Model output discussion - Into 2021

[Frigid]

26 minutes ago, Eskimo said:

WAIT, is that a...


 

Such a good run of 18z GFS charts over the past few days until today. Hopefully it doesn't verify

[ghoneym]

I think we need to get used to the fact various models will spit out some strange outputs now, particularly 120+ hours out.  The SSW will be playing havoc and the Bias corrections required will inevitably cause these variations in predictability.

I know this has been covered here and there recently but the Strat really hasn't been mastered by any model yet, yes they are improving over time and increasing the layers and grid resolution but it is still a huge issue.

For example here is a snippet from the ECMWF known forecasting issues 

A link to the full table - 

Known IFS forecasting issues - Forecast User - ECMWF Confluence Wiki

CONFLUENCE.ECMWF.INT

 

Unsure how the GFS // is handling the upcoming stratosphere influence and what improvements they have made in that field but the GFS 18Z tonight certainly looks lost at sea.

[bobbydog]

I wouldn't discount anything verifying at this time, however unlikely it seems.

However, those worrying about the Atlantic train returning, don't....

The train has lost its engine... 

[Don]

6 minutes ago, Scott Ingham said:

Yes it is mate. 

I genuinely feel volatitlity is through the roof. There is so much going on that i feel its a case of sitting back and keeping a level head and staying true to your beliefs on what should be getting churned out

At least we are in a far far better position compared to this time last year!

[Scott Ingham]

4 minutes ago, Don said:

At least we are in a far far better position compared to this time last year!

Theres not much to worry about, there will be 10s of different runs all month because we have such a chaotic atmospheric state that needs deciphering. 

If anything enjoy the ride. 

Could be worse we could have just bought a ticket to the theme park and had it stolen the night before you go (last year)

Edited January 1, 2021 by Scott Ingham

[Notty]

FI starts 5th Jan - hope models get a better handle on things soon.

Edited January 1, 2021 by Notty

[danm]

16 minutes ago, feb1991blizzard said:

The ensembles have gone much flatter towards mid month - desperately need either a split SSW (proper one) or very good displacement to the East with no residual energy left to the NW in the lower strat and trop.

Is this what you were more expecting.

Sure, but the ensembles you refer to, from one model, are for two weeks away and before the full impacts of the SSW are realised. Surely saying that the wheels are starting to fall off is not right? 

[Allseasons-Si]

27 minutes ago, Stu_London said:

FI starts 7th Jan, based on those ensembles. 

To be fair Stu that is wrong,they look OK to me out to day ten

Edited January 1, 2021 by Allseasons-si
typo

[feb1991blizzard]

11 minutes ago, danm said:

Sure, but the ensembles you refer to, from one model, are for two weeks away and before the full impacts of the SSW are realised. Surely saying that the wheels are starting to fall off is not right? 

But i have seen these things before, it started with an uptic in temperature graph at the end of both main suites, saw it coming and when i told people they laughed, and now people are starting to see it in reality, its like they just cannot bring themselves to admit it, it happens every year.

12z GEFS.

But overall still as long as the SSW is decent re- placement of residual votice(s) and quick downwelling, i am optimistic another ridge will be thrown up like someone pointed out at the end of the 18z GFS.

Edited January 1, 2021 by feb1991blizzard

[Weathizard]

Worrying about long term ensembles in a volatile modelling period when the charts we have in the next 7 days are so good is really not going to be good for your mental model well-being Feb  

GFS ensembles being flat in FI when blocking is involved is like Groundhog Day really.

[sheikhy]

7 minutes ago, Allseasons-si said:

To be fair Stu that is wrong,they look OK to me out to day ten

Where do you find these ensemble graphs that come out earlier?!i normally gota wait till 12.30am to view the same graphs on netweather!!

[The Enforcer]

15 minutes ago, bobbydog said:

I wouldn't discount anything verifying at this time, however unlikely it seems.

However, those worrying about the Atlantic train returning, don't....

The train has lost its engine... 

Or as I see it, according to that chart, the Atlantic train is forecast to have lost its engine by 16 days from now.

[bobbydog]

2 minutes ago, The Enforcer said:

Or as I see it, according to that chart, the Atlantic train is forecast to have lost its engine by 16 days from now.

Long before then mate. Thats just the nuts and bolts the scrap men left behind...

[Allseasons-Si]

1 minute ago, sheikhy said:

Where do you find these ensemble graphs that come out earlier?!i normally gota wait till 12.30am to view the same graphs on netweather!!

On Wetterzentrale.de

Wetterzentrale.de - Diagrams

WWW.WETTERZENTRALE.DE

---

Forecasted Temp 850hPa & Precipitation from GFS, 18Z

they come out as the mean/control runs are rolling out,i hope that helps

[Paul_1978]

52 minutes ago, feb1991blizzard said:

Another flat GFS op, forget that potential brutal drop at the end of the GEFS now, it aint happening.

The wheels are starting to fall off.

