Model output discussion - into the start of Winter

[ItNeverSnowsInWindsor]

Some interesting synoptics are emerging in the run up to December which after a mild November could offer potentially wintry conditions not seen in the past 7 winters.

 

Options showing up include Easterlies and Northerlies but time will tell which one will emerge.

[ItNeverSnowsInWindsor]

Need a few more members testing the -10c line

 

[Zak M]

GFS control run is very similar to the GFS op - which one do you think is more drunk?

   

Also checked the ECM 500hpa anomalies. High pressure near Greenland and Scandi with low pressure wedged between them most of the time is a good thing if it's cold you're looking for - and that's exactly what the charts below show:

ECMWF Forecasts

WWW.ECMWF.INT

I remember checking these back in mid-November when it showed a chart similar to the two charts posted above for the first week of December, so these are performing quite well at the moment.

I think it's pretty much guaranteed that next week will be colder than average, with plenty of frosty and foggy mornings on offer, and some snow to higher ground. I still remain positive for December and January in terms of snow... I'll be very surprised if we don't get at least one day of widespread cold and snow this winter as we are heavily overdue!

Saw this on Twitter a few hours ago - BBC Weather going for a couple of days of snow over Princetown (Dartmoor) with maxes at only 3-4c on one day - bare in mind that the BBC use a mixture of the GFS and ECM:

   

But, you should also bare in mind that the BBC always over-eggs whatever symbols it's showing. This was from early August this year - I'm still waiting for my 72 hours of constant lightning.

So, I said, there's a chance of some colder weather next week, with some snow likely over higher ground in the south, and potentially to lower levels in the north.

Edited November 28, 2020 by Zak M

[Scott Ingham]

7 hours ago, northwestsnow said:

Day 9...

Wedges beginning to appear ??

As mentioned yesterday longer term its that power house Russian Hp setting us up for further into winter. Also snow chances from this initial surge of cold air have always been knife edge. Its how much in situ cold we can build as troughs engage with this. 50/50 for initial cold. Still believe middle to end of January into Feb for the real deal

[Scott Ingham]

7 hours ago, Mike Poole said:

Looks like a direct hit from the north on the JMA T192:

Good 12z output today, confirms the view we are in the game, and probably will be for a few weeks if the strat and trop vortexes stay disconnected, actually getting more so on the NAM plot, based on todays GFS 0z:

Thereafter, the scene seems to be set for a possible SSW with the Aleutian low, Russian high combo, a significant precursor, so recurring in the output, illustrated on the ECM T240 chart:

With the start of winter only 4 days away, coldies could hardly have more irons in the fire, so to speak...

 

Im 100% on the same page. Early to mid December snow surprises with no deep cold. Settling down late decemeber with high pressure. Unsettled early Jan. Main meal late jan

Edited November 28, 2020 by Scott Ingham

[Scott Ingham]

7 hours ago, northwestsnow said:

Agreed Mike...

There has been an abundance of blocking to the NE this November...

Could we see a SSW later in December??

I referenced this block earlier, at 1050mb its a monster ...

Last week in December a real chance of one for me as the tropics continue to give against what is expected in a strong nina

[Scott Ingham]

4 hours ago, Steve Murr said:

Rain approaching from the SW will soon turn to snow when it hits air with -10c dewpoints !

There is the snow surprise i spoke about yesterday. Cold stagnant air being hit from the south or northwest

[Cheshire Freeze]

ICON blows up a potential snow storm out at day 6- uppers are around -5

[Snowman.]

22 minutes ago, CreweCold said:

ICON blows up a potential snow storm out at day 6- uppers are around -5

Remnant heights around GL as well. As far as all things go this is looking to be a cracking start to winter. 
 

Also first post this year woohoo! 

[Snow lover 2020]

34 minutes ago, CreweCold said:

ICON blows up a potential snow storm out at day 6- uppers are around -5

Is icon reliable? 

[Cheshire Freeze]

45 minutes ago, Snow lover 2020 said:

Is icon reliable? 

Not particularly, but FWIW it looks closer to UKMO than the GFS

[northwestsnow]

Looking good if you live on a big hill next week...I'm thinking Pendle Hill in the North West at 500m asl as an example...

GFS produces a very cold run this morning with lots of frosty weather on offer .

UKMO looks OK upstream just a little concerned its going to drag its feet with the troughing dropping from the North ...need the energy going south !

[Griff]

What's occurring in the almost reliable? Just waiting on the ECM. 

At a punt I'd say it will follow UKMO and ICON. 

[northwestsnow]

EC looks identical to GFS at 96...

[Griff]

5 minutes ago, northwestsnow said:

EC looks identical to GFS at 96...

GFS  ecm and ukmo at 120

[northwestsnow]

Hoping EC isn't going to blow up lows over the UK...

[SMU]

Another lovely overnight GFS & Mean - thats 2 full runs 18z & 00z with no zonality -.

UKMO a bit heavy on the low pressure.

ECM we just need to clear the low east a bit quicker

[northwestsnow]

Day 8 looks OK to me....

Is that block to the NE going to become a player in December?

Edited November 28, 2020 by northwestsnow

[northwestsnow]

Day 9 so academic but this is not a normal December set up..

Edited November 28, 2020 by northwestsnow

[Gowon]

ICON, please be right

[Snow lover 2020]

32 minutes ago, Griff said:

GFS  ecm and ukmo at 120

 

Edited November 28, 2020 by Snow lover 2020

[SMU]

3 minutes ago, D.V.R said:

ICON, please be right

Ha - More chance of winning euro millions.

I will take the GFS again today. ECM nice but not quite as nice

Still no atlantic past 192 - counting day 2 ...

[That ECM]

Gfs & ECM now and what was showing for now. 

[jules216]

Well there you go. Weeks ago I was mentioning the high pressure in Eastern Europe/East Scandi and Western Russia that just wont go away if anything it just strenghtens because of that possibly cut of low around Ireland.Good luck trying to find any cold source to tap in to in extended modeling.

[Mr Frost]

Morning all!

Getting slightly excited now! 

Latest UKV chart snapshots below for Thursday at 0:00 

OC Isotherm (m)

 

Dewpoint Temperature (c)

 

850HPA Temp

528 dam line digging South - much lower for NW/N Scotland.

 

Precipitation Type:

 

That is what I call a proper start to Winter - showers get going late Wednesday afternoon.

Snowfall down to very low levels in parts of Scotland, risk of wintry (maybe even snow) showers for other areas such as NW/N England, Northern Ireland, Ireland and Wales (hopefully all the other areas would get something later on) - could see plenty of snowfall over higher hills/mountains throughout the UK and Ireland.
Bit of instability as well with this flow - thunder/lightning/graupel risk.  

All the above subject to change at this range but worth keeping an eye on - especially with the UKMO 120/144 charts this morning. 

UKMO 120:

 

UKMO 144:

 

Lovely stuff for December if this becomes reality! 

Have a good weekend everyone - all the best! 

Edited November 28, 2020 by Mr Frost