Model output discussions pm 31/12/15

[Liam J]

4 minutes ago, stewfox said:

More of a worry at T24 rather then T192 regarding the specfics

Yeah, the GFS does like to overcook depressions outside the reliable and currently has limited support for such a feature, one to watch though, if it's still there with support next weekend then will be more concerning. 

[ukpaul]

7 minutes ago, stewfox said:

More of a worry at T24 rather then T192 regarding the specfics

Similar charts been thrown out on other runs so not isolated. I'm also looking at those suggestions from GFS at that particular timeframe given how unhelpful it is to the overall search for a colder pattern. If, as I hope, GFS is overdoing it again, then all to the good as regards that also.

[Vorticity0123]

I made a post about the long range teleconnective field (like ENSO, MJO etc), and connected them to look at any predictive value these may have. In fact, the signals together do point towards a risk on northerlies. You can read it all in the link below!

https://forum.netweather.tv/topic/82525-long-range-forecasting-and-teleconnections/

[DAVID SNOW]

7 minutes ago, Ed Stone said:

Never 'co pare' BA, it can be dangerous!

If the ECM para  and the ECM  op wish to consummate, then lets get involved Pete

Just don't let the GEF and ENS in on the party!

[Mucka]

ECM London ensembles

 

 

Not bad at all.

[tight isobar]

A little disappointed in the 18z gfs.

Would have liked such tight suites 12z ec/18 gfs, to have run a little tighter together!  But that doesn't transmit atm "anyway"

Plenty more time for compliance. 

[Methuselah]

3 minutes ago, DAVID SNOW said:

If the ECM para  and the ECM  op wish to consummate, then lets get involved Pete

Just don't let the GEF and ENS in on the party!

Ne ne nene ne... I think I need sleep; the Russian Standard has got to me.

 

 

[chionomaniac]

1 minute ago, Mucka said:

ECM London ensembles

 

 

Not bad at all.

You can probably make out strong clustering from the 13th. A good trend.

[DAVID SNOW]

1 minute ago, Ed Stone said:

Ne ne nene ne... I think I need sleep; the Russian Standard has got to me.

 

 

Night Pete , god bless.

[feb1991blizzard]

Judging by the mean, the GEFS far more members are depicting a Greenland high on the 18z.

[SMU]

3 hours ago, Shuga ice said:

I agree with your thoughts and I believe many on here will be looking for a flow from the east on future runs.

ignore the quote its keeps coming up on phone

 

 

GFS ensembles have moderate support for blocking across the pole - about 5/20

ptb 7,19,20 are the best-

This is the best chart since 2010 with a standing 3 wave pattern -

[nick sussex]

Oh dear I see the GFS 18hrs run has come out with some ridiculous overblown storm.

It was going along nicely till it went AWOL. Because of the overblown low the troughing can't clear east and instead this phasing pushes the troughing north.

Putting aside the GFS on LSD tonights outputs are a step in the right direction for cold.

[feb1991blizzard]

4 minutes ago, Steve Murr said:

ignore the quote its keeps coming up on phone

 

 

GFS ensembles have moderate support for blocking across the pole - about 5/20

ptb 7,19,20 are the best-

This is the best chart since 2010 with a standing 3 wave pattern -

Yes Steve, that's a stonker, no easy way back to anything mild from there, an absolute ripper.

[Mucka]

7 minutes ago, Steve Murr said:

ignore the quote its keeps coming up on phone

 

 

GFS ensembles have moderate support for blocking across the pole - about 5/20

ptb 7,19,20 are the best-

This is the best chart since 2010 with a standing 3 wave pattern -

 

About 25% show good Atlantic ridge as well so a minority but big improvement on 12z.

Tomorrow evening could be buzzing in here.

[feb1991blizzard]

And at lest 6 members are a stonker, admittedly in deep FI.

[lorenzo]

There's a thought Nick the GFS on LSD - i wonder what that would do for it's verification statistics.

Aside, the examination of the 18z GFS perbs is useful as to the ECM vs GFS work up of the MJO and AAM impacts. GEFS Faster ECM slower, amplified.

I had hoped that the GFS 18z would have twigged something and the folklore GFS 18z following 12z may have happened, we shall wait and see for tomorrow's output.

Going to fling these in at this point.

1 Is the PV plot at 475K that shows the vortex weakening to within a B^^hair of a split.

others are the anomalous cold profiles for Dec.

