Model output discussion - after the beast, what next?

[Frosty.]

The Gfs 12z shows a much colder spell on the way from the end of the week ahead and it would feel bitter in the Ely / SEly winds but out of the wind and in the strengthening mid march sunshine it would feel pleasant enough, it looks like it would be quite a dry cold spell with plenty of sunshine and a few wintry showers, even some snow across the s / se so it would be a huge change from the very mild weather of recent days.

Edited March 11, 2018 by Frosty.

[Derecho]

Better.... though still a rather difficult job to allign the path of the cold pool directly to the UK, it seems the cold prospects are back on despite a surprisingly big wobble from the 06z's

[Mike Poole]

Had to laugh just now.  Here was I perusing the 12z GEFS - here's the ensemble mean at T240 by the way, showing signs of the possible easterly:

And the lights briefly went off and there was a massive clap of thunder!  In March! That's unusual in Oxfordshire. I think we should look out of the window for the weather a bit more maybe!

Edited March 11, 2018 by Mike Poole

[nick sussex]

The models do seem to be making a lot of drama over the early stages with reliability in recent days falling off a cliff .

Its a shame they’re reluctant to disrupt more energy se after T96 hrs.

 

[Summer Sun]

12z London ens shows the op is on the cold side of both the mean and control between the 18th and 25th

Towards the very end the control and op then go on the warm side of the mean

 

[Matthew.]

Just 2 weeks till British summertime begins let’s hope the ECM has something like this

[Eastnorthwest]

2 hours ago, Daniel* said:

Oh dear...

The rather epic cold spell just gone there were times when ensembles had cold feet, nearer on some well most went cold some sizeable number went mild, after seemingly all we’re interested in cold easterly and then they went back to it. Best to follow the operational I’d say. From what I’ve seen today no real change evident, ECM op was quite frankly off on one let’s see what 12z does. BBC Weather are being quite bullish which is unusual of them, with a cold easterly flow setting in next weekend. 

Just seen the latest AO and an upgrade on yesterday for all red lines staying negative till end of the month, keep that theme in the coming days and the main models will favour another block to the north, I am pleased tonight 

[Eastnorthwest]

11 minutes ago, Matthew. said:

Just 2 weeks till British summertime begins let’s hope the ECM has something like this

If not tonight, hopefully tomorrow 

[SMU]

Tonights ECM 96 shows the advection heading just east of Iceland now & deep cold heading SSW-

A possible upgrade if your still considering cold...

 

[chris55]

UKMO 144 poised to bring in some remarkably cold air for the time of year .

Quite a chart really!

 

 

[chris55]

Yes Steve ECM looking loaded at t96, very similar to UKMO at the same time period, will be interesting to see where it ends up.

120 and the high is well positioned!

Edited March 11, 2018 by chris55

[feb1991blizzard]

4 minutes ago, chris55 said:

UKMO 144 poised to bring in some remarkably cold air for the time of year .

Quite a chart really!

 

 

ECM 120 trumps it!!!

[nick sussex]

Nice ECM T120hrs .

Crucial now to clear that shortwave energy away from near Iceland to allow pressure to rise nw there.

 

[chris55]

High being squeezed from the north and south, cold air heading west!

Thats some mega cold pool for March!!

Edited March 11, 2018 by chris55

[Mike Poole]

So ICON, GFS and UKMO all paint a colder picture this afternoon, common theme that we need the High to be more northerly to really get another memorable cold blast before Spring takes hold.  ECM therefore definitely of interest, here at T168:

My thoughts are that the models still have some way to go to get this right, and taking into account the strat - we need to watch the models in conjunction with events in the stratosphere - in my view a final colder spell is possible from the East that will impact the South most significantly, from around a week Monday (19th).  To clarify re the strat, 10mb, 60N wind reversal shown again at 20/3/18, a formal SSW unless it becomes the final warming that heralds the summer:

Edited March 11, 2018 by Mike Poole

[chris55]

168, main thrust of instability/cold to the south, but with some very cold air engulfing the UK

 

Edited March 11, 2018 by chris55

[nick sussex]

The PV lobe is the issue here, a delay in that heading se would help direct the colder air into the UK.

This means less pressure on the high, regardless a better trend in the earlier timeframe from the ECM.

 

[feb1991blizzard]

1 minute ago, nick sussex said:

The PV lobe is the issue here, a delay in that heading se would help direct the colder air into the UK.

This means less pressure on the high, regardless a better trend in the earlier timeframe from the ECM.

 

Yes, I take it you mean the bit that's around Svalbard at 144, it puts too much forcing on only a smallish Scandi high, meaning all the frigid air is heading for you rather than us.

[Singularity]

 

Even without optimal orientation of the high, this is quite something for mid-March.

Ridiculously large swing from the preceding few runs, making for tragic levels of confidence with respect to conditions next weekend; temperatures could be +double digits or just a few above freezing!

[nick sussex]

5 minutes ago, Singularity said:

 

Even without optimal orientation of the high, this is quite something for mid-March.

Ridiculously large swing from the preceding few runs, making for tragic levels of confidence with respect to conditions next weekend; temperatures could be +double digits or just a few above freezing!

That cold pool for this late into March is exceptional.

What a bizarre month this could turn out to be , a bitter cold start , a milder  ten days then very cold and then if the next PV lobe to the ne could be directed sw more fun and games !

Edited March 11, 2018 by nick sussex

[ICE COLD]

5 minutes ago, feb1991blizzard said:

Yes, I take it you mean the bit that's around Svalbard at 144, it puts too much forcing on only a smallish Scandi high, meaning all the frigid air is heading for you rather than us.

The good news is tho plenty of time for it to correct further north as it's at days 6/7 . Hopefully we can get a direct hit and it prolongs for longer . 

Pretty impressive this tho for March . 

[Chesil View]

Ecm certainly setting things up nicely within the reliable timeframe. Beyond 144 is speculation at the moment.

[ICE COLD]

1 minute ago, Broadmayne blizzard said:

Ecm certainly setting things up nicely within the reliable timeframe. Beyond 144 is speculation at the moment.

Yep good until 144 . Didn't the models have it going into France on the last easterly for a good few runs and then in corrected north ?? 

[feb1991blizzard]

Just now, ICE COLD said:

The good news is tho plenty of time for it to correct further north as it's at days 6/7 . Hopefully we can get a direct hit and it prolongs for longer . 

Pretty impressive this tho for March . 

Yes - personally I just think we will fail but plenty of options on the table down the line from the North / North East, either way I just hope this dispels the myth that you cant get severe cold very late in season, you can - its just that in any given random year without knowing any teleconnections to know how the dice are loaded, it might be a 50-1 shot in late March as opposed to a 10-1 shot in mid February but it CAN happen.

[chris55]

We look to be firming up on the initial interaction between the disrupting Atlantic system, WAA  and the developing Scandi high. Day 4 from both UKMO and ECM show this.

How things progress from this point will no doubt change in the coming runs, but one things for sure and that is we are certainly in the hunt for another marked cold spell, even though it is mid March!