Model output discussion pm 13/01/2016

[karlos1983]

Hi GP

I'm presuming that means it is a good reason to discount the Op?

[mountain shadow]

4 hours ago, Weather Wonder said:

Without taking an in depth look at the latest output I think the gfs is more likely to be correct in modelling the tropical low than ukmo, I expect to see the ukmo backtrack slightly and most likely meet halfway with the gfs.

The Hurricane forecast is for it to travel due North towards Greenland not West to East so in that regards the GFS cannot be right. 

[Froze were the Days]

What we can assume after the car crash differences between the GFS and UKMO early in the run that both models take away the block over the country quicker so looking like that will be out of the equation - looking at the UKMO the pattern to the west looks somewhat further north but with heights to the north just and only just sending the jet south of the UK. ECM will be interesting tonight...surely it can't be progressive like the GFS.

My God...will we see an end to the differences, fingers crossed tonight.

Edited January 14, 2016 by Froze were the Days

[bobbydog]

9 minutes ago, SN0WM4N said:

It's poor because it's inconsistent and reminds me of a flapping fish.

or it could be inconsistent because the input starting data lends itself to a large range of possible outcomes. the UKMO may be consistent but could be consistently wrong! obviously i hope its not but we just need to wait and see what happens....

[Singularity]

2 minutes ago, Glacier Point said:

Op GFS has just shifted in a massive 600m in its 500 hPa geopotential height over Kara Sea at day 7 between 06z and 12z runs. It also now has the North Atlantic a seething pool of meridional flow where once there was a unified deep upper low....

With a swift return of the Arctic High to follow, that being the import from Kara... the AO doesn't spend long near neutral on this run!

As far out as this is, it's a total classic in terms of having the HLB, mid-Atlantic ridge and pressure from the Canadian vortex segment. That trough by Greenland looks rather troubled though - such splitting is something I remember Steve Murr once making a lot of as a precursor to (big?) height rises over Greenland.

How close will this run get I wonder... I think we're finally starting to get to the long-awaited point where GFS in lower-res should start producing some entertaining charts as it sees the next period of potential driven by the various forcing mechanisms that GP has outlined very nicely in recent days.

[igloo]

the GEM and the the GFS also this mornings ECM have been consistent on another euro slug in the latter parts of there runs bad news as we no what that means more flooding 

[cowdog]

3 minutes ago, mountain shadow said:

The Hurricane forecast is for it to travel due North towards Greenland not West to East so in that regards the GFS cannot be right. 

It appears to have Alex's track kind of on the most expected path, but what it hasn't got right is its pressure. Its off by over 20mb currently, and also has it strengthening when it goes further north, which surely has to be unlikely, also the NWS expect it to weaken in 12 hours not continually strengthen - GFS really seems to have got it wrong.

 

FORECAST POSITIONS AND MAX WINDS

INIT 14/1500Z 31.5N 28.4W 75 KT 85 MPH
12H 15/0000Z 34.3N 27.7W 80 KT 90 MPH
24H 15/1200Z 38.9N 27.7W 75 KT 85 MPH
36H 16/0000Z 45.3N 28.6W 60 KT 70 MPH...POST-TROP/EXTRATROP
48H 16/1200Z 53.0N 31.5W 60 KT 70 MPH...POST-TROP/EXTRATROP
72H 17/1200Z...DISSIPATED

[bluearmy]

I see gfs taking alex into the main s of Greenland circulation by T 60 . seems reasonable to me. not sure where everyone sees it headed east ????

the models are all handling this the same. what the remnants of that ex trop air do when mixed with the w atlantic trough is open to some question but at T48/T60, the models should all be on the same page with it. perhaps GFS is over reacting to the input of the warm air into the system. or perhaps it will be right ........

 

Edited January 14, 2016 by bluearmy

[Turnedoutniceagain]

11 minutes ago, Glacier Point said:

Op GFS has just shifted in a massive 600m in its 500 hPa geopotential height over Kara Sea at day 7 between 06z and 12z runs. It also now has the North Atlantic a seething pool of meridional flow where once there was a unified deep upper low....

 

Atlantic hurricanes in January, this is just bonkers.

Indeed. Hurricane Alex is the first January hurricane since 1938. God knows how GFS will model that one !!

[Geordiesnow]

5 minutes ago, igloo said:

the GEM and the the GFS also this mornings ECM have been consistent on another euro slug in the latter parts of there runs bad news as we no what that means more flooding 

I'll be surprised if the ECM follows the UKMO in terms of how far it keeps the Atlantic at bay for so long but I will also be surprised if it breaks everything down as quick as the GFS did. I would not be surprised at all if the ECM has similar charts to those at 168 hours as its been consistently forecasting such a pattern in its FI runs lately. 

