Model output discussion - is the beast awakening?

[Man With Beard]

18 minutes ago, Mucka said:

 

Undoubtedly.

Here is the track of the low in 24h steps from 96h through to 192h - physics!

 

What's really bamboozling is that, after missing the first attempt at an easterly at T120/T144, the ECM then misses the second attempt because a random low drops from the Arctic into Scandi at T192, just as the "beast from the east" was getting off the ropes for another go!

Those kind of details make analysis late into the run a waste of time, frankly.

[Gowon]

Another good chart for today - the JMA looks the GFS.

[bluearmy]

Day 7/8 mean on eps pushes the scandi trough extension closer to the U.K. and Low Countries 

[jam]

2 hours ago, winterof79 said:

Delayed..... No... The days longer the sun stronger.. The paths warmer.... Can't think of owt else

The sun stronger argument surely died a death in March 2018 ?  

[Man With Beard]

3 minutes ago, londonblizzard said:

My memory of the lead up to the 2018 beast from the east was that the GFS was the latest to latch on to it (with ECM etc showing it first). Almost showing zero cold spell, and then over the course of 2 runs suddenly showing -15 uppers. I want someone to correct me if i'm wrong about this though?

GEFS mean showed a 1030mb Scandi High on all runs except one between T360 and T0 - that's about 60 runs. I remember because I checked each one at the time!

ECM ensemble mean was broadly on the same page but not as convincingly as GFS.

Op runs didn't do too badly but more dramas than the ensemble means.

Bit different this time as I think we're on a much more tricky trajectory. 

Edited January 31, 2021 by Man Without Beard

[Anthony Burden]

ECM is actually holding the northern blocking till the following week and keeping most of U.K. 

perhaps not Scotland under unsettled Atlantic driven lows diving south east.Possible snow 

where the mild air hits the cold this continues through the weekend and possibly into early following 

 week.Interesting stuff but confident northern blocking will arrive to all of U.K. but held up

for a while.

[Stu_London]

4 minutes ago, Winter Hill said:

GFS was very consistent with the 2010 cold outbreak. 
 

2018, the models were a bit like now if I remember correctly 

2018 was a lot more consistent, although it did end up hitting us 2-3 days later than first modelled. 

2010 was just counting down the hours with some subtle variations along the way.  

Other cold spells were much more volatile - Jan 2013 was a bit of a model fiasco which dated back to December 2012 - lots of chopping and changing and massive stand offs between the models right down to +48hrs sometimes. 

March 2013 - the cold was modelled really well - but a couple of big fails with ppn distribution.

Going further back 2006 had a big failed beast at about 72hrs - came back with a watered down version a week or so later that more or less verified. 

[Djdazzle]

1 minute ago, jam said:

The sun stronger argument surely died a death in March 2018 ?  

The sun strength was probably the difference between the severe spell that we got, and the historic spell that it could have been had it occurred a month earlier.

[Bermuda High]

11 minutes ago, MR_E said:

Does anyone remember how some previous cold spells such as 2018, 2010 etc were reflected in the models? Were they consistent across the board at this stage or were there inconsistencies as there are now?

 

Separately, how does what the cold models now are showing compare to some of the famous cold spells from previous years 1987, 60s etc?

2018 BTFE 1 and 2 were clean and all models on board. 

[Man With Beard]

Just now, Bermuda High said:

2018 BTFE 1 and 2 were clean and all models on board. 

GFS and UKMO were quicker than ECM latching onto beast no. 2 

[bluearmy]

Back end of ec ops with a vortex off Newfoundland again  ........ on the mean too 

[Stu_London]

1 minute ago, Man Without Beard said:

GFS and UKMO were quicker than ECM latching onto beast no. 2 

Amazing how quick the weather flipped after beast 2 - I recall playing golf in shorts and t shirt a week later and coming across drifts that had accumulated in the bunkers 

[JamesL]

4 minutes ago, Djdazzle said:

The sun strength was probably the difference between the severe spell that we got, and the historic spell that it could have been had it occurred a month earlier.

