[Winter 2023/24 Chat and Discussion]

How long before any month with a CET below 6C is described as a 'cold' month?

[Winter 2023/24 Chat and Discussion]

8 hours ago, Metwatch said:

Slightly late reply but it's not looking overly wet next week. Majority of rain will be across mountainous areas with the leeward which is much of England a lot drier. Wind main issue coming days. UK high may also make a quick return next weekend.

The main problem is that bands of rain get stuck and don't clear. I quite regularly see them clearing the East coast, but it will still be raining here. No wonder the Ock Valley floods so easily.

[Winter 2023/24 Chat and Discussion]

5 hours ago, CLH said:

We've seen the EXACT DATE that a WALL OF SNOW will BURY the UK and cause CHAOS

But, this is a new one

[Winter 2023/24 Chat and Discussion]

7 hours ago, Metwatch said:

Ironically if you live near a river which has flooded in recent weeks / months, that's a very reassuring looking accumulated precip chart.

Down to 13 flood warnings and 62 alerts tonight.

And yet all that good work will be undone by the time the weekend is done.

[South West and Central Southern England Discussion - Dec 2023 onwards]

Last 24 hours precipitation. No comment required.

[Winter 2023/24 Chat and Discussion]

I took my leap of faith and faceplanted in the river - last 24 hours precipitation:

[South West and Central Southern England Discussion - Dec 2023 onwards]

1 hour ago, Alderc 2.0 said:

Just seen huge green meteor! wooow

Neber seen anything like that before, was emerald green and really really bright. 
 

was falling towards the western sky.

1 hour ago, Dorsetbred said:

Wait for the phone calls to the emergency services, from people saying they've just seen a green space rocket cross the sky..Pictures?

 

29 minutes ago, nettie said:

Maybe it's  the aliens   from the Miami Mall incident  last week

-2 here now .  

More chance of seeing a meteor, a green rocket or aliens than snow in a cold spell in winter.

[Model Output Discussion - Colder but how cold and for how long?]

1 hour ago, kold weather said:

Man that front is close to the south coast, or even on the south coast on Wednesday on the 12z runs.

Honestly its well within the margin of error still. I recall a similar rain event which progged to only brush the south coast but ended up producing a pretty signifncant rain event back in December. 

Thats not to say I think its the likely outcome, I think its not. But its still close enough call that it will need very close watching right through to Wednesday, we are talking literally 10-20 miles making the difference between basically nothing and 3-5cms into southern coastal counties. 

I remember that one, forecast at T+06z: dry; actual: hours of heavy rain.

There has been more than one instance where rain was not supposed to reach my location in the most recent forecast, but ended up as far north as Manchester. There was one where an upper front popped up at T+0. Not sure why models couldn't detect it before then? I recall another band of rain that was supposed to skim South Wales and instead covered the entirety of Wales in heavy rain, all change at T+0. I am sure these examples only stick in the mind, because they are so unbelievably wrong at such short range and when there is zero or negligible departure short range it is 'no news', so that probably remains the majority. However, suffice to say that there is sufficient evidence to merit a 'watching brief' up to T+0.

[Model Output Discussion - Colder but how cold and for how long?]

32 minutes ago, tight isobar said:

Wow we lose the lp- but the drop slant into France raises wash/ North Sea precipitation inland…

Agreed - that's certainly not wishbone-wind direction.

[Model Output Discussion - Colder but how cold and for how long?]

3 minutes ago, Don said:

You are still in a more favourable location than me for next week.  Anyway, enough said for now.

Of course if the front attacks from the South, but when all opportunities for snowfall are considered.

[Model Output Discussion - Colder but how cold and for how long?]

13 minutes ago, Don said:

Strange how the people responding to my post happen to be in more favourable locations for snow next week?! 

You must be joking. Even when conditions favour snow and there is precipitation about, check the yellow circle (December 2022):

[Model Output Discussion - Colder but how cold and for how long?]

7 minutes ago, alexisj9 said:

Wow, seriously, how about letting this cold spell play out, and I'm not so sure about the warm up, icon might be showing the way, we will see later in the week. I'm not looking for the next spell just yet.

It is akin to writing an obituary for someone who hasn't died yet.

[Model Output Discussion - Colder but how cold and for how long?]

1 minute ago, mountain shadow said:

Not impossible at all. We are pretty much 90% certain where snow will fall and 100% where it won't for some.

Well for a start, the chart is 5 days away. Last Monday was dry 5 days away and yet that had mostly light snow across large parts of the South.

Secondly, the chart is not a high-resolution precipitation chart, so it doesn't contain any details, good or bad.

Thirdly, even if a high resolution chart at T+6 says no, the verification is not 100% and nowcast would still need to be applied.

[Model Output Discussion - Colder but how cold and for how long?]

39 minutes ago, mountain shadow said:

Even if you knew it only meant snow for mainly Scotland and zero for Gloucestershire?

 

Impossibe to ascertain from a T+96 500hpa chart.

[Model Output Discussion - Colder but how cold and for how long?]

