The Weather Outlook

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Gandalf The White
04 January 2025 11:01:19
A quick run through the various high res output seems to suggest the precipitation band is coming in a little slower than earlier runs indicated and this suggests a longer period of snow for some.  

For my patch Arpege shows snow starting around 11pm and not stopping until around 6am or 7am tomorrow morning, by which time it suggests around 10cm of snow will have fallen.

The ICON D2 09z run shows snow from around midnight until 4-5am.

The 06z UKMO run shows just 2-3 hours of snow from around midnight, before it turns to rain.

Alaro 06z has the snow starting around 9pm and continuing until 5am, delivering 6-7cm of falling snow.

So, still a measure of uncertainty even this close, but my expectations of seeing some snow on the ground in the morning have increased a little.


Location: South Cambridgeshire

130 metres ASL

52.0N 0.1E



Chichesterweatherfan2
04 January 2025 11:09:29

Good luck or bad luck (whatever your persuasion) for this weekend. The frost is melting here and we won’t see snow this far south. The focus is on Weds now and as this weekends system trended north the next one looks trending south so we’ll probably miss again.

It was ‘easier’ in the old days I’m sure of it. 

Originally Posted by: nsrobins 

Share your pain Neil too! Still we had falling and lying snow here in Chi back in November and I fully expect that to be it for this winter…temp here now up to 2.2 and  frost all gone….but yesterday was absolutely stunning with harsh frost and beautiful sunshine…a proper winter wonderland….

Rob K
04 January 2025 11:10:01

Good luck or bad luck (whatever your persuasion) for this weekend. The frost is melting here and we won’t see snow this far south. The focus is on Weds now and as this weekends system trended north the next one looks trending south so we’ll probably miss again.

It was ‘easier’ in the old days I’m sure of it. 

Originally Posted by: nsrobins 

Still frosty at this end of Hampshire but I'm less optimistic for snow than I was yesterday. Looks like beginning as rather fragmented band, and it turns to rain well before the heavy stuff arrives.


Yateley, NE Hampshire, 73m asl

"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome

Matty H
04 January 2025 11:22:08
Up to 2c now and frost has melted. Expecting all rain here 
Yate, Nr Bristol

TBFTEIARBSC

nsrobins
04 January 2025 11:44:56
The current GEFS mean offers something for the Weds channel slider - but will the ground conditions be suitable after the brief mild blast?

Beyond that there’s also still a low chance of an easterly tug.

More current and the areas identified in the Amber warnings still looking good for prolonged snowfall tonight.


Neil

Fareham, Hampshire 28m ASL (near estuary)

Stormchaser, Member TORRO

ballamar
04 January 2025 11:51:03
For the SE not expecting anything and this sort of set-up is possibly the most frustrating as I know the next lows that offer hope will be either to far south or we will manage to get some positive dew points! North Yorkshire will be very snowy later and look forward to some pics. Reckon a few favoured spots will see 50cm+
Brian Gaze
04 January 2025 12:04:30
Cold air aloft. DP -1C. Temp 0.7C. Let it rain.... wonders never cease.
Brian Gaze

Berkhamsted

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scillydave
04 January 2025 12:46:44

The current GEFS mean offers something for the Weds channel slider - but will the ground conditions be suitable after the brief mild blast?

Beyond that there’s also still a low chance of an easterly tug.

More current and the areas identified in the Amber warnings still looking good for prolonged snowfall tonight.

Originally Posted by: nsrobins 

Neil,

I'm very happy to stand corrected but I've always thought that (to a large degree) ground conditions made little difference to snow settling. Obviously dry surfaces and those that conduct heat quickly have snow settling on them the most readily but if the temperature is very near or below freezing then it settles everywhere readily.  A good example of this would be the rain to snow events. Clearly it does make a difference but  think only a brief and marginal one.

It's a bit like the old 'cold air is hard to shift' one which I think is also untrue.

