Model output discussions pm 31/12/15

[nick sussex]

Just now, Radiating Dendrite said:

Let's just hope this is not a repeat of what happened last week. The ECM and UKMO were both optimistic and then back tracked to more of a blended version of what the GFS had showed.

The GFS gets criticised for showing messy scenarios when the Euros can often be cleaner but sometimes they are too clean and the ECM has had a tendency to over amplify things the last 18 months.

Theres messy and completely wrong. The GFS is all at sea , compare the last 3 runs for its pattern in the USA. The situation is however quite complicated because much depends on the interaction between the south/north streams of the jet over there. The GFS is notoriously poor at dealing with these situations, generally if the GFS has the flattest solution upstream within T144hrs and the Euros disagree then the GFS is always the one to backtrack.

[Ali1977]

I hope the last GFS is wrong, but looking at latest METO forecast the cold only looks short lived - which ties in with latest GFS

[Radiating Dendrite]

4 minutes ago, nick sussex said:

Theres messy and completely wrong. The GFS is all at sea , compare the last 3 runs for its pattern in the USA. The situation is however quite complicated because much depends on the interaction between the south/north streams of the jet over there. The GFS is notoriously poor at dealing with these situations, generally if the GFS has the flattest solution upstream within T144hrs and the Euros disagree then the GFS is always the one to backtrack.

I agree.....just careful not to get too sucked in.

It only takes one shortwave to be in the wrong place or a little bit too much energy and the whole thing can crash like a pack of cards.

This is the best opportunity this winter so far though. Hopefully the GFS will sort itself out soon as it did well with the similar situation we saw in 2010.

[Cheshire Freeze]

This is the ensemble mean at 180- not a big fan of the ensembles but it is what it is- pretty decent 

Strong suggestion of Greenland heights by 216

 

Edited January 4, 2016 by CreweCold

[Mucka]

A real mixture withing GFS ensembles some garbage, some ok, some stunning.

Just for pure eye candy and to dream p17 wouldn't be bad.

[tight isobar]

4 minutes ago, nick sussex said:

Theres messy and completely wrong. The GFS is all at sea , compare the last 3 runs for its pattern in the USA. The situation is however quite complicated because much depends on the interaction between the south/north streams of the jet over there. The GFS is notoriously poor at dealing with these situations, generally if the GFS has the flattest solution upstream within T144hrs and the Euros disagree then the GFS is always the one to backtrack.

couldn't agree more on them notes. gfs loves to ramp the jet then tends to fail miserably .and falls over itself on over progression.thus throwing up sometimes bizzare synoptics!

[feb1991blizzard]

3 minutes ago, CreweCold said:

This is the ensemble mean at 180- not a big fan of the ensembles but it is what it is- pretty decent 

 

Yes, another upgrade for those wanted cold on the GEFS, I know respected forecasters on here have told us to look at clusters and ignore means but if the mean is a Greenland high way into the 200's then the cold clusters will look exceptional!!

 

Edited January 4, 2016 by feb1991blizzard

[Ali1977]

4 minutes ago, CreweCold said:

This is the ensemble mean at 180- not a big fan of the ensembles but it is what it is- pretty decent 

Strong suggestion of Greenland heights by 216

 

That mean at 226 is really good

[nick sussex]

Just now, Radiating Dendrite said:

I agree.....just careful not to get too sucked in.

It only takes one shortwave to be in the wrong place or a little bit too much energy and the whole thing can crash like a pack of cards.

This is the best opportunity this winter so far though. Hopefully the GFS will sort itself out soon as it did well with the similar situation we saw in 2010.

Of course but at this point its not whether cold will verify but the longevity and depth that's more of an issue. On the latter I think we'll need a few more runs to see what happens with any WAA towards Greenland and those PV lobes flying around to the north.

[Mucka]

6 minutes ago, CreweCold said:

This is the ensemble mean at 180- not a big fan of the ensembles but it is what it is- pretty decent 

Strong suggestion of Greenland heights by 216

 

 

I like the mean 216 chart and as expected it is better than the Op for Atlantic ridge and Greenland height rises which puts the Op run in its proper perspective

Edited January 4, 2016 by Mucka

[swilliam]

2 minutes ago, feb1991blizzard said:

Yes, another upgrade for those wanted cold on the GEFS, I know respected forecasters on here have told us to look at clusters and ignore means but if the mean is a Greenland high way into the 200's then the cold clusters will look exceptional!!