Hmmmm we had the coldest March day on record at -5 in Tredegar with drifts up to the guttering 

Pretty historic here lol 

[TSNWK]

1 minute ago, bluearmy said:

Back end of ec ops with a vortex off Newfoundland again  ........ on the mean too 

What does that mean for us broadly speaking please? usually I would be nervous of that purple monster way out west and north... but well this winter is odd in so many wAy

[Chesil View]

All in all some good runs this evening. The biggest move definitely from the ecm and although many would like to have seen it switch from its southwesterly horror show on the 0z to a long fetch easterly on the 12z. That was never likely, .what was always more likely was an incremental step back from the southwesterly horror show towards soemthing more in line with the ukmo and gfs and that is what happened.  The even better news is that this incremental step has been made with plenty of time for further adjustments in favour of an even colder outcome.  

[northwestsnow]

10 minutes ago, bluearmy said:

Day 7/8 mean on eps pushes the scandi trough extension closer to the U.K. and Low Countries 

I'm liking the sound of that frigid air getting closer Blue!

[londonblizzard]

18 minutes ago, MR_E said:

Does anyone remember how some previous cold spells such as 2018, 2010 etc were reflected in the models? Were they consistent across the board at this stage or were there inconsistencies as there are now?

 

Separately, how does what the cold models now are showing compare to some of the famous cold spells from previous years 1987, 60s etc?

Just for fun, and a bit of a side note since BFTE dates were in deep FI at this point, but this is the GEFS ensemble immediately after the SSW just over 2 weeks before the BFTE started.

.


Only 1 run there (the -15 coldest outlier after 27th feb) resembles what would actually happen.

[northwestsnow]

8 minutes ago, bluearmy said:

Back end of ec ops with a vortex off Newfoundland again  ........ on the mean too 

Eps?

Is that day 10-15 Blue?

[bluearmy]

1 minute ago, northwestsnow said:

Eps?

Is that day 10-15 Blue?

back end op - day 10 

 

8 minutes ago, TSNWK said:

What does that mean for us broadly speaking please? usually I would be nervous of that purple monster way out west and north... but well this winter is odd in so many wAy

It means the Atlantic won’t become quiet .....hopefully a greeny wedge can deflect it far enough to the south 

[Bristawl Si]

10 minutes ago, JamesL said:

Hmmmm we had the coldest March day on record at -5 in Tredegar with drifts up to the guttering 

Pretty historic here lol 

March '18 - Minus 2c at 2 oclock in the afternoon in balmy Bristol, with snow still falling. Historic, for sure.

[Daniel*]

18 minutes ago, bluearmy said:

Day 7/8 mean on eps pushes the scandi trough extension closer to the U.K. and Low Countries 

Yep continued improvements coming from EPS

00z > 12z

[Don]

4 minutes ago, bluearmy said:

It means the Atlantic won’t become quiet .....hopefully a greeny wedge can deflect it far enough to the south 

Not the best for cold then but subject to change and could be a high risk/high reward scenario, would you say?

Edited January 31, 2021 by Don

[damianslaw]

Are we any clearer of likely evolution through first week of February, a bit more so this evening but still some level of uncertainty.

ECM has moved more in line with UKMO and GFS this evening.

General theme - staying unsettled, cold/mild boundary moving through the UK early in the week to lie somewhere over Central/N Scotland by Wednesday where it becomes stuck, and then retreats back south very slowly through Thursday and into Friday as heights to the north exert greater influence.

The low pressure is a rather shallow affair but becomes slow moving and cut off to an extent from the jetstream, eventual forcing will see it sink away to the south / south east, enabling a colder NE/E flow to make its presence felt through the upcoming weekend, more so in the north but everywhere at last.

I'll not comment on models past the 144hr timeframe, all dependent on the robustness of heights to our north.

Quite a complex set up in what is turning into since Christmas as least the most complex winter to forecast probably since 12/13... similarities strong with that one in terms of the SSW.. 

Edited January 31, 2021 by damianslaw

[danm]

22 minutes ago, Man Without Beard said:

GEFS mean showed a 1030mb Scandi High on all runs except one between T360 and T0 - that's about 60 runs. I remember because I checked each one at the time!

ECM ensemble mean was broadly on the same page but not as convincingly as GFS.

Op runs didn't do too badly but more dramas than the ensemble means.

Bit different this time as I think we're on a much more tricky trajectory. 

Yes the remarkable thing about the build up to the BFTE in 2018 was the consistency shown in the model runs. It was pretty much drama free compared to many of the other cold spells we’ve had. 

[Matt H]

To my surprise the ECM 12z ensemble mean looks fantastic at t168 with a decent easterly wind!