Model Output Discussion 29th December - Into mid-Winter.

[IDO]

Feeling bitter on the 12th in NW'ern areas near the coast battered by strong winds, snow showers and a clean cold upper flow:

Edited January 8, 2017 by IDO

[Frosty.]

What a pleasure to post charts like these from the 6z which are now within the reliable timeframe!

[Duane S.]

OK, this is getting interesting.

Good to see that, on the whole, the ECMWF is so far not drawing anybody in with its very tasty D9 / D10 charts. Treat with great suspicion until we see this in the much closer time frames. That said a perfectly plausible evolution just perhaps an outside bet at present. The MJO going into low amplitude phase5 however is going to have didly squat impact on whether this occurs or not.

Berlin charts this morning (for yesterday) certainly shows that appetite for the Azores High to turn from foe to friend..

I was going to say I would favour a more Mid Lat block, drawing in a weaker and drier PC airmass than that on the EC FI charts but in reality it is actually more of a Mid Lat block than HLB anyway. So a lot of it will come down to orientation and fine details. If of course, and more importantly,  it occurs!

 

[IDO]

At no point does the GFS look like following ECM after D5 and it maintains the consistency of feeding lower pressure under the Greenland heights:

[Ali1977]

4 minutes ago, IDO said:

At no point does the GFS look like following ECM after D5 and it maintains the consistency of feeding lower pressure under the Greenland heights:

Yep, another ECM climbdown coming on the 18z, it hasn't been performing well with regard this next week or so. 

[IDO]

The channel low at D6 a bit further north bringing in a warm sector and warming out the uppers, so a rain event on this run:

Though this will chop and change for days to come...

[bluearmy]

1 minute ago, IDO said:

The channel low at D6 a bit further north bringing in a warm sector and warming out the uppers, so a rain event on this run:

Though this will chop and change for days to come...

Assuming the feature isn't 'history' within 6 hours in which case something else will chop and change for days to come. Such is following the GFS with 4 runs per day and 6 hourly charts within it! 

 

[January Snowstorm]

I mentioned last night I saw nothing more than a 24 hour toppler. The 06z is firmly in that camp this morning.

Snow showers on Thursday/night

[Jason M]

By 150 heights much more prevelant over Iberia. Usually game over when that happens.

ecm good but given the backdrop to this winter of euro heights GFS seems much more likely to me. Each GFS run seems flatter than the one previously so the 6z run is not good news albeit hardly surprising as it's just a repeat of what we have already seen.

lets see what the GEFS say, but at shortish timescales I'd be surprised if the overall story is much different.

[Radiating Dendrite]

6 minutes ago, Ali1977 said:

Yep, another ECM climbdown coming on the 18z, it hasn't been performing well with regard this next week or so. 

Firstly it doesn't have an 18z run and secondly next week has not happened so we have no way of knowing how well it has performed yet.

[Ali1977]

Just now, January Snowstorm said:

I mentioned last night I saw nothing more than a 24 hour toppler. The 06z is firmly in that camp this morning.

Snow showers on Thursday/night

Just about to say the same, going on this run this is a pretty dissapointing short cold snap, albeit with the chance of snow about anywhere. I hope this isn't all this month has to offer.

[IDO]

1 minute ago, bluearmy said:

Assuming the feature isn't 'history' within 6 hours in which case something else will chop and change for days to come. Such is following the GFS with 4 runs per day and 6 hourly charts within it! 

 

Looking at the GEFS 0z run I was surprised it had over 50% support, hence the interest. I suspect it is quite likely as the PV and HP interlock with the jet sending satellite lows into the flow:

[Ice Day]

6 minutes ago, Ali1977 said:

Yep, another ECM climbdown coming on the 18z, it hasn't been performing well with regard this next week or so. 

Not sure about that.  Leaving aside the ECM for now, the differences between the GFS and UKMO at 120 are stark. 

More amplification on the UKMO and it doesn't blow up the low to the south of Greenland in the same way.  I certainly wouldn't be putting my weight behind the GFS just yet!

[Ali1977]

1 minute ago, Radiating Dendrite said:

Firstly it doesn't have an 18z run and secondly next week has not happened so we have no way of knowing how well it has performed yet.

Ok, it comes out at 18z. I think we have a good idea on it not happening, but yes I agree we can't be sure!!

[karyo]

I was hoping to see some changes in the 6z to give some support in prolonging the cold but if anything it breaks it down faster. The 6z is even less amplified than previous runs and the odd one out of the main three. Having said the ECM and UKMO are also not agreeing with each other. 

[Scandinavian High.]

A possible snow event in the south just need The low  further south not a done deal yet with the low to the south west channel low .

[swfc]

Whatever your thoughts on the gfs the 0z and 6z out to the 200 hour mark are almost identical.Rubbish id agree but thats how i see it.Also altho in fi the high pressure coming of the esb is still showing its hand.BA mentioned this so this may aid some decent ridging if it does varify .

[markw2680]

11 minutes ago, Ali1977 said:

Just about to say the same, going on this run this is a pretty dissapointing short cold snap, albeit with the chance of snow about anywhere. I hope this isn't all this month has to offer.

It hasn't happened yet so how can you say a disappointing short snap? If it was showing raging a easterly and snow you would be saying upgrade!! There's loads of time for changes

[IDO]

The d9 GFS chart is awful, with no potential, really dont want the trend in this direction>>>PV moving from Canada/Greenland to Siberia taking a week or so, blocking any height build to the NW and NE:

The Azores remaining the UK driver. Not good...

[Gustywind]

To be honest I don't know why peeps bother paying much attention to either the 6 or 18z runs with the GFS, they are little better than the likes of NOGAPS from what I've seen. 

Less we forget it was the 6z that produced 'that run' a couple of weeks back, so why anyone thinks it's more likely to be right now I don't know.

 

[northwestsnow]

Bloody gfs!!!

Is anything straighforward in this country!!!!!!!

6z cuts the cold off by saturday, its much worse than the 0z run 

...

[ArHu3]

1 minute ago, Gustywind said:

To be honest I don't know why peeps bother paying much attention to either the 6 or 18z runs with the GFS, they are little better than the likes of NOGAPS from what I've seen. 

Less we forget it was the 6z that produced 'that run' a couple of weeks back, so why anyone thinks it's more likely to be right now I don't know.

 

why would it be worse than the 0z or 12z?

[Frosty.]

The Gfs 6z looks very progressive compared to the Ecm 00z..Fingers crossed the ecm is right, it should be..it's a superior model!

Edited January 8, 2017 by Frosty.

[snowice]

9 minutes ago, Ice Day said:

Not sure about that.  Leaving aside the ECM for now, the differences between the GFS and UKMO at 120 are stark. 

More amplification on the UKMO and it doesn't blow up the low to the south of Greenland in the same way.  I certainly wouldn't be putting my weight behind the GFS just yet!

Storm Barbara was an example of how the GFS over does the minimum central pressure, even though it was a bad storm. I hope UKmo Gfs ecm start to agree between 120 144hrs so we see were this cold snap is going.12z should clear it up in this evenings outputs as the time frame is now approaching fast

[Gustywind]

1 minute ago, ArHu3 said:

why would it be worse than the 0z or 12z?

Not sure, although I've seen posts in the past that say they have less data than the other 2 runs.

As I say it's just my perception from 12 years of model watching, they seem to come out with more volatile and extreme outputs than the 0 or 12 runs, be that cold, storms or heat.