SE, London & EA - Weather Discussion

[Harry's House]

Days of thunder heard at my house in Pagham in each year from 2016:

2016: 10

2017: 11

2018: 12

2019: 10

2020: 4

2021: 9 (omitting 8th September when I was away and I could well have missed thunder on that day)

2022: 17, the highest I've observed since the thundery year of 1999 when I observed 19 days when I was living in Shinfield near Reading

Days of sleet/snow at my house in Pagham in each winter period from 2015/16:

2015/16: 3

2016/17: 3

2017/18: 12 (estimated)

2018/19: 6 (estimated)

2019/20: 1

2020/21: 8

2021/22: 6

20222/23: 1 up to and including 2nd January

[MAF]

well all this talk of 'winters over' is a load of tosh. is blinking cold out there, nothing like spring or summer

[Snowangel-MK]

3 hours ago, MAF said:

well all this talk of 'winters over' is a load of tosh. is blinking cold out there, nothing like spring or summer

We had a frost last night !

Hope you get on okay tomorrow for your eye op  
 

I had my stitches out this afternoon, my hand has healed well but I needed a tetanus shot, apparently I hadn’t had once since 1969

 

 

 

 

[MAF]

2 hours ago, Snowangel-MK said:

We had a frost last night !

Hope you get on okay tomorrow for your eye op  
 

I had my stitches out this afternoon, my hand has healed well but I needed a tetanus shot, apparently I hadn’t had once since 1969

to be honest, i am really nervous (scared) i have only been to hospital once before for minor surgery and it was a painful experience. as the doctor said when i was still in pain a week after 'he butchered you there'

i had a tetanus a good few years ago when fluffy caught my arm with his teeth, was the first booster i had had since my first one as a kid. 

i need to be at the hospital for 0730 tomorrow, and have to get two buses there, so it's a half five start start for me in the morning. usually get up that time for work, but been off for the last three weeks and only going back to work today, silly o'clock start tomorrow will be a pain 

'night all

 

[snowrye]

Certainly a door and window rattler tonight 

[alexisj9]

5 hours ago, Snowangel-MK said:

We had a frost last night !

Hope you get on okay tomorrow for your eye op  
 

I had my stitches out this afternoon, my hand has healed well but I needed a tetanus shot, apparently I hadn’t had once since 1969

 

 

 

 

Vso did we till tge showers turned up and warmed things up. Not sure about after that though got to sleep properly when shower stopped .

[Sparky68]

12c on the way in and wet. Not liking this weather!

[Tn9]

On 02/01/2023 at 11:53, Eagle Eye said:

My post copied over from the model thread,

"

I'm going to copy over my pretty much non-biased (hopefully) texted forecast long-term to one of my friends...

Firstly, we have the Atmospheric Angular Momentum (AAM) which is the amount of torque or rotational force in the atmosphere. Positive AAM (+VE means positive and I'll be using that) typically results in a pattern where +VE temperature anomalies move poleward and see we have hotter than average temperatures over the Arctic whereas the cold from the Arctic falls to the mid-latitudes (including us) and we see negative(-VE) anomalies there (known as Nino-esque). It's important to note that +VE AAM doesn't cause -VE temperatures everywhere in the mid-latitudes, it depends where the warmer air moves into(advects or WAA) the poles and therefore the cold partly falls on the other side of it to somewhere. If this happens over North America that can potentially fire up the Atlantic and for the UK that means the mild and wet that we've been getting recently though we may still get a visit from the Polar Maritime air for a bit. Whereas if we get WAA into Greenland that can often result in the Atlantic effectively being shut off and can lead to cold air falling to the UK in the form of say an Easterly or a Northeasterly and with that there's the threat of snow. It's what happened in early December this Winter.

There's also negative(-VE) AAM which results in a fairly flat and 'normal' system (known as Nina-esque) where we in the UK usually get mild and wet though it depends on the strength of the -VE AAM.

