in many a moon.

[bobbydog]

25 minutes ago, Mike Poole said:

Hi bobbydog!  In a nutshell and shamelessly copied from a post I made in another thread:

• All long range models giving a highish probability of a mild winter.
• Low solar activity at solar minimum, which the models apparently don't deal well with, this should lead to a more meridional jet. 
• Big strat trop disconnect forecast to continue for the foreseeable.
• SSTs in Indian Ocean favourable for increased westerlies (as per MO Contingency Planners forecast and discussion in teleconnections thread).
• Possibility of an early SSW.
• Low arctic sea ice.  

Other than that, it's wet.

Hi Mike, in my experience, long range weather forecasts are often 'revised' at short notice... 

From what I've seen, the teleconnections are a little 'unusual' this year. I don't expect this winter (or the next...) to conform to our usual expectations... 

[Frosty.]

Tonight's Ecm 12z ensemble mean is looking pretty unsettled longer term and also trending less cool / milder, more so than the 0z.

Edited November 12, 2019 by JON SNOW