Model Output Discussion - 05/01/2016 18z onwards

[SMU]

Guys - your focussing to much in the wrong area -

The subtropical low isnt the problem... ( we seem to have weathered that mostly )

The problem is how much energy is digging SE towards SW greenland at around 120

The simple explanation is the less that digs ( & lifts out ) the better the high pressure in the atlantic is

There is a 50/50 balance between all the models & indeed the ensembles - so noone can tell...

middle ground is the NAVGEM 00z

 

as you see the enrgy lifts out NE & high pressure builds -

also UkMo lifts it out as well

thats the area to watch tonight - if we get a close off low digging SE to iceland its game over for the most part

if it all lifts out like the Euro etc then were fine...

CIAO

[SMU]

17 minutes ago, Johnp said:

Steve, I agree,although surely you mean the low moving SW, not  SE?

No SE

the more energy that drops SSE the more of an issue it is...

s

[london and south east kent]

I think the meto are going with ukmo model

Edited January 8, 2016 by abbie123456

[Man With Beard]

GFS ensembles for London

Op and control run are miles off the main cluster, which continues to be frigid, perhaps even moreso than before. Very similar situation in the ECM ens.

This is not over.

But you'd want the ECM op to be in the cold cluster tonight to have confidence in the colder long-term solution, rather than just a 3/4 day marginal cold snap.

[SMU]

17 minutes ago, bobbydog said:

so do you think this is the "starting conditions" ian mentioned in his tweet that the models are struggling with?

Unlikely TBH

starting conditions probably relate to subtropical low or the current atlantic low

the system Im talking about ( or process ) of energy going SSE over greenland is at 120

S

Edited January 8, 2016 by Steve Murr

[nick sussex]

I don't mind these model dramas and uncertainty if the final solution is the cold one! But often the whole drama ends up with the milder outcome.

As for the GFS 06hrs run well no move to the UKMO. That shortwave energy near Iceland is the sticking point and this needs to not develop and head se, south at worst not sw into the Atlantic.

 

[phil nw.]

An encouraging tweet from IF but I have moved the posts  over to the Cold Spell thread here

 

so we can keep this thread for model discussion only.

 

[bobbydog]

1 minute ago, Steve Murr said:

Unlikely TBH

starting conditions probably relate to subtropical low

the system Im talking about ( or process ) of energy going SSE over greenland is at 120

S

would the first not affect the latter? something is obviously affecting the models considerably as of now. it would be interesting to know what, as we could watch evolutions on the ensembles to see how this 'feature' ( it could be something else- bigger driver or teleconnection maybe) develops and as it firms up, get an idea of where we are heading

[ukpaul]

I also think the polar area is being modelled poorly, contributing to those starting condition concerns. The better runs keep the centre of the high polewards but many are forcing it back away towards Northern Russia. The former tend to link up Arctic and Greenland high pressure systems, the latter bit by bit replace it with low heights.  Perturbation 15 was one I looked at, as by 120h it hadn't created that drift. NOAA may well be wrong, but if right then It's the sort of  120 to 192 hour outcome that may well start to be seen more frequently.

Edited January 8, 2016 by ukpaul

[nick sussex]

The latest JMA 06hrs run at T84hrs looks a whole lot better than the GFS 06hrs run for the same time.

I'm scratching around here for outputs that disagree with the ECM/GFS!

[Southender]

22 minutes ago, Man With Beard said:

GFS ensembles for London

Op and control run are miles off the main cluster, which continues to be frigid, perhaps even moreso than before. Very similar situation in the ECM ens.

This is not over.

But you'd want the ECM op to be in the cold cluster tonight to have confidence in the colder long-term solution, rather than just a 3/4 day marginal cold snap.

Yes, some decent cold clustering out to around 18th/19th. The OP and Control go off on one from 16th. Can't be discounted but a more extreme milder solution, that is unlikely to verify IMO. If the Op and Control didn't go off on one, the mean would remain around -5 for a good week or so. In a disturbed pattern that is ample for last minute features to pop up and bring snow to some. I will happily take that right now!...No need for panic and toy throwing just yet. Chill and let the models adjust to the pattern change for a couple of days.

Edited January 8, 2016 by Shrimper

[london and south east kent]

16 hours ago, nick sussex said:

Yes the UKMO for that timeframe is superb. And it also has a front heading se at T120hrs and a shortwave dropping south at T144hrs from Scotland. Both those of snow.

I'd settle for an ECM/UKMO combo but of course would love to see the UKMO verify. I think with both the ECM and GFS against it that will be difficult.

Anyway the ECM postage stamps are out in about half an hour, we'll see how much support there is for the UKMO solution.

 

[Barry12]

The GFS 06z backs up the thought that this may be a prolonged cold spell, next weekend is looking very cold for everyone with -5 uppers at worst, snow could fall anywhere, including the south.

 

Friday

Friday will be bitter with max temperatures of 0-4C. Much of Scotland will remain below freezing. So any precipitation should fall as snow.

 

Saturday

Saturday is also very cold with temperatures between 0-5.

 

The medium range is not looking bad at all, many of us will see snow, and Scotland/parts of Northern England could even get ice days, which are certainly not to be sniffed at living in the UK.

 

[nick sussex]

1 minute ago, abbie123456 said:

 

That stood last night before the ECM went downhill this morning. We want nothing to do with either the ECM or GFS today. They're a tin of spam compared to the UKMO's Dover Sole.