Point being, we have an anom. Kara high vs a standing W1 from a historical Nino and now a potential decent Greenland Block with an Blocked up Trop Vortex, and still this monster stands.

In the face of all that we still have a cold shot, some winter and some fun modelling to look at.

In a season where records are falling by the day then prepare for some more in Jan I reckon, the Greenland block locale is the one that does the vortex in and that Kara effort and AAM will have been more than 'toxic'.... Timing off as far as our forecast is concerned, lots of learning there still, but I feel we are in good company as many of these anomalies are unseen and new.

That AAM hit is real, these charts will continue to be of interest... onto tomorrow...

 

[Glacier Point]

and interestingly Tony, those fragments of the Kara ridge breaking away south and east are dropping useful troughs in the Western Pacific, helping to keep the amplified flow going in the longer term.

[nick sussex]

Been looking at the NCEP state forecasts for those in the path of that cold that's expected to dig south into the USA.

The set up of cold there correlates with the amplitude of that upstream pattern and the troughing in the eastern USA. The suggestion is that although theres some uncertainty this is more in relation to whether the cold is upgraded.

In terms of both GFS 12hrs and 18hrs runs neither take the deep cold as far south as Kansas which you'll note the ECM solution does and they expect this to happen.

Comments were also made regarding the negative EPO this is expected to last till the middle of the month which correlates with the strong amplified ridge in the western USA.

The main issue at present is the longtitude of this ridge and not whether it will remain amplified.

Overall I think theres a strong signal for a favourable upstream pattern, also troughing to the east/ne. The bit in the middle is a bit more difficult.

There  are still issues with possible shortwave activity to the sw, the GFS shortwave is a possibility however the superstorm it picks on the GFS 18hrs has to be taken in relation to the GFS bias.

Another issue is the cross polar high and how much ridging heads north to meet it, if the former verifies.

We also have to be a bit cautious in terms of how far east the pattern might get.

If things do fall favourably for the UK and hopefully me here in sw France! Then I think thankyou letters to the MJO will be in order. Its the progression of this IMO which has shuffled the NH pattern and given this window of opportunity.

Lets hope for a stress free route to cold and snow which would certainly be deserved for the many cold and snow lovers in here who have had to put up with some of the worst outputs over December.

 

[Mucka]

GFS 00z not wanting much to do with any Atlantic ridge and looks more interested in a Scandi high than Greenland high by 192h

 

UKMO looks better upstream IMO out to 144h, UKMO GFS comparison.

 

GFS FI has the Scandi ridge and Arctic high combo instead and though I would much prefer to see a strong Atlantic ridge link up with the Arctic high instead it is encouraging to see a possible different route to cold being modeled if thins went our way.

 

GEM not a million miles away from last nights ECM.

Edited January 4, 2016 by Mucka

[forecaster]

On 1/1/2016 at 9:35 PM, Timmytour said:

Weren't there times in previous runs where it had all those places being above average for the week 4th-10th January as well?

I think so, yes. 

[Mucka]

GFS ensembles very uninspiring as far as an ECM type solution goes.

If it turns out there is a strong Atlantic ridge then GFS needs a reboot because it isn't picking it up.

[knocker]

An overview of this mornings GFS. The Uk remains within the circulation of the filling low until Wednesday when a deep slow moving depression forms in mid Altantic moves slowly east. A shortwave forms in it's southern circulation and nips across the country on Thursday bringing yet more wet weather. Meanwhile the depression that has developed in the Caribbean is winging it's way NE towards the UK. It deepens and runs through the channel en route to Denmark and points east. This scenario will obviously be subject to change in the next few days but needs watching.

As an aside if the MJO is in phase 8 then it's not a million miles away from the possible outcome looking at some of the latest outputs.

Edited January 4, 2016 by knocker

[knocker]

The GEFs anomalies this morning are still running with a sharp Alaskan ridge running over the Pole with heights building into Greenland but the trough in the southern States and the upper low to the NW of the UK still spells bad news on the wet and windy front.  In the ext period it's still pushing extended ridging into Greenland by the Azores HP to the west of the UK and a trough to the east so the game is still afoot but until the ecm and NOAA come on board caution prevails.

Edited January 4, 2016 by knocker

[Ali1977]

ECM has dropped the idea from last night unfortunately, still not bad at day 9 but the PV looks like it's getting organised over in Canada again. 

[terrier]

Well a rather uninspiring set of output this morning ecm seems to have dropped last nights idea. Which isn't a surprise really. Hopefully gp is onto something with his torpedo.