Model output discussion 24/01/21

[MJB]

This has to be an outlier , just wonder what support it has ...................if any 

[ALL ABOARD]

Perfect. 

Enough of the vortex left across Canada to prevent the high retrogressing to far west. 

Low heights into the majority of Europe. 

Lows spawning and running under the block.. 

As good as it gets. 

[Methuselah]

Finely balanced 06Z @T+225? Although superficially similar to the yuck-fest many experienced, at the start of January, the cold pool out east, considerably deeper than it was back then... So, hopefully, that potentially troublesome orange elephant will eventually become more of an elephant shrew!

    

Which, thankfully, happens by T+276!

    

Edited January 29, 2021 by General Cluster

[stratty]

6 minutes ago, Notty said:

... and new warnings for snow and ice for a large part of the UK for Monday, Tuesday and Wednesday

Woohoo!  That's quite an advanced warning with regards this situation too!

[Cuban Zebra]

There’s charts lurking but I refuse to get drawn in yet, I’ve had my heart broken too many times!!!!

I hope I’m wrong but I can sense a horrible, horrible twist in the tale that will leave some on here truly suicidal!!!

 

#reverse psychology!!!

[ICE COLD]

Alright one more . I’m in love with it 

[Ice Day]

Save this chart, the 6z is pretty much delivering the holy grail for the UK and Ireland.    

 

Absolutely superb run.  Easterly, followed by a slightly 'milder' day or so before the north easterly.  Textbook!

[Battleground Snow]

The east coast would be under a foot of snow at 300 if this came off.. we have definitely got a ticket atm!

[tight isobar]

1 minute ago, MJB said:

This has to be an outlier , just wonder what support it has ...................if any 

???. We'll see the supports..but more than feasible given both evolutionary=upper atmospheric dynamics.

[SqueakheartLW]

I have done my analysis of the period between 4th and 10th February since that period looks to be of interest in terms of a colder spell at least

Here are the ensemble charts for Scunthorpe for both the GFS 00z and GEM 00z

The GFS seems more keen on a longer colder spell compared with GEM on the 00z runs. Is this GEM backing down from the cold now that GFS is deciding to me more on board with it?

Now to compare all ensemble members between GFS 00z, GEM 00z and GEFS Legacy and count up all the outcomes in set categories as follows:

Cold Options     (East)     (NE)     (North)

No particular outcome

Mild Options     (South)     (SW)     (West)

The directions are the origin of the cold or mild spell

GFS 00z Outcomes

4th Feb to 10th Feb

Cold           22/32
    North     3/32
    NE          6/32
    East       13/32

Example best charts I could find from the easterly runs

N/A            2/32

Mild           8/32
    South    2/32
    SW         4/32
    West      2/32

Example worst chart I could find from the milder runs

GFS is quite keen on a colder outcome in the 4th to 10th February period with 22 of 32 options showing a cold setup. Easterlies are the favoured option with 13 of the 22 and some are proper beasterly options but others are more high pressure or drab options. A few northerlies in there too at 6/22 but it would seem cold from the north is unlikely at just 3/22

GFS still has the dreaded milder options in there at 8 of 32 runs and it seems SW winds are favoured if this does happen and with 25% showing mild then we can't rule out this happening too to spoil our chances of cold

GEM 00z Outcomes

4th Feb to 10th Feb

Cold          13/22
    North    1/22
    NE          6/22
    East       6/22

Example best charts I could find from the easterly runs

N/A           1/22

Mild          8/22
    South   0/22
    SW        3/22
    West     5/22

Example worst chart I could find from the milder runs

GEM 00z seems less keen on a colder spell between 4th and 10th February with only 13 of 22 options showing this but like GFS easterlies seem to be favoured with 6 of 13 going for them but NE winds could also be a viable option too with 6 of 13 showing this outcome. Northerlies seem very unlikely with just 1 of 13.

GEM has many dreaded milder options with 8 of 22 runs showing mild in the 4th to 10th period and westerlies are favoured with 5 of the 8 showing this. With GEM seemingly backtracking somewhat on the cold then don't rule out a burst of westerlies that could ruin everything

GEFS Legacy Outcomes

4th Feb to 10th Feb

Cold          18/21
    North    0/21
    NE         6/21
    East      12/21

Example best charts I could find from the easterly runs

N/A           3/21

Mild          0/21
    South   0/21
    SW        0/21
    West     0/21

As no options came up mild then I fortunately have no example mild charts to post here

Of all the models I have featured here it is the GEFS Legacy that has come out best of all for the colder outcomes with 18 of 21 runs showing cold in the 4th to 10th February period and the other 3 runs were very much average or unable to determine. Easterlies are heavily favoured here with 12 of the 18 cold options showing this. The other options were all NE wind options.