Right now though, it's fairly neutral and so we're relying on 'events' of gain of torque to increase or decrease the AAM and this is where we get to first know the EAMT or East Asian Mountain Torque. A +VE EAMT event is where warm air hits the Himalayas and we find Him a laying in the Stratosphere wave activity moves vertically up into the Stratosphere and we see the gain of AAMin the Trop-Strat this way. On the other hand we have -VE EAMT where cold hits the Himalayas and there's a loss of momentum into the Earth....

With such a fairly neutral AAM it's unlikely to be the main driver but as a basic signal it's fairly good at explaining how things work.

Right now and in the mid-term forecasts, for the end of the first week of January it's looking like we will get warm air moving upwards into the Himalayas and a propagating vertical wave vector into the Stratosphere fairly quickly which results in a +VE EAMT event and an increase to +VE AAM. This will probably result in an extension of the zonal jet in the Pacific. Normally, an extended jet globally is the last thing that we want but just over the Pacific it's fairly good and as I noted +VE AAM tends to drive poleward warm air influence and we don't want that to be over the Pacific (an extended Pacific jet tends to stop that from happening) and instead would prefer it to be towards Greenland for cold for us. 

 

Now it's time to combine this with the MJO signal...

Combining the MJO with an EAMT event is fraught with danger because that event can shift the Rossby wave (a ridge and a trough or rather a high on one side then a low on the other sort of) pattern from each of the MJO phases and Rossby waves help shift energy throughout the Atmosphere. Luckily, the Atmosphere is being fairly helpful to me and offering me two patterns that come to roughly the same conclusion with the +VE EAMT and MJO phase.

There are 8 different MJO phases

 

Phase 1 is fairly non-descript for us though I find it to usually be mild and wet may just be because that's how the 'average' part of Winter is for us.

Phases 2 and 3 tend to drive the mild and wet muck that not many people like and you can probably include phase 4 in that. As these seem to help +VE Azores region Hadley cell development and the Euro high tends to form because of this.

Phase 5 is fairly non-descript.

Phases 6 and 7 are heralded mostly by UK cold lovers because they help with warm air advection towards Greenland (known as a -VE NAO) or sometimes Scandinavia(?) and that often results in a colder pattern for the UK as air can move in from the East/Northeast.

Phase 8 drives high-latitude North American blocking and potentially a west based -VE NAO as well. Though a west based -VE NAO is dangerous for cold as it leaves the door open for the Atlantic as well and so in a strong westerly system (depending on how the East of North America evolves as well) it can end up being a 'wasted' solution and we revert back to type (mild and wet). Although, this type of far west based -VE NAO (so far that it doesn't count) can still be cold with quick shots of Polar Maritime air as it's more North West centred so the air coming down is potentially from a colder place with a steeper gradient and so areas such as the North and Scotland do best from this and even places as far as the south might be able to escape the mild and wet. Instead it may be cold and wet or if it gets cold enough, cold and sleety/snowy. Polar Maritimes aren't always the best but they're the best we're probably going to get soon...

Currently, the forecasts suggest that the +VE EAMT event will coincide with phase 7/8 and high latitude North American blocking looks to be the most driven solution out of this despite both being fairly under amplified because putting them together and you've got yourself poleward driven warm air around North America. This is slowly evolving now with the MJO phase 6/7 lag over the coming days building mid-high latitude blocking and as phase 7 properly pushes in, I think long-term and we'll get increasing Polar Maritime(PM) potentially as this acts like a far west based -VE NAO. It doesn't look overly like zonal mild and wet though a quick Southeast US trough linking up with the Canadian low may mean that for a time that returns very strongly.