You said the same thing 3-4 days ago. It’s a T+270 chart. It won’t happen. There’s a SSW in the pipeline, vortex wind speeds are already lower than they’ve ever been at this time of year for years. There’s so much stacked in our favour. Any mild interlude (if it ever arrives) will be brief. Stop worrying about things nearly 300 hours away!!

[The Enforcer]

Just now, bobbydog said:

Long before then mate. Thats just the nuts and bolts the scrap men left behind...

Good. Is there an earlier chart? The earlier the better.

[Uncertainty]

17 minutes ago, Scott Ingham said:

Yes it is mate. 

I genuinely feel volatitlity is through the roof. There is so much going on that i feel its a case of sitting back and keeping a level head and staying true to your beliefs on what should be getting churned out

Agreed Scott but the day 11-15 signal *taken at face value* shows westerlies returning backed up by BBC/METO musings. For 4 days now the FI signal has been weakly flat so we can’t ignore it...The EPS were all over the present pattern and most of them are poor in the 15 day time period.

Thankfully we have a 2 week + reversal so even if we did revert to type it would be hard pushed to establish.

But as you say it’s so chaotic, going through the ens at day 8+ shows just about every pattern and wind direction you can think of, don’t even now if/how/what angle that trough is going to drop at day 6 so until that happens it’s a case of wait and see.

Really buoyed by the end of the 30dayer from Exeter vis increased chance of snow that to me says downwelling expected.

Also CANSIPS first seasonal to drop. The first passing bells are a ringing...

Last months run for Jan:

This months run:

Oops!

[Updated_Weather]

Still baffles me people cry and get stressed over some runs that go rogue IN FI - do we not learn anything?

a lot is going on at the moment? & we have more on our side for cold than not this winter,

even if we have to patient and endure some mild charts in FI - chance of them verifying are slim imo.

relax.

[bobbydog]

11 minutes ago, feb1991blizzard said:

But i have seen these things before, it started with an uptic in temperature graph at the end of both main suites, saw it coming and when i told people they laughed, and now people are starting to see it in reality, its like they just cannot bring themselves to admit it, it happens every year.

12z GEFS.

But then we haven't seen a smashed polar vortex like this in years. 

Seriously mate if you want to see the vortex any more split than its going to be, you're gonna need one of these...

[A Frayed Knot]

Wowser it's like a YO-YO in here at times. 

All because a chart go's a bit wonky like Charlie everyone gets up in arms and think this prolonged cold spell is OVER Yeh I said over. 

It ain't we are in for a few shocks this Winter believe me.

All starting from Monday onwards and a few surprises before then. - 1.3 here and last night got down to - 5.2 and I am located in South East of . 

[feb1991blizzard]

Uptick at the end of the graph even bigger on this suite, its not like i am not providing evidence.

 

[Updated_Weather]

2 minutes ago, feb1991blizzard said:

Uptick at the end of the graph even bigger on this suite, its not like i am not providing evidence.

 

All at day 10.

next

its like nothing changes nearer the time is it? No-one can call what’s going to happen.

we will have to wait and see but people expecting this run to verify have me laughing.

[Scott Ingham]

1 minute ago, Uncertainy said:

Agreed Scott but the day 11-15 signal *taken at face value* shows westerlies returning backed up by BBC/METO musings. For 4 days now the FI signal has been weakly flat so we can’t ignore it...The EPS were all over the present pattern and most of them are poor in the 15 day time period.

Thankfully we have a 2 week + reversal so even if we did revert to type it would be hard pushed to establish.

But as you say it’s so chaotic, going through the ens at day 8+ shows just about every pattern and wind direction you can think of, don’t even now if/how/what angle that trough is going to drop at day 6 so until that happens it’s a case of wait and see.

Really buoyed by the end of the 30dayer from Exeter vis increased chance of snow that to me says downwelling expected.

Also CANSIPS first seasonal to drop. The first passing bells are a ringing...

Last months run for Jan:

This months run:

Oops!

Oh i agree.

They cant be ignored and they could prove to be correct but to my mind they dont make any actual sense other than they are picking up on the early MJO signals working through 3 and 4 and imprinting these as fact.

I just cant see how those heights in the polar region could be antwhere near what they are with no fuel to get the vehicle moving.

All will be revealed. You and feb make very valid points backed up by very valid ensemble evidence so i have empathy and understanding on why you would come to that conclusion.

But for me no. I just dont see it. I think this period will look very different this time next week.

Only time will tell. If it turns out we do hit s mobile period then we do and ive got it wrong as is normally the case anyway forecasting but either way i would then only see the end of january revert to very cold type again

[mbrothers]

4 minutes ago, feb1991blizzard said:

Uptick at the end of the graph even bigger on this suite, its not like i am not providing evidence.

 

U answered your own question. ‘At the end of the chart ‘ 

[bobbydog]

5 minutes ago, The Enforcer said:

Good. Is there an earlier chart? The earlier the better.

Ok, well here's what's happening right now-

 

And here's a week's time-

We'd normally see temps of down to -88c in a strong vortex. As you can see, its a shadow of its former self in just a week's time.

(It's trying to look happy but it's a strained smile...)