Model output discussion - proper cold spell inbound?

[Day_9]

I don’t think I can take much more of this but why i do come here is for pure cold charts (I couldn’t tell a cold one from a warm one but can tell an experienced / expert from a hype generator.

All I know is this.  You can get snow to sea level in the UK even in April.   On Easter Sunday 1998 I woke up to snow on the beach whilst my now wife and I were having a weekend away in a caravan and it was bloody freezing.....  it’s obvious that SSW science is VERY young therefore when a warning as dramatic as this one which is in chartered territory, even the experts are unsure....

[Man With Beard]

45 minutes ago, That ECM said:

 Gfs mean with heights to the ne that drift to the nw. 

Yes, noticed that!

The 1030mb Scandi High has been pushed back a day but the reason it isn't higher on the mean is partly due to an attempted migration of heights from Scandi to Greenland, resulting in a deep cold Scandi trough on a couple of members.

If I hadn't seen the 06Z, I'd have assumed the general GFS pattern of the last two days was just carrying on with the 12Z

Edited February 11, 2018 by Man With Beard

[Johnp]

Ecm still on the naughty step at 144....

[Duane S.]

ECM an improvement on the 00z but not as good as the GFS at D6

ECM

 

GFS

Let’s see where we go from here, should end better.

 

[Frosty.]

4 minutes ago, Johnp said:

Ecm still on the naughty step at 144....

I might be wrong but there doesn't look much difference between the Gfs / Ecm 12z at T+144 apart from the ecm being a little slower with the high building NE.

[igloo]

8 minutes ago, Johnp said:

Ecm still on the naughty step at 144....

Yes it looks even worse than the last few runs the UKMO doesnt look much better either i think its time to move on i feel i just cant see the euro models getting this wrong sadly 

Edited February 11, 2018 by igloo

[ICE COLD]

Ecm 192 hrs is terrible ?

[Met4Cast]

47 minutes ago, Daniel Smith said:

That's some drop in the mean on the 12z compared to the 6z.

06z

12z

It's almost as if the models are struggling at the moment & Shannon Entropy is high.

Okay, todays 12z is an even bigger drop when compared to both this mornings 06z and yesterdays 12z

[Ali1977]

ECM and GFS at complete loggerheads again, this isn't good for us lot knowing whats going on.  I wonder where MOGREPs stands - cold by next weekend, or with the ECM.  

[Johnp]

6 minutes ago, Frosty. said:

I might be wrong but there doesn't look much difference between the Gfs / Ecm 12z at T+144 apart from the ecm being a little slower with the high building NE.

Well it's all about opinions I guess, but I could tell straight away from that 144 ECM it was going to be a terrible run.

[Frosty.]

8 minutes ago, Frosty. said:

I might be wrong but there doesn't look much difference between the Gfs / Ecm 12z at T+144 apart from the ecm being a little slower with the high building NE.

Actually, scrub that, the Gfs looks much better at T+168 whereas the ecm is pumping milder swly winds up across most of the uk apart from the colder s / se..T+192 is even milder..yikes..another ecm going teits up!!

Edited February 11, 2018 by Frosty.

[Captain Shortwave]

I will say that the good news is that whilst the ECM is bad, it is considerably flatter at day 6 even compared to the UK which has the Azores high angled to push into the UK. 

ECM

UKMO

Oddly the flatter solution towards our part of the world is actually caused by the extra amplification achieved in the Pacific which seems to push the Canadian lobe further east. So there is a chance that the ECM is overdoing things upstream and hence we might gain extra amplitude on that Euro based high and develop something a little better.

[Mike Poole]

I think this might be one of those occasions where the destination's clearer than the route to which we get to it.   Here's the probability of >1030 mbar at T+192

All across the UK, but by the end of the run, clear high latitude blocking Suggested towards Greenland 

These probability charts from meteoceil are good but why are they just shades of blue? Surely they should be in glorious technicolor like the rest of their charts!   Anyway, it looks like we're on a road to somewhere. 

[Banbury]

ECM is a shocker .....our luck will prove ECM right 

[Duane S.]

Huge Eastern Pacific ridge on the ECM. Seems to be part causing the flatter solution for us. Plausible I suppose.

Northerly anyone? Really??

[mountain shadow]

7 minutes ago, ICE COLD said:

Ecm 192 hrs is terrible ?

Yeh, I think a quick tropospheric response to the SSW is now off the cards, we are almost certainly now looking towards the start of March for favourable blocking heights.

[tight isobar]

Heres a prime example of hem-trop-response +vortex miss manage!!..

