Model Output Discussion - Into Winter

[nick sussex]

The ECM looks like it’s going to split the shortwave energy over the eastern seaboard day 5 into 6 and so can’t evolve like the GFS .

Whether that adds up to a more wintry scenario we’ll know very soon .

[TillyS]

42 minutes ago, lassie23 said:

i can't get excited about anything coming from the West or NW, that usually transfers as 7c and sleety rain in London at best

Am inclined to agree. They often promise much but seldom deliver, even for the NW of the country except over highest ground although some wet snow showers can come in on a brisk cold wind even to lower levels on north facing coasts.

There’s just too much fetch across the (warm) seas so that even if the -5 hPa dam crosses the country the results are weak for snow on the ground, especially inland and further south.

At the moment, and this may change, we’re seeing a classic example of how the GFS 19 times out of 20 wildly exaggerates these northerlies, only to downgrade them on subsequent runs. Not its finest hour.

We need northerly blocking and / or greater amplification with a mid-Atlantic block. 

 

 

[February1978]

From the Meteograms, it looks ECM is a cold outlier....but it is ice cold in Scotland at the end

[johncam]

1 hour ago, Derecho said:

From the model output I can foresee three possible scenarios

1) We get a northerly and a wedge towards the Greenland area that helps sustains a colder pattern - can't see this happening. Looking at the previous round of GFS ens this is the closest I can find.

2) We don't get northern blocking but high pressure avoids Europe for a little while allowing for alternating periods of chilly and mild up to christmas or just after christmas. Potentially a stormy pattern and at least holds some interest as the cold shots will be sharper and pushing further south.

3) High pressure leeches into Europe and as a result mild air wins the battle in the south with fleeting chilly and mild spells in the north. This is the scenario we don't want but it could happen. Time and time again in recent years (and the cold spell at the start of the month) pressure has somehow found a way to increase over Spain or central Europe to end our cold spells early. SLP trends over time have shown that pressure has increased over the continent as our climate warms.

I often therefore sit on the fence when committing to a cold spell unless I can be sure heights over Europe won't be an issue.

It'll be difficult to see some decent cold for the rest of December if the outcome of this pre-festive period is a poor one so hopefully we can get 1) or 2) but prepare for 3).... Sorry to be a scrooge but the output isn't very exciting at the moment from my perspective though the situation can change.

 

So another mild Dec on the cards then 

[Day 10]

This looks like it could be better.

[Kasim Awan]

ECM joins GEM/JMA/UKMO which in my opinion is the significantly more favoured solution given earlier support on GFS - such as was the case during the last cold spell when the GFS switched to less amplification coinciding with the euro models trending cold.

Edited December 14, 2023 by Kasim Awan

[booferking]

Jma wow please be right.

[mountain shadow]

2 minutes ago, booferking said:

Jma wow please be right.

I hope your £150 isn't resting on the JMA!

[January Snowstorm]

All jokes aside the JMA is very cold and wintry!!

[Day 10]

A rash of wintry showers, the usual.... the higher up the better etc.

[Kasim Awan]

ECM with a one day toppler & snow accumulation restricted to 300m+.

[January Snowstorm]

BUST!!

 

[Lukesluckybunch]

Well that was great from the ECM...for one day!

[booferking]

Ec short lived cold blast at best 1 half day at best all eggs in 1 basket the JMA basket

We may wait another 13 years for white christmas at this rate.

Edited December 14, 2023 by booferking

[weathercold]

With no northern blocking on show any cold can’t be sustained, the jet stream is too powerful.

i think it’s time to move on from Xmas and look beyond into the new year.

Hopefully Jan can show its wintry hand and we’re not chasing down that ticking clock to spring. 

Edited December 14, 2023 by weathercold

[Kasim Awan]

4 minutes ago, booferking said:

Ec short lived cold blast at best 1 half day at best and eggs in 1 basket the JMA basket

We may wait another 13 years for white christmas at this rate.

Starting to feel the same, can we even get cold/snow within Meteorological Winter? Maybe it should be rephrased "True Autumn" with November and March being called "The Winter Months"?

[Sweatyman]

So as usual it all gets watered down to bugger all. Great

[weathercold]

Just now, Sweatyman said:

So as usual it all gets watered down to bugger all. Great

It was hardly much to begin with, it was desperate scraps if we’re being honest

[Kasim Awan]

The ECM12Z does look to have somewhat of a Bartlett in place.

[mountain shadow]

3 minutes ago, Sweatyman said:

So as usual it all gets watered down to bugger all. Great

Not even bugger all, it's worse. Polar North Westerlies replaced by mild South Westerlies.

Horrendous ECM.

[BartyHater]

ECM is absolutely kack overall…24-36hrs of rather cold/cold, followed by what will be a mild, wet Xmas Day IF the 240 were to verify.

Let’s hope it’s a raging mild outlier.

[mountain shadow]

1 minute ago, Kasim Awan said:

The ECM12Z does look to have somewhat of a Bartlett in place.

Incorrect. This is just a ridge from the Azores High.

A Bartlett is an area of HP extending across the Atlantic and needs to last weeks.

The MJO is moving into favourable sectors which will support ringing towards Greenland,  even if the are temporary. 

[johncam]

So is the one day cold blip outlr final third Dec cold 

[Rob 79812010]

35 minutes ago, johncam said:

So another mild Dec on the cards then 

Cold spells are rarely long in my experience. I'd say that pretty normal other than a few exceptional winters. Certainly in my 60 years anything 7 days plus is pretty good really. Not saying we haven't had sustained periods of cold but they are few and far between and in my part of the world always were

[johncam]

Just now, mountain shadow said:

Incorrect. This is just a ridge from the Azores High.

A Bartlett is an area of HP extending across the Atlantic and needs to last weeks.

The MJO is moving into favourable sectors which will support ringing towards Greenland,  even if the are temporary. 

When is it gonna show though