Model Output Discussion. 3/12/2022. How cold will it get?

[Mark wheeler]

3 minutes ago, CreweCold said:

And that is how an ensemble suite can flip in one run.

Ha , as stated earlier eh . Thanks for you're continued input , so much appreciated. 

[Brassmonkeylily]

Well the GFS18Z  now develops a trough  feature over SE England  for this Sunday morning ..and its snow!..howzatt !

[Singularity]

All I really have to say about the 18Z GFS is that what it does between days 9 & 11 is about the best demonstration I’ve ever seen of the model being too zonally progressive in trough disruption situations.

[cold snap]

4 minutes ago, Brassmonkeylily said:

Well the GFS18Z  now develops a trough  feature over SE England  for this Sunday morning ..and its snow!..howzatt !

I'm not being pro cold because I've checked the ens .

Sorry to say I wouldn't believe a word of that run in any shape or form. 

It's wrong  .

[cold snap]

Runs need ens support . Heat or cold 

If it's against its suite it's mostly wrong.

If by chance 0z drops the same and there is backing  I will believe it. 

Weather needs support and that has little.

Chance it happening 15 percent for now. 

[Eagle Eye]

I'm just finding it fun watching the Hurricane models try and make sense of invest - 99L. Marvelling at the feat's we've made to understand Hurricanes but also how far we've got to go to truly understand.

HRWF 

HMON

This post isn't really meant to evaluate everything just proving that one of the pinnacles of physical modelling still has far to go to stop 'minor mistakes' and we all have seen that minor differences make big differences down the line.

[minus10]

Even by the 16th the majority of ens still below minus 5 850s..

 

[Mark wheeler]

14 minutes ago, Brassmonkeylily said:

Well the GFS18Z  now develops a trough  feature over SE England  for this Sunday morning ..and its snow!..howzatt !

What a shame it's the GFS doing it . Happy to have egg on face .

But hey , small features are bound to turn up . Lets hope this is one of them.

Edited December 7, 2022 by Mark wheeler

[damianslaw]

1 hour ago, chionomaniac said:

You couldn’t make this up. Everylow pressure in winter in the history of mankind moves towards the east. Except when we want it to undercut, then it stagnates and moves northwestwards!

At least the end result will be just as good

Has this not been the theme of 2022 by and large with exceptions in February and mid Oct through November, low pressure seemingly cut off to our SW and held at bay by high pressure blocks - the persistance of such a pattern quite remarkable, hence the very lengthy dry periods we have seen this year, we are in yet another one now..

[Frigid]

This time yesterday, there were many ens going for mild around the 14th.. today they've all disappeared. What a turn around 

[Met4Cast]

The trouble maker of a low is now fully formed out in the Atlantic and I suspect that's why we've seen a sudden convergence on modelling re it's track today. It's generally easier for modelling to predict a system that actually exists vs not only predicting a hypothetical system but then having to try and plot it's track on top of that.

Also of note is the cold front sinking south across northern Britain heralding the start of our cold spell properly.

[ICE COLD]

The control is belter 

[chionomaniac]

33 minutes ago, CreweCold said:

And that is how an ensemble suite can flip in one run.

Sure is. And that’s why it’s important to look at the bigger picture at all times. I’m liking this positive CC lol

there are those that have the faith looking at the background factors and those that react run by run. Always stick to the background signals when looking at inter run variability. This will act as a good guide. Still could change but now we see ensembles in line with background signals. Hence westerly momentum is stagnated

Edited December 7, 2022 by chionomaniac

[alexisj9]

2 hours ago, STRiZZY said:

99L is clearly extratropical
1. Front
2. Broad wide field
3. Little to no convection near the center

I am starting to believe that this doesn't have more then a 20% of being named.

well that's one headache out of the way. so the low is likely to be mature and have less energy when it gets here. probably why models have been moving it south. if it did develop. or still does, that puts more energy in the low and that's where the north runing lows came from. it worth keeping an eye on this invest, and hope the extratropical look continues.

[goosey007]

33 minutes ago, CreweCold said:

And that is how an ensemble suite can flip in one run.

See it fairly regular CC although I must admit its usually cold to mild 

[BlueHedgehog074]

1 hour ago, Portlander said:

1st post, long time reader over many years. Usually in the storm watching threads. Hi

Question… can anyone show me what a regular early winter chart looks like compared to the Synoptics that are around at the moment?

How far away are the blues and purples usually?

Hi Portlander, have used examples of charts on 7th December using a 10 year sample from 2005 to 2015:

You’ll notice there can be variation to the pattern from year to year. However, I think overall would say a typical early Winter chart is one where we get a flow off the Atlantic in general, which most charts above show in some from - usually between the South and West. Flow from the North-West can be fairly common too. The purples (from the Polar Vortex - low upper heights), tending to occupy us close by to our North and North-West around the Greenland area, especially towards Northern Canada. Along with this, Low Pressure systems on average take a South-West to North-East or West to East track through the North-West and North of the UK as they swirl around the upper low heights to our North-West/North.

