The hunt for cold - Model discussion (late November)

[Mike Poole]

I would say that the ensemble mean chart from ECM at T144 is supportive of the increased strength of the block, with a considerable number of members sending energy SE:

[feb1991blizzard]

The mean just has it blasting through.

[Summer Sun]

UKMO extended is out would be interesting to see what the 850's are with that precipitation over the UK

[northwestsnow]

2 minutes ago, feb1991blizzard said:

The mean just has it blasting through.

Of course.. the Atlantic is coming.. the angle of attack is of interest ..

[Frosty.]

Looking at the Ecm 12z it's a Mexican standoff between the Scandinavian block and the atlantic, I see lots of potential for trough disruption and some rather cold air in the mix so a chance of some wintry precipitation but especially with elevation...fascinating watching this unfold and to think there's several months of wintry potential for coldies to look forward to!..it's only just begun!!

[feb1991blizzard]

Just now, northwestsnow said:

Of course.. the Atlantic is coming.. the angle of attack is of interest ..

Yes, i just hope for a snow event.

[northwestsnow]

Just now, feb1991blizzard said:

Yes, i just hope for a snow event.

Me too Feb

[Stuie]

2 minutes ago, northwestsnow said:

Of course.. the Atlantic is coming.. the angle of attack is of interest ..

If only it was N/S and not NW/SE...

Edited December 7, 2018 by Stuie W

[northwestsnow]

3 minutes ago, Summer Sun said:

UKMO extended is out would be interesting to see what the 850's are with that precipitation over the UK

Hmmmm  the second beast of a low i mentioned earlier looks the killer unfortunately..

 

[Mike Poole]

5 minutes ago, northwestsnow said:

Of course.. the Atlantic is coming.. the angle of attack is of interest ..

Yes, it is mean chart of 51 runs, until we see the clusters, we need to imagine what it might be the mean of, and the angle is significant.  On average we would expect the Atlantic to win?

Edited December 7, 2018 by Mike Poole

[northwestsnow]

Hard to see as im at work and being a bit naughty but EC mean looks better than the 00z mean..

 

[Stuie]

7 minutes ago, feb1991blizzard said:

Yes, i just hope for a snow event.

Well, after the ECM you could say the clear winner was returned with a hotdog return to save the point... (not sure why I used a tennis analogy)

[BlueHedgehog074]

ECMWF in a Christmassy mood tonight! 

Nice surprise to see the Scandinavian block next week putting up more of a battle against the big, bad, Atlantic. More pressure put on the Lows trying to reach the U.K from the West.

The Atlantic does still sorta win the boxing match (and to be honest, still think the block will lose some of its power, for now). However, the Lows struggle to penetrate far enough East through the U.K, with some of the Low Pressure disrupting and dropping to our South-East into mainland Europe.

Even if the cold weather fans have to endure another spell of Atlantic weather, hopefully no chance of this happening soon:

But this would do: 

Edited December 7, 2018 by DiagonalRedLine

[ItNeverSnowsInWindsor]

41 minutes ago, Winter Hill said:

@northwestsnow

got to love living in the North West looking at that chart eh 

Or the South

[Seasonality]

Been busy doing other stuff. Come back and check ECM and find this. Lovely run. The cold air just comes in and stays until day 10 for Central Europe. 

Edited December 7, 2018 by Seasonality

[Methuselah]

When we start hearing rumours of a mysterious Cornishman buying-up all the red crayons, in all the village shops, will be when we need to start worrying?

In the mean time, the week between Xmas and New year looks like a good bet...

[Singularity]

The models are currently very keen to take the atmospheric state into a temporary Nina-like condition next week with a broad N. Atlantic trough and rising heights through Europe being the general response. However, with the El Nino event now well connected to the atmosphere this isn't likely to take place in reality, and while the models continue to insist otherwise in the longer-term - just look at ECM days 9-10 and how awkwardly it suddenly changes track - there comes a point at which the reality of observation data forces them to make adjustments toward lower Euro heights and a less broad, more disrupted N. Atlantic trough.

I still feel that it's going to be a big ask to get the overall battleground line wholly west of the UK, but I'm less resigned to it staying just out of reach to the east next week as I was this morning; the fight back by the blocking highs during the second half might have enough to it after all (to produce at least one appreciably-sized snow event in the UK... somewhere! Eastern parts having the better chance as things currently look).

