South East and East Anglia Weather Discussion Sept 2020 onwards

[Nick F]

06z ECMWF still has a snow signal across SE England Friday morning, very marginal, but with stronger vorticity around the low close to the SE than the other models it breaks out heavier ppn. - which in turn lowers the wet bulb freezing level / enhances evaporative cooling. DPs marginal, too high towards E Anglia/Kent

[snowrye]

15 minutes ago, alexisj9 said:

Won't snow here, to early in the year for costal snow. Although I do live in land on a hill .

Same as, im 70m asl, not that that makes a huge difference lol, it's just the overall excitement of it all, thrill of the chase etc, hopefully this winter we'll all get some hefty snowfalls, and deep accumulations, that would be brilliant, i've not had a decent covering where it's lasted since march 2013

[dallas]

2 minutes ago, Nick F said:

06z ECMWF still has a snow signal across SE England Friday morning, very marginal, but with stronger vorticity around the low close to the SE than the other models it breaks out heavier ppn. - which in turn lowers the wet bulb freezing level / enhances evaporative cooling. DPs marginal, too high towards E Anglia/Kent

Most of the snow I have seen from marginal events is when the ppn relay peps up

[SMU]

10 minutes ago, Nick F said:

06z ECMWF still has a snow signal across SE England Friday morning, very marginal, but with stronger vorticity around the low close to the SE than the other models it breaks out heavier ppn. - which in turn lowers the wet bulb freezing level / enhances evaporative cooling. DPs marginal, too high towards E Anglia/Kent

Somewhere like the surrey downs would be good - Box hill ?

[Bradley in Kent]

Good afternoon all, hope all is well whichever Tier you are in!

As is often the case, the upcoming snow forecast is a real knife edge scenario, but it seems this time even narrower than normal. I'll certainly be looking at the traffic cameras and radar.

If it pulls off it would probably go down as a miracle snow event! After all, its early December!

My feeling is the North Downs and Chilterns will wake up to a wet dusting for a couple of hours. I hope I'm wrong though!

[Nick F]

14 minutes ago, Steve Murr said:

Somewhere like the surrey downs would be good - Box hill ?

I'm hedging my bets on around where I live up on the downs near Caterham seeing some snow settling briefly. Fortunately got the day off to report if so.

But all up in the air if EC is correct, 09z UKV not on board. And if EC anywhere near, will depend on how heavy ppn. is, we get yellows/oranges/reds on the Netwx radar, then it'll be game on.

 

Edited December 2, 2020 by Nick F

[Hillsnow93]

Ditchling beacon might be Worth a drive here’s hoping a few surprises in our part of the country! 

[Dami]

1 hour ago, alexisj9 said:

Won't snow here, to early in the year for costal snow. Although I do live in land on a hill .

i'm in a valley so it is has to be dammed cold to snow.

[Radiating Dendrite]

46 minutes ago, Nick F said:

I'm hedging my bets on around where I live up on the downs near Caterham seeing some snow settling briefly. Fortunately got the day off to report if so.

But all up in the air if EC is correct, 09z UKV not on board. And if EC anywhere near, will depend on how heavy ppn. is, we get yellows/oranges/reds on the Netwx radar, then it'll be game on.

 

I think you have a good shot - not expecting much down here in Purley.

Kenley is probably also a good shout and across to Riddlesdown - may have to go for a walk on Friday morning.

[Polaris]

Hi Everyone, 

I guess it’s all down to the intensity of the ppn on the western flank come Friday morning. Woburn, Beds tends to do rather well in marginal set ups (Meto app has me down for 3 hours of light snow from 9am Friday) that’s if the ppn even makes it this far inland. 
If it does I imagine Dunstable downs/Chilterns could see some of the white stuff. 

[Blazerblue]

So essentially, east Suffolk has zero chance, maybe some sleet? Or should I just stay in bed Friday morning?

[Blessed Weather]

1 hour ago, Hillsnow93 said:

Ditchling beacon might be Worth a drive here’s hoping a few surprises in our part of the country! 

A warm welcome to the forum Hillsnow. Yes, lots of us hoping for a snowy surprise and keeping everything crossed. At least if this weekend doesn't deliver the prospects over the coming few weeks continue to look promising if current model output is to be believed. But be warned - it will turn manic in here if it starts snowing!!

[Nick F]

29 minutes ago, Blazerblue said:

So essentially, east Suffolk has zero chance, maybe some sleet? Or should I just stay in bed Friday morning?

Cold rain I suspect.

[Tom Quintavalle]

Afternoon all,

Hope I find yourselves and your Families, well.

I hope Malcolm doesn't mind but wanted to request, that if and when our Region manages some Settling Snow, that those Members lucky enough to see it, have their Cameras at the ready and are able to post up some photographic evidence, if at all possible.

It would be of great benefit to me, in "hosting" my Winter Weather predicting Competition.

The Settling Snow predicting Category, applies exclusively to our Region.

Much thanks, in anticipation.

Regards,

Tom.  

[Hillsnow93]

22 minutes ago, Blessed Weather said:

A warm welcome to the forum Hillsnow. Yes, lots of us hoping for a snowy surprise and keeping everything crossed. At least if this weekend doesn't deliver the prospects over the coming few weeks continue to look promising if current model output is to be believed. But be warned - it will turn manic in here if it starts snowing!!

Thankyou! I’ve been lurking on the forum for a good 10years I’d say an love the atmosphere it’s brings, especially so when we have such exciting model output at the moment. Good luck to all an may we all get what we crave soo much SNOWWWW!!  

