Model Output Discussion - Deeper into Autumn

[Allseasons-Si]

10 minutes ago, RainAllNight said:

Would someone mind showing a novice where these shortwaves are to be seen on the GFS 18z charts?

these are little lows of pressure that form at the base of a parent low that may get ejected from the parent low to meander around and sometimes phases with another or existing parent low or be totally on it's own and fade depending if it runs into higher pressure,these little lows are incredibly hard to forcast upto at least 24-48 hrs

the gfs shows this one at 192 hours that could be gone on the next run,hope that helps

forgot to add,you can see the little low break of the parent low to it's north here at 164.

Edited November 23, 2022 by Allseasons-si

[Allseasons-Si]

So far,...that's a def trend to colder...

12z vs 18z.

nom! nom!

Edited November 23, 2022 by Allseasons-si

[Rain All Night]

9 minutes ago, Allseasons-si said:

these are little lows of pressure that form at the base of a parent low that may get ejected from the parent low to meander around and sometimes phases with another or existing parent low or be totally on it's own and fade depending if it runs into higher pressure,these little lows are incredibly hard to forcast upto at least 24-48 hrs

the gfs shows this one at 192 hours that could be gone on the next run,hope that helps

Got it, thank you! 

Anyone who is excited to see evidence of upcoming colder weather should try playing the animation on the page below (crank up the speed setting too), it is the GEFS 18z T850 anomalies for the next 15 days:

https://www.tropicaltidbits.com/analysis/models/?model=gfs-ens&region=nhem&pkg=T850a&runtime=2022112218&fh=378

Edited November 23, 2022 by RainAllNight

[Cheshire Freeze]

2 minutes ago, Allseasons-si said:

So far,...that's a def trend to colder...

12z vs 18z.

nom! nom!

Yep significant cold clustering now 

[Allseasons-Si]

And it just get's stronger,..mean geo pots...

18z 372 vs 12 384.

[Allseasons-Si]

Def trending colder

[Cold Winter Night]

4 minutes ago, Allseasons-si said:

And it just get's stronger,..mean geo pots...

18z 372 vs 12 384.

Some very tasty perturbations in there.

Like this textbook example of an Omega-Greenland High, p7:

[Allseasons-Si]

14 minutes ago, Cold Winter Night said:

Some very tasty perturbations in there.

Like this textbook example of an Omega-Greenland High, p7:

There is quite a few that show E to N...

and with a mean like that,...i am not suprised.

Edited November 23, 2022 by Allseasons-si
Added chart

[Kirkcaldy Weather]

 

 

 

Same idea @Allseasons-si

Worth sharing this too

 

Edited November 23, 2022 by Kirkcaldy Weather

[JBMWeatherForever]

Yes, looks increasingly interesting into December. Building blocks starting to come together for a cold spell perhaps before the end of the first week of December. The growing trend for cold continues !  

[Rayth]

If any cold fan had a nightmare last night, it will continue when you look at the 00z GFS run

 

 

[Ali1977]

12 minutes ago, Rayth said:

If any cold fan had a nightmare last night, it will continue when you look at the 00z GFS run

 

 

The mean at day 10 is good though, as is the control and many ENS.

[Rayth]

Yeah @Ali1977 just flicking through and won’t be surprised if the 00z is outlier territory 

[Rayth]

3 minutes ago, Rayth said:

Yeah @Ali1977 just flicking through and won’t be surprised if the 00z is outlier territory 

Yep , and also a bit of a cold cluster maintaining now, let’s hope the op had a wobble 

 

 

[Mark Smithy]

Yep the 18z was right on the outer rim:

 

If the milder scenarios start coming into the mainstream then it's more of a problem.

However, all of this is really candy fluff. Anything past T168 isn't worth losing sleep over right now, be that mild or cold.

[Mark Smithy]

The real problem at the moment, it seems to me, is the one identified on the main NW headline this morning. To quote:

"with a strong jet powering across the Atlantic"

I know the jet can amplify, buckle, and split but right now it is so darned powered that the tendency is always going to be for it to blast out any blocking. 

It's like dragon's breath:

[iceman1991]

Are the models backing off now from cold ? 

[NewEra21]

Just as we started to get some run to run consistency of sorts, the op runs go off on one. Typical!

[Mark Smithy]

4 minutes ago, iceman1991 said:

Are the models backing off now from cold ? 

That depends if you think they were ever really on it? UKMO never was, although admittedly only goes out to T140. ECM was never really into it. And the GFS has flirted with it out past T168, and really out past T240, alternating from cold to mild.

I don't know how often it needs to be said but we really ought to heed this as winter approaches: the second half of every GFS run should NOT ever be treated as gospel. I frankly wish they would stop producing it. If they knew the grief and stresses it causes cold lovers in the UK every winter perhaps they would desist.

Past T168 is not, ever, to be taken as probable, nor even likely.

Have a nice day everyone.

Edited November 23, 2022 by Mark Smithy

[Cheshire Freeze]

1 minute ago, Mark Smithy said:

 

Past T168 is not, ever, to be taken as probable, nor even likely.

Except in summer when we ticked down to 40c heat from about 10 days away.

[TSNWK]

Para feeling grumpy this morning ad well. Nedd a good ECM

[Mark Smithy]

Just now, CreweCold said:

Except in summer when we ticked down to 40c heat from about 10 days away.

Well, yes. I guess the scientific or meteorological difference there is that it was in a highly blocked situation with the jetstream barely a whisper on the distant horizon. It's the jet which powers into these shores and so often scuppers cold set ups. Or at the very least adds a huge dose of lady luck into the forecasting out past T168.

So, I need to qualify what I wrote: from autumn through spring.

[IDO]

Do not often see a mean like this one as we enter December:

It could be wrong, but that is a strong signal at D14.

Of course spoiler lows as we enter the reliable are a genuine worry, but at this range we are just seeing the potential for when we enter T120. Just need this mean to be consistent and then wait to see whether we can avoid those spoilers as we get in the reliable.

[KTtom]

To be fair + 168 can be a useful tool if its used wisely, i.e. looking for trends...the sort of pattern we are likely to get has been showing up from +300, its just the specifics whch change run for run...last nights 00z is really out on its own tho, the mean is heading steadily down hill below the seasonal average... 

[iceman1991]

5 minutes ago, Mark Smithy said:

That depends if you think they were ever really on it? UKMO never was, although admittedly only goes out to T140. ECM was never really into it. And the GFS has flirted with it out past T168, and really out past T240, alternating from cold to mild.

I don't know how often it needs to be said but we really ought to heed this as winter approaches: the second half of every GFS run should NOT ever be treated as gospel. I frankly wish they would stop producing it. If they knew the grief and stresses it causes cold lovers in the UK every winter perhaps they would desist.

Past T168 is not, ever, to be taken as probable, nor even likely.

Have a nice day everyone.

Seen it so many times on here people all get there hopes up then suddenly models start backing away that why don’t get all excited till it’s actually here