Be a nice twist if it does follow the UKMO more though but too me, the uncertainty is probably more down to when will the mild air win out rather than IF.

[A.J]

some good posting in here this afternoon, but sadly too many posts either one-liner, designed to get a reaction, or just plain off topic are creeping in.....please proofread your posts before posting....thanks

Also, some seemingly knee jerk reactions to the GFS output, saying it's poor, cannot be taken seriously, is wrong etc etc....how people can say this when it is a predictive simulation of what may or may not happen in the future is frankly laughable....How about waiting and seeing what happens before making judgement?

[Singularity]

aaand GFS has made a mess of things after +288. The model sure is hapless with tricky situations at that range.

 

Anyway, just noticed that UKM has finally returned to the MJO projections:

This is rather interesting isn't it? The MJO signal has amplified over the past 24 hours a little beyond what the models were foreseeing and UKMO continues this trend far more than the other models, even edging it into phase 3 briefly. So much is achieved in the space of 24 hours in fact that I wonder if it could be making a difference to how keen it is on that trough disruption by adding just a bit more amplification upstream? I'm not sure the signal usually propagates across as fast as would be needed, though. Also, ECM has the least amplification and was among the flattest of the morning runs upstream. Coincidence?

 

Longer term, the models look a bit lost. The most logical path given the forcing from the (sort of central Pacific but not really) El Nino is, I gather, toward 6/7 for a new cycle to initiate that runs through 7/8/1. CANM seems to think about it but that's as good as it gets for now.

[Captain Shortwave]

The one thing I will say is whilst the GFS is very very progressive with the Atlantic signal, but it goes wrong at a timeframe where we cannot really use the "GFS has a westerly bias" excuse here. Ultimately the GFS is throwing out different solutions each run, the last 3 UKMO runs have also been very different out to day 6. We are at a point where to be honest the only answer we can give is that we simply do not have a clue how things will pan out after this weekend.

Simple as I'm afraid. Lets see what the ECM churns out later. One thing I will say is that one hideous GFS output isn't really going to sway me, but if it repeats it on the 18z and 00z runs then I would be getting concerned.

Edited January 14, 2016 by Captain Shortwave

[Jason M]

2 minutes ago, ajpoolshark said:

some good posting in here this afternoon, but sadly too many posts either one-liner, designed to get a reaction, or just plain off topic are creeping in.....please proofread your posts before posting....thanks

Also, some seemingly knee jerk reactions to the GFS output, saying it's poor, cannot be taken seriously, is wrong etc etc....how people can say this when it is a predictive simulation of what may or may not happen in the future is frankly laughable....How about waiting and seeing what happens before making judgement?

And just to back up your point, the GEFS and Control strongly back the opp run. On this occasion I think i'll wait for the chickens to hatch before i start counting them 

[offerman]

Gfs showing breakdown early  next week with transitional snow probably rain in the west but as that tracks over to the east and bumps into the deeper cold is most likely to fall As snow then perhaps stalling.    That is only GFS. 

[Eskimo]

8 minutes ago, offerman said:

Gfs showing breakdown early  next week with transitional snow probably rain in the west but as that tracks over to the east and bumps into the deeper cold is most likely to fall As snow then perhaps stalling.    That is only GFS. 

Not according to the current run, rain for most with snow chiefly on higher ground, before turning back to rain and then yes, fizzling out. However, only one run so we'll see what the 18z has to offer. 

[radiohead]

16 minutes ago, ajpoolshark said:

some good posting in here this afternoon, but sadly too many posts either one-liner, designed to get a reaction, or just plain off topic are creeping in.....please proofread your posts before posting....thanks

Also, some seemingly knee jerk reactions to the GFS output, saying it's poor, cannot be taken seriously, is wrong etc etc....how people can say this when it is a predictive simulation of what may or may not happen in the future is frankly laughable....How about waiting and seeing what happens before making judgement?

Indeed. To illustrate just why the GFS needs to be taken seriously, here is the GFS from 6 days ago showing today, the 14th :

Not far off what we actually go today :

By comparison, the UKMO on the 8th was quite different with it's depiction of the pattern for the 14th :

Certainly wouldn't dismiss any of the major models including the GFS. ECM is still my preferred model for handling these type of setups though.

 

[nick sussex]

I thought someone had hacked the GFS computer when I saw its output, astonishing change within the T72hrs timeframe.

If this stupid tropical storm has indeed caused this drama then really someone has it in for cold and snow lovers in the UK because it seems its just one thing after another, with variables popping up determined to derail any snow prospects.

