Model output discussion - heading into 2018

[nick sussex]

I’d advise not looking too far ahead because the ECM makes a change upstream as early as T120hrs over Newfoundland .

It develops a shortwave and more dig sw of energy which will hold back the low. As this runs east it phases with the main low which stops some of the eastwards momentum.

Neither the GFS or UKMO develop this. 

Given we’re expected to see a big increase in the zonal winds one wonders if the NWP initially overreacted sending everything too far east and the slower progression seen in the Euros is a reflection of that.

 

[I remember Atlantic 252]

8 minutes ago, Frosty. said:

That's some impressive mild mush later on the Ecm 12z this evening..hohoho

Great if it's dry Frosty! I won't be complaining

[bluearmy]

1 minute ago, northwestsnow said:

Have to laugh at the EC depth charts ! Can one imagine how much it will show if we ever get a convective easterly with snow showers piling in off the north sea? LOL they would have to change the scaling ..

(Not that we will see a convective easterly anytime soon).

What’s up with them this time ?

remember they show all falling snow as settled with no melt 

[CK1981]

10 minutes ago, Frosty. said:

That's some impressive mild mush later on the Ecm 12z this evening..hohoho

The stuff of nightmares! I think we’ll see some better output soon though.

[Frosty.]

7 minutes ago, I remember Atlantic 252 said:

Great if it's dry Frosty! I won't be complaining

Well I just thought I would add some balance since this is the model output discussion and not all about cold chasing and hopecasting! 

Edited December 23, 2017 by Frosty.

[northwestsnow]

2 minutes ago, bluearmy said:

What’s up with them this time ?

remember they show all falling snow as settled with no melt 

Well for a start they show an inch or so IMBY- i dont think i will see a flake!

[bluearmy]

3 minutes ago, northwestsnow said:

Well for a start they show an inch or so IMBY- i dont think i will see a flake!

Looks like it comes overnight xmas into Boxing Day - probably a few showers off the irish Sea ?

[nick sussex]

Interesting UKMO T168hrs. 

With the limited view you can just about see the flow from the se just to the ne of Scotland .

There must be some weak heights remaining to the ne to cause that change of flow to the se.

Edited December 23, 2017 by nick sussex

[I remember Atlantic 252]

3 minutes ago, nick sussex said:

Interesting UKMO T168hrs. 

With the limited view you can just about see the flow from the se just to the ne of Scotland .

There must be some weak heights remaining to the ne to cause that change of flow to the se.

wondered why SS hasn't posted it, looks interesting

[blizzard81]

2 minutes ago, nick sussex said:

Interesting UKMO T168hrs. 

With the limited view you can just about see the flow from the se just to the ne of Scotland .

There must be some weak heights remaining to the ne to cause that change of flow to the se.

Let's hope there is something in this. Like you, I also noticed the pronounced difference between yesterday's ecm 168 and today's 144. In fact the 144 raised both eyebrows at my end! It sadly let itself down thereafter but your post about the ukmo 168 chart has raised one eyebrow. Do you have a link please? 

[Summer Sun]

UKMO extended

Best have a brolly handy it looks a bit wet

[nick sussex]

1 minute ago, blizzard81 said:

Let's hope there is something in this. Like you, I also noticed the pronounced difference between yesterday's ecm 168 and today's 144. In fact the 144 raised both eyebrows at my end! It sadly let itself down thereafter but your post about the ukmo 168 chart has raised one eyebrow. Do you have a link please?

Here you go:

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

It might not amount to much given the jets on steroids but interesting to see if we can get some more changes.

[feb1991blizzard]

21 minutes ago, bluearmy said:

What’s up with them this time ?

remember they show all falling snow as settled with no melt 

Even taking that into consideration, they're still overdone - they were pumping out 15 inchers on the last slider for Manchester, to put it into perspective, the biggest fall in the last 36 years or so for Manchester city centre was about 6 inches (didn't measure it) on 5th Jan 2010, its not great for snow as I know to my cost on feb 1st 2009, its the lowest altitude ive ever lived at by some distance, in fact it wouldn't surprise me if the City has never ever had a 15 inch fall and this nonsense was pumped out run after run.

[feb1991blizzard]

No prizes for guessing the mean wind direction on the extended eps.

[joggs]

1 minute ago, feb1991blizzard said:

No prizes for guessing the mean wind direction on the extended eps.

Opposite to ne?

[I remember Atlantic 252]

2 minutes ago, feb1991blizzard said:

No prizes for guessing the mean wind direction on the extended eps.

E'ly, if they go as far as April

[blizzard81]

32 minutes ago, nick sussex said:

Here you go:

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

It might not amount to much given the jets on steroids but interesting to see if we can get some more changes.

Thanks Nick. Let's just hope tonight's ecm 168 chart is as wrong as last night's.

[nick sussex]

If we can keep adding a one day cold extension every day the mild mush might never arrive!

Looking at the ECM spreads we could squeeze out another day . It’s going to be a hard slog to extend much further unless my master plan comes together ! 

 

[feb1991blizzard]

re - eps, there is signals for a sceuro high but I doubt any cluster that actually brings in or looks like bringing a UK Easterly flow down the line is more than 5%

[blizzard81]

Ecm control goes cold towards the end. Wonder if a mlb sets up as it looks dry.