So still looking fairly mild and wet long-term especially in the south but further North may actually fare quite well and I don't see why some of the cold can't make it far south enough to bring the midlands or even the south some snow for a time. I think the GFS going for a large -VE NAO long-term is fairly dubious. My thoughts are more along the lines of the MJO progressing more quickly than the forecasts are showing into Phase 8 and that continues to interact with the +VE EAMT reaction forming North American blocking but no large -VE NAO. Though, if the current MJOprojections are correct then we stay largely in Phase 7 with it amplifying for a time and so maybe we can get a -VE NAO and cold via an Easterly/Northeasterly that way. If it does interact with how the Pacific jet evolves that way then we can get excited about Tropospheric based significant cold potential for late January but for now I don't think it's going to be amplified enough nor under-progressive enough for that to happen. Instead PM may be our best chance of cold at least away from the Stratospheric pattern...

 

 

The Strat pattern continues to show signs of displacement as the main part of the vortex appears over Greenland area and displacement is a good thing as it generally leads to the weakening of the Strat westerly winds (zonal winds) due to abnormal Rossby wave thermal transfer and the resultant net easterly force from Rossby waves. So, a slowing down due to displacement but not a sudden warming just yet. A sudden Stratospheric warming (SSW) is characterised with the reversal of the Strat zonal winds between 60-65N (apparently) and typically that happens with a large displacement or a split. Generally a split right down the middle of the vortex, perhaps a displaced vortex is more associated with a major SSW and a large displacement with minor SSW's but I think I've heard of one or two major SSW's that were displacements but I don't think it's enough to just rely on a displacement especially to get one in the first place. The polar-night jet formed very strongly recently and we have an anomalously +VE Strat zonal winds in the first place so to get a SSW from just a displacement alone is probably unlikely though it does look like it's going to weaken it quite a lot to perhaps below average but beyond that relies on how the Trop pattern evolves...

If Wave-2(2 warming areas, Wave-1 is 1) increases then a split considering the initial displacement is fairly likely if we can get a strong Wave-2. Recent trends have had it increasing at the end of the run going into mid January but nowhere near where need it to be. As the large Pacific wave connects up with the North American response to the +VE EAMT and MJO phase 7/8 event, it should start slinking away from Siberia which may be a good thing. A +VE Ural Block (UB) in the Trop pattern could provide the upward wave flux we need for a Wave-2 signal though I think it probably needs to be a lot stronger than where it is currently at on the models, at least it's a start. The 2018 SSW had a persistent UB pressuring the Strat beforehand plus it was Wave-2. A UB isn't the best indicator as it may be the only vertical wave flux and so Wave-1 signal such as the 2019 one which seemed to mostly have been UB based with no other real intense blocking and at the time the forecasts were showing a displacement event. It's important to note that SSW's do evolve relatively slowly as the pressure and displacement increases (especially Wave-1 followed by Wave-2 events) and then the snap happens. 

In the current scenario a split would only really happen if Wave-2 increased fairly significantly and that would possibly be to do with the timing of the UB omega (?) block expansion and the initial warming Wave moving towards the Pacific/North America perhaps negating the need for an Alaskan blocking in the Trop but for now the UB times itself just too early and instead focuses itself on strengthening Wave-1 similar to how 2019 evolved, I think that was a former UB on top of a re-strengthened UB. 

So in other words, it's possible that even if a SSW does happen it could be similar to 2019 but importantly, at this time the zonal wind looks to be around average so this wouldn't be the onset of a SSW, just something to keep it displaced for now. It seems like a wasted +VE UB block but it's important in keeping up the pressure on the Strat and also for the secondary displacement towards Greenland where it looks to shrink back a little bit. This leaves room for what would be the most helpful thing considering the placement of Wave-1. A Scandi high would split the vortex in two but when we need it there's no real sign of it, yet. Although, the stretching of the Strat and the general movement of the Wave-1 heights would suggest that a UB a few days after the end of the GFS run would be a good way to split it  with the increasing Wave-2. It's at times like this where you get a little bit mad at your luck. 

This has looked the case on recent runs but it's still quite far out. Given how everything is timing itself though it does like an increasing of Wave-1 towards North America with the vertical wave flux propagated by the +VE heights over North America and combined with the +VE UB doing similar, the Wave-1 continues to get a lot of support from below it and keeