Model Output Discussion - 05/01/2016 18z onwards

[lorenzo]

It's late to the party bless it, again. A psychiatrist would have a job deciphering the proclivities of the pub run.

Stick with the top verifying models and what they are doing.. there is a reason they are the hi-top models.

The low below that blooms here is visible on the GEFS output earlier. 18z just takes it to nuclear.

This table from the same location as where the furious low is spawned, at the same time frame, tonights 18z represents a 30mb diff.

Now at a similar time frame the best verifying model in the world has...

Where would your money be?

 

[phil nw.]

4 minutes ago, lorenzo said:

It's late to the party bless it, again. A psychiatrist would have a job deciphering the proclivities of the pub run.

Stick with the top verifying models and what they are doing.. there is a reason they are the hi-top models.

The low below that blooms here is visible on the GEFS output earlier. 18z just takes it to nuclear.

This table from the same location as where the furious low is spawned, at the same time frame, tonights 18z represents a 30mb diff.

Now at a similar time frame the best verifying model in the world has...

Where would your money be?

 

Furthermore way further west with the ridge than the 12z GFS mean

which compares nicely with the ECM so i will put my money with yours L.

[Nouska]

Panic not!

This is the coldest set of 850 uppers (at T+360) that I've seen on the ECM extended ensembles.

 

[nick sussex]

6 minutes ago, marksiwnc said:

The next frame on the fax would be full of amazing potential I think with all the fronts and trophs waiting in line.  #waitforit

The fax chart looks better than the UKMO raw output. They've modified that data and have weakened the low near the se and elongated this and some changes upstream. This looks like a nod towards the ECM operational run.

[Mucka]

ECM London ensembles.

Cold looks pretty much nailed on for 5 days thereafter scatter and a bit of a split.

Who wouldn't of taken those at the end of December?

[simshady]

All looking good to me...hopefully this will be just the first bite of the cherry...

[swilliam]

1 minute ago, Mucka said:

ECM London ensembles.

Cold looks pretty much nailed on for 5 days thereafter scatter and a bit of a split.

Who wouldn't of taken those at the end of December?

Quite - looks rock solid till the 14th and then a few rogue members v. unlikely to verify. Then a bigger split around 17/18 which I would imagine is to do whether the ridge gets reinforced by the Azores low sliding up the W side of the ridge and reinforcing the block.

[Timmytour]

Quote

 

A useful way of seeing how the models are performing are the very excellent posts BornFromTheVoid puts up in the CET threads where he does a running forecast of the mean CET for the month based on a GFS run for the following ten days.

the forecast for the 11th from the 12z put up on saturday had the mean CET running at 6.3C.  That had dropped to 6.1C based on the yesterdays 6z, and then 5.9C from this mornings 6z.   Will be fascinating to see where it ends up, but it certainly shows how the models have "flipped"....I certainly can't remember any such reduction in the forecasts this winter....though i wouldn't rule out us having seen increases on the same scale from Nov or Dec!!!

[Singularity]

15 minutes ago, nick sussex said:

Well there has to be some drama! lol I'd disregard the GFS 18hrs run for the ne USA and Canada, the earlier shortwave though near Iceland is one of those things that might appear but because the pattern upstream isn't helpful to develop more WAA then it takes an age to edge the pattern further se.

The GFS flattens out the upstream troughing and flies against this from NCEP:

LATEST GUIDANCE MAINTAINS THE STATUS QUO WITH RESPECT TO THE EXPECTED MEAN PATTERN THROUGH THE PERIOD. A BROAD UPR LOW OVER E-CNTRL CANADA WILL ANCHOR AN AMPLIFIED TROUGH THAT EXTENDS INTO THE LOWER 48 WHILE ANOTHER TROUGH PERSISTS OVER THE E-CNTRL PACIFIC. BUNDLES OF ENERGY EJECTING FROM THIS LATTER TROUGH WILL HEAD INTO/PASS THROUGH A MEAN RIDGE NEAR THE WEST COAST.

 

 

I was struck by how the 18z appeared to have wound the clock back 24 hours in terms of that U.S. trough. If anything the way the trough sort of falls apart and then become strung out east to west as a series of shallow troughs looks totally bizarre.

Those who have been wondering what a proper 'wobble' in the run-up to a cold spell looks like, well the 18z GFS det. is probably it. Perhaps a poor assumption made somewhere, or some manner of bias showing its hand in a particularly ugly way. We'll find out tomorrow of course.

Blimey, that GFS run sure does stray a long way from the consensus of the day, how ridiculous is that? It could have redeemed itself around +264 but the zonal bias just trashed everything. Not uncommon during these situations, it has to be said.

[ukpaul]

Panel GEFS at 180h.

EDIT: Sorry, changed to 18z now.

Edited January 6, 2016 by ukpaul

[Mucka]

Extended JMA 12z very snowy

That low is from the SW and I think this could come into play later. It could act as a snow machine or a spoiler if it stalls and raises heights across Europe or it could end up fairly irrelevant.

