Model Output Discussion - moving into Winter

[Ali1977]

Just now, Skullzrulerz said:

Yes it is a "upgrade" for "uppers" but unless you live on a hill.

That's exactly what you're going to get.

Still ICON is better then to this morning's.

 

It’s the set up that’s important, give it 24 hours on and most of the U.K. would be cold enough for snow. That set up would keep us very cold for several days.

Ideally the GFS, GEM and ECM have a quicker route to the cold 

[Kasim Awan]

do we have a whole winter of chasing specifics on each model run for a timeframe >5 days out ?

[bluearmy]

4 minutes ago, Skullzrulerz said:

Yes it is a "upgrade" for "uppers" but unless you live on a hill.

That's exactly what you're going to get.

Still ICON is better then to this morning's.

 

Icon is virtually dry - where is the cold rain coming from? 
 

the difference between ecm T192 and icon T180 is nuts.  The two models are usually reasonably aligned 

[NorthYorksWeather]

The main difference with the ICON this afternoon is more noticeable on the NH view. Big changes the other side of the Arctic with the PV. 
0z

12z

 

[Mike Poole]

Pleased with the ICON.  No sign of the cold plunge veering too far west, which is the thing we wish to avoid.  Including the ensembles, I’m expecting most runs this afternoon to be OK, but would like to see a reduction in those significant minority that hint at the pattern trending too far west.

[Singularity]

I don't usually give ICON the time of day but it is interesting to see where it sits relative to the 00z ECM and GEM runs as of +180 hours.

It's a little more like ECM on the Pacific side, yet far more like GEM on the Asian side.

Judging by the ECM 12z of yesterday, the Pacific side seems of relatively low importance, as it was more like today's 00z ECM than 00z GEM, yet the run panned out like the latter.

On this basis, it seems to me that what sent the 00z ECM on such a different path was the additional amplitude to the ridge through Greenland. The high was thrust across so vigorously that it forced a trough partition on the Asian side.

What if it was just an example of ECM's tendency to over-amplify at the 6+ day lead times?

[Frosty.]

I sincerely hope the ECMWF 12z ensemble mean will build on this from the 0z!!!!.. WOW…we are very close to the tipping point now regarding how things evolve during the crucial period next midweek onwards!!!..and I’m frankly EXCITED!!!!️  

 

 

Edited December 1, 2022 by Frosty.

[East_England_Stormchaser91]

Before we get to the 12z rollouts, here’s a rational and if you like, a sobering post. As we head into this event, there will be chops and changes, there will be extreme roller coaster rides and some runs we would rather not see! 

Through experience, I’ve never known a clean transition with no disagreements into a good cold spell, it’s always been very dramatic, emotional, hair raising and tense. I tell no lie when I say I have seen the big two titans (The ECMWF and GFS) saying the exact opposite to each other at less than 72 hours from the day of commence. I’m sure that was on the lead up to the Feb 2021 cold spell. 2018 and 2013 also had similar conflicts! The best one was Dec 2005, when the easterly got binned off 48 hours from the day, only for the forecasts to do a 180 degree turn and have it back!! 
 

I hope we see a fantastic event, but just be prepared, nothing is a guarantee! 

[Turnedoutniceagain]

27 minutes ago, Kasim Awan said:

do we have a whole winter of chasing specifics on each model run for a timeframe >5 days out ?

Welcome to NetWeather - a place where everything is 10 days out

[Allseasons-Si]

1 minute ago, East_England_Stormchaser91 said:

Before we get to the 12z rollouts, here’s a rational and if you like, a sobering post. As we head into this event, there will be chops and changes, there will be extreme roller coaster rides and some runs we would rather not see! 

Through experience, I’ve never known a clean transition with no disagreements into a good cold spell, it’s always been very dramatic, emotional, hair raising and tense. I tell no lie when I say I have seen the big two titans (The ECMWF and GFS) saying the exact opposite to each other at less than 72 hours from the day of commence. I’m sure that was on the lead up to the Feb 2021 cold spell. 2018 and 2013 also had similar conflicts! The best one was Dec 2005, when the easterly got binned off 48 hours from the day, only for the forecasts to do a 180 degree turn and have it back!! 
 

I hope we see a fantastic event, but just be prepared, nothing is a guarantee! 

"I TOTALY AGREE WITH THIS",...and should be pinned

[chionomaniac]

I love the shape of this block at  T+114 - Id say its almost perfect 12Z GFS

 

[Ice Day]

UKMO at 120 looks absolutely super

Edit - but somewhat different to the GFS at the same stage

Edited December 1, 2022 by Ice Day

[Captain Shortwave]

Day 5

UKMO

 

GFS

 

Both teeing up the plunge from the north east nicely. Just differences regarding a cross polar flow from the Greenland ridge. Both are a little slower, but this may control the push of cold air a little better (less risk of the polar airmass pushing into the Atlantic).

Edited December 1, 2022 by Captain Shortwave

[Downburst]

4 minutes ago, Captain Shortwave said:

Day 5

UKMO

 

GFS

 

Both teeing up the plunge from the north east nicely. Just differences regarding a cross polar flow from the Greenland ridge.

A bit of difference in mid Atlantic also. UKMO seems to be missing a possible low developing. 

[Frostbite1980]

GFS delaying the colder 850s this time round

[Allseasons-Si]

UKMO 144...

not shure what will happen with that little feature N of Iceland would do though which could scupper things,it shows on the gfs for that same time.

Edited December 1, 2022 by Allseasons-si
Added text

[iceman1991]

Metoffice drop the wording for lower level snow for next week just rain hope I’m wrong models probably start down playing cold spell now 

[TSNWK]

12Z too far east with the plunge ?

[Tim Bland]

GFS gets there in the end as the low pulls away south west, plenty of cold waiting in the wings …

[Vikos]

1070 Greenland High drops to 1055

 

Edited December 1, 2022 by Vikos

[sheikhy]

Hmmm need ecm to come to the rescue again!getting very messy indeed!!

[Captain Shortwave]

5 minutes ago, TSNWK said:

12Z too far east with the plunge ?

The cold will come, but more from an easterly vector this time as the cold air runs around the Atlantic high.

Despite discussions regarding this mornings ECM, the GFS of anything is drifting further away from that solution. The good news is if the cold misses in this manner, you will likely to get another shot a day or so later as another low dives down the eastern flank of the high.

Edited December 1, 2022 by Captain Shortwave

[Downburst]

Just now, Vikos said:

From 1070 Greenland High drops to 1055

 

Thats on top of an ice cap a mile high, so ignore over the actual landmass as it's well up into the atmosphere the surface level interior Greenland

[Ice Day]

The GFS has quite a different profile over Greenland at 174 vs the 6z

 

Some subtle changes for sure, run to run wobble or a new signal?  As always, interesting where this takes us next

 

[Geordiesnow]

This afternoon runs are showing why I don't believe in a true Greenland high set up as we are getting into the time frame where spoilers pop up and we do see that on the UKMO in particular. 

The GFS spoiler seems to be the Iberian low once again, still room for upgrades though but not quite the output that will get this place celebrating.