[Wivenswold]

1 hour ago, Blazerblue said:

So essentially, east Suffolk has zero chance, maybe some sleet? Or should I just stay in bed Friday morning?

It's not over at all. These models will be wrong at even 12 hours out because this is a marginal set-up for us.  There will be surprises and disappointments across the board and sometimes within half a mile of each other. Nowcasting starts Friday. 

[SMU]

So a few finer details plucked from a high res model.

The best track for widespread snow ( based on the fact that theres some elevated locations ) is just across East kent.

This is because the system keeps the milder WAA to the East & actually tucks in colder air & lower dewpoints from the west - 

Seen here

This is achieved by having a system that does have some rotation > not loads so the North sea air mixes into it & not to shallow as the cold air doesnt make it-

So whats being modelled right now for about T30-36 is a system that sits rights in the zone for advecting cold air over the SE right at the time when the PPN hits...

Here is a snap shot of high res model- for Friday 07am 

So if things follow the forecast ( or at least the most promising forecasts ) the rain / Sleet will turn to snow from the west as that cold air digs across with the process taking an hour or 2

In terms of the GFS I highlighted a part of the ENS thats much under used IMO which is the ENS height of the 0C isotherm ( Freezing level )

For the SE to see settling snow Ive set my benchmark at 150-200M > Which covers the downs & chilterns

Friday 09z was the peak of the PPN so heres the 00z ENS for that time

There was 5/30 under 200M ( not very promising ) & 6/30 Under 300M

Heres the 06z

There was 4/30 under 200M & 9 under 300M 

So a definite jump into the 2s but not 1s.

Hot off the press there are

6/30 under 200 & 10 under 300.

This indicates to me that the GFS is moving towards rather than away from the snowy solution, its doing this by 3 metrics

* Deepening the system & increasing the rotation across the SE through the early hours

* Sharpening up the jet thats over the SE coast pulling it slightly west so the PPN belt is over Lon & home counties not East kent

* Enhancing the PPN plumes thus dragging the ZDL level down.

 

Based on all that then if it all holds together as planned a few CMs could occur > 200M & locations >100M could well see snow falling but not necessarily settling.

Im 140M so feeling very much 50/50 but luckily have the 240M lookout point at west kingsdown radio mast just 2 miles away

hope this helps !

S

 

[Laurence Hill]

6 minutes ago, Steve Murr said:

So a few finer details plucked from a high res model.

The best track for widespread snow ( based on the fact that theres some elevated locations ) is just across East kent.

This is because the system keeps the milder WAA to the East & actually tucks in colder air & lower dewpoints from the west - 

Seen here

This is achieved by having a system that does have some rotation > not loads so the North sea air mixes into it & not to shallow as the cold air doesnt make it-

So whats being modelled right now for about T30-36 is a system that sits rights in the zone for advecting cold air over the SE right at the time when the PPN hits...

Here is a snap shot of high res model- for Friday 07am 

So if things follow the forecast ( or at least the most promising forecasts ) the rain / Sleet will turn to snow from the west as that cold air digs across with the process taking an hour or 2

In terms of the GFS I highlighted a part of the ENS thats much under used IMO which is the ENS height of the 0C isotherm ( Freezing level )

For the SE to see settling snow Ive set my benchmark at 150-200M > Which covers the downs & chilterns

Friday 09z was the peak of the PPN so heres the 00z ENS for that time

There was 5/30 under 200M ( not very promising ) & 6/30 Under 300M

Heres the 06z

There was 4/30 under 200M & 9 under 300M 

So a definite jump into the 2s but not 1s.

Hot off the press there are

6/30 under 200 & 10 under 300.

This indicates to me that the GFS is moving towards rather than away from the snowy solution, its doing this by 3 metrics

* Deepening the system & increasing the rotation across the SE through the early hours

* Sharpening up the jet thats over the SE coast pulling it slightly west so the PPN belt is over Lon & home counties not East kent

* Enhancing the PPN plumes thus dragging the ZDL level down.

 

Based on all that then if it all holds together as planned a few CMs could occur > 200M & locations >100M could well see snow falling but not necessarily settling.

Im 140M so feeling very much 50/50 but luckily have the 240M lookout point at west kingsdown radio mast just 2 miles away

hope this helps !

S

 

Bloody brilliant Steve, thanks very much for keeping us in the loop.

[Polaris]

A big time follower for 6 years + ( third post) 

The model thread hasn’t changed in all my years as a guest. 12z showing SWesterly airstream in FI La La land = winters over!!

Until next week ... rinse and repeat = anyone else knackered? 

Who needs an episode of Eastenders
 

 

[Tom Jarvis]

I think Crowborough could get some snow. 

[SMU]

Updated Euro 4 for Fri AM

Theres a 15cm in there just SE of London

[jamesgold]

8 minutes ago, Steve Murr said:

Updated Euro 4 for Fri AM

Theres a 15cm in there just SE of London

The things I would do for that chart to come off Absolute sweet spot here in Bromley

[dallas]

9 minutes ago, Steve Murr said:

Updated Euro 4 for Fri AM

Theres a 15cm in there just SE of London

I wonder if the Thames could play a part in feeding that

[SMU]

Wait for it

 

ECM BRINGS 10 inches of snow across the day on the wrap around to SW london ! ( more the outskirts up in the surrey hills 

[John Stevens]

4 minutes ago, Steve Murr said:

Wait for it

 

ECM BRINGS 10 inches of snow across the day on the wrap around to SW london ! ( more the outskirts up in the surrey hills 

Thanks Steve... hopefully that will happen and we’ll be enjoying a very snowy day up here in the Surrey Hills!!