Model output discussion - late November

[IDO]

There is nothing wrong with the NH profile in the next 12+ days, it is just the usual story, by hook or by crook the UK misses out on the fun.

JFF the NH profile at D11:

Cold to mid-latitudes in three sectors. That is what we want to see just need the pattern to realign. The US may get another record breaking spell (usual caveats):

"Polar Vortex invades the US"!

[Duane S.]

This morning’s chart output look decent enough to me. Definitely ALL to play for as we near the start of winter proper. Potential wedge set up can’t be dismissed for about a week’s time. Certainly no raging classic zonal dross around the next corner. I suspect high pressure will eventually settle over but what to follow?

Edited November 23, 2019 by Paul

[Met4Cast]

All to play for..

Anyone not seeing the move away from a decent shot at cold must be looking at entirely different model runs. Any cold spell continues to look brief & widespread snow certainly isn't in the forecast at this stage. 

ENS support a +NAO pattern in the mid-extended range, as do the GEFS.

[SMU]

* Anyone got the pencil sketch of the GFS horse along the timeline *

[Frosty.]

3 minutes ago, Danielvn said:

 the models don’t really seem to be all that confident about it at present.

The Ecm 0z ensemble mean certainly isn't showing a cold extended outlook into december, it's trending milder thanks to the azores high.

Edited November 23, 2019 by JON SNOW

[Met4Cast]

The colder option is in the minority cluster on the EPS with the largest cluster supporting the return of an Atlantic, westerly regime. 

 

[Blessed Weather]

Can we stop the tit for tat and the unnecessary sarcasm please. Any further posts that are off topic will be removed. Folk come in here and want to read constructive posts about what the models are showing.
Thank you.

[MATTWOLVES 3]

1 minute ago, JON SNOW said:

The Ecm 0z ensemble mean certainly isn't showing a cold extended outlook into december, it's trending milder thanks to the azores high.

Its getting a bit heated in here Karl... Is it safe to come out yet!! Yes the mean does trend milder by day 10....but out to day 14 it does begin to trend down again.... I think it's going to be difficult one way or another to work out which way we are heading at the moment mate... I wouldn't at all be surprised to see the 12z ECM trend colder again. 

[Methuselah]

Not a pretty picture? But, I did take note of Paul's info regarding the 06Z's 30% data deficit...which cannot be ignored:

   

Soon to be further compounded by a shortage of balloon data...?

[Jordan S]

24 minutes ago, Danielvn said:

That’s exactly how people feel reading the ramping and pseudo science posted on here sometimes. When it’s showing what people want in FI model X is great at sniffing out these situations, when it all changes then people talking about how it’s still all to play for and anything could change. We all know that when the models move away from a cold solution it’s far far more likely to verify than the eye candy charts that get posted on here all the time.

I have to agree with this. But this whole heated debate is just getting out of hand.  I'm going to focus on the shorter range model output because a lot to talk about.

[IDO]

The mechanics of the next 14 days or so based on current output seem feasible. We have the Russian/Euro monolithic high squeezed east, ejecting HP cells east to be replaced by a mega Scandi-Euro trough. That energy dissipates from the high and some manages to be consumed within a Pacific ridge but the rest traverses the meridian to the UK landing pad, blocked by the trough to our east:

Start:  End: 

So assuming status quo as to likely pattern, we should expect cold to mid-latitudes in the next 12 days as the Russian/Siberian high slowly dissipates, then the dam finally releases flattening the upstream.

So after D12 not a pretty site for the UK as we await a new pattern.

[Weathizard]

What about the ECM bias for over amplification? Today’s 144 compared to yesterday’s 168

[Skullzrulerz]

35 minutes ago, Danielvn said:

That’s exactly how people feel reading the ramping and pseudo science posted on here sometimes. When it’s showing what people want in FI model X is great at sniffing out these situations, when it all changes then people talking about how it’s still all to play for and anything could change. We all know that when the models move away from a cold solution it’s far far more likely to verify than the eye candy charts that get posted on here all the time.

After seeing the last few days here I have also have to agree with this statement personnely anythings besides a short lived northerly around the end of the month/into December is what were going to get 

Not to help that there's support for +NAO for next month doesn't help matters...

