South East and East Anglia Weather Discussion January 2021 onwards

[Polaris]

PPN decaying like no tomorrow. 
 

Nice to hear reports of snow north of the region if rather wet and pitiful. 
 

Maybe Saturday might held some wet sleet amongst yet more rainfall that we don’t need 

[Frostbite1980]

6 minutes ago, Captain Shortwave said:

pretty clear as to where the front stalled for the majority of the past 36 hours. 30mm of rain here as well as a couple of hours of moderate wet snow. We really need some dry weather as much as anything. Hopefully we can get blocked and cold without the mass onslaught of rain. So we probably need to avoid the west based -NAO over the coming weeks.

Yep i am a DFCO and had loads of flood alerts come through today and really shocked there have been no weather warnings for today. I hope there is for saturday as those alerts could turn to warnings and Bedford has had an awful time of it lately as has other areas.

[Hotspur62]

Yes I am in that yellow bit in lb of Bromley-30mms of rain is an awful lot on already sodden ground and no wonder my flower beds flooded this morning in the heavy rain between 6.9 am today.At least a dry cold day tomorrow but more rain Saturday but then dry again Sunday and MondayAfter that who knows.

 

Currently 1.8 here in Locksbottom but feels colder than that.Strange day in that it was 5 degrees at 7am but very slowly dropped throughout the day to its current level.

 

[Gowon]

The Channel 4 weather showed a period of snow in our region before it turns back to rain on Saturday morning - it's still be nice to watch even if doesn't settle I suppose. 

[Methuselah]

12 minutes ago, D.V.R said:

The Channel 4 weather showed a period of snow in our region before it turns back to rain on Saturday morning - it's still be nice to watch even if doesn't settle I suppose. 

Och well, sure beats being shafted with the rough end of a pineapple, I suppose?!

[Alpine glow]

I'm a bit confused in the mod thread...  i'm having a quick catch up and am i right in thinking that the models are still trying to deal with the effects of the SSW and it's all still in the balance?

[Gowon]

14 minutes ago, General Cluster said:

Och well, sure beats being shafted with the rough end of a pineapple, I suppose?!

Ouch! I'll settle for the temporary wet snow/sleet 

[lawrenk]

1 hour ago, winterfreak said:

In other news the cold is just ten days away according to the models.., 

No two ways about it, this has been one of the best “ten days away winters” I can remember.

The reality of course, this far, has been utter sh**e.

[Jason T]

45 minutes ago, Alpine glow said:

I'm a bit confused in the mod thread...  i'm having a quick catch up and am i right in thinking that the models are still trying to deal with the effects of the SSW and it's all still in the balance?

Hi Alpine, i was going to try and explain, but there is no real easy way...The only answer I can give is that during an SSW and even after the event, Data is in turmoil as the models have to try and work out what's actually going to happen...Remember (Try)..so any output will show an answer but this could be way off to actual. For us all excluding some knowledgeable's and certainly Chio, No offence Ed, just trying to help some including myself. This link will really help and in laymen term explain, ie a much easier way to understand the terminology of an SSW event and it's effects.

Sudden stratospheric warming responsible for UK's icy blast - BBC Weather

WWW.BBC.CO.UK

---

The icy blast moving across the UK has its roots high up in the stratosphere days ago. As BBC Weather's John Hammond writes, it makes longer-term forecasting unusually tricky.

 

[Alpine glow]

1 minute ago, Jason T said:

Hi Alpine, i was going to try and explain, but there is no real easy way...The only answer I can give is that during an SSW and even after the event, Data is in turmoil as the models have to try and work out what's actually going to happen...Remember (Try)..so any output will show an answer but this could be way off to actual. For us all excluding some knowledgeable's and certainly Chio, No offence Ed, just trying to help some including myself. This link will really help and in laymen term explain, ie a much easier way to understand the terminology of an SSW event and it's effects.

Sudden stratospheric warming responsible for UK's icy blast - BBC Weather

WWW.BBC.CO.UK

---

The icy blast moving across the UK has its roots high up in the stratosphere days ago. As BBC Weather's John Hammond writes, it makes longer-term forecasting unusually tricky.

 

Thank you Jason.

Yes, i've followed the models thread for a couple of years so my jets are cooled!  I was there for That ECM   Massive rollercoaster, but that's exciting, eh!  I can normally sift the wheat from the chaf from the Model thread but couldn't catch up tonight for some reason.

[chionomaniac]

4 minutes ago, Alpine glow said:

Thank you Jason.

Yes, i've followed the models thread for a couple of years so my jets are cooled!  I was there for That ECM   Massive rollercoaster, but that's exciting, eh!  I can normally sift the wheat from the chaf from the Model thread but couldn't catch up tonight for some reason.

I think the thing to realise is that the SSW is still in its infancy to how it affects us at the surface level. So, the models will still be variable as to ascertaining what the correct trop response will be for a while yet. So past day 6 small differences in how the SSW affects the trop can make big differences here - from a mild Southwesterly to a cold northerly. It all depends on how and where a block sets up and orientates

[Great Plum]

Just popped out to the local coop - no rain now in Reigate but it’s brass monkeys out here! Could well be some ice in the morning!