More experienced TWOers (Neil included) please feel free to tell me I'm spouting nonsense 🤣


Currently living at roughly 65m asl North of Cowbridge in the Vale of Glamorgan.

Formerly of, Birdlip, highest village in the Cotswolds and snow heaven in winter; Hawkinge in Kent - roof of the South downs and Isles of Scilly, paradise in the UK.

Retron
04 January 2025 12:52:07

Neil,

I'm very happy to stand corrected but I've always thought that (to a large degree) ground conditions made little difference to snow settling. Obviously dry surfaces and those that conduct heat quickly have snow settling on them the most readily but if the temperature is very near or below freezing then it settles everywhere readily.  A good example of this would be the rain to snow events. Clearly it does make a difference but  think only a brief and marginal one.

It's a bit like the old 'cold air is hard to shift' one which I think is also untrue.

More experienced TWOers (Neil included) please feel free to tell me I'm spouting nonsense 🤣

Originally Posted by: scillydave 

The cold air is hard to shift one is nonsense, as we've seen it happen many a time. What's more important is the angle of attack of warm air, the more easterly the winds in advance the better.

And frustrating though it may be to watch heavy snow melt on impact, I've seen snow settle on wet ground - even puddled ground - several times over my life. Get the dewpoint low enough, get the snow heavy enough and it will settle. The trouble is much of our snow is so marginal to begin with it doesn't stand a chance!


Leysdown, north Kent
tallyho_83
04 January 2025 12:54:23
The Met Office radar shows precipitation over Okehampton for past 2 hrs but looking out it's dry with alto stratus clouds at 1.5c and very windy and bitter. Frost melted already

I wonder if the precipitation is evaporating? On another radar (can't remember which) shows snow in the precipitation type with rain just ahead and to our south but snow over Dartmoor. But again nothing seen outside as yet.


Home Location - Vixen Tor Close, Okehampton, Devon (221m ASL)

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Sean Moon

Magical Moon

www.magical-moon.com

roadrunnerajn
04 January 2025 12:59:39
Very little rain here still.. just enough to dampen the ground.
Germoe, part of the breakaway Celtic Republic. 80m asl
westv
04 January 2025 13:01:31
I'm not expecting anything but rain here in Hull - as per the forecast anyway.
Big heat in May

Summer will be spray.

Bolty
04 January 2025 13:13:48
The Met Office automated forecast has snow from 21:00 to 08:00 at my location, before it turns to sleet. It never gets past sleet though and stays at that for the rest of the day, and from past experiences that can mean anything here. Either way, it's looking on a knife edge once the transition arrives.

Interestingly, OTOH, the BBC is much more pessimistic. The precipitation starts as sleet before turning to snow from 23:00 to 06:00, and then to sleet and eventually to rain. It's actually very rare to see the Met take a more optimistic approach. It seems to be the opposite, in my experience anyway.

Time will tell.


Scott

Blackrod, Lancashire (4 miles south of Chorley) at 156m asl.

My weather station 

Brian Gaze
04 January 2025 13:22:40

The Met Office automated forecast has snow from 21:00 to 08:00 at my location, before it turns to sleet. It never gets past sleet though and stays at that for the rest of the day, and from past experiences that can mean anything here. Either way, it's looking on a knife edge once the transition arrives.

Interestingly, OTOH, the BBC is much more pessimistic. The precipitation starts as sleet before turning to snow from 23:00 to 06:00, and then to sleet and eventually to rain. It's actually very rare to see the Met take a more optimistic approach. It seems to be the opposite, in my experience anyway.

Time will tell.

Originally Posted by: Bolty 

I'd be surprised if it doesn't turn back to sleet and then rain tomorrow. When I looked at it yesterday the boundary was between Leeds and Newcastle. GFS 06Z data (screenshot below) for Chorley has 850s climbing above 0C by midday.

UserPostedImage


Brian Gaze

Berkhamsted

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Bolty
04 January 2025 13:26:00

I'd be surprised if it doesn't turn back to sleet and then rain tomorrow. When I looked at it yesterday the boundary was between Leeds and Newcastle. GFS 06Z data (screenshot below) for Chorley has 850s climbing above 0C by midday.

