SE and East Anglia generalweather discussion 08/11/2017 onwards

[stainesbloke]

2 minutes ago, Danny* said:

Bare in mind the Met Office warnings are disruption based, you could see snow falling outside of the warning zones, it's just unlikely to settle and thus, wont be disruptive hence no warning

Fair point but it doesn't look too great for any kind of snow, falling or otherwise, S of the warning area. There have been quite a few shifts in the snow zone though, so tomorrow could show something different? As for Monday....looks like some severe weather for many of us.

[Met4Cast]

3 minutes ago, stainesbloke said:

Fair point but it doesn't look too great for any kind of snow, falling or otherwise, S of the warning area. There have been quite a few shifts in the snow zone though, so tomorrow could show something different? As for Monday....looks like some severe weather for many of us.

I think London/N Kent will see some snow falling on the leading edge but it'll likely turn to rain fairly quickly. 

This cold spell doesn't look very exciting for those South of the M4. Hopefully the signals the heights to our NE materialise later in the month/January and we get some classic Easterly streamers across the region.

[Daniel*]

The southern extent of the snowfall is tauntingly close to London, all it takes is a minor S adjustment, very heavy precipitation high risk but high reward. 

[stainesbloke]

1 minute ago, Danny* said:

I think London/N Kent will see some snow falling on the leading edge but it'll likely turn to rain fairly quickly. 

This cold spell doesn't look very exciting for those South of the M4. Hopefully the signals the heights to our NE materialise later in the month/January and we get some classic Easterly streamers across the region.

That M4 really is a horrible motorway! I'll be surprised to see any snow in my area on Sunday but I live on a hill so there's a small chance lol. Monday may well be an interesting day for many of us, though. 

Agree with you about heights to the NE, a proper Scandi high with ice days, showery troughs and a Channel low....classic synoptics for the SE. This winter could be a memorable one.

[ITSY]

Haven't posted in a while - and I'm too busy to give it a real go. But I would say that, speaking from an IMBY POV, Cambs is unlikely to see any significant accumulations. Meto warning almost hand in glove with ARPEGE - which is far closer to GFS than ECM. Won't take very many last minute changes (with a 50 mile correction southwards and eastwards for example) for parts of our county to get a serious snowfall, but on the basis of the current forecast I suggest expect little or nothing to avoid disappointment. The issue is the wrapping of the low as it spins NNW while travelling Eastwards across the UK; it spurts warmer uppers into our region at just the worst moment, meaning that the system may have frontal and back-edge snow while the bulk is rain for most in central East Anglia. Central midlands, perhaps even East Midlands if the system moves northwards enough, could get 4-6inches widely I suspect. 

[sunnijim]

Flooding and potential wind damage could well be a story for those South of London.

Gusts predicted between 60mph and 70mph on Sunday and Monday

Rainfall predictions in a two hour window in the early hours of Monday have 2 inches of rain or more falling in 2 hours! (In excess of 50mm)

[Southender]

Would love someone to produce a document on why the M4 area almost always seems to be the rough line between snow & rain.

It really has it in for us lot doesn't it.

Do the weather systems constantly take the same track?

Is it the modification in terms of temps and dews from the channel on a Southerly draw?

Genuinely interested on the reasons behind the M4 areas ability to act as a heat shield and turn the snow to rain.

 

[Mark Bayley]

 

 

In all seriousness, highlights how marginal it is. Will be a fine line between getting pasted and seeing sleet / cold rain, further north and west you are the better (thats if you see any precipitation!) 

[Alpine glow]

4 minutes ago, Mark Bayley said:

 

 

In all seriousness, highlights how marginal it is. Will be a fine line between getting pasted and seeing sleet / cold rain, further north and west you are the better (thats if you see any precipitation!) 

That's the closest i've seen it to Brighton 

[Southender]

5 minutes ago, Mark Bayley said:

 

 

In all seriousness, highlights how marginal it is. Will be a fine line between getting pasted and seeing sleet / cold rain, further north and west you are the better (thats if you see any precipitation!) 

Would love to know how that NMM PPN chart comes to the conclusion the likes of the IOW will be under 10mm p/h PPN rates of SNOW with DP's around 3-4c.

[Rob Deacon]

1 minute ago, Alpine glow said:

That's the closest i've seen it to Brighton 

Yeah, if that's correct then should be amazing on the downs around the Beacon or devils dyke

[stainesbloke]

17 minutes ago, Daniel* said:

The southern extent of the snowfall is tauntingly close to London, all it takes is a minor S adjustment, very heavy precipitation high risk but high reward. 

Some output is putting much of our region in a snow zone. I'm sceptical/realistic/negative but happy to be wrong.

[FetchCB]

2 minutes ago, ITSY said:

Haven't posted in a while - and I'm too busy to give it a real go. But I would say that, speaking from an IMBY POV, Cambs is unlikely to see any significant accumulations. Meto warning almost hand in glove with ARPEGE - which is far closer to GFS than ECM. Won't take very many last minute changes (with a 50 mile correction southwards and eastwards for example) for parts of our county to get a serious snowfall, but on the basis of the current forecast I suggest expect little or nothing to avoid disappointment. The issue is the wrapping of the low as it spins NNW while travelling Eastwards across the UK; it spurts warmer uppers into our region at just the worst moment, meaning that the system may have frontal and back-edge snow while the bulk is rain for most in central East Anglia. Central midlands, perhaps even East Midlands if the system moves northwards enough, could get 4-6inches widely I suspect. 