Ecm cuts the main canadian- and drop double segs-into atalntic...not factoring in data responce acordingly and amplification cant be factored due to ec-like for such prog..

Gfs...very clean in finding evolvement and offer-s ens to support....

Ecm op- clearly not modeling flux- and manage of warming -correct' @ the pole!!!

Gfs on the money.

I-ll also in a while nominate mjo- markings...that show the ec- up for its doubtful synops......

Edit;.. 18z  will likely be even more cut/steafast in showing both height-and vortex switching!!

Edited February 11, 2018 by tight isobar

[Eskimo]

Nothing to see here. 

[ICE COLD]

1 minute ago, mountain shadow said:

Yeh, I think a quick tropospheric response to the SSW is now off the cards, we are almost certainly now looking towards the start of March for favourable blocking heights.

I do agree mate with the first bit of your post but we could still get something in Feb ECM only goes to the 20th so around 8 days left after that so it's still very possible last week of Feb ?

[Fingers]

Model watching is tough going at the mo, especially since we haven’t seen lying snow on the south coast for 5 years!

I still believe that we could be on to something special. The models haven’t had a lot of SSW occurrences to be getting these 5-15 day forecasts right and with a record -40m/s reversal (not predicted until the 15th) and a favourable mjo i’m not sure we’ll get a decent handle on this until midweek..... at the earliest. Yes we can look for trends but I believe it’s time to keep the faith! 

Half term this week, may travel north Tuesday so my 5 year old can experience snow for the first time. ?

Clem

Snow starved southerner! 

[Captain Shortwave]

Tonights ECM has been cancelled and has instead in true TV style, put on a repeat of a previous winter, unfortunately it could be from any one of the last few winters.

In other news, it appears that the three ghosts in the famous Charles Dickens novels can die twice. ECM not impressed by their suggestion of coldie redemption.

If this ends up being close to the mark then I will eat my bobble hat with a sprinkling of 7 day old socks. Thankyou

Edited February 11, 2018 by Captain Shortwave

[bluearmy]

2 minutes ago, Fingers said:

Model watching is tough going at the mo, especially since we haven’t seen lying snow on the south coast for 5 years!

I still believe that we could be on to something special. The models haven’t had a lot of SSW occurrences to be getting these 5-15 day forecasts right and with a record -40m/s reversal (not predicted until the 15th) and a favourable mjo i’m not sure we’ll get a decent handle on this until midweek..... at the earliest. Yes we can look for trends but I believe it’s time to keep the faith! 

Half term this week, may travel north Tuesday so my 5 year old can experience snow for the first time. ?

Clem

Snow starved southerner! 

Yesterday’s ec op was -25m/s. Nothing shabby about that but it’s a long way from 40m/s. The 12z gefs seem to bottom out around -28 m/s. and whilst there is a historic analysis built into the nwp, the idea that it won’t do a reasonable job in the short term just doesn’t stack up imo. of course if it makes some erroneous calculations early in the run due to under estimating certain parameters then there will be consequential issues by day 7/8. I would still be looking for that second attempt at amplification in the  6/8 day timeframe. 

[Duane S.]

Look at the AO profile here.

I get the fact we may see the tropospheric vortex wind up as the warming hits above but Shirley by this point and time we would expect to see a much more pronounced negative AO setting in. Wouldn’t we??

[Derecho]

Thought I'd show the 3 main models at T144 to get a better grasp of what is going on

                         GFS                                                      ECM                                                          UKMO


The reason why the ECM goes pear shaped is that the is no instability to our SW which leads to stronger heights over Europe. The GFS and UKMO at least both develop low enough heights over Europe to allow a ridge to set up shop to the UK.

Coldies though may have to be patient unfortunately. The ECM is at odds with the others but it is a plausible scenario and can't be dismissed.

That pesky PV pouring cold air into the north Atlantic is keeping us under more westerly regimes then usual. Is this something we are going to have to live with along with less cold pooling over the continents? I'm in no way throwing the towel yet though for this winter. The UKMO would probably go the same direction as the GFS.

Anyhow if we can't get deep cold I'm looking forward to some spring warmth come March. I will go into a much more detailed technical post about how this winter has developed and why we are seeing the patterns that have occurred at the end of the month. Obviously though a lot hinges on the SSW and whether it will effectively make it down to the surface.

Tonight we are none the wiser.

[blizzard81]

Will somebody please wake ecm up. Oh yeah, I forgot. It seems to go on a full on bender at the weekends. It will sober up tomorrow.