Model Output Discussion 01/09/17

[northwestsnow]

Just now, karlos1983 said:

less in the way of shortwave drama on the 06z, not sure where this will end up.

Looks very wet as we head into the following week, quite suprised when i looked at the precip charts, just shows how far them lows extend!!

[Paul_1978]

30 minutes ago, nick sussex said:

It’s a bit of a mess this morning with a game of model musical chairs .

The UKMO is an improvement at T144hrs with a more favourable looking shortwave to the west.

The GFS again has problems ejecting the upstream shortwave cleanly and this now becomes absorbed by the main low which isn’t good.

The ECM has now moved a little towards the GFS/UKMO , it’s not as sharp upstream and is now thinking of ejecting a shortwave at T144hrs.

Overall still no resolution as to what to expect, the ECM at least doesn’t deliver the dreaded west based negative NAO.

The key time frame is around T144hrs to T168hrs , if that falls kindly then a decent spell of colder weather is possible, but it’s trying to overcome those shortwave problems that’s turned into a big hurdle.

Hi Nick, not a post goes by where you don't mention a shortwave .

I know you've probably been asked this before, but could you provide a brief explanation as to what a shortwave is and why these are often problematic? (Problematic at seemingly scuppering our opportunities of cold!)

And is there ever a situation where a shortwave is a good thing? (For coldies?)

[Kieran]

Attempt on a Greenland high at +192. Not sure if it will make it...

[northwestsnow]

1 minute ago, Kieran said:

Attempt on a Greenland high at +192. Not sure if it will make it...

Dont think it will- we do have a greeny high in place but pressure too high over europe (again)- probs end up with a west based -NAO.

Hope im wrong

[karlos1983]

8 minutes ago, northwestsnow said:

Looks very wet as we head into the following week, quite suprised when i looked at the precip charts, just shows how far them lows extend!!

I'll take this chart as the GFS admitting it was very naughty overnight, but rather than flipping back to cold it's going to take its time and try and do it with dignity. At least there is hope come the 12z that the GFS could well revert back!

Can't post the chart for some reason.... getting an error  (+192 chart for reference)

EDIT: this could turn into a crazy cold low res....Heights digging further south with each frame

 

Edited November 13, 2017 by karlos1983

[tight isobar]

A much better...slightly cleaner run 6z...

And n/hemisphercaly' its good good good.

Just for this pesky fly in the ointment!!!

But still a lot to be resolved before such time!

[bluearmy]

36 minutes ago, winterof79 said:

Totally agree. No matter how many times the models hinted at cold scenarios last Winter ,the METO extended was never interested. There is a clue there somewhere

They were on board for early December cold and snow last year .......

[BLAST FROM THE PAST]

1 hour ago, snowray said:

The Sun has been spotless for the last two weeks after being quite active last month, seems that we might be entering a prolonged minimum phase early and could be on the cusp of the next grand minimum.

Indeed, 80 spotless days 2017 compared to 31 in 2016.  2010 had 51 after the huge spotless amount in 2009.  

Although quiet re sunspots the sun is currently active re coronal holes and solar wind bursts.  A large one on 7th saw Aurora visible down in Nebraska.  There has been another due to strike Earth 14/15 Nov.  Activity to yo yo but ramp up to major flare during last week of Nov.  

Let’s see if model activity continues to fluctuate next couple of days as it is believed that the jet stream is affected by the strong solar winds.

For me I am erring with ECM but I suspect more twists and turns yet.

BFTP

Edited November 13, 2017 by BLAST FROM THE PAST

[swfc]

So 6Z flips back towards euros.get that low south at 228 hrs and not looking to bad imo             well I jinxed that call on the low!!!!

Edited November 13, 2017 by swfc

[coldwinter]

2 minutes ago, bluearmy said:

They were on board for early December cold and snow last year .......

Selective memories 

[stodge]

Morning all

It's far too early in the year for me to get too interested in the models - ask me again in mid January. Skimming the 00Z GFS Ensembles at T+240, a healthy majority kept some cold or very cold air over the British Isles. The possibility of several days of cold anticyclonic weather isn't without a lot of appeal and cold without snow is still cold at the end of the day. ECM hints at retrogression but it's so far removed from the GFS this morning it's like a chalk-like substance encountering some camembert.

Perhaps worth noting the considerable intra-run variation still apparent. The 6Z OP is very different, keeping the jet well to the south in a classic west-based negative NAO. That is in itself a rarity for late autumn in my experience.

It still seems probable the PV will rev up and by the end of the month it could look quite stormy. Those expecting 90 days of storm force easterlies and -20 Uppers are going to be disappointed (again) it would seem.

 

[northwestsnow]

6Z is really wet for the UK- hoping thats not right!!!

[tight isobar]

6z gfs certainly -reverts- and finds more organisation.

And the mid-bou d shortwave/feature cuts through fairly well...

'However' im still of the opinion that now going forward it may well be russian waa that saves the day.

And pacific ridge holding well also.

[snowray]

4 minutes ago, swfc said:

So 6Z flips back towards euros.get that low south at 228 hrs and not looking to bad imo

Yes need to get that low south, a better run, lots of cold air to tap into. The nasty little shortwave near Iceland early doors has gone on this run, I think that the GFS is still over doing these Atlantic lows.

