Southeast England and East Anglia - Weather Chat

[Captain Shortwave]

Tomorrow

Strong west/south westerly winds

Early rain will clear to some showers, it will become brighter and cooler during the day.

Temperatures

7-10C

 

Overnight

A ground frost is likely in sheltered spots.

 

Friday

Gentle westerly winds

Sunshine and showers, mostly of rain, but they could contain a little hail and sleet.

Temperatures

4-7C

 

Overnight

Dry and clear with a widespread air frost

Temperature

temperatures down to -2/3C

 

Saturday

Gentle westerly flow again

A few troughs in the mix which could bring some showers, these will be of sleet, hail and possibly snow.

Temperature

3-5C

 

More later.

[NO LONGER POSTING]

81mph exposed north west Wales.. Cor!

[Captain Shortwave]

Tonight wet and windy spell.

Still looks pretty gusty (50-60mph, maybe a little more in exposed areas)

These will ease a little during tomorrow morning, increasing again during the afternoon.

Looks wet too with 10-20mm overnight.

[Daniel*]

"Errr. No. You need an unstable airmass and/or warm sea: none of which is true for this synoptic and this time of year which is why Jan tends not to be too snowy,"

You are on the pounce yes it totally would - we have positive anomalies encasing the whole british isles, with them sort of uppers you would get convective potent snow showers like 2010, with uppers below -8C on that particular chart and North Sea, 6-10C with a gradient of 16C that is quite a range? It is in the kitty for the reliable timeframe 100% no mild to be seen. In the reliable timeframe. January tends to be the snowiest month, it is not unusual to see snow at this time of year. It is a dead cert it is going to get much colder.

[Jax]

Temps appear to be rising here now, a few light spots of rain, nothing much and the wind still remains breezy with just the odd stronger gust.

[VillagePlank]

"Errr. No. You need an unstable airmass and/or warm sea: none of which is true for this synoptic and this time of year which is why Jan tends not to be too snowy,"

You are on the pounce yes it totally would - we have positive anomalies encasing the whole british isles, with them sort of uppers you would get convective potent snow showers like 2010, with uppers below -8C on that particular chart and North Sea, 6-10C with a gradient of 16C that is quite a range? It is in the kitty for the reliable timeframe 100% no mild to be seen. In the reliable timeframe. January tends to be the snowiest month, it is not unusual to see snow at this time of year. It is a dead cert it is going to get much colder.

image.jpg

 

Essentially it's too small of a sea track to behave like that.

 

The 'Beast from the East' requires a very specific set of circumstances. 850hPa's of -8C really aren't 'that' cold, and, of course, very dry air feeding of the continent due east is likely to dry out all the way up - effectively, just like summer where there's a dewpoint depression sufficient enough to kill off thunderstorms, and thus convective potential. Think of all the latent energy evaporating away as it rises without condensing since the air is too dry - you need proper saturation to realise full potential, which is why moist air is best for convection; no energy is wasted, and thus is more efficient.

 

Long NE tracks tend to be the best for east-coast 'lake-effect' snow, potential.

 

In my view, unless there is some sort of high theta-w advection (Biscay?) from some hitherto unknown source, it totally wouldn't. It'd be dry and cold with some snow on boundary conditions out West of London.

Edited January 14, 2015 by Sparkicle

[Daniel*]

Essentially it's too small of a sea track to behave like that.

 

The 'Beast from the East' requires a very specific set of circumstances. 850hPa's of -8C really aren't 'that' cold, and, of course, very dry air feeding of the continent due east is likely to dry out all the way up - effectively, just like summer where there's a dewpoint depression sufficient enough to kill off thunderstorms, and thus convective potential.

 

Long NE tracks tend to be the best for east-coast 'lake-effect' snow, potential.

 

In my view, unless there is some sort of high theta-w advection (Biscay?) from some hitherto unknown source, it totally wouldn't. It'd be dry and cold with some snow on boundary conditions out West of London.

You are entitled to your opinion - I can have mine.

Personally -8C below 850s is when it starts getting interesting for such developments such as streamers, the colder the better, the air is dry but the North Sea acts as a moisture laden spoon, it acts as the fuel the ignition is the cold air the more colder the upper air profile the better. E'ly do deliver just remember 2010, I got hit by some mega snow showers, gave me a coating in minutes, mental. Crazy snowfall rates.

[blackprince]

Roll on the snow.... this forum is starting to sound like the mod lot! shall we get back to those friendly nights of informative and good natured posts,perhaps the snowless winter we had to endure last time has dulled the spirit so as I said...ROLL ON THE SNOW.

[alexisj9]

Some really beefy gusts around here now at times, been dry I think since the showers earlier. 

[VillagePlank]

You are entitled to your opinion - I can have mine.

Personally -8C below 850s is when it starts getting interesting for such developments such as streamers, the colder the better, the air is dry but the North Sea acts as a moisture laden spoon, it acts as the fuel the ignition is the cold air the more colder the upper air profile the better. E'ly do deliver just remember 2010, I got hit by some mega snow showers, gave me a coating in minutes, mental. Crazy snowfall rates.

 

If I recall 2010 (not sure I do) that was a channel low interacting with a warm sector, not a straight feed from the near continent. -8C 850hPa's are, in fact, still in the marginal category for the UK: especially the SE, perhaps just the right side of marginal.

 

Can you get hold of the chart for 2010? I'd love to know.

Edited January 14, 2015 by Sparkicle

[VillagePlank]

Wind certainly picking up

 

http://www.xcweather.co.uk/

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

 

i  know  the people say its no good  but  it always seems there abouts  after  the  storm   we  could see  some  of the white stuff   might!!  just put all the things  which could fly in the garage  ,winds picking up  out  side

[AdamStorm7891]

Welcome the ramping. This is where people see charts that might as well be the next decade and go mad. Subsequently they are really disappointed and blame just about everyone else. LOL

 

Kent only.

