Model output discussion - into the start of Winter

[Met4Cast]

Well then.. for a "cold spell" without much cold, there's certainly a lot of potential for Friday. Pinning down that lows track though is going to be an absolute bottom ache, every single model has the low & snow risk over a different area. Hopefully we can nail down the details in the coming days.

The EC46 offers a very blocked picture for December with low heights over Europe, that'd be fantastic!

[kold weather]

We are certainly moving closer to a very interesting set-up now, both short term and long term.

Short term prospects for snow continue to improve, it is mega marginal so any altitude and time of day will make a big difference to any snow chances. Given the LP has dropped further south it has relaly increased the chances. Remember if your on the left side when its moving north and right side when coming back south that will be the zone where the snow action will be. At the moment a little too early to zero on where that might be and could still easily downgrade again, but at the moment looking interesting for an early season marginal event.

Longer term is also still looking interesting, blocking very much theme of the day, even if we do get a small spell of flatter weather near the mid month. I'm feeling increasingly confident that the week before Xmas will give a decent cold shot, its just from what direction it comes from. The one thing that is obvious now is we are staying away from mild for the time being and a below average month looking increasingly possible, even probable.

@BLAST FROM THE PAST we are moving closer to that superb outlook now!

Edited November 30, 2020 by kold weather

[Cheshire Freeze]

 

So here we are...I've been keeping a watching brief over the past few days...seeing how this all unfolds. We stand on the edge of a December cold spell, possibly an extended one. As you can see from the image above, this can be traced back to around 6 weeks ago and has progressed to where we sit now. The potential upcoming pattern comes as no surprise to me as one by one all of the precursors I look for come mid-late autumn have been ticked off. 

It looks almost a certainty that we will see a SSW come January too- 6 weeks of precursor pattern in the 'bank'.

Enjoy.

[Sweatyman]

38 minutes ago, andy989 said:

I'm 1002ft above sea level in Snowdonia and the met office and BBC have nothing but rain for my location through Thursday and Friday

Wouldnt worry. They give Brum snow showers

[Zak M]

It's kind of funny to think that some posters were writing off the whole of winter last month! I would pay every single penny to see their reactions to the models tonight, including the EC46.

Lots of surprises could be on offer this month and running up to Christmas, including the possible snow event on Friday, and the potential for more cold shots. It's a very promising outlook.

So, moral of the story - don't be a numpty!

[feb1991blizzard]

1 minute ago, CreweCold said:

 

So here we are...I've been keeping a watching brief over the past few days...seeing how this all unfolds. We stand on the edge of a December cold spell, possibly an extended one. As you can see from the image above, this can be traced back to around 6 weeks ago and has progressed to where we sit now. The potential upcoming pattern comes as no surprise to me as one by one all of the precursors I look for come mid-late autumn have been ticked off. 

It looks almost a certainty that we will see a SSW come January too- 6 weeks of precursor pattern in the 'bank'.

Enjoy.

Im now going for a 20th -30th Jan SSW.

[mountsbaysnow]

At least the Daily Express are not on board just yet with front page headlines that should hopefully be a good thing right?

 

Edited November 30, 2020 by mountsbaysnow

[Zak M]

➡

I see the BBC is also drunk and showing me this. Could they be right?!

Edited November 30, 2020 by Zak M

[BlueHedgehog074]

24 minutes ago, Zak M said:

Wow, it's absolutely buzzing here tonight!!!

We’ll all end up turning into big, fuzzy, bumble bees at this rate

24 minutes ago, Zak M said:

I decided to go a step further and tell them that multiple days of December will exceed 25c - the funniest part was that they believed me 

And how could you? Now we’ll end up with loads of Northern blocking, cold and snow and temperatures of -25*C

Just had a little look at the 18Z GEFS mean as well at 240 hours and it looks quite good. Not thrown down as many drinks from the pub, mind, than the heavenly operational lol

 

Despite Low Pressure across the North-West, it keeps the Azores High out to our South-West with troughing South through the UK and extending down into mainland Europe. Together with High Pressure sticking about over Scandinavia, would help keep the Jetstream on a North-West to South-East alignment towards us. A chilly pattern maintained. And 850 hPa temperatures below 0*C for the UK, except for the far South-West. 