This might not be the most accurate answer, mind, despite the amount of years experiencing Winters in the UK. (Some with more experience would probably be able to give a better answer), but hope it was of some help.  

Edit: Sorry, should have added welcome to Netweather  

Edited December 7, 2022 by DiagonalRedLine

[Mark wheeler]

18 minutes ago, Frigid said:

This time yesterday, there were many ens going for mild around the 14th.. today they've all disappeared. What a turn around 

Makes a change eh , you waiting up for the Mighty Mighty Navgem? . Comes out at 12.45am

This was the the 12z , hopefully we can get an improvement. it was going under though. 
 

My take is all roads at the moment lead to cold . yayyyyyyy

Edited December 7, 2022 by Mark wheeler

[Snowman.]

9 minutes ago, ICE COLD said:

The control is belter 

Some absolute filth in the GEFS. Some them need a 18+ rating.

It's likely all to be different tomorrow, but its been a good day in regards to keeping cold for a much longer period of time.

[damianslaw]

If you like cold dry sunny weather you will be very happy with how today's models have trended, such conditions look set in for at least the next 7 days, with much of the UK locked in uppers sub -5 degrees, meaning harsh frosts which will be slow to clear and daytime temps in the range of 0-4 degrees for most, in places struggling to get much above freezing for the best part of the day. That is a very cold outlook in any book and quite unusual for this early stage in the winter season but not unprecedented.

The weekend may bring an added risk of freezing fog which would be very slow to clear, not seen much of that in recent years.

Those wanting snow may be more dissapointed, some places more so N Scotland and coastal parts in the west and east may see a light covering, but otherwise at least in the next few days, need to rely on any trough features, which will probably only give a light cover at best as the airflow is very slack and very stable generally.

Into next week things could become more interesting on the snowfall front especially further east as we pull in more of an easterly flow, and colder uppers, could see better convection than the last easterly, much colder source this time around.

In the meantime, enjoy the frost, sunshine and dry weather. 

[Delka]

hope i don’t get a telling off for off topic posting but just had to say a little thankyou for all the knowledgable posts and updates on here, currently on my 3rd night staying with my grandad who’s on end of life care in the hospital and this threads been a big play in getting me by, obviously aided by what could be incoming

so yeah, thankyou! 

Edited December 7, 2022 by Delka

[Dancerwithwings]

Atm the GFS mean for Thursday week is still good 

the Jet stream is well on it’s holidays still…South of the UK

the cold is still over us

and we are still awaiting a Westerly flow

so right now nothing is a given

 

 

Edited December 8, 2022 by Dancerwithwings

[Derecho]

A few runs bring the Greenland High back into play with P9 properly cold. A bitter northerly develops in the middle of next week.

Cold extreme? Yes but I think a lot of ens members here show either a Scandi High or Greenland High keeping as cold in various ways. What a turnaround from yesterdays jitters. More confidence on the development of 99L has cleared things up today, to the benefit of those with a cold persuasion for once.

[BlueHedgehog074]

40 minutes ago, Mark wheeler said:

This was the the 12z , hopefully we can get an improvement. it was going under though. 
 

My take is all roads at the moment lead to cold . yayyyyyyy

Good ol’ NAVGEM trying to get the Low under. Has a South-Easterly track to it.

Apart from the way the GFS is trying to make things as complicated as figuring out a way out of a massive maze with the handling of the Azores/Atlantic low pressures next week, the favourite scenario today is to try to get the low pressure to push through to our South. At least it not causing much issues for putting a stop to the cold weather. Will likely take a few more runs or so to know for sure, but things have looked good today for these wanting longer lasting chilly conditions.
 

25 minutes ago, Delka said:

hope i don’t get a telling off for off topic posting but just had to say a little thankyou for all the knowledgable posts and updates on here, currently on my 3rd night staying with my grandad who’s on end of life care in the hospital and this threads been a big play in getting me by, obviously aided by what could be incoming

so yeah, thankyou! 

I’m afraid I’m gonna have to delete this post…

But in all seriousness, sorry to hear about what your Grandad’s going through. Some difficult times for some on here at the moment it seems. What ever happens, it’ll be all okay (even though I understand it will be tough for a while). Am glad the thread’s been of help to you and provides you with comfort - we’re always here for support

Edited December 8, 2022 by DiagonalRedLine

[DJ Fart]

Well, if nothing else, everyone's favourite adage will be getting a proper test over the next couple of weeks! Plenty of cold getting locked in! My concern is that any snow at all just keeps staying tantalisingly out of range of the reliable. 

[Mark wheeler]

Navgem 18z 

says

ok 

Cold it is .