UserPostedImage

Originally Posted by: Brian Gaze 

To be honest, that's what I think as well. Your forecast is more in-line with what I'm expecting to happen. Snow until around 08:00, sleet for a while and then back to rain by late morning. I think the MO one is too optimistic.


Scott

Blackrod, Lancashire (4 miles south of Chorley) at 156m asl.

My weather station 

Tim A
04 January 2025 13:32:49
The Met Office app differences is because it uses UKV or UKMO or some secret blend of their models but those models keep the snow line South of Leeds against all the other models. 

Mogreps shows it is far from decided. 

https://www.theweatheroutlook.com/charts/mogreps/mogreps850leeds.png 

Ground temps are more certain, not rising much above freezing, but turning to freezing rain/ice pellets or very cold regular rain, who knows ..?

 

Snow amounts vary significantly...

https://www.theweatheroutlook.com/charts/mogreps/mogrepssdleeds.png 


Tim

NW Leeds

187m asl

 My PWS 

Brian Gaze
04 January 2025 13:34:36

To be honest, that's what I think as well. Your forecast is more in-line with what I'm expecting to happen. Snow until around 08:00, sleet for a while and then back to rain by late morning. I think the MO one is too optimistic.

Originally Posted by: Bolty 

The UKV based hourly forecast shows it staying as snow until about 8pm, but if you toggle data source to Arpege I think it's closer to midday.

https://www.theweatheroutlook.com/twoforecasts/hourly-weather-forecast.aspx?loc=chorley--lancashire 

UserPostedImage


Brian Gaze

Berkhamsted

TWO Buzz - get the latest news and views 

"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan

nsrobins
04 January 2025 13:34:43

Neil,

I'm very happy to stand corrected but I've always thought that (to a large degree) ground conditions made little difference to snow settling. Obviously dry surfaces and those that conduct heat quickly have snow settling on them the most readily but if the temperature is very near or below freezing then it settles everywhere readily.  A good example of this would be the rain to snow events. Clearly it does make a difference but  think only a brief and marginal one.

It's a bit like the old 'cold air is hard to shift' one which I think is also untrue.

More experienced TWOers (Neil included) please feel free to tell me I'm spouting nonsense 🤣

Originally Posted by: scillydave 

I was using the term ‘ground’ to describe all parameters, not just soil and surface conditions - my bad 😊 I’m a bit resigned to the fact this episode won’t deliver much here, but there’s still a low chance of something Wednesday.


Neil

Fareham, Hampshire 28m ASL (near estuary)

Stormchaser, Member TORRO

Quantum
  • Quantum
  • Advanced Member Topic Starter
04 January 2025 13:37:14
There is a curious feature where evap cooling creates a cold pouch near the LP centre tommorow at around 3pm for parts of south yorkshire giving a wierd very mild->cold->coldish->cold        south to north pattern
25/26 (850hpa temp) 11 days snow/sleet falling

18/11 (-4) 19/11 (-6) 20/11 (-6) 01/01 (-7) 04/01 (-10) 10/01 (-7) 11/01 (-3) 30/01 (-1) 13/02 (-6) 15/02 (-4) 18/02 (-6)

24/25 10d

18/11 (-6) 19/11 (-6) 23/11 (-2) 22/12 (-5) 04/01 (-5) 05/01 (0)14/02 (0) 15/02 (0)12/03 (-6) 13/03 (-6)

23/24 8d

29/11 (-6) 30/11 (-6) 02/12 (-5) 03/12 (-5) 04/12 (-3) 16/01 (-3) 18/01 (-8)08/02 (-5)

22/23 7d

18/12 (-1)06/03 (-6) 08/03 (-8) 09/03 (-6) 10/03 (-8) 11/03 (-5) 14/03 (-6)

21/22 12d

Quantum
  • Quantum
  • Advanced Member Topic Starter
04 January 2025 13:39:27
On this note, we are all focusing on whether it will be further south or east than expected (better for snow) but what we haven't talked about is what happens if the air is 0.5C colder than forecasted. That would be enough to make huge differences.