 

[Duane S.]

Worth remembering that despite my recent derision of ENS versus OPs, this is where they do come into their own. If there is a problem with starting conditions then the Hi Res OPs will quickly head off down the wrong path. With this sort of setup and taking into account the teleconnections, i.e. the monster +global AM spike, the OPs are likely to be literally be all over the place for a few days yet.

What a great time to be chart watching I say!

[Eskimo]

3 minutes ago, Barry95 said:

The GFS 06z backs up the thought that this may be a prolonged cold spell, next weekend is looking very cold for everyone with -5 uppers at worst, snow could fall anywhere, including the south.

The 06z is terrible for a prolonged cold spell. It's showing sw-erly winds by day 9!

[Weather Boy]

17 minutes ago, nick sussex said:

The latest JMA 06hrs run at T84hrs looks a whole lot better than the GFS 06hrs run for the same time.

I'm scratching around here for outputs that disagree with the ECM/GFS!

I'm surprised you say that Nick, because what about the GFS ensembles?  Surely it is something of a relief to coldies that the op run is poorly supported by its ensembles?  It is not quite an outlier, but it is very mild for that period.  The op can drag its ensembles round, but not always.  GP says stick to your ensemble means, which suggests more sustained cold currently.

We had the position where the ops were rock solid for cold, but the METO seemed dubious.  Now the models are wavering, METO sound more bullish for cold!  AS someone said that suggests that their models that we can't see suggest longer term cold.

[SLEETY]

2 minutes ago, PerfectStorm said:

The 06z is terrible for a prolonged cold spell. It's showing sw-erly winds by day 9!

too far out to worry yet ,its a mild outlier at that time,anyay,ok

[Eskimo]

1 minute ago, SLEETY said:

too far out to worry yet ,its a mild outlier at that time,anyay,ok

I've noticed the GFS isn't handling this very well and it may be the case that the UKMO or even the ECM might be closer to the mark. However, prolonged cold spell coming from 06z specifically, as mentioned by Barry95, is not going to happen. 

[Frosty.]

Despite reading some depressing posts earlier today the models are showing a cold spell next week, especially through the second half of next week with a chance of snow for most of the UK along with ice and widespread frosts with temps below average for the first time this winter so I'm happy now that a cold spell is definitely on the way.

[Neilsouth]

Wasn't the GFS supposed to be the NEW GFS which came about in 2014? It doesn't seem to be all that better, and I'm not talking about this cold spell, but the fact that it constantly tries to make low pressure systems about as destructive as possible

[mb018538]

Although I'm fairly new here I've been an avid model follower over on TWO for a good 13 years, so I've seen plenty of these come and go in that time!  I certainly won't be taking any model at face value, I was merely stating the 6z wasn't great as an individual run. Glad to see its in a minority and the majority is still cold!

[bluearmy]

The ecm parallel on the same page as the op but takes the snow line as far as the borders rather than Yorks/lancs day 8/9.

as Steve says, one of the main tipping points is quite early on near Greenland. You would think that the ops are going to be making the running at this timescale. That's not good news for coldies. 

 

The sub tropical system potentially being caught in the jet and driving a euro ridge ahead of it added to the polar profile has made a tricky evolution almost impossible to model at a distance. We had op and ens and x model agreement and yet it still looks unlikely to be enough on this one for sustained cold.

extended eps and naefs both raising an iberian high anomoly so that makes it even tougher to get back onto a decent cold track though not impossible depending on the Scandi trough and Atlantic high behaviour in week 2.

 

 

 

[london and south east kent]

14 minutes ago, nick sussex said:

That stood last night before the ECM went downhill this morning. We want nothing to do with either the ECM or GFS today. They're a tin of spam compared to the UKMO's Dover Sole.

 

ukmo is on to something

 

[nick sussex]

19 minutes ago, Weather Boy said:

I'm surprised you say that Nick, because what about the GFS ensembles?  Surely it is something of a relief to coldies that the op run is poorly supported by its ensembles?  It is not quite an outlier, but it is very mild for that period.  The op can drag its ensembles round, but not always.  GP says stick to your ensemble means, which suggests more sustained cold currently.

We had the position where the ops were rock solid for cold, but the METO seemed dubious.  Now the models are wavering, METO sound more bullish for cold!  AS someone said that suggests that their models that we can't see suggest longer term cold.

Theres two ways of looking at this, the higher resolution of the operationals should be better at picking up changes but also might become too jumpy and over react.

I'm going to keep the faith and fall back on the real MJO signal which has this in phase 7 and not entering phase 8 as the ECM/GFS suggest.

The UKMO is a closer match to phase 7. The ECM/GFS are including too much interference from the ENSO and Kelvin wave and for this reason are throwing out these different solutions especially with blocking in the north Atlantic.

This is my comfort blanket approach to todays outputs. Its a bit way out there but not totally outlandish as I'm using this as the basis for my desperate attempts to ignore the ECM/GFS! lol

The above was specifically designed by some researchers to address the issues with the normal dynamic model forecasts which can show an innacurate movement of the MJO.

The case for the defence rests! lol

The above is the composite anomaly for phase 7 MJO ENSO positive.

Research has shown that the biggest NH impact during MJO, ENSO positive or declining is to the west of the UK in the North Atlantic.

I know I should stop digging an even deeper hole for myself but  I'm in no mood for either the ECM or GFS today!

 

 

Edited January 8, 2016 by nick sussex