 

What was said was that if the mean is showing something close to the climatological average then it is not much use. If it shows a signification deviation from this then it is very useful. This is the case here

[Cheshire Freeze]

3 minutes ago, Mucka said:

 

I like the mean 216 chart and as expected it is better than the Op for Atlantic ridge and Greenland height rises which puts the Op run in its proper perspective

However, the control also fails with the Greenland heights but does manage impressive heights to our N and NE deep in FI.

 

Edited January 4, 2016 by CreweCold

[feb1991blizzard]

Just now, swilliam said:

What was said was that if the mean is showing something close to the climatological average then it is not much use. If it shows a signification deviation from this then it is very useful. This is the case here

Yes thats exactly what I meant in  roundabout way of saying it, we want more and more members jumping into the cold cluster from here on in.

[Cheshire Freeze]

From here on in this evening I'd like to see a solid ECM followed by a better GFS 18z....with a better control run to boot. I'm not entirely convinced of these height rises yet.

[ukpaul]

GEFS for London, a trend beginning to develop.

[booferking]

1 minute ago, CreweCold said:

From here on in this evening I'd like to see a solid ECM followed by a better GFS 18z....with a better control run to boot. I'm not entirely convinced of these height rises yet.

We would be hitting a jackpot if we get all 3 to confirm the night fingers crossed..

[feb1991blizzard]

1 minute ago, CreweCold said:

From here on in this evening I'd like to see a solid ECM followed by a better GFS 18z....with a better control run to boot. I'm not entirely convinced of these height rises yet.

Yes, I think it may be a bit early myself, more attacks on the vortex needed followed by a complete reversal up top in Early Feb is and always has been my forecast from very early on in this winter.

[swilliam]

Just now, ukpaul said:

GEFS for London, a trend beginning to develop.

Yes - if the mean goes below -5 then confidence should rise in the cold shot but of course we would like to see in a shorter timescale.

[summerplume18]

Good set of ensembles from the GFS 12z. Slowly getting colder in FI. ECM keenly awaited tonight. 

[northwestsnow]

Those GEFS 12z are awesome. The trend is there for all to see really.

At last,it looks very much like winter 2015/6 is going to be with us in a week or so

 

[Glacier Point]

Very appealing GEM Ensemble and GEFS tonight, illuminating a strong coherence to the mean over Greenland just sniffing Iceland in the extended range (especially the GEM).

I would rate the GEM of most value here, as I think it has a particularly good handle on the Arctic basin.

Edited January 4, 2016 by Glacier Point

[northwestsnow]

2 minutes ago, Glacier Point said:

Very appealing GEM Ensemble and GEFS tonight, illuminating a strong coherence to the mean over Greenland just sniffing Iceland in the extended range (especially the GEM).

I would rate the GEM of most value here, as I think it has a particularly good handle on the Arctic basin.

Ahhh the great man has spoken

Cheers Stewart- i mentioned the GEFS this evening and its a big swing to cold clear for all to see.

I hope the woodshed has insulation

[Captain Shortwave]

Day 10 anomalies

GEFs

GEM ens

Decent positive anomalies to our north west with a clear ridge on both respective surface charts. A clear tendency to clear low heights eastwards with a flow from a northerly quadrant likely. It is building but it will be nice to get a clearer picture on the polar profile in the earlier timeframes. This mornings ECM suite shows a similar picture.

Edited January 4, 2016 by Captain Shortwave

[chris55]

Some good output from GEFS tonight. Of course there is a long way to go. But again we are faced with some potential (unlike December lol). The last possible cold shot failed to make it to our patch, so lets enjoy the ride and hope this next attempt provides the goods!

These ens are very good! Coldest of the winter by a margin!

This is what i love about model watching in the winter months, the chase is the best bit! (as long as something actually ends up delivering ha)

Consistency is the key as always though, so more runs needed!

[northwestsnow]

1 minute ago, chris55 said:

Some good output from GEFS tonight. Of course there is a long way to go. But again we are faced with some potential (unlike December lol). The last possible cold shot failed to make it to our patch, so lets enjoy the ride and hope this next attempt provides the goods!

These ens are very good! Coldest of the winter by a margin!

This is what i love about model watching in the winter months, the chase is the best bit! (as long as something actually ends up delivering ha)

Consistency is the key as always though, so more runs needed!

Im wondering GEFS is suggesting some sort of scandy high in FI? Perhaps.