Summary

So to summarize between the models we have:

                            Cold                                                         N/A                 Mild

                            Total       E            NE        N                   Total              Total     S         SW        W       

GFS 00z              22(69%) 13(41%) 6(19%) 3(9%)            2(6%)             8(25%)  2(6%)  4(13%)  2(6%)

GEM 00z             13(59%) 6(27%)   6(27%) 1(5%)            1(5%)             8(36%)  0(0%)  3(14%) 5(23%)

GEFS Legacy      18(86%) 12(57%) 6(29%) 0(0%)            3(14%)           0(0%)   0(0%)   0(0%)   0(0%)

Combining the totals we get

Cold                                                            N/A                 Mild

Total      E             NE          N                   Total               Total      S         SW        W      

53(71%) 31(41%) 18(24%) 4(5%)            6(8%)              16(21%) 2(3%) 7(9%)    7(9%)

What the above shows with the overall totals is that we have a 71% chance of a colder spell between 4th and 10th of February and this is most likely to come from the east if it happens but with no real outcome and milder still taking some of the share we cannot rule this out yet

[ALL ABOARD]

You can see how hard Europe wants us back.. 

Its changed the weather to make an ice bridge

 

[Nick F]

COBRA run in FI - T+300 T850 -15C line a stones throw over the N Sea, but surface low developing in the very unstable flow over N Sea prevents it making to east coast. Such a tease ...

Edited January 29, 2021 by Nick F

[Griff]

Do we win a prize if the purple gets here?  

[MJB]

1 minute ago, tight isobar said:

???. We'll see the supports..but more than feasible given both evolutionary=upper atmospheric dynamics.

Every solution is feasible ..............it's the UK , I'd love it to be in a large cluster but I doubt it ........I am VERY happy to be wrong 

[Purga]

06z is looking even better..

[PiscesStar]

2 minutes ago, Nick F said:

COBRA run in FI - T+300 T850 -15C line a stones throw over the N Sea, but surface low developing in the very unstable flow over N Sea prevents it making to east coast. Such a tease ...

Yesssssssssssssssssss. Looking good  

[ALL ABOARD]

2 minutes ago, Nick F said:

COBRA run in FI - T+300 T850 -15C line a stones throw over the N Sea, but surface low developing in the very unstable flow over N Sea prevents it making to east coast. Such a tease ...

Even with the surface low looks like it could make it. 

New area of heights pushing towards Greenland out of newfoundland. 

 

[ICE COLD]

2 minutes ago, Nick F said:

COBRA run in FI - T+300 T850 -15C line a stones throw over the N Sea, but surface low developing in the very unstable flow over N Sea prevents it making to east coast. Such a tease ...

I think it’s made it

[chionomaniac]

Jeez

 

I think I have just witnessed a 'THAT GFS' moment. Blimey

[BLAST FROM THE PAST]

 

East Anglia, SE, East Coast....cut off communities....stay home message not needed

 

BFTP

[ALL ABOARD]

Just now, BLAST FROM THE PAST said:

 

East Anglia, SE, East Coast....cut off communities....stay home message not needed

 

BFTP

Also the run isn't finished.. 

Renewed amplification into Greenland, low pressure dropping from the North. 

Extension of cold locked in. 

[Methuselah]

That should put Aslan back to sleep!       

 

[SqueakheartLW]

6 minutes ago, Nick F said:

COBRA run in FI - T+300 T850 -15C line a stones throw over the N Sea, but surface low developing in the very unstable flow over N Sea prevents it making to east coast. Such a tease ...

On the other hand a surface low in those uppers could be a snow making machine

[nick sussex]

Not bad ! Could be better ! Seriously though this evolution is what you want to see as any cold pool needs topping up.

The key thing here is to get the shortwave which comes down from the north to be a shallow affair , so it comes south and then edges slightly sw towards the end .

You need the block to the nw to be trapped and stopped from edging west , in these situations it’s better to have a miss a bit further east with that shortwave as long as it you get that edging sw at the end . 

We don’t want the shortwave moving south any further west .

[winterof79]

56 minutes ago, MJB said:

And for Sunday 

Have to say on behalf of all Northerners, sincere apologies for our cold air pushing a little too far south. 

Having said that it's in response to the numerous occasions in the past  you lot have pushed your mild air too far North and kiboshed everything up here. 

Seriously though, its looking rather eventful for many many people.