Model output discussion - is the beast awakening?

[bluearmy]

9 minutes ago, mushymanrob said:

Oh come on, you know better then that!

Its normal for the ops to go off on one after previously agreeing in the 7-10 day timeframe.

To get a clearer picture of whats most likely out of this synoptic mess recent runs have thrown up... use the anomalies!  They are not so prone to these wild swings and are more often then not much nearer the mark for the timeframe they cover. This would save so much wasted time and energy, silly posts like "its all over" and such like.

The anomalies are consistent, have a 5/5 confidence rating for the 6-10 day mean

this chart shows
- Ridging from the mid Atlantic through to the Arctic North of Siberia
- Troughing over Portugal
- Most Atlantic energy tracking well South of the UK
- Slack mean Northwesterly over the UK
- A slack mean upper flow IMHO allows the positive and negative surface pressure anomalies to determine more of the surface flow.

This chart is a cold one. So im not buying the wild swings of the ops... as far as these charts are concerned, the cold spell is still very much on.

Rob -the majority of times you’ll be right but the small feature that ec ejects from the Canadian vortex and drops through se of greeny is a spoiler for nw Europe receiving a clean flow 

Gfsp looks like a much more palatable evolution all round !!

[Don]

6 minutes ago, Griff said:

I think I'm going to be surprised... 

That wonderful 10 day timeframe again!

[dallas]

1 hour ago, Nick F said:

Blimey, that limpet low over Ireland/western UK from Tuesday-Friday takes an age to finally clear SE, this is all that's holding back the floodgates to prevent deep cold flooding out of NE Europe towards us.

Trouble is, the loitering low close to the west through next week becomes removed from the jet stream which sinks away south into France and Germany, so there is little impetus for it to move. But the models do struggle with low movements when they are away form the jet and upper flow is weak.

Anyway, the NEly arrives in the end next weekend on 06z GFS, but it's the north that benefits from deep cold, hopefully corrections south for deep cold to benefit us all, IF this is the route we will take of course. Need all models on board to get the Ely or NEly going in the first place. This will all depend on how the low to the west moves and also how blocking develops to our north. Ideally we need arctic high and ridge from Atlantic flow amplification combining. But models always struggle with northern blocking, so more twists and turns to come.

Nick, do we need this low to dissappear or move S/E?

[Froze were the Days]

6 minutes ago, northwestsnow said:

Gfs para is a beauty...

Shame it's rubbish at verifying post a week.

[Don]

1 minute ago, Froze were the Days said:

Shame it's rubbish at verifying post a week.

One of these days aye?!

[Griff]

5 minutes ago, Don said:

That wonderful 10 day timeframe again!

No, as its been showing since Thursday, next Friday is when the cold starts to arrives. This is showing that it persists at day 10, but I appreciate your scepticism

[Vikos]

6 minutes ago, Don said:

That wonderful 10 day timeframe again!

Isn't it always @ D10 ?

[Tim Bland]

5 minutes ago, Froze were the Days said:

Shame it's rubbish at verifying post a week.

Good job it brings in the cold from the east at day 6 then

[nick sussex]

There might well be some fireworks around day 6 tonight as there’s not much between a very good set up and the ECM/UKMO at that point .

The orientation of the block to the ne running ne/sw is good to cause more trough disruption .

 

[Griff]

Oh you guys! Bless you

Anyhow, it finally seems to be departing around 270 hours. 

Amazing how many times since December that ecm has played catch up with gem and gfs/gfsp. Ask Steve M! Oh yeah... 

No doubt ecm will be right this time to keep everyone blissfully happy and optimistic

I'm cool, I'll graciously receive the 'told you so'. 

You are my sunshine, my only sunshine, you keep me happy when skies are blue... 

The chorus of joy! 

I'm just happy enjoying my sleet fest here this morning. 