[swilliam]

Unfortunately there is quite a bit of support of the Op from the ensemble members - this is reflected in the change in the mean at 192

12Z

18Z

 

Lets hope this is not a trend even though it gives a few days of cold weather still - as the Meto say - still a question on the longevity

Sorry about the extra picture  - seems to be bug if you make a mistake

Edited January 6, 2016 by swilliam

[feb1991blizzard]

1 minute ago, swilliam said:

Unfortunately there is quite a bit of support of the Op from the ensemble members - this is reflected in the change in the mean at 192

12Z

18Z

 

Lets hope this is not a trend even though it gives a few days of cold weather still - as the Meto say - still a question on the longevity

Yes I noticed that a few frames ago but didn't want to dampen the mood.

[chionomaniac]

Day 10 GEFS anomaly chart

No trough at southern tip of Greenland like the op. #outlier

 

Day 11

Edited January 6, 2016 by chionomaniac

[nick sussex]

2 minutes ago, Singularity said:

I was struck by how the 18z appeared to have wound the clock back 24 hours in terms of that U.S. trough. If anything the way the trough sort of falls apart and then become strung out east to west as a series of shallow troughs looks totally bizarre.

Those who have been wondering what a proper 'wobble' in the run-up to a cold spell looks like, well the 18z GFS det. is probably it. Perhaps a poor assumption made somewhere, or some manner of bias showing its hand in a particularly ugly way. We'll find out tomorrow of course.

Blimey, that GFS run sure does stray a long way from the consensus of the day, how ridiculous is that? It could have redeemed itself around +264 but the zonal bias just trashed everything. Not uncommon during these situations, it has to be said.

The key thing is that the troughing remains amplified in that crucial part of the evolution, I really don't think the GFS 18hrs run has suddenly found a new real trend. I was more concerned of a strong block setting up too far west not no block! lol

For that reason I won't be losing any sleep over this GFS run.

[Abyss]

The BBC weather for the week ahead mentioned it will probably stay cold for all of next week and when the block sets in like it's FC to be it's hard to shift. 

Edited January 6, 2016 by -Bomber-

[swilliam]

5 minutes ago, feb1991blizzard said:

Yes I noticed that a few frames ago but didn't want to dampen the mood.

Well as I had already put my head above the parapet once I thought I would risk it again.

Edited January 6, 2016 by swilliam

[Singularity]

3 minutes ago, nick sussex said:

The key thing is that the troughing remains amplified in that crucial part of the evolution, I really don't think the GFS 18hrs run has suddenly found a new real trend. I was more concerned of a strong block setting up too far west not no block! lol

For that reason I won't be losing any sleep over this GFS run.

There was a moment when I thought the 18z was going to deepen the trough further west than the 12z, before all that strung-out nonsense. However I do feel that the broad Sceuro trough will help us out if there is more of a west-based neg. NAO for a time. Maybe not the deepest of cold in that scenario but still wintry.

Turning in now, tomorrow beckons.

[Bullseye]

Well the good old GFS goes from splitting the PV on the late afternoon runs to reforming PV this evening at or around day 10/11. Which offers two options: is FI still at day 5/6 or is the GFS just being clueless to the ongoing changes? The US mets seem to be getting frustared with the GFS poor consistently in past month or two. As seen here:

 

 

[ukpaul]

12z London GEFS

18z London GEFS

[ALL ABOARD]

Ian Fergusson– ‏@fergieweather

@paul78310011 ...but my hunch is it probably returns mobility too easily. Often an issue in these situations. But hey-ho, time will tell!

 

Regarding the 18z...

Is there a sneaky hint in there?

Dissapointing 18z ensembles btw. I dont know wether to laugh or cry! Not as prounouced as the 12z and after the ecm I was expecting to see some follow this pattern. Im going to be diagnosed with vertigo soon with all these ups and downs!

 

[Cheshire Freeze]

9 minutes ago, ukpaul said:

12z London GEFS

18z London GEFS

Ouch, cold cluster definitely not as pronounced on the 18z suite. I was hoping for a cracking 18z then early to bed...looks like I'll be staying up for the 0z now. Here we go again eh!

Control looks to follow the op there too.

Edited January 6, 2016 by CreweCold

[Weathizard]

9 minutes ago, ukpaul said:

12z London GEFS

18z London GEFS

There's not a massive difference really just longer term the OP leads it's ensembles off but that isn't surprising. Anyone heading for the Prozac cupboard just because of one run I think need to get real. I don't think I've ever known a cold spell in the UK arrive with zero hiccups in the models. 

Edited January 6, 2016 by Weathizard

[feb1991blizzard]

Just now, CreweCold said:

Ouch, cold cluster definitely not as pronounced on the 18z suite. I was hoping for a cracking 18z then early to bed...looks like I'll be staying up for the 0z now. Here we go again eh!

yes it just makes you think the met office have this game nailed now and the models almost correct towards mo predictions.

[Abyss]

God it's one run. M.O and Ecm were great and it's FI in GFS when it goes t1ts up compared to previous run. Who'd read this forum lol