25/26 (850hpa temp) 11 days snow/sleet falling

18/11 (-4) 19/11 (-6) 20/11 (-6) 01/01 (-7) 04/01 (-10) 10/01 (-7) 11/01 (-3) 30/01 (-1) 13/02 (-6) 15/02 (-4) 18/02 (-6)

24/25 10d

18/11 (-6) 19/11 (-6) 23/11 (-2) 22/12 (-5) 04/01 (-5) 05/01 (0)14/02 (0) 15/02 (0)12/03 (-6) 13/03 (-6)

23/24 8d

29/11 (-6) 30/11 (-6) 02/12 (-5) 03/12 (-5) 04/12 (-3) 16/01 (-3) 18/01 (-8)08/02 (-5)

22/23 7d

18/12 (-1)06/03 (-6) 08/03 (-8) 09/03 (-6) 10/03 (-8) 11/03 (-5) 14/03 (-6)

21/22 12d

The Beast from the East
04 January 2025 13:59:59

On this note, we are all focusing on whether it will be further south or east than expected (better for snow) but what we haven't talked about is what happens if the air is 0.5C colder than forecasted. That would be enough to make huge differences.

Originally Posted by: Quantum 

Is it though? Sod’s Law it probably be more likely the other way 


Purley, Surrey, 70m ASL

"We have some alternative facts for you"

Kelly-Ann Conway - former special adviser to the President

Brian Gaze
04 January 2025 14:03:41
Arome is worth a look. I modified (IIRC Darren flagged this issue up) the ppt charts in November to show graupel as well as snow and rain.

Start from here

https://www.theweatheroutlook.com/twodata/arome.aspx?run=06&charthour=8&chartname=preciprate&chartregion=uk-region&charttag=Precip%20rate 

UserPostedImage


Brian Gaze

Berkhamsted

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"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan

Retron
04 January 2025 14:09:41

Arome is worth a look. I modified (IIRC Darren flagged this issue up) the ppt charts in November to show graupel as well as snow and rain.

Start from here

Originally Posted by: Brian Gaze 

Good stuff! I wonder, though, whether Arome is using graupel as a proxy for freezing rain in this case, as it doesn't have a field for that (AFAIK, anyway).


Leysdown, north Kent
tallyho_83
04 January 2025 14:19:10

Arome is worth a look. I modified (IIRC Darren flagged this issue up) the ppt charts in November to show graupel as well as snow and rain.

Start from here

https://www.theweatheroutlook.com/twodata/arome.aspx?run=06&charthour=8&chartname=preciprate&chartregion=uk-region&charttag=Precip%20rate 

UserPostedImage

Originally Posted by: Brian Gaze 

Many parts of Midlands as as Wales will see graupel instead of snow which was forecasted. It's strange how the beeb don't mention this as well as Met Office at best they will say wintry mix. As for the here and now the temp is still +2.0c and there hasn't even been a drop of rain let alone a flake of wet snow or sleet so it appears the front has stalled or precipitation has evaporated. As latest radar shows precipitation over Okehampton. Even "roadrunner" of Helston said (and hours ago) there has only been spits of rain and drizzle to dampen ground and Helston is in the far west of cornwall. Yet the met and bbc had this in heavy rain by now. So clearly the front is taking longer which is a worry as it will allow the warmer airmass to arrive...prior.


Home Location - Vixen Tor Close, Okehampton, Devon (221m ASL)

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Sean Moon

Magical Moon

www.magical-moon.com

tallyho_83
04 January 2025 14:52:33
Temp fallen to 1.8c  -finally a few spits of sleet in the wind here in Okehampton.
Home Location - Vixen Tor Close, Okehampton, Devon (221m ASL)

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Sean Moon

Magical Moon

www.magical-moon.com

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