Edited November 30, 2020 by DiagonalRedLine

[Beanz]

4 minutes ago, Zak M said:

It's kind of funny to think that some posters were writing off the whole of winter last month! I would pay every single penny to see their reactions to the models tonight, including the EC46.

Lots of surprises could be on offer this month and running up to Christmas, including the possible snow event on Friday, and the potential for more cold shots. It's a very promising outlook.

So, moral of the story - don't be a numpty!

Happens every year....besides, I seem to remember you weren’t too excited about cold and snow yourself a few weeks back Zak...

[Zak M]

2 minutes ago, Beanz said:

I seem to remember you weren’t too excited about cold and snow yourself a few weeks back Zak...

I remember that too... but strangely enough, I am now!

It's so busy in here and I'm loving it! The forum makes the run-up to winter even better.

[MP-R]

9 minutes ago, Zak M said:

➡

I see the BBC is also drunk and showing me this. Could they be right?!

Now if this follows the same track the deluge of rain did on 2nd October, everywhere would get a pasting. Imagine a line of snow literally straddling the country from N-S.

[kold weather]

So the thing to remember in these types of set-ups is usually the LP will adjust southwards and weaker as we move closer to the time. We already have seen that in the last 36hrs from the models and whilst they should be zeroing in towards a general zone, there may yet be further movement south of the LP as it forms on Thursday.

Exactly where it forms will determine snow risks and how large that zone ends up being.

[BARRY]

4 minutes ago, kold weather said:

So the thing to remember in these types of set-ups is usually the LP will adjust southwards and weaker as we move closer to the time. We already have seen that in the last 36hrs from the models and whilst they should be zeroing in towards a general zone, there may yet be further movement south of the LP as it forms on Thursday.

Exactly where it forms will determine snow risks and how large that zone ends up being.

wise words been here to many times caution is required

[ghoneym]

My cactus has recently flopped over badly and is dying for some reason, had it 10 years. Must know what's coming......... Looking good early winter for a change. Cross model promise for the foreseeable rather than zonal dross! That's all we can ask for at this stage. Who cares if we get overexcited at a Fi chart that we would typically bin, it's 2020 and been the worst year in living memory. Stick your "caution" "more runs needed" "been here before" posts right into my veins because I don't care

[BlueHedgehog074]

22 minutes ago, ghoneym said:

Who cares if we get overexcited at a Fi chart that we would typically bin, it's 2020 and been the worst year in living memory. Stick your "caution" "more runs needed" "been here before" posts right into my veins because I don't care

Yep, it’s been a funny ol’ year really. I might have said in some posts from the past about being cautious of what charts in FI show to prevent disappointment, which still holds true. But, equally, I can see why we’ve also been getting all ecstatic about what they show. The beauty of this thread really is allowing anyone to discuss any charts whether it’s from the short range, the medium range, the long range, the super range. Anything really (as longs of course it’s model related But with the case of the blasted Covid-19 this year, like to believe we’ve been a bit lighter with the restrictions in the thread recently and allowed a bit more in the way of banter). Another thing is that without all the excitement in here, I feel some of the heart and soul of the thread would be lost. Also, what fun would it be if no one was allowed to discuss the FI/longer range charts?

Edited December 1, 2020 by DiagonalRedLine
Re-wording sentence

[Geordiesnow]

1 hour ago, northwestsnow said:

By this stage frozen ponds etc on the menu...

Very very cold 18z...

I thought I have a look at the upper air temperatures on the GFS run as I thought with you mentioning frozen ponds, it was an epic cold run and I was disappointed, uppers barely reaching - 4hpa and air temperatures reaching mid single figures in eastern areas with rain showers off the North Sea. Because of the lack of meaningful cold air, thicknesses are also higher so I dont think an easterly will be all that unstable so could be quite cloudy with showery rain under that set up. 

I do not see for the life of me why people are getting excited over a cool easterly wind, the weather will be dull literally, Frost likely to be limited and certainly no snowfall(the continent affect does not come into it with a ENE'ly) . 

