South East and East Anglia weather discussion/Chat - A new year

[Kent Blizzard]

Weekend looking cold, crisp, frosty and pretty much dry to me, I think our main chance will come overnight Thursday into Friday for Snow, perhaps Wednesday some sleet over higher ground in PM.

Thursday PM eyes to the West, if it moves to the South of us then Evaporative cooling will play a part for Northern/NW Areas of the Region.

Interesting 24hrs ahead and how the charts play as we get nearer, because of the tricky mess these things bring I think that's why the TV forecasts are keeping cards close to chest, very hard to pinpoint where and when snow will fall.

I'm amazed some are worrying and looking beyond Sunday at this stage, a lot of weather to get through before worrying what will happen next week. We can confidently predict 48/72hrs ahead let alone go into FI again.

 

Edited January 11, 2016 by Kent Blizzard

[Jo S]

just finished my night shift, roads flooded rolling onto the roads off of the fields, a mad woman driver who dropped me off home,didnt stop for nothing glad to be in one bit, think if we get some snow, will walk home and play snow angels  well theres always hope 

[Jo S]

3 minutes ago, Jo S said:

just finished my night shift, roads flooded rolling onto the roads off of the fields, a mad woman driver who dropped me off home,didnt stop for nothing glad to be in one bit, think if we get some snow, will walk home and play snow angels  well theres always hope 

ok for me no Angel 

[VillagePlank]

If anyone's interested in how my snow risk percentages are worked out, here's the equation,

where t-e is the 850hPa theta-e temperature at the time. And here's the resulting chart,

I did take this from empirical research (Bradbury, 1970) but the resulting equation - as far as I know, is original.

 

Edited January 11, 2016 by VillagePlank

[Kent Blizzard]

9 minutes ago, VillagePlank said:

If anyone's interested in how my snow risk percentages are worked out, here's the equation,

where t-e is the theta-e temperature at the time. And here's the resulting chart,

I did take this from empirical research but the resulting equation - as far as I know, is original.

 

Interesting stuff Village, way to advanced for my limited knowledge though as you can probably tell that I've gone for a cool dry weekend and your numbers suggest our highest snow risk is the weekend... lol

Edited January 11, 2016 by Kent Blizzard

[VillagePlank]

1 minute ago, Kent Blizzard said:

Interesting stuff Village, way to advanced for my limited knowledge though as you can probably tell that I've gone for a cool dry weekend and your numbers suggest our highest snow risk is the weekend... lol

Sorry, me bad. - my percentages assume precipitation, so the snow risk only applies if stuff is falling out the sky! Oh, and it's for mean-sea-level, too.

So, if we look at the precipitation charts, there seems to be a lot around on Thursday evening,

If we then look at the 850hPa Theta-e chart, we can see that the value is  approximately 16degC,

So, based on the above this means that approximately 76% of the time, that precipitation will fall as snow at MSL. I am at height, so I would expect to see snow based on this run from GFS.

[VillagePlank]

Here's the numerical chart,

At the worst, I reckon, this isn't such a bad rule of thumb. Of course, other factors do come into play, such as the heaviness of the precipitation, height, etc etc.

Edited January 11, 2016 by VillagePlank

[Kent Blizzard]

13 minutes ago, VillagePlank said:

Here's the numerical chart,

At the worst, I reckon, this isn't such a bad rule of thumb. Of course, other factors do come into play, such as the heaviness of the precipitation, height, etc etc.

I see thanks Village ...it's going to be an interesting learning curve this week.

[VillagePlank]

So, looking at Thursday morning between 3am and 6am, according to GFS06z, and theta-e rule of thumb, the far SE is looking at approximately 6 inches of snow with a 84% probability - assuming this model is correct, of course.

Edited January 11, 2016 by VillagePlank

[Kent Blizzard]

1 minute ago, VillagePlank said:

So, looking at Thursday morning between 3am and 6am, according to GFS06z, and theta-e rule of thumb, the far SE is looking at approximately 6 inches of snow with a 84% probability - assuming this model is correct, of course.

I best watch how I word this BUT i would love 6 inches of...Snow  would be amazed if we got that much but maybe some lucky location might on higher ground, I'll be happy with an Inch just so it covers he road  ...6 inches would see the curb disappear 

[VillagePlank]

9 minutes ago, Kent Blizzard said:

I best watch how I word this BUT i would love 6 inches of...Snow  would be amazed if we got that much but maybe some lucky location might on higher ground, I'll be happy with an Inch just so it covers he road  ...6 inches would see the curb disappear 

Well, of course, there's the other 16% which covers 850hPa temps to high, DP too high etc. I have looked at the atmospheric column that covers most of the cloud until the surface, and that looks OK:

But may well be modified before it touches down to rain,

ie the marginality is at the surface layer; orography, height, location all critical. 850hPa thickness of 130dm pretty much means all precipitation type possible! You need to be at or below 129dm for the layer to be freezing all the way. I would say that there's near enough 100% chance that the precipitation will leave the cloud as snow based on the above scenario. Here, 20m height could make all the difference!!

Edited January 11, 2016 by VillagePlank

[Ben Lewis]

Very uninspiring from Met Office:

 

Outlook for Wednesday to Friday:

Wednesday and Friday frosty initially, especially Wednesday, and mainly dry with sunny spells. Thursday showers or longer spells of rain, low risk of becoming wintry. Generally cold or rather cold

Those 5 day ago black holes/ strong Greenland heights with an incredible block charts, really are a distant memory!!!

