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

[shane303]

There are increasing signs seaside and even the BBC and met office long range are saying this is the likely outcome and they have better sources then us when it comes to model tools / information. 

[shane303]

Just now, shane303 said:

There are increasing signs seaside and even the BBC and met office long range are saying this is the likely outcome and they have better sources then us when it comes to model tools / information. 

 

13 minutes ago, seaside 60 said:

Why is it likely that WSW winds will be back in 6/10 days.

Have you got a crystal ball, because its more likely that you will have a better return from that than believing what the model;s are forecasting in 6/10 days, thats why its an interesting winter.

 

[Snowman.]

Some differences on the 12z

 

Much slower in in sending the low NE

[Interitus]

4 hours ago, bobbydog said:

This is now- 

That was then-

We actually have a stronger arctic high now than back then and the overall profile is very similar. Also, we have an SSW forecast. The strat was behaving in a similar way back then. -

1991

2017

Eerily similar don't you think?.....

Absolutely no coincidence, the Atlantic/Euro high is part of the troposphere wave 1 pattern which propagates to give a strong wave 1 forced warming in the stratosphere. Ironic if the criticised current high were to lead to cold via an SSW later on!

[IDO]

The GFS 12z is like watching paint dry,you just know it cannot develop into anything cold in the medium term, the best outcome if you want a cool (feeling below average) setup. We have been looking at charts with "potential", but its hard to call the upcoming period that.

The only good thing about the GFS op is that it is more interesting than the horrible GEM, a classic zonal pattern till past D10:

No HLB's with a PV ruling the roost, though weak compared to normal recent January's, just no forcing from the trop or strat, so basically prime time NH pattern wasted. The rest of January is seemingly looking for a sign of what may come in February? I am sure this is only a temporary hiatus, as there is still no sign the PV will become organised, but January looks like ending in a zonal take, just when that initiates and whether the UK is in a upper trough (GFS) or ridge (ECM) or zonal (GEM) preceeding that zonal period (D10-15+).

Edited January 15, 2017 by IDO

[bobbydog]

18 minutes ago, IDO said:

The GFS 12z is like watching paint dry,you just know it cannot develop into anything cold in the medium term, the best outcome if you want a cool (feeling below average) setup. We have been looking at charts with "potential", but its hard to call the upcoming period that.

The only good thing about the GFS op is that it is more interesting than the horrible GEM, a classic zonal pattern till past D10:

No HLB's with a PV ruling the roost, though weak compared to normal recent January's, just no forcing from the trop or strat, so basically prime time NH pattern wasted. The rest of January is seemingly looking for a sign of what may come in February? I am sure this is only a temporary hiatus, as there is still no sign the PV will become organised, but January looks like ending in a zonal take, just when that initiates and whether the UK is in a upper trough (GFS) or ridge (ECM) or zonal (GEM) preceeding that zonal period (D10-15+).

No forcing from the strat? What's this then?-

[Nouska]

On the subject of the stratosphere and current modelling - both GFS and ECM take the 10 - 30mb stratosphere temperatures down to -80C in our vicinity in roughly eight to ten days time. There may be another opportunity to see the beautiful Nacreous clouds that we saw in early February of last year.

http://www.metoffice.gov.uk/learning/learn-about-the-weather/clouds/nacreous

 

ECM current to this

GFS 10mb         

Last year, early Feb chart.

                       

Not a certainty but certainly possible.

 

[blizzard81]

Signs of raising heights in the Scandi vicinity as early as day 8 on the gfs ens.

[Summer Sun]

 

[SMU]

9 hours ago, IDO said:

FWIW the 18z is currently easily the best performing run by the 4 GFS daily suites; SLP especially, so I would not dismiss up to D10:

Yesterday there was no cross-model agreement viz where the next wave of heights came from, but ECM have flipped to the GEM solution of a UK flanked two wave attack in our sector. Of course this is the worse case scenario and will mean the rest of January killed for any wintry potential. GEM maintains that theme but relaxes on the heights so we are left with a zonal mess from D6-10 at least (we know when a model picks up a new pattern it's bias it to overblow heights, so ECM likely to move that way). The GFS is therefore the only model to still maintain the one wave mid-Atlantic height build, but as expected those heights have downgraded with each run. It leaves the GFS solutions very messy re surface flows. The GEFS (here) support this pattern with nominal respect to the ECM solution. 