It hasn't helped with a few that with biased views or this model is "in the bin" when it's not showing what they want 

I think I sit on the side lines for the now and hope we might just get lucky with a cold spell

[BLAST FROM THE PAST]

Point of note

11 minutes ago, IDO said:

T

 

A NW’ly hurricane.......that should verify

 

IDO not a response to your post.....just pinching your screenshot

 

BFTP 

 

Edited November 23, 2019 by BLAST FROM THE PAST

[SMU]

19 minutes ago, Weathizard said:

What about the ECM bias for over amplification? Today’s 144 compared to yesterday’s 168

I guess you have decide ( if you want to be bothered ) how badly each models nuances are going to impact the overall evolution.

I would sum it up by saying on occasion the UKMO tends to be a bit slow & amplified gravitating its 120 > 144 evolutions towards that footprint where as the GFS 00z & 12z tend to exhibit all the bias I highlighted above meaning they are normally a long way East & flatter than the Euro by 168 ( or course not all the time )

The 06z operational is by far the worst with its failings being even flatter & even further East with its solutions past 168.

Net Net you would estimate that the likley meeting point of the 2 blended ( exc 06z Operational ) is somewhere towards the 80% Euro plot but often probably not quite as amplified as originally touted at the start -

This is of course a long term statistical generalisation covering many years & in certain scenarios where the UKMO excels ( wedge highs to the North ) that meeting point may work towards 90% - however on occasion where the GFS seems to do better that may be nearer 50%.

The current output circa 120-168 I would go with UKMO / ECM blend 80% & nearer 90% relating to 06z operational.

Post 192 now as it stands the current model tendency ( thats the ECM & more so the GFS ) is to over estimate the eastward position of the jet in which case you would expect that atlantic high to finally end up further North & West than currently progged. 

With that in mind thats why I highlighting the shift in GFS means as we count down from 204 yesterday as that appears to be the trend....

Edited November 23, 2019 by Steve Murr

[swfc]

4 minutes ago, Skullzrulerz said:

After seeing the last few days here I have also have to agree with this statement personnely anythings besides a short lived northerly around the end of the month/into December is what were going to get 

Not to help that there's support for +NAO for next month doesn't help matters...

It hasn't helped with a few that with biased views or this model is "in the bin" when it's not showing what they want 

I think I sit on the side lines for the now and hope we might just get lucky with a cold spell

Good points there.i suspect it will be a long winter on here "when it starts" .look at the models has an idea of what may happen after all there computers!obv short term there pretty accurate but how many times have you seen a weather forecast 24 hours before the event say"Wel keep you updated with the track or position of the low etc"granted it's not on a nhp scale but you get my point.Anyway very unsettled week with not wanted rain again.hopefully an anticyclonic spell may arrive asap.chill guys!

[SMU]

Just to reinforce the point about how the models are changing - The 06z mean out to 192-240 is still washing out much change however at 192 it was more amplified-

Lets be clear we are * NOT* looking to suddenly transform from where we are now to a greenland High- We are seeing if that amplification can be enough to put a wedge into Scandi to back the cold into the UK-

Take PTB 9 this is the kind of slower evolution I was referring to....

Meteociel - Cartes Ensemble GFS (ENS/GEFS)

WWW.METEOCIEL.FR

---

meteociel propose des rubriques météo temps réel, forums, modeles...

Thanks

[markw2680]

From my very limited experience on here if the models are showing let’s say a really cold snowy blast that actually verifies we 90% of the time end up with a watered down version so to me don’t set your heights too high in the first place and you won’t get so disappointed if it dosnt actually happen.

as regards to the models at present, they are just trying to iron out what may actually happen so there will be wild swings run to run it’s the bigger picture that remains and I’d say at this time of year it could all be a hell of a lot worse. I mean how many times heading towards December will we be talking about Greenland highs etc? Not many. Just see how this exciting model watching actually turns out you never no in a couple of weeks we could well be at the start of a big . Who knows.

I really enjoy reading everyone’s thoughts in here well in the main, keep up the good work

[swfc]

1 minute ago, Danielvn said:

Exactly, I suspect the atmosphere will always be too chaotic for 100% of forecasts to be 100% accurate 100% of the time.
 

i mean it’s interesting to see the models try, but they’re so far off being accurate it’s not funny.

Yes it's frustrating.the high being forecast was never going to reach Greenland it coudnt.,ieSteve's recent post.if you look which direction the weather is approaching the UK and look for nhp differences early on then that's the way imo.atmospheric changes leaving the ESB are a good guide run to run.all imo and il get my coat

[Paul]

So, just as a reminder - these are the forum guidelines, some people need to urgently read them.

https://www.netweather.tv/forum/guidelines/

Below is a line from those guidelines, we've had just about every one of the items on that list this morning alone. 