I am a little bit more encouraged with the WNW'ly, at least on the GFS run it's showing it to be a touch colder upper air temps wise(uppers of - 6 hitting some north Western areas) so once the low heads through the UK and slacken the winds off, any PPN is hitting upper air temperatures of around -5 and given such low thicknesses, it might mean the snow risk is a bit higher but high ground is still much favoured in all this. 

It's definately not 80s set up though, the 80s had colder air in general over the continent, it certainly would not have positive anaomolies quite like we are going too see during the week in Scandinavia. 

[booferking]

Yes please.

[Geordiesnow]

5 minutes ago, booferking said:

Yes please.

Yes, that's a better looking chart, part of the PV in Scandi, low heights which encourages lower upper air temperatures and of course lower thicknesses which favours the sunshine and shower set up. 

Not denying something significantly cold could occur as we do have a disrupted PV over Greenland and there is blocking to be had but when Scandinavia is forecast to have upper air temperatures which are going to be upto 10C above average in parts then I certainly would not look east for any meaningful cold at the moment. 

[Snowman.]

16 minutes ago, Geordiesnow said:

Yes, that's a better looking chart, part of the PV in Scandi, low heights which encourages lower upper air temperatures and of course lower thicknesses which favours the sunshine and shower set up. 

Not denying something significantly cold could occur as we do have a disrupted PV over Greenland and there is blocking to be had but when Scandinavia is forecast to have upper air temperatures which are going to be upto 10C above average in parts then I certainly would not look east for any meaningful cold at the moment. 

Unfortunately we require the Russian high to setup the first stage of the pattern which is assisting in keeping the Atlantic at bay and deflected in Europe. Soon it will need to bugger off by being pushed down from the top allowing lower heights into Scandi or retrogress with the Atlantic high forming a greenie block and opening up that side for much colder uppers. 
 

it’s going to take time either way but if we can keep hold of the block long enough it will come eventually even the 18z has the cold starting to making inroads into Eastern Europe. 

[SMU]

Morning

Not withstanding the excitement at 72 for the bit of snow, the UKMO 144 00z is superb, pushing cold uppers south & the atlantic alligned to continue cold proceedings 

[desverger2]

10 minutes ago, Steve Murr said:

Morning

Not withstanding the excitement at 72 for the bit of snow, the UKMO 144 00z is superb, pushing cold uppers south & the atlantic alligned to continue cold proceedings 

Where did you make the snowline Steve on the GFS 00z?

[Daniel*]

There’s Nick S elongated lows not normal at all. Wedge alert! I think this is going to be a very good run. 
 

Not quite weak HP not sufficient - unsettled and chilly poor. 

 

Edited December 1, 2020 by Daniel*

[BlueHedgehog074]

Probably what you would have imagined, but models such as the 00Z ICON and 00Z GFS showing differences with the centre and movement of the Low Pressure still later in the week. Just small details really that can make a stark difference to the concentration of where any rain, sleet or snow ends up. For an example this Friday, ICON winds up the centre of the Low Pressure over North-Eastern UK (but does start as 2 Low Pressure centres at first)

 

Where as the GFS has the centre of the Low for that day sticking to the South-East of the UK like glue!

Marginal 850 hPa temperatures again, but it does seem like those more toward the East of the UK becoming the favourite for a wintry mix of weather. Best of the wintry conditions over high ground, but some sleet or snow a possibility to some low levels in heavy bursts. 
 

The ICON over the weekend gradually clears away the Low Pressure system to the North-East of the UK. But another Low West in the mid Atlantic, deepening at the surface level, slides down the Azores High to become situated over South-Western UK. The Azores High becomes very amplified behind it (does seem to be a common theme at the moment) and turns into a dog bone.

 

Not a bad start for the morning really

Edited December 1, 2020 by DiagonalRedLine
Typos and corrections

[jason6347]

11 minutes ago, Steve Murr said:

Morning

Not withstanding the excitement at 72 for the bit of snow, the UKMO 144 00z is superb, pushing cold uppers south & the atlantic alligned to continue cold proceedings 

Are we any clearer as to where snow may occur yet Steve ,will it be height based?