Very difficult to be confident after D6 viz the UK pattern. The only thing I am reasonably certain about is the continued cycling of the PV to Siberia then back to NE Canada, so opportunity for a blocked pattern is poor without forcing and, as the Azores has proved all Winter it cannot get better than a MLB without a Pacific wave to assist. Signs from the GEFS around D13 that there may be height rises in the Pacific region but la la land at the moment, and in any case that is for February. Of course the mobility of the PV has meant many opportunities for cold air to drift south, but unfortunately the UK has had more misses than hits. With seemingly no strat to trop forcing either we can see why the UK pattern has been quite repetitive this season; no resets to maybe get a better solution.

We can only hope the GFS outcome is in the ball park, though the variations on that theme in the GEFS are good and bad (for cold); if not then we are heading for a poor wintry setup for the rest of the month into early Feb. 

Your reading it wrong @IDO its the error so the higher the number the worse the model

means 18z is the worse...

Edited January 15, 2017 by Steve Murr

[Interitus]

1 minute ago, Steve Murr said:

Your reading it wrong @IDO its the RMS error so the higher the number the worse the model

means 18z is the worse...

It's anomaly correlation in this case, so higher is better - a score of 1 would be perfect.

[TomDav]

4 minutes ago, Steve Murr said:

Your reading it wrong @IDO its the error so the higher the number the worse the model

means 18z is the worse...

The higher the number the better

[Interitus]

10 minutes ago, Nouska said:

On the subject of the stratosphere and current modelling - both GFS and ECM take the 10 - 30mb stratosphere temperatures down to -80C in our vicinity in roughly eight to ten days time. There may be another opportunity to see the beautiful Nacreous clouds that we saw in early February of last year.

http://www.metoffice.gov.uk/learning/learn-about-the-weather/clouds/nacreous

 

ECM current to this

GFS 10mb         

Last year, early Feb chart.

                       

Not a certainty but certainly possible.

 

Yes, we came quite close to a chance at the start of the month but in the end the lowest temps didn't quite reach so the clouds were only seen widely over Scandinavia.

Incidentally, they're rarely seen as high as 10mb because of the lower pressure, the temperature has to be lower for the clouds to form, the temperature graphs on the NASA-Goddard site have handy markings delineating the approximate thresholds for cloud formation at the different pressures - https://acd-ext.gsfc.nasa.gov/Data_services/met/ann_data.html eg.

 

[nick sussex]

There seems to be some conflict going on in the modelling with uncertainty over where that energy in the Atlantic goes. The GFS takes more se'wards initially but even the UKMO is debating that and we still see low pressure in the Med. So something has to give.

The MJO might be causing some of this uncertainty and so until the above issue is resolved then we might still see an alternative way forward.

 

[chris55]

Yep

GFS Vs UKMO at 144

GFS

UKMO

Gfs actually bringing in some very cold surface temps especially at night by later next week!

FRI/SAT/SUN

 

 

[SLEETY]

That's one positive having low pressure in the med,surely the high cant sink ,if low pressure still persists in that location maybe all is not lost yet.

[SMU]

1 hour ago, Interitus said:

It's anomaly correlation in this case, so higher is better - a score of 1 would be perfect.

Yeah I thought it was the RMS score

 

however - Its NH so of little consequence to the UK, hence why the current set up was never picked up by IDO means forecastsing...

[nick sussex]

The ECM thought about sending some energy se'wards at T120hrs but doesn't follow through at T144hrs. This would make a difference going forward. The GFS sends that energy se'wards so we still have a divergence here.

[Methuselah]

2 minutes ago, Steve Murr said:

Yeah I thought it was the RMS score

 

however - Its NH so of little consequence to the UK, hence why the current set up was never picked up by IDO means forecastsing...

So what are the stats, for the UK, Steve?

[chris55]

Who's modding the thread tonight....bit harsh for deleting my post IMO, though i understand you have a job to do.

Meanwhile, ECM looking slightly odd but mild at 168

 

[karyo]

The ECM sinks the high by 192 hours, quite a bit faster than the earlier run.

[snowray]

This is a lot better, Euro slug being shifted a lot quicker, Canadian High taking shape...could be a half decent chart at D10.

[chris55]

Northerly/north easterly incoming.....eventually ...maybe ?

[booferking]

30 minutes ago, chris55 said:

Northerly/north easterly incoming.....eventually ...maybe ?

Looks zonal wet average type weather to me the high in the Atlantic will not get anywhere near Greenland.

Sorry i agree looking at the 240 chart on wetterzentrale there is potential.

Edited January 15, 2017 by booferking

[Banbury]

4 minutes ago, chris55 said:

Northerly/north easterly incoming.....eventually ...maybe ?

I understand where you are coming with that