[Paul_1978]

5 minutes ago, northwestsnow said:

6Z is really wet for the UK- hoping thats not right!!!

Well for me it's miles better than the 00z! Look at the size of the Greenland High for a start. We've been waiting for a proper GH for years and now we've got one. Just need things to slot into place, which is what half the fun is all about.

[northwestsnow]

Thanks but no thanks 6z- looks very stormy and a lot more wet than white for pretty much everyone.

METO update will be erm, interesting to say the least-

Well BBC monthly has updated- and it sounds cold and dry- absolutely nothing like 6z gfs thats for sure 

Edited November 13, 2017 by northwestsnow

[karlos1983]

4 minutes ago, northwestsnow said:

Thanks but no thanks 6z- looks very stormy and a lot more wet than white for pretty much everyone.

METO update will be erm, interesting to say the least-

Are you expecting it to change off the back of 2 very different GFS runs? I'm not.

Edited November 13, 2017 by karlos1983

[bluearmy]

4 minutes ago, northwestsnow said:

Thanks but no thanks 6z- looks very stormy and a lot more wet than white for pretty much everyone.

METO update will be erm, interesting to say the least-

They will stay on the fence with their ‘uncertainty’ comment. I see no strong reason for them to change their wording. 

It’s not the gfs runs that will dictate a change but the nature of the extended eps which are trending a more cool zonal look with less amplification 

 

Edited November 13, 2017 by bluearmy

[northwestsnow]

Just now, bluearmy said:

They will stay on the fence with their ‘uncertainty’ comment. I see no strong reason for them to change their wording. 

 

BBC monthly has updated blue - EC det all the way acc to them

[Paul]

I know the drama in here is part of it, but those jumping about like cats on hot tin roofs based on every run, probably need to calm down a tad. Especially since it's not even mid-November yet. 

All this talk about the cold being gone, winter being over, or the next 1947 being on the doorstep blah blah blah, based on single runs, is going to get tiring very quickly - especially in this thread. (Hint: head to the model banter thread to ramp/moan). 

Taking today's 00z as an example. Here are the ensemble means vs climatic averages - hardly mild, and a negative NAO.

 

 

 

That's not to say it's exactly how it'll play out, but we're looking at forecasting models at 7 days plus here - you're not going to get exact or consistent answers from it. Best to step back a tad, and look at trends, and the wider picture.

[swfc]

6z looks great imo up to the 210 hour mark till the low develops and pushes north east.all in all decent upgrade and plenty of time to get things that bit further south

[bluearmy]

2 minutes ago, bluearmy said:

They will stay on the fence with their ‘uncertainty’ comment. I see no strong reason for them to change their wording. 

It’s not the gfs runs that will dictate a change but the nature of the extended eps which are trending a more cool zonal look with less amplification 

 

 

2 minutes ago, northwestsnow said:

BBC monthly has updated blue - EC det all the way acc to them

Actually the meto updated overnight with a more blocked outlook looking fairly solid in their opinion.  no sign of mild in the modelling I have seen but the cold pulls back for sure current suites as week 2 progresses.

[jvenge]

1 minute ago, Paul said:

I know the drama in here is part of it, but those jumping about like cats on hot tin roofs based on every run, probably need to calm down a tad. Especially since it's not even mid-November yet. 

All this talk about the cold being gone, winter being over, or the next 1947 being on the doorstep blah blah blah, based on single runs, is going to get tiring very quickly - especially in this thread. (Hint: head to the model banter thread to ramp/moan). 

Taking today's 00z as an example. Here are the ensemble means vs climatic averages - hardly mild, and a negative NAO.

 

 

 

That's not to say it's exactly how it'll play out, but we're looking at forecasting models at 7 days plus here - you're not going to get exact or consistent answers from it. Best to step back a tad, and look at trends, and the wider picture.

Seems a good time to post the NAO forecast, then. I don't think I'm allowed to post the ECM one, but it is a little different in it sends things neutral/positive towards the end of the run and it doesn't send it as negative as the GEFS. 

 

 

[Singularity]

I wonder how much of a role the resolution of the model plays in handling situations where the wavelengths may be particularly short, such as Sun-Tue next week? This being when ECM has them very short indeed, facilitating (by my interpretation, at least) the hold-back of the Atlantic trough to the west as it and the trough over N. America become so close together that they directly interact, resulting in disruption of the Atlantic trough and movement of the N. American trough sufficiently far NE to prevent the HLB retrogressing to E. Canada.

UKMO might be heading that way as of +144 but I'm not sure - can anyone post the +168 from that obscure site to which my links never seem to bookmark properly? TIA 

 

[Yarmy]

21 minutes ago, Singularity said:

I wonder how much of a role the resolution of the model plays in handling situations where the wavelengths may be particularly short, such as Sun-Tue next week? This being when ECM has them very short indeed, facilitating (by my interpretation, at least) the hold-back of the Atlantic trough to the west as it and the trough over N. America become so close together that they directly interact, resulting in disruption of the Atlantic trough and movement of the N. American trough sufficiently far NE to prevent the HLB retrogressing to E. Canada.

UKMO might be heading that way as of +144 but I'm not sure - can anyone post the +168 from that obscure site to which my links never seem to bookmark properly? TIA 

 

https://ruc.noaa.gov/hfip/tcgen/

Click the ukmo UM, prp, and D7 buttons.