Model Output Discussion - mid Autumn

[RJBingham]

2 hours ago, northwestsnow said:

Very happy with this mornings runs..

EC has a run of well below average temps from the end of this week onwards .

You can't get a better time of year for a cold ridge..

Superb conditions for Xmas markets - Friday evening temps are already sub zero in the North and a cold weekend follows...

 

Like the Chatsworth House Christmas market 

[CryoraptorA303]

And here is where we all learn the value of having multiple forecasting models I know we all like to have a good laugh at GFS and the like but all popular models have their merits at some point. Otherwise they wouldn't continue to be used.

Edited November 20, 2023 by CryoraptorA303

[Battleground Snow]

Disappointing to see the blocking signal fade away past 144 on the latest runs, but still perhaps some wintery showers for a few this weekend.

Note sure what icon is doing, looks hopelessly wrong at just 90 hours.

[bluearmy]

3 hours ago, Dennis said:

well i thought it would bring some hope (more) on winter in december

im  sorry then (im a long range forecaster) into my studies of strato and tropo

However, now it’s beginning to get some gefs support with a small mean height anomoly by day 15 we shouldn’t discount it ! 

[Mcconnor8]

8 minutes ago, Battleground Snow said:

Disappointing to see the blocking signal fade away past 144 on the latest runs, but still perhaps some wintery showers for a few this weekend.

Note sure what icon is doing, looks hopelessly wrong at just 90 hours.

ICON keeps churning out the same thing with the low further east and heights not building at all really, even as pretty much every other model has shifted now, don't think it is a very good model to be honest but not sure on its verification stats.

[alexisj9]

53 minutes ago, knocker said:

There is a strong rumour doing the rounds that this thread is going to be renamed the gymkhana thread.

Where a laugh emoji when you need one, lol

[CryoraptorA303]

3 minutes ago, Battleground Snow said:

Disappointing to see the blocking signal fade away past 144 on the latest runs, but still perhaps some wintery showers for a few this weekend.

Note sure what icon is doing, looks hopelessly wrong at just 90 hours.

It's early days yet, can't hope for much in ENSO+ November.

[Battleground Snow]

1 minute ago, Mcconnor8 said:

ICON keeps churning out the same thing with the low further east and heights not building at all really, even as pretty much every other model has shifted now, don't think it is a very good model to be honest but not sure on its verification stats.

It's nailed the beast from the east in 2018 over the other models, and was having non of the Xmas day 2021 cold snap, other than that we just look at it because its the first model that comes out with the latest data

[Metwatch]

Latest graphic from the Met Office

[northwestsnow]

7 minutes ago, Metwatch said:

Latest graphic from the Met Office

Cold  dry ,Northerly winds ...

Hopefully light winds and given the time of year ...frosty

 

 

[Bats32]

21 minutes ago, Metwatch said:

Latest graphic from the Met Office

Happy with that.

[throwoff]

42 minutes ago, CryoraptorA303 said:

And here is where we all learn the value of having multiple forecasting models I know we all like to have a good laugh at GFS and the like but all popular models have their merits at some point. Otherwise they wouldn't continue to be used.

The past however many years I have been on NW the GFS seems to be the one when it comes to snow under 48 hours out. 

The FI charts are laughable but they seem to have some of the most accurate short term charts. They pretty much nailed the past few years of when and where snow would fall in my neck of the woods.

[Mcconnor8]

41 minutes ago, Battleground Snow said:

It's nailed the beast from the east in 2018 over the other models, and was having non of the Xmas day 2021 cold snap, other than that we just look at it because its the first model that comes out with the latest data

Yeah it does come out quickly so I do watch it too, just wasnt sure how it has done historically but doesn't sound bad, strange it is so far away from every other model here but sure it will catch up today.

[TSNWK]

4 minutes ago, Mcconnor8 said:

Yeah it does come out quickly so I do watch it too, just wasnt sure how it has done historically but doesn't sound bad, strange it is so far away from every other model here but sure it will catch up today.

If ICON came out after / during GFS / UKM it would not get any airtime.... wheeled out when there is a sniff of winter.  

[MATTWOLVES 3]

You know what amazes me on here folks? Some start congratulating themselves on there forecast before that said outcome has even materialised! Well fair play to ya if you know the outcome regarding sypnotics in the UK with a million and one variables at play. I'm pretty sure some of you are hoping for a mention in the Kings honours list come Xmas,or better still a blue Peter badge

Hey you lot take a look at many of those ens from the 6z...looks like a pretty messed up NH too me. We go colder by the end of the week and out of little acorns grow big conker trees ok I made that one up.

Let's bring it home...The snow the cold the Euro 24 the Eurovision song contest.....the whole lot...I mean business

 

[Kasim Awan]

1 hour ago, Battleground Snow said:

Disappointing to see the blocking signal fade away past 144 on the latest runs, but still perhaps some wintery showers for a few this weekend.

Note sure what icon is doing, looks hopelessly wrong at just 90 hours.

Imo nothing looks flat after 168h just a pause in the northwards push in blocking which is to be expected in a phase of amplification cycles.

[Kirkcaldy Weather]

On 07/11/2023 at 01:43, Kirkcaldy Weather said:

Long Post incoming by the end you'll possibly be casting a thought to "where did I put that snow shovel"

 

On 07/11/2023 at 01:43, Kirkcaldy Weather said:

Patterns for November week 4 through the 1st week of Dec are emerging as the long awaited new MJO cycle[s] start.