1 hour ago, kumquat said:

Looking forward to the cold dry weather that is progged up until next weekend. Plenty of little features will pop-up to give snow to lucky places prone to the north west especially up north, Scotland and Northern Ireland / Eire. Also anything sticking out from the East coast anywhere down. All of those NW facing coasts might do OK , Cheshire Gap Streamers and the odd dangler into Pembrokeshire and out the other side into Exmoor and south west peninsulars. Wishbone and troughs. Fun times might pop-up. Also think the northern extent of ppn from the SW low could come increasingly north as a wraparound from N France/ Belgium and hit Kent and the South East. Not ruling out a pasting into the far South coast and moving north more than progged into higher up South West into Cotswolds and as far as the Midlands This is my Pub Run and I'm sticking to it. Covering as many areas as possible and even a little bit into Oxon and Leics.

And of course when NickSussex gets off the plane.

Good luck all! 

I saw it mentioned earlier that if 'dry' charts are forecast then it will be dry. However, I don't agree with that analysis, because, frankly, the charts are hopeless at modelling precipitation. Even the hi-res ones I have seen, let alone the low-res ones that are more frequently posted on here.

There was a week in late autumn where two storms were forecast with yellow warnings over SW & CSE. On one of these the actual was a short period of light rain, on the other there was light winds and no rain. On another day that week when only a few showers were forecast the actual was heavy rain for about 6 hours. And then there was Monday 8th Jan across the South. I have talked about favourable teleconnections analysis then requiring a giant leap of faith to translate into something tangible snow-wise. However, you don't attempt that leap now - you do it at T+0.

1 hour ago, blizzard81 said:

If I was to sum things up after today's offerings by the models - The vast majority of coldies are wanting something more than a dry, frosty week. Mainly because of the uneventful (for most) winter so far, on top of the uneventful winters of the last 10 years plus. That's it in a nutshell. 

Yes and no. I am desperate for a day of snow, but highly sceptical of any detailed output at range, irrespective of what people say the background drivers are forecast to do. So now there has been one below average week with a colder one to follow. None of the stinker runs shown at various points have come to fruition over this period. This feels like a victory. See above for my opinion on micro-details. Moreover, this colder and drier interlude is critical in allowing flooding to recede and an opportunity to repair flooring, fencing, gutters and walls that all got trashed during 4 weeks of incessant wind and rain.

[Model Output Discussion - Colder but how cold and for how long?]

Not enough charts being posted, for next week, so I thought I would. Latest T+96 from several models, some at 12z, others at 18z. Almost creates a bespoke set of ensembles:

GFSUKMOECMWFGEMICONARPEGEJMANAVGEMCMAKMANASA/GEOS5CFS

It is apparent how much micro-scale variation there is at that range between those at the same time. This is really important. Also, I detest mild sectors, but as these go this would be one of the coldest mild sectors over the UK I have seen.

[Model Output Discussion - Colder but how cold and for how long?]

Well there are no stinker runs next week:

GEFS:

GEM:

ICON:

ECMWF:

[Model Output Discussion - Colder but how cold and for how long?]

24 minutes ago, AWD said:

Spot next weeks, midweek LP on the latest UKV;

Hint -

If sending the LP South is meant to keep the UK on the cold side of the polar front, why is there rain over inland parts of the UK?

[Model Output Discussion - Colder but how cold and for how long?]

14 minutes ago, Man With Beard said:

I appreciate it doesn't happen every time but I'm always mindful of January 2010 - the time the entire country (except Bournemouth!) went white due to a feature only modelled within T48 - and that was on a northerly.

And it went from a M4-south event to an M40-south event within T+12.

[Model Output Discussion - Colder but how cold and for how long?]

10 minutes ago, Mike Poole said:

There’s a lot going on.  I will be fascinated to see how the models manage to contrive a snowless breakdown to mild out of this!  

The weather managed to conjure up a snowless breakdown in December 2022. Not only was there no snow, there wasn't even any rain (which would be a blessing this time round for sure).

[Model Output Discussion - Colder but how cold and for how long?]

2 hours ago, bluearmy said:

Updated day 4 and 5 fax charts 

     
 

as expected, day 4 not looking as clean as day 5 did yesterday 

the shortwave now picked up - we need to wait for a few more runs to be sure how this shortwave will track. Imo, it’s now become pretty much the most important feature re next week. 

Ah yes, that's much better:

[Model Output Discussion - Colder but how cold and for how long?]

GEFS 06z, 12z & 18z:

 

Main area to concentrate on is 15th/16th/17th. The main change from 12z to 18z is that 17th is colder. Anything after that is mostly white noise.

[Model Output Discussion - Colder but how cold and for how long?]

That really cold run on the 06z distorts the scale, making it harder to compare these, but ostensibly I am focussed on what is happening on around 15th/16th/17th. It went up a bit on 15th & 16th and a lot on 17th. Hopefull 18z will push it back down again.

[Model Output Discussion - Colder but how cold and for how long?]

24 minutes ago, I remember Atlantic 252 said:

Straight northerly is wishbone effect, showers down east coast, and a possible Pembrokeshire dangler, dry with clear blue skies for central parts

But - the main objective of this northerly is to provide the polar maritime air that is required to become embedded over the UK. Without this, there would be insufficient resistance to an approaching LP from th SW with all the mildness wrapped up in it.

The depth of cold being as deep as possible and the extent of the northlerly being as far south as possible is the microscale ingredients that for me takes precedent over anything else shown in the models thereafter.

[Model Output Discussion - Colder but how cold and for how long?]

6 minutes ago, bluearmy said:

I thought was moving to n Italy ?.

They obviously want to be based in a location where they are least likely to get snowed in or out.