Currently met Office showing Heavy snow for Peterborough and St ives on Sunday from 6am through to 6pm so I would expect accumulations.

The Met Office have a highly accurate short range model https://www.metoffice.gov.uk/research/news/2012/ukv So I would expect that at this range they have a good handle on likeleyhood and impact of any snow hence the move to an amber warning and this is reflected in the Chief Forecasters text "There is increasing certainty in the track and location of the heaviest snow."

The attached although related to Birmingham will be similar to other councils and highlights the impact of a weather warning given out by the Met Office

http://www.birminghamprepared.gov.uk/advice/specific-risks/met-office-severe-weather-warnings/

Currently East OF England is at a level 3 cold weather alert

https://www.metoffice.gov.uk/public/weather/cold-weather-alert/#?tab=coldWeatherAlert

Given all of the above and its implications and consequences I have faith at this range that the Met Office have the best handle on the disruption that is likely to occur in Cambs

[Mark Bayley]

3 minutes ago, Southender said:

Would love to know how that NMM PPN chart comes to the conclusion the likes of the IOW will be under 10mm p/h PPN rates of SNOW with DP's around 3-4c.

Dewpoints are generally between 0 and 1c, and heavier precipitation will bring that down a little. 

Edited December 8, 2017 by Mark Bayley

[ITSY]

2 minutes ago, FetchCB said:

Currently met Office showing Heavy snow for Peterborough and St ives on Sunday from 6am through to 6pm so I would expect accumulations.

The Met Office have a highly accurate short range model https://www.metoffice.gov.uk/research/news/2012/ukv So I would expect that at this range they have a good handle on likeleyhood and impact of any snow hence the move to an amber warning and this is reflected in the Chief Forecasters text "There is increasing certainty in the track and location of the heaviest snow."

The attached although related to Birmingham will be similar to other councils and highlights the impact of a weather warning given out by the Met Office

http://www.birminghamprepared.gov.uk/advice/specific-risks/met-office-severe-weather-warnings/

Currently East OF England is at a level 3 cold weather alert

https://www.metoffice.gov.uk/public/weather/cold-weather-alert/#?tab=coldWeatherAlert

Given all of the above and its implications and consequences I have faith at this range that the Met Office have the best handle on the disruption that is likely to occur in Cambs

Don't doubt they have a better handle than I do. Just making my own observations on an internet forum. 

[Methuselah]

I don't want to generate too much unfettered maniacal excitement - but, there are anvils on the horizon over the North Sea!

[bobbydog]

9 minutes ago, Alpine glow said:

That's the closest i've seen it to Brighton 

the current warnings are all for sunday. nothing mentioned yet for monday but the winds look more intense- 

and then there's this-

could well be that us lot in soggy sussex join in the fun and games as well! 

[Dami]

I'm just out of the amber doesn't mean it's a dead cert ofc, but it's only Friday. If I still see snow symbols and my warning hasn't gone saturday night then I shall be on the bailey's.

Still a case of pick nicer looking model run

Edited December 8, 2017 by Dami

[Southender]

Let's hope this is way wide of the mark.

2-3" of rain quite widely for our region over the course of Sunday and Monday.

http://modeles2.meteociel.fr/modeles_gfs/runs/2017120806/78-777.GIF?08-6

If only that was snow....

Shropshire and parts of the Midlands will have a foot by close of play Monday.

Edited December 8, 2017 by Southender

[bobbydog]

9 minutes ago, Ed Stone said:

I don't want to generate too much unfettered maniacal excitement - but, there are anvils on the horizon over the North Sea!

be careful out there....

[stainesbloke]

3 minutes ago, Dami said:

I'm just out of the amber doesn't mean it's a dead cert ofc, but it's only Friday. If I still see snow symbols and my warning hasn't gone saturday night then I shall be on the bailey's.

Still a case of pick nicer looking model run

At the moment, your area is the most likely in the whole of the SE region to get heavy, disruptive snowfall. Post some pics, please, if that happens 

[lassie23]

it'll be rain in London, i can feel it in my trousers

[Matty88]

Looking at this mornings charts - anyone that says we are in for a milder spell next week should think again, its going to be a cold week - snow or no snow, with 0 Degree Isotherm levels primarily negative. Some charts do point to a slightly milder spell towards Christmas however - either wet mild or a HP (the preferred scenario). 

Regarding the snow line on Sunday - everyone should know the charts (particularly GFS) generally always struggle to model the displacement of the cold air - as it is hard to shift. My gut feel, is anywhere from a Line from West Suffolk/South Cambs to Herts/Northampton etc will be right on the border line for significant snowfall. This could well be further north, or less likely - could be further south. If you get lucky it will be pay day - 10cm+ of snow which isn't likely to go anywhere fast, coupled with the potential for a further 10cm+ on Monday along with gale force winds. It has the makings of a really iconic snow fall event. 

Where you are in regards to that boundary though is make or break - a lot of people (including myself!!) should be braced for major disappointment come the end of the day Sunday... when all you see is wet puddles outside. Although there is an extremely low chance of this changing, I can fairly confidently say that it looks as though London/The South East are rain bound for both Sunday & Monday as it stands (but that could come back to bite me!).

Best word of advise for our part of the World - expect rain, anything more than that will be a bonus ! 

[KDME]

2 minutes ago, bobbydog said:

be careful out there....

That is what came to my mind . TBH, I prefer snow ...

[username home]

1 minute ago, lassie23 said:

it'll be rain in London, i can feel it in my trousers

30mm?? ;-)