Edited January 30, 2021 by Griff

[Froze were the Days]

2 minutes ago, Tim Bland said:

Good job it brings in the cold from the east at day 6 then

If you live in Scotland or Northern England...yawn! In general we're looking beyond day 7 for cold which might take out marginality nationwide. We need upgrades ASAP and not at D10.

[IDO]

3 minutes ago, Froze were the Days said:

Shame it's rubbish at verifying post a week.

Yes, in the last 16 10-day verification stats for 0z it has only beaten the gfs op two times! Where as in the the earlier 15, it was only beaten three times!

0z> 12z

Clearly the gfsP is struggling lately. The 12z stats are also worse than the to soon be sacked gfs op. That is clearly a flaw and although it is better in more normal conditions, it is worse when you need it to be better, that is, when there are heights building. My feelings are that it is not ready at the d10 range, but ecm op still runs and it also has issues, so maybe they will ignore that in the medium term?

[StormyLincs]

In summer that D10 chart would bring warm and sunny weather with a scattering of thunderstorms, which is what we will get soon if that D10 doesn’t get any closer. 

[Don]

11 minutes ago, Griff said:

No, as its been showing since Thursday, next Friday is when the cold starts to arrives. This is showing that it persists at day 10, but I appreciate your scepticism

I'm always sceptical when it comes to getting widespread cold into the UK!  Just hope our luck will change in February but this is one hell of a roller coaster ride!

[Blessed Weather]

Models really struggling with continuity at the moment, but if we consider the complex dynamics currently at play – the SSW with ongoing impact and the MJO meandering between Phase 6 and 7 – maybe it isn't surprising?

Let’s look in a bit more detail at the MJO progress using the latest GEFS biased corrected ensemble (but noting the ECM ensemble has been showing very similar). On the 23rd and 24th January it was in Phase 6; on the 25th and 26th it meandered into Phase 7; on the 27th January it returned to Phase 6 where it has performed a loop. The ensemble now sees the MJO returning to Phase 7 on the 4th February.

Source: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpb.shtml

Any impact on the North Atlantic profile from the MJO typically takes around 12 days to show its hand. An impact is not guaranteed but some research suggests it does have an impact on around 70% of occasions. So, taking the fact the MJO has been looping around in Phase 6 from 27th January to date, if we compare the Phase 6 composite for January with this morning’s GFS 0z and 6z NH 500hPa anomaly forecast for 10th February (28th January plus 12 days), we can see the possible influence of the MJO at play. I’ve rotated the charts for ease of comparison:

Comp   0z  6z

Source composites: https://www.meteonetwork.it/models/mjo/

To conclude – the progress of the MJO in the last week has been erratic and imo adding to model inconsistency as the signal from the tropics changed. If the current forecast of more consistent progress into Phase 7 from 4th Feb is correct, we could see model output reflecting the following composite NH pattern by around 16th Feb (just about to coming into furthest GFS range). But the emphasis is on the word “could”; there are no guarantees with the MJO.

Phase 7 Feb/Nina composite:

[bluearmy]

4 minutes ago, IDO said:

Yes, in the last 16 10-day verification stats for 0z it has only beaten the gfs op two times! Where as in the the earlier 15, it was only beaten three times!

0z> 12z

Clearly the gfsP is struggling lately. The 12z stats are also worse than the to soon be sacked gfs op. That is clearly a flaw and although it is better in more normal conditions, it is worse when you need it to be better, that is, when there are heights building. My feelings are that it is not ready at the d10 range, but ecm op still runs and it also has issues, so maybe they will ignore that in the medium term?

They don’t rely on the ops at day 10 though - only the bbc weather seems to use a day 10 op chart !!

[IDO]

Just now, bluearmy said:

They don’t rely on the ops at day 10 though - only the bbc weather seems to use a day 10 op chart !!

Yes, and nor do I, but on this forum we are hardcore and do look at d10 ops!!!

But, yes I get where you are coming from, d10 ops that are showing overblown heights will not be as relevant to pro-forecasting as they use ensembles like MOGREPS, eps and gefs. So maybe it is not as important as the stats suggest?