[Jason T]

6 minutes ago, Alpine glow said:

Thank you Jason.

Yes, i've followed the models thread for a couple of years so my jets are cooled!  I was there for That ECM   Massive rollercoaster, but that's exciting, eh!  I can normally sift the wheat from the chaf from the Model thread but couldn't catch up tonight for some reason.

Love your reply Alpine....Brilliant. As for the rollercoaster ride, Can you imagine if Alton towers had the BIG 3 ride, (behave some with that phrase) Into the darkness we all go with not a clue what's going to happen next...that is about the truth of our reality right now lol. @chionomaniacthanks for like...Much appreciated..

[bluebell]

28 minutes ago, Alpine glow said:

Thank you Jason.

Yes, i've followed the models thread for a couple of years so my jets are cooled!  I was there for That ECM   Massive rollercoaster, but that's exciting, eh!  I can normally sift the wheat from the chaf from the Model thread but couldn't catch up tonight for some reason.

Sift wheat from chaff.. yes this exactly! Plus I couldn’t sort/sift to reach a rational reasoned  conclusion about our chances for snow either from the latest MOd commentary either! Perfect analogy !

[londonblizzard]

latest met office video forecast has snow on saturday morning for much of london and the northern side of our region

[Chertseystreamer79]

The whole meto update for us southerners is dire all the way through! 

 

Good news is its changed 3 times in 3 days! 

 

Clueless....keep the faith!

[If Wishes made Weather]

Hello- on the models.  Perhaps it might’ve just help to think of them like this.  What I am going to write is a massive simplification but here goes:

- the models are not conscious and do not work out right or wrong answers.  They are just a set of equations run by computers that start with numbers and generate outputs that are other numbers.  These output numbers are then turned into charts that we humans can read.

- the input data is a set of measurements of temperatures, pressures, humidity, wind speeds and direction (and maybe some other things as well).

- these input data has no inherent predictive value.  It’s just numbers.  The predictive element comes in by the programmers choosing which equations to use to change these numbers into other numbers.  So a simple and false example.  Imagine that at a certain place it is known that if the temperature is 20c at 8am, then 80% of the time in June the temperature will be 30c at midday, then the programmers may use an equation to provide an output that is has a value of 30c for the midday chart.  Of course it will be wrong 20% of the time, but it is still reasonably accurate.  The input data may be said to have a high predictive value.

- now, this is a little more complex.  At the moment with the SSW, these sort of assumptions don’t hold so well.  Also - bearing in mind that millions of calculations are done to create the charts - some of the predictive assumptions built into the models ( i.e. which calculations to use) conflict.  This all means that the high predictive value that can be put on the data normally no longer holds true.  It is said to be more entropic.

- a further aggravating factor is that time.  The models I believe use some of the output data as input data for their next chart.  Thus some of the output that creates the midnight chart (say) goes into creating the chart that is for 6 hours later, and of course when this output is already not very predictive, then anything based upon it will be even less predictive.  There is a point often called F I where the outputs are of no predictive value (in terms of saying what the actual weather will be).  They are just for indicating what, given the input data and the laws of physics, is possible.  Not necessarily probable.

 

Hope this helps a bit and my apologies to any mathematicians reading this.

[stainesbloke]

My friend in Pontefract in Yorkshire sent me a pic this afternoon, she couldn’t get to work as public transport all ground to a halt up there

[Paul Sherman]

Hoping we dont get too many more days like that this winter, absolutely rough with a strong raw wind off the North Sea and temps ranged from 2-4c all day with 36mm of rain taking the monthly total to 52.6mm. Absolute carnage on Road and Rail down here as well with major roads closed and the C2C Line closed at times today.

 

[Downpour]

32 minutes ago, londonblizzard said:

latest met office video forecast has snow on saturday morning for much of london and the northern side of our region

I’d expect that to be downgraded to yet more cold rain nearer the time. 

[Daniel*]

4 minutes ago, Downpour said:

I’d expect that to be downgraded to yet more cold rain nearer the time. 

God we are a bunch of optimists. 

Edited January 14, 2021 by Daniel*

[steveinsussex]

27 minutes ago, stainesbloke said:

My friend in Pontefract in Yorkshire sent me a pic this afternoon, she couldn’t get to work as public transport all ground to a halt up there

But northerners love to tell us that never happens up there, only down south?!

[Captain Shortwave]

5 minutes ago, Downpour said:

I’d expect that to be downgraded to yet more cold rain nearer the time. 

There is a good chance that the precipitation will start off as snow on Saturday and the front looks quite active (5-10mm from only a few hours of precipitation). However I would probably suggest that if you want to see snow, then you should probably avoid having a lie-in on that morning....

[stainesbloke]

1 minute ago, Daniel* said:

God we are a bunch of optimists. 

Definitely unlucky in the SE so far, but it’s only half way through winter, so plenty of time for a snowy spell to occur. 

[stainesbloke]

Just now, steveinsussex said:

But northerners love to tell us that never happens up there, only down south?!

Happens more up there than down in the south, for sure, but still not very often