 

On 14/11/2023 at 19:49, Kirkcaldy Weather said:

Extremely happy how this is developing plus the signal into a bit of a higher amplified +PNA will boost wintry prospects 

Nice progression as conducive parameters for snow gradually arrive with a flow angled into the Northeast > East 

Should see the shot of a snowstorm into the Northeast of America currently looks like 2 weeks from now as the +PNA really comes through 

 

 

On 07/11/2023 at 01:43, Kirkcaldy Weather said:

 

 

Long Post incoming by the end you'll possibly be casting a thought to "where did I put that snow shovel"

Patterns for November week 4 through the 1st week of Dec are emerging as the long awaited new MJO cycle[s] start.

This will be accompanied by some other influencing features however I'll begin with the extremely fun 500hpa patterns to emerge in 3.5 - 4 weeks approximately.

We first have to work out the exact route the MJO will be on through the remainder of November , you'll be aware I've been discussing us being on a relaxing pace with regard to the MJO this comes to the fore here, we know for certain we've moved into part of the indian ocean a la phase 2 which in its own right provides good insights to the aforementioned setups 

There are a few dynamics which can be noticed originating with a November phase 2 

Blocking increasing to the Northeast plus Scandi with north Atlantic cyclonic developments taking on a classic \ alignment with some scope of an associated link with trough from the Pacific Northwest and or California. 

Next we have the first part to figure out as this is where the models begin to come in with differing scenarios especiallyin regards with speed. It's fairly reasonable why the MJO is decreasing in amplitude as it attempts to get through to the eastern portion of the indian ocean which is currently being heavily influenced by the likely peak strength of this negative indian ocean dipole 

 

Very useful thoughts by Mr Roundy which is in line with the above 

 

Normally the progress should be in numerical order which we see with the EC and JMA

FOLLOW THE ENS MEAN ABOVE

We will start with this scenario as its the most reasonable 

Phase 3 

Close dynamics which begin in phase 2 and also note the separation from the elongating joined high from phase 8 

Phase 4

This sees retrogression begin to appear 

We'd be keeping close watch on a big cold pool setting in on the Eastern flank of the block 

Putting Ninò into the equation a few tweaks and it's a very wintry situation 

Phase 5

Cross polar high heights 

Deepening of North Atlantic cyclonic developments 

GOLD TIER NOVEMBER PHASE 6

Akin to classic Ninò responses for winter 

With the re emerging journeying across the Pacific this adds up as I'd be expecting some final typhoon signal to end the season. Last nights GFS was rather spectacular with dual major typhoon development which would lead on with eventual feedback upstream [possible blocking enhancing?] As we watched in October after Bolaven.

There's both of the setups I've covered in lots of recent postings the trough into Florida with further wave break cut off low development across California. There has also been a persisting signal between multiple models of high pressure building through the middle of USA centred possibly northern states Dakotas Iowa etc

Already exhibiting the influence of this MJO cycle lovely first trending on CFS 

There can be multiple routes to cold and potential snowy setups in the UK and this is most akin to the methods which set out during late November 2010 

 

At our current stage I can forsee at least a few weeks as discussed in the above with completely below average temps at both surface and upper levels.

This being a distinct feature combining many teleconnections MJO PNA NAO AO EL NINÒ QBO 

Excited seeing an increasing amplitude through 8 + 1

Mix with highest impactful precursor patterns on weakening the Stratospheric Polar Vortex 

This cycle means business and I'm excited, eyes on a retrogressing high from Northeast into Greenland as December ticks on ..

 

[Weather vane]

2 hours ago, ANYWEATHER said:

Well just typical for the Gfs 06z, it’s now undoing the buttons as regards the phantom cold spell in true Gfs Style.

Yes, but let's be fair here. A week ago, ECM and others had us almost in Euro slug territory, or at least a very flat jet. The GFS was correct in seeing a pressure build in Greenland, which will probably lead to a significant pattern change. At least on this occasion, we can be happy that the GFS was 'mostly' right - otherwise, if we judge the model as always inferior, then why bother looking at it at all !

[nick sussex]

The ICON backtracking to the stronger ridge at T90 hrs .

[Lukesluckybunch]

You couldn't make this up..ICON now taking the gfs route

[TSNWK]

from a very low base ICON has improved somewhat on its 06Z effort - low pressure less round / more acute angle and heights much stronger into Greenland - GFS take note!

[Ali1977]

12z’s, time for a back track back to the freezer me thinks

[Downburst]

@Kirkcaldy Weather - I am a little confused due to reading back and catching up on some of the thread. ECM/GFS and now ICON arguments etc so forgive me I'm almost tired.

 

Find that last chart intriguing. Assuming it's not Day After Tomorrow, but what is the event the adjacent chart showing, the days before and after what? Is that before and after a Phase in MJO or an SSW etc?

[Daniel*]

Let’s remind ourselves what ECM was showing nearly 48 hours ago a flat mild westerly typical +NAO pattern. The vast majority of EPS did not have much interest either. So it strikes me this model underestimated MJO forcing meanwhile GFS more effectively expressed it. It’s fair to say this has not been the models finest hour. Verifications stats are posted but in reality there is not an actual significance difference between them, perhaps some models excel better in North Atlantic region. None is perfect.

now for 24th

Edited November 20, 2023 by Daniel*

[Dennis]

ICON12z