Model output discussion - Closing in on Christmas

[bluearmy]

Have to go to work but events in the strat could well become the story of the day .... and a quick look at the ecm op strat data reveals unusually strong  support right up to 10hpa for the scandi trough at day 10 

[Catacol]

4 hours ago, CreweCold said:

 

What a stunner

Yes. The very best of the options that were on the table a week ago modelled in that one chart. It’s nearly time to hide behind the sofa and watch each run come out with only one eye open.............

[Ali1977]

From some good sources - lots in FI but note the mention of a second cold spell possible towards new year

LOTs of positives for coldies here, nothing assured of course but nice to read.

 

 

 

Edited December 18, 2020 by Ali1977

[Day 10]

Since we are on page 63, I'll keep the above going with this lovely chart from the control at Day 10.

[feb1991blizzard]

33 minutes ago, bluearmy said:

6 eps clusters in the extended ...... hello Shannon !

Are more of them decent than not though??

[ICE COLD]

Well I sense some very exciting days ahead . Think the strat thread is just about to take of . . The gfs 00z was a stonker 

[kold weather]

Well that was pleasant viewing of the 00z suite, the 00z GFS op in particular is very impressive for its length of cold spell.

Quite the snapback from the 12z suite yesterday which were keen to push the PV across Greenland and only move ESE which left us in alot of cases in anticyclonic gloomy WNW.

There does seem to be good signs of upper troughing being present to our east to some extent.

We've also solidified the idea of a seasonal looking xmas....but beyond looking much more interesting today, albeit at fairly long distances.

 

[sheikhy]

No change on icon 06z!!same as 00z at 120 hours!!and does not follow ukmo in leaving that low towards the azores!!!joins ecm in that sense!!!

[mathematician]

1 hour ago, Iceaxecrampon said:

Fantastic Chart....!

But -  first it was the 22nd 23rd then 24th and 25th........

Now the 28th.

Same old GFS.

It's always 10 days, isn't it? 

[Frosty.]

That was a sensational Gfs 0z operational...one for the books..even Mr Spock thinks it’s logical!..what could possibly go wrong?

ps..the charts are in a illogical order!

 

[alexisj9]

1 hour ago, Vikos said:

Hmm...

I know those snow cover outpouts from a global model aren't worth a lot but, I don't see a lot of snow coming in midterm...

It's to early to look there any way, I do hope the pattern holds though, snow won't be a problem. It'll come as lake effect of the North sea. Models won't see that yet, as it's not front related.

[johnholmes]

As it has been for 3-4 days now NOAA 500 mb anomaly remains committed to the meridional pattern. Its 8-14 showing the first signs of this starting to turn more westerly!

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

 

[alexisj9]

1 hour ago, bluearmy said:

6 eps clusters in the extended ...... hello Shannon !

I knew she was coming, I'll make her a cuppa.

[Mike Poole]

Wow, made my last post on the far reaches of the 18z, so must have been past 11pm, and there’s 5 pages more posts to read this morning!!  Fantastic output across the piece, GFS a stunner.  That idea of a second ridge after the first failed that appeared during yesterday’s later runs seems to be gaining much traction.  

GFS 6z rolling, so on we go...

[nick sussex]

Regarding the low to the sw.

This seems to be taking on mythical status . Whether it moves ne or remains cut off won’t decide the medium term outlook.

Regard the low there as a wannabe z list celeb . An overinflated sense of their own importance ! 

The most important area is the eastern seaboard of the USA and Greenland not that low .

If the upstream pattern doesn’t play ball then that’s it , regardless of what the now infamous low does .

 

Edited December 18, 2020 by nick sussex

[TSNWK]

5 minutes ago, johnholmes said:

As it has been for 3-4 days now NOAA 500 mb anomaly remains committed to the meridional pattern. Its 8-14 showing the first signs of this starting to turn more westerly!

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

 

Thanks John - A consideration I guess.. so much going on, I simply do not know where to turn.. Buckles up for the 06Z, Jeeze its relentless this - I go back to the days of Ceefax and waiting the refresh of page 401 / 403 twice a day

[Tim Bland]

13 minutes ago, mathematician said:

It's always 10 days, isn't it? 

My memory may be playing tricks but we have been looking at Christmas Day onwards for the change to something colder for a while now. It was just a question over whether it was a short snap or something more prolonged, the latter now looking likely.

Ensembles still show that we are likely to be cold towards new year, just how cold and how snowy is the question? Looks below average but not ice day territory...yet.

most won’t be happy until they open their doors to scenes like the below in New York this moorning!.. 

[alexisj9]

2 minutes ago, nick sussex said:

Regarding the low to the sw.

This seems to be taking on mythical status . Whether it moves ne or remains cut off won’t decide the medium term outlook.

Regard the low there as a wannabe z list celeb . An overinflated sense of their own importance ! 

The most important area is the eastern seaboard of the USA and Greenland not that low .

If the upstream pattern doesn’t play ball then that’s it , regardless of what the now infamous low does .

 

It is still important for the short term though. But yes looking ahead, always look left.

[Matt H]

Obviously the GFS 06z will be more interesting this morning but out to t120 the ICON 06z is more amplified than the 00z.

00z:

06z:

Edited December 18, 2020 by Frosty Winter

[Skullzrulerz]

18 minutes ago, sheikhy said:

No change on icon 06z!!same as 00z at 120 hours!!and does not follow ukmo in leaving that low towards the azores!!!joins ecm in that sense!!!

Didn't the ICON last nignt make a bit of a change to the UKMO last night ?

[nick sussex]

1 minute ago, alexisj9 said:

It is still important for the short term though. But yes looking ahead, always look left.

In the short term it helps to prop the high up and makes a difference to how quick the cold heads se.

But in terms of the medium term even with that low if upstream says no it’s a no .

I think it’s best to view any cold over Christmas as a starter , we’re still not sure what will be served up as the main course.

[sheikhy]

2 minutes ago, Skullzrulerz said:

Didn't the ICON last nignt make a bit of a change to the UKMO last night ?

Yeh it did but seems to have gone back!but as nick says seems as though that low has nothing to do with the long range pattern!!so no danger with that low apart from maybe temporarily pushing milder air further north!!

[Thunder and Lightning]

Here are the highlights for this mornings model outputs

The NetWx-MR shows a stronger high across the Atlantic brining down a cold northerly into Christmas:

ICON showing a stronger low bringing a northerly as well, just not so much of a high in the mid atlantic.

UKMO showing a very strong high right across the mid atlantic as well

Access-G (don't really know this model) brings a large high into mid atlantic, similar to NetWx-MR and UKMO. This time the low to the E is much weaker and further E.

The GFS has a similar ridge but it is squished to give a NW flow (as everyone has seen)

Let's not talk about the ECMWF... 

CMA (another model I don't really know) showing another strong high

GFS 500mb height anomaly show the ridge to be quite extensive across the Atlantic:

ECMWF seems to have ridging not extend into Greenland north enough originally, which seems to allow low pressure to slide over the top of the ridge and then break it down before it 'builds up' again.

I hope you survived my boring nonsense rambling

 

 

[That ECM]

You’ve got to feel for that low. It thought it was important and turns out it’s not.

[nick sussex]

Quite a difference between the GFS and UKMO even if they agree with the cut off low to the sw .

The GFS splits the energy into two separate shortwaves at T114 hours , the latter keeps this as one deeper system .

With these differences at an early timeframe it’s not inspiring much confidence .