Since when? Most forecasts I've seen have stated this will be a widespread event.

[VillagePlank]

Since when? Most forecasts I've seen have stated this will be a widespread event.

 

The snow next week? The front really only interacts with the West, and when it gets to the far SE. For sure, gusts of 50-60mph are likely to be widespread. But who knows: very complex setup tonight: the only real way to know is observations.

Edited January 14, 2015 by Sparkicle

[Daniel*]

If I recall 2010 (not sure I do) that was a channel low interacting with a warm sector, not a straight feed from the near continent. -8C 850hPa's are, in fact, still in the marginal category for the UK: especially the SE, perhaps just the right side of marginal.

Can you get hold of the chart for 2010? I'd love to know.

This highlights this point well ^

In an Easterly? Even a NW only needs -6, -7 for snow to low levels. With a continental flow, where the continent has entrenched cold, you can 850's of -1, -2 and get snow.

Yes, often folk take the 850hPa prognosis too literally. Chilled continental boundary layer critical.

No way is -8C marginal you would get snow in IOW quite easily dependant on other variables. Even with a full blown W'ly you would get wintriness like parts of the West Country saw yesterday.

Here you go December 1st 2010

On Wednesday 1 December the wind shifted from a north-easterly to a more easterly direction bringing heavy snowfalls across south-east England. The M25 was badly affected with 400 lorries stranded overnight, and Gatwick Airport was closed. There were also delays and cancellations on the rail network.

Edited January 14, 2015 by Daniel*

[Sno' problem]

Heard a couple of gusts of wind about 5 minutes ago, then suddenly the wind has hit with a flourish... Just saw a dustbin go past my window horizontally!!!   

Is there any reality to the idea of a cold sector digging in on the tail edge? That would be fun!

Edited January 14, 2015 by Sno' problem

[VillagePlank]

No way is -8C marginal you would get snow in IOW quite easily dependant on other variables. Even with a full blown W'ly you would get wintriness like parts of the West Country saw yesterday.

Here you go December 1st 2010

image.

 

I stand corrected.

 

(do you have 850hPa for the day before??)

Edited January 14, 2015 by Sparkicle

[Marie]

wind has just started to get going here , nothing major but can hear it whistling and am watching the lamp post sway slightly across the road .When are the worst of the winds due?

[VillagePlank]

No way is -8C marginal you would get snow in IOW quite easily (in)dependa(e)nt on(from) other variables. Even with a full blown W'ly you would get wintriness like parts of the West Country saw yesterday.

 

Well, it can snow at 8C 2m degC so I guess we can each pull up charts to support each others viewpoint.I've seen it snow with 850hPa's of -5C on a westerly (it bumped into cold air in the east) I've also seen it rain with -10 degC 850hPa. There is *so* much more to consider. -8C 850hPa feed on a dry easterly crossing the North Sea *is* marginal in my view: one of those horrible overcast cold and 'nothingness' days .... almost like a dirty high ....

 

The physics really aren't as simple as picking out a temperature from a scale and asserting, if it precipiates, it will snow. See my post a few pages back using theta-e and theta-w temperatures to more accurately predict the likelyhood of snow vs rain vs sleet. If it were that simple, we'd have no need for armies of weather forecasters utilising vast quantities of supercomputing power only to be accurate within a few days (not even the week you are going out to)

Edited January 14, 2015 by Sparkicle

[Daniel*]

I stand corrected.

 

(do you have 850hPa for the day before??)

Why day before?

[VillagePlank]

 

image.jpgimage.jpgimage.jpg

Why day before?

Thanks for those. Always willing to learn more. Lifetime pursuit and all that.

 

[Weathizard]

Aside from tonight's nastiness - it's only when you look back you realise what incredible charts & sypnotics they were as pictured above, saying that I preferred DEC 2009 as it lasted longer IMBY and then there was another shot in early jan I believe.

Look at these stonkers. I want more charts like these haha!

Edited January 14, 2015 by Weathizard

[Daniel*]

Thanks for those. Always willing to learn more. Lifetime pursuit and all that.

It's ok sorry about before I came across blunt. I do get passionate haha. All we need is some snaw. Even though the MOD thread is not most friendliest of places it is a good learning tool - through the clutter (didn't mean that!) there's some top notch posts which are 100% objective with no bias. Steve Murr can get a little carried away but that's why we like him so much, you know something is stirring when he posts. You learn something new in little bits it adds up.

[Crepuscular Ray]

wind has just started to get going here , nothing major but can hear it whistling and am watching the lamp post sway slightly across the road .When are the worst of the winds due?

Round 3 or 4 a.m. It's certainly nothing to write home about here yet. The most that is flying is dead leaves and plastic bags.

[VillagePlank]

It's ok sorry about before I came across blunt. I do get passionate haha. All we need is some snaw. Even though the MOD thread is not most friendliest of places it is a good learning tool - through the clutter (didn't mean that!) there's some top notch posts which are 100% objective with no bias. Steve Murr can get a little carried away but that's why we like him so much, you know something is stirring when he posts. You learn something new in little bits it adds up.

 

No worries, my apologies, too.

 

In my view we all have our little 'rules of thumb' that we can rely on, when, really, weather is so complex, one can be right and the other wrong one day, give it another day, the inverse is true!

 

I know you've shown good evidence of a feed from the east giving snow, I just recall countless times in seeing it and it never amounting to anything. I think this is a classic case of confirmation bias on my part.

Edited January 14, 2015 by Sparkicle