[Kent Blizzard]

3 minutes ago, Ben Lewis said:

Very uninspiring from Met Office:

 

Outlook for Wednesday to Friday:

Wednesday and Friday frosty initially, especially Wednesday, and mainly dry with sunny spells. Thursday showers or longer spells of rain, low risk of becoming wintry. Generally cold or rather cold

Those 5 day ago black holes/ strong Greenland heights with an incredible block charts, really are a distant memory!!!

I expected no different to be honest, it's exactly how it looks apart from the " Low Risk " statement, I'm surprised only at that part I think risk would of been better term especially as it seems likely Evaporating Cooling will be a key factor, but fair play for them not sitting on the fence I guess....Next couple updates will be interesting.

Edited January 11, 2016 by Kent Blizzard

[Jo S]

1 hour ago, Jo S said:

 

trying not to get excited again, ah the ups and downs of the good old British weather 

[NO LONGER POSTING]

On 1/8/2016 at 1:30 PM, Jimmyh said:

 

Sorry JimmyH no idea why you are quoted into this not aimed at anyone.

 

We need to take a step back for one second we are chasing an event that is over 48 hours away absolutey no point looking at finer detail until Wednesday earliest. In fact not till Thursday daytime really things change rapidly when it comes to snow and cooler conditions!

BUT that aside the things you want to look at is Cold and PPN.

Okay looks good ^

PARTY POOPER ALERT! ^

ERRRRRR 

 

 

[Kent Blizzard]

When I use my kindle or iphone It puts someone's quote in my text box also, not sure why it does it, when I'm working and using laptop it's ok though

Anyway look out for the Winter is over posts for those that don't see the fluffy white stuff come the end of the week even though it'll only be the halfway point of Winter 

Edited January 11, 2016 by Kent Blizzard

[Ben Lewis]

50 minutes ago, Kent Blizzard said:

I expected no different to be honest, it's exactly how it looks apart from the " Low Risk " statement, I'm surprised only at that part I think risk would of been better term especially as it seems likely Evaporating Cooling will be a key factor, but fair play for them not sitting on the fence I guess....Next couple updates will be interesting.

I think thats what I found most annoying "low risk" - Not that I am saying they are are wrong, far from it. It just looked like 2 days ago there was a real chance of something more organised. Now even to get a sleet shower looks like pulling teeth. 

Baring in mind that if we hadn't just had the warmest December on record along with another snowless winter so far, this weeks sorry excuse for a cold spell would not be generating half as much interest as it is now.

[Kent Blizzard]

10 minutes ago, Ben Lewis said:

I think thats what I found most annoying "low risk" - Not that I am saying they are are wrong, far from it. It just looked like 2 days ago there was a real chance of something more organised. Now even to get a sleet shower looks like pulling teeth. 

Baring in mind that if we hadn't just had the warmest December on record along with another snowless winter so far, this weeks sorry excuse for a cold spell would not be generating half as much interest as it is now.

I don't suppose yourself or any members have archived the written forecast/outlooks for either the 2013 event we had or the 2010 event? It would be good to compare how they was worded in the lead up to them events although of course they was of a different nature.

I could only find details on the warnings that was issued 09/10 with only one negative given against warnings issued- 

Negative - 10 January 2010
Initial warnings for snow across England and Wales overplayed, but forecasts and communications were modified as the situation developed - some media criticism but praise received from local planners for providing useful updates. 

Positive -  12-13 January 2010
Weather warnings issued for heavy snow across many parts of Britain including the south-west and Wales, where the heaviest snow fell, although more snow than expected fell in some parts of the south-east on Wednesday morning. This fell onto frozen ground leading to extremely difficult travel conditions.

Edited January 11, 2016 by Kent Blizzard

[Jimmyh]

seems like no cold actually penetrate this far am I right?

[snowray]

Indeed the French Arpege model 06z still picking up a nice crop of snow over East Anglia early doors Thursday, might be see a few flakes in parts of London too.

[snowray]

BBC now showing rain for London Thurs and 6c, although the forecaster said PPN could be Wintry!

 

Seems we are always clutching at straws, what happened to all those lovely charts last week, black holes and all???

Edited January 11, 2016 by snowray

[Kent Blizzard]

8 minutes ago, Jimmyh said:

seems like no cold actually penetrate this far am I right?

Depends what you class as cold Jimmy, Thursday daytime around 4*c , Friday daytime perhaps a touch cooler especially in clear spots and same through the weekend, feel like temps a lot colder.

Surely we are due a met office written update soon?

Edited January 11, 2016 by Kent Blizzard

[snowray]

Snow depths...

[Jimmyh]

13 minutes ago, Kent Blizzard said:

Depends what you class as cold Jimmy, Thursday daytime around 4*c , Friday daytime perhaps a touch cooler especially in clear spots and same through the weekend, feel like temps a lot colder.

Surely we are due a met office written update soon?

Unfortunately I know it will be a shock to the system but I want some genuine cold days 0 or 1 degree is what I am looking for with some snow about looks marginal to me with a 3 hour period Thursday morning. I hope this gets colder as time goes on.

[Kent Blizzard]

1 minute ago, Jimmyh said:

Unfortunately I know it will be a shock to the system but I want some genuine cold days 0 or 1 degree is what I am looking for with some snow about looks marginal to me with a 3 hour period Thursday morning. I hope this gets colder as time goes on.

Just wear less clothes and it will feel more colder