I think the swear filter may need to go into super mode if that GFS is anywhere near being correct!

[phil nw.]

It's certainly headscratching time,especially with the differences between the 2 so early in the run.

Like Captain S said the truth is we can't say with confidence which model will prove correct.Another look at the GFS/UKMO at day 4

really unusual to see the jet profile so different at that range.

I keep in my mind that the GFS op is around 36/48hrs quicker than it's 00z/006z ens sets in bringing in the south westerlies.The last 3 runs have shown similar which keeps some doubt in my mind on it's early evolution.

The UKMO continues to show some form of blocking across the UK with trough disruption heading se.I note too it has a stronger Kara high through it's run which would do no harm in maintaining the cold block over much of N.Europe/Scandinavia and prevent it being pushed too far east.The modeling of the Atlantic floundering against this has been a fairly consitent theme with this model over the last 4 days.

Crazy times -what will the ECM make of it all i wonder.

[The Enforcer]

24 minutes ago, Glacier Point said:

Atlantic hurricanes in January, this is just bonkers.

"Earlier on today, apparently, a woman rung the BBC and said she heard there was a hurricane on the way...

well, if you're watching, don't worry, there isn't!"

[Cheshire Freeze]

8 minutes ago, phil nw. said:

It's certainly headscratching time,especially with the differences between the 2 so early in the run.

Like Captain S said the truth is we can't say with confidence which model will prove correct.Another look at the GFS/UKMO at day 4

really unusual to see the jet profile so different at that range.

I keep in my mind that the GFS op is around 36/48hrs quicker than it's 00z/006z ens sets in bringing in the south westerlies.The last 3 runs have shown similar which keeps some doubt in my mind on it's early evolution.

The UKMO continues to show some form of blocking across the UK with trough disruption heading se.I note too it has a stronger Kara high through it's run which would do no harm in maintaining the cold block over much of N.Europe/Scandinavia and prevent it being pushed too far east.The modeling of the Atlantic floundering against this has been a fairly consitent theme with this model over the last 4 days.

Crazy times -what will the ECM make of it all i wonder.

I'll say this. GLOSEA is ROCK SOLID in terms of its Atlantic/Greenland ridge (with attendant Scandi/Euro trough) scenario from here on in. The latest update carries on where the others left off. That's about 5 months of consistency. As such I'll be highly sceptical of any Scandi heights/ easterlys appearing in the models. My expectation over the long range evolution would be reamplification upstream with the Azores backing N & W with time.

Edited January 14, 2016 by CreweCold

[fromey]

I thinks sone need to jump over to the southwest discussion thread. Let's say a very interesting update from Ian Ferguson

[shotski]

3 minutes ago, CreweCold said:

I'll say this. GLOSEA is ROCK SOLID in terms of its Atlantic/Greenland ridge (with attendant Scandi/Euro trough) scenario from here on in. The latest update carries on where the others left off. That's about 5 months of consistency. As such I'll be highly sceptical of any Scandi heights/ easterlys appearing in the models. My expectation over the long range evolution would be reamplification upstream with the Azores backing N & W with time.

Hi CC

how do you know ? Obviously you have access to Glosea 5. 

I feel if that's the case the best part of winter could be yet to come. 

[nick sussex]

The fog is clearing, I think one of the issues seems to be the handling of low pressure over the ne USA.  You need to compare the evolution upto T72hrs in that region on the 06hrs with the 12hrs.  Its the different phasing and much weaker low exiting Newfoundland which goes some way to explain why it pushes more energy eastwards.

I've looked at the GEM that handles that area like the GFS 06hrs run,  I'm pretty certain that this is a big factor. The deeper low exits Newfoundland and phases with the upstream trough this adds an anti-clockwise motion which helps to pull the trough further nw.

 

Edited January 14, 2016 by nick sussex

[Captain Shortwave]

Lets do a nice round up so far of the models at day 4

GFS/UKMO/GEM

            

 

Add to that the Arpege

Statistically the GFS does look to be on its own at the moment, the others seems to have a similar profile to the UKMO, the GEM does slowly warm things through over the UK (It takes until Thursday for conditions to slowly get milder), though I would be dubious of it recent obsessions with mega high anomalies over France. Only the GFS shows no split flow from the Atlantic trough as it re-organises and aligns SW/NE towards Scandinavia.

It is worth noting that the Arpege never gets any Atlantic precipitation further that SW England and south Wales. There is also a weak front trying to move south through Scotland moving into day 5.

Edited January 14, 2016 by Captain Shortwave