Quote

Don't disrupt the discussions - posting really off topic, trolling (posting to get a reaction or wind up), being overly defensive of your position or just making anti-social disruptive posts isn't on and isn't what the community is about.

Those creating these issues need to stop now to avoid it becoming a really short winter on here for themselves. Otherwise the team will be acting swiftly to ensure this sort of stuff doesn't continue.

[johnholmes]

Oh dear here we go again, the ups and downs of the model thread. Come on folks stand back, perhaps stop looking for the perfect chart past 192 h, you know really in your own mind that whatever the chart shows is not likely to be correct at T+00. Very few of you check like with like but watch each frame coming out at distant time scales from run to run. Fine if you simply want to enjoy seeing charts of deep cold and snow to enjoy but usually they do not verify.

Having said that how about the upper air pattern for the next 6-10 days. Shall we have a look, I did do a quick post yesterday that seemed to suggest a degree of ridging NW of the UK. Is that still the case?

EC-GFS this morning

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Well only EC out but to me that looks a reasonably 'cold' pattern, it showed similar unless I am mistaken Friday morning.

How about NOAA?

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

To my eyes that looks quite similar to the EC output, also NOAA has had similar charts over the last couple of days. Not especially a cold contour height(s) for the UK but the air is certainly not from the warmer side I would suggest.

Remember the charts above are 'mean' charts over the 6-10 day period, there can be quite substantial differences in the actual 500 mb chart on a day to day basis. What they do allow, IF used carefully and accepting that 4+4=8!, is that during the 6-10 day period a rather cold or even at times cold air mass is going to affect the UK (all of it). The surface weather is going to be predicted on a day to day basis by what I call the synoptic models from H+ 120 they will, say UK, GFS and ECMWF, all gradually converge on the same or very similar looking charts. Take a look at UK Met Fax charts, link below, to see how the mix of man and machine is dealing with the various model outpus, they become pretty accurate, usually, from T+84 downwards, yes there will be exceptions but the best we have. Don't expect too much from ANY model you have access to regarding ppn, will it be rain or snow and how much and where. If you have been on here through the summer, think how many times the ppn forecast has not been all that good even 24 hours out. With snow there are at least EIGHT other variables for your back garden to bring into the equation. 

Fax chart link

UK Met Office Fax Charts - UKMOMSLP Analysis and Prognosis - org

WWW.WEATHERCHARTS.ORG

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UK Met Office . . Europe and North Atlantic MSLP analysis and prognosis charts

Net Wx snow predictor= see below

If you take all the above on board, it may take away some of the ecitement of the 'chase' this winter but it will certainly help prevent quite a bit of the disappointments that may otherwise occur.

There is a Net Wx link to trying to take the 8 variables into account in the learning area. Well worth a try.

I hope you don't feel I am pouring cold water on your hopes but I am just trying to suggest ways you can enjoy the models without too much disappointment.

 

 

Edited November 23, 2019 by johnholmes
adding link

[Mr Frost]

Maybe time for A Hunt for Cold Thread and In Depth Model Discussion Thread? (Just a suggestion) That way we all get to separate the wheat from the chaff.

Having to wade through the utter drivel in this thread this morning was hard work to say the least. (I have never put anyone on ignore in ten years and never will as it’s nice to see what everyone has to say - even if it is total guff. )

Models/charts/ look great to me - very seasonal for Scotland on both the ECM and GFS for the start of Winter. 
 

ECM

 

GFS

 

 

Have a great weekend! 

[knocker]

Tricky call. Way above my pay grade

[Jordan S]

I'm going to focus on the remnants of ex hurricane Sebastien and how it may enhance rainfall coming in for tuesday. 

Here is the Gfs chart for monday morning..

The chart's above show where tropical storm Sebastien is.. 

12 hours later.. 

By this point tropical storm Sebastien likely transitioning into a extra tropical system with an area of low pressure just to the north of it.

By Tuesday midday you can see what will likely be ex Sebastien at this point close to northwest Spain but the low to the north has drawn some of this systems remnant energy into its own weather front therefore enhancing the rainfall coming in..

A lot of rain likely for Western and perhaps southern areas from this system for tuesday afternoon/night depending on how this low pressure area interacts with Sebastien. 

Edited November 23, 2019 by jordan smith

[bluearmy]

19 minutes ago, knocker said:

Tricky call. Way above my pay grade

Yes knocks - the ridge twice as likely based on probs but the op/control at 33% still with more than just a shout ..... thereafter plenty of spanner’s in works that can change things away from a straightforward +NAO or MLB although my general expectation of an MLB is still holding its own ......