Regardless, there remains good teleconnection support for that blocking high to make a move toward Greenland (but at how high a latitude, it's unclear) by early the following week but at the moment, the models are still turning things too Nina-like for that to be depicted properly (this being why you see some runs going with mid-Atlantic ridges instead; these are the most Nina-like). A really interesting question going forward is then whether that stage of high-latitude blocking sticks around long enough to merge with the impacts of a major SSW... presuming that does occur. I expect that'll be the main deciding factor in what manner of weather we experience during the festive week this year. Seeing a very wide range of possibilities for that one!

[bluearmy]

Days 5 to 7 - spread is to the south 

 

Edited December 7, 2018 by bluearmy

[Duane S.]

8 minutes ago, northwestsnow said:

Hard to see as im at work and being a bit naughty but EC mean looks better than the 00z mean..

 

Comparing with 06/12 12z mean, it is a slight improvement. Clusters will show more obviously

.

A subtle 'blink and you'll miss it' new appetite for a very small height rise over central Greenland emerging from across the 12z suite as well at around D7 as energy separates better. This has probably helped steer the slight pattern improvement.

May fill in by the 18z / 00z or may expand further, who knows!

 

[Methuselah]

12 minutes ago, Singularity said:

The models are currently very keen to take the atmospheric state into a temporary Nina-like condition next week with a broad N. Atlantic trough and rising heights through Europe being the general response. However, with the El Nino event now well connected to the atmosphere this isn't likely to take place in reality, and while the models continue to insist otherwise in the longer-term - just look at ECM days 9-10 and how awkwardly it suddenly changes track - there comes a point at which the reality of observation data forces them to make adjustments toward lower Euro heights and a less broad, more disrupted N. Atlantic trough.

I still feel that it's going to be a big ask to get the overall battleground line wholly west of the UK, but I'm less resigned to it staying just out of reach to the east next week as I was this morning; the fight back by the blocking highs during the second half might have enough to it after all (to produce at least one appreciably-sized snow event in the UK... somewhere! Eastern parts having the better chance as things currently look).

Regardless, there remains good teleconnection support for that blocking high to make a move toward Greenland (but at how high a latitude, it's unclear) by early the following week but at the moment, the models are still turning things too Nina-like for that to be depicted properly (this being why you see some runs going with mid-Atlantic ridges instead; these are the most Nina-like). A really interesting question going forward is then whether that stage of high-latitude blocking sticks around long enough to merge with the impacts of a major SSW... presuming that does occur. I expect that'll be the main deciding factor in what manner of weather we experience during the festive week this year. Seeing a very wide range of possibilities for that one!

A fascinating read, as always, S...But I feel I must ask a simple question: how can the models 'know' when to produce a Nino-like atmospheric pattern? Or is this a simple coincidence?

Or ought I just keep taking the s!

[ANYWEATHER]

Evening All!! Next week battle ? Will it happen, Perhaps it will , perhaps it wont, perhaps stuck in the middle with you..! The age old battle continues , its very early winter, but with these Synoptics  expect anything....very interesting!

[Man With Beard]

Well this is turning into a real nail-biter (for you up north, not expecting anything for myself   ). When it's on a knife-edge like this, expect to be in the "snow-zone" on one run, then out of it the next run ... but that won't tell you the outcome just yet!!

Anyway, onto another interest of mine, the potential for height rises in the Atlantic around 18th December. You can see something starting if you look south of Greenland on this chart (17th Dec)

Will it turn into a more significant rise and potential northerly for the UK? Or will the jet ride over the top? Or will the signal just disappear altogether (it's been there 5 days and still going, so not expecting that really).

Plenty of time to go before this one gets firmed up.

[Methuselah]

Here's the 12Z GEFS ensemble: 

Nae much help, is it?

[shaky]

Just now, Ed Stone said:

Here's the 12Z GEFS ensemble: 

Nae much help, is it?

Take a look at those blue straddlers goin for the -10 mark!!imagine if the 18z goes for one of those this thread will be buzzing!!

[Mike Poole]

The trend continues it seems! Block stronger on the ICON 18z, only goes out to T120, but here it's further west than on the 12z, here 18z first then 12z at same time