[Catacol]

For those hoping for some cold and seasonal weather heading into January the signals have taken a significant turn for the worse. Negative anomalies in the tropical western pacific forecast to be removed altogether, allowing a big surge in trade winds and removal of AAM from extratropical regions

 

Vortex profile also now forecast to grow substantially, with the 10 day Berlin chart not making pretty reading - unless westerly influence at mid latitudes is what you are after... 

Loss of AAM at 10 days now sees ensemble data remove pretty much all high lat blocking, with high pressure instead forming a neat belt around most of the hemisphere in mid latitudes. As Cohen has reported recently, this is really a setup now pointing at a mild January with cold bottled up in the arctic. 

All of this is then reflected in the excellent GWO tool - for the first time in a good while the spiralling rise in GLAAM has zigged back towards 7.00 on the phase chart... and we are headed now for a period of phase 1-2-3 activity.... low on blocking and high on westerlies in a more "classic" Nina setup.

It has been a sudden and somewhat unexpected turnaround. There was no suggestion of a sudden removal of tropical pacific convection strength: indeed the NOAA report of only a week ago saw a slow and steady movement through 7/8.. and ongoing wave 1 activity via favourably positioned blocks had kept the vortex quiet. So what has changed? A very good question. I scan the web and twitter pretty frequently and have not spotted an explanation yet: only observed reality and a prognosis for the next 15 days brought in line with observed data. We know from IF that Glosea suddenly lost its SSW signature... and we can see that the massive surge of heights into the arctic from alaska is now forecast to moderate very quickly and be suppressed. What is driving this? Has Nina simply won the day? Is a warming world making composite data and analysis less accurate? Has extreme arctic sea ice loss got wider ramifications than we are currently aware of? 

We will see what comes out of this analysis as the days/weeks progress because I'm sure some of the big guns out on twitter will have their say in time... but for now it might be a good time to take a break from model watching. Current conditions will take a good 2 weeks to play out - maybe closer to 3 or 4. Winter is not over yet by a long chalk... but we we will need to see factors alter again if the drivers that create the NWP are to produce some better eye candy. For a while the best we can hope for is some mid lat blocking to take the sting out of the atlantic and give some calm, chilly maybe frosty days. MetO forecasts hint at exactly this I think. 

Edited December 23, 2017 by Catacol

[snowray]

2 hours ago, northwestsnow said:

EC snow lottery charts now show the bulk of the precip missing the midlands!!

Incredible stuff!

Yes incredible alright, even further south on the 18z runs .

[Southender]

25 minutes ago, Catacol said:

For those hoping for some cold and seasonal weather heading into January the signals have taken a significant turn for the worse. Negative anomalies in the tropical western pacific forecast to be removed altogether, allowing a big surge in trade winds and removal of AAM from extratropical regions

 

Vortex profile also now forecast to grow substantially, with the 10 day Berlin chart not making pretty reading - unless westerly influence at mid latitudes is what you are after... 

Loss of AAM at 10 days now sees ensemble data remove pretty much all high lat blocking, with high pressure instead forming a neat belt around most of the hemisphere in mid latitudes. As Cohen has reported recently, this is really a setup now pointing at a mild January with cold bottled up in the arctic. 

All of this is then reflected in the excellent GWO tool - for the first time in a good while the spiralling rise in GLAAM has zigged back towards 7.00 on the phase chart... and we are headed now for a period of phase 1-2-3 activity.... low on blocking and high on westerlies in a more "classic" Nina setup.

It has been a sudden and somewhat unexpected turnaround. There was no suggestion of a sudden removal of tropical pacific convection strength: indeed the NOAA report of only a week ago saw a slow and steady movement through 7/8.. and ongoing wave 1 activity via favourably positioned blocks had kept the vortex quiet. So what has changed? A very good question. I scan the web and twitter pretty frequently and have not spotted an explanation yet: only observed reality and a prognosis for the next 15 days brought in line with observed data. We know from IF that Glosea suddenly lost its SSW signature... and we can see that the massive surge of heights into the arctic from alaska is now forecast to moderate very quickly and be suppressed. What is driving this? Has Nina simply won the day? Is a warming world making composite data and analysis less accurate? Has extreme arctic sea ice loss got wider ramifications than we are currently aware of? 

We will see what comes out of this analysis as the days/weeks progress because I'm sure some of the big guns out on twitter will have their say in time... but for now it might be a good time to take a break from model watching. Current conditions will take a good 2 weeks to play out - maybe closer to 3 or 4. Winter is not over yet by a long chalk... but we we will need to see factors alter again if the drivers that create the NWP are to produce some better eye candy. For a while the best we can hope for is some mid lat blocking to take the sting out of the atlantic and give some calm, chilly maybe frosty days. MetO forecasts hint at exactly this I think. 

Well that’s added a rather urine flavour of gravy to the festive Turkey. Half of Jan at least written off cold & snow wise? Well at least the NW servers can take a break, as can the coldie members.

Edited December 23, 2017 by Southender

[I remember Atlantic 252]

maybe snowy, NW Midlands? I expect this to be modeled much further south though, in next few days, M4 southwards to have any possible snow

[Johnp]

Thanks for that  @Catacol. Happy Christmas to you too!