[Purga]

And.. a third reversal is due in short order

[Drifter]

11 minutes ago, Purga said:

And.. a third reversal is due in short order

Third time lucky for us?

 

[Cold Winter Night]

Not being an early bird, like some on here, I always quickly look out the morning model output in its entirety, before I go on this thread to read comments.

My impression of the output this morning: All is well, an improvement on the 12z's. Especially up to +144h, and that is what matters most.
Then I go here and I see the usual whining and complaining. What a surprise.
Let me be clear, EC Op is not exciting in the later timeframes, neither is GFS in deep FI, but in the ensemble EC Op is at the mildest end for day 6-9.

The models are clearly struggling. An uncooperative low on the Atlantic at 72h-96h (without much forcing) and an Arctic High that is always difficult to track (with insufficient data input in the Arctic area), guarantee uncertainty. Tiny differences there have a huge impact later.
FI is at 120h at most, I would say.

If you would have looked no further than 144h for the past few days, you would have seen upgrades and you would have been excited about all the possibilities after 144h, instead of being disappointed about FI charts that did not verify.

[khodds]

7 minutes ago, Cold Winter Night said:

Not being an early bird, like some on here, I always quickly look out the morning model output in its entirety, before I go on this thread to read comments.

My impression of the output this morning: All is well, an improvement on the 12z's. Especially up to +144h, and that is what matters most.
Then I go here and I see the usual whining and complaining. What a surprise.
Let me be clear, EC Op is not exciting in the later timeframes, neither is GFS in deep FI, but in the ensemble EC Op is at the mildest end for day 6-9.

The models are clearly struggling. An uncooperative low on the Atlantic at 72h-96h (without much forcing) and an Arctic High that is always difficult to track (with insufficient data input in the Arctic area), guarantee uncertainty. Tiny differences there have a huge impact later.
FI is at 120h at most, I would say.

If you would have looked no further than 144h for the past few days, you would have seen upgrades and you would have been excited about all the possibilities after 144h, instead of being disappointed about FI charts that did not verify.

This post is all I needed to read today, thank you. I couldn’t tell which way we were going by some of the posts I’ve skim read! 

[Cold Winter Night]

25 minutes ago, Blessed Weather said:

Any impact on the North Atlantic profile from the MJO typically takes around 12 days to show its hand. An impact is not guaranteed but some research suggests it does have an impact on around 70% of occasions. So, taking the fact the MJO has been looping around in Phase 6 from 27th January to date, if we compare the Phase 6 composite for January with this morning’s GFS 0z and 6z NH 500hPa anomaly forecast for 10th February (28th January plus 12 days), we can see the possible influence of the MJO at play. I’ve rotated the charts for ease of comparison:

Comp   0z  6z

 

As we are at the borderline between January and February, you could also use the February Phase 6 composite. This setup would be a better fit to that 6z anomaly.

I always wonder, if the MJO is in phase 6 in January, and the lag takes the effect into February, which one is the best to use? It's not a hard border of course, neither are these charts solid blueprints.

[sheikhy]

Gfs big pressure outlier between 4th and 8th feb!pretty big outlier aswell with how low the pressure gets!ah well get ready for a stonking set of 12zs then

[winterof79]

That is some moyenne it smacks of an easterly feed.

[Blessed Weather]

3 minutes ago, Cold Winter Night said:

As we are at the borderline between January and February, you could also use the February Phase 6 composite. This setup would be a better fit to that 6z anomaly.

I always wonder, if the MJO is in phase 6 in January, and the lag takes the effect into February, which one is the best to use? It's not a hard border of course, neither are these charts solid blueprints.

Agree with you CWN. On the macro scale the Feb Ph 6 composite fairly similar to the Jan composite. As we're on a new page, for ease of comparison here are both side by side and again compared with this morning's 0z and 6z NH anomalies for 10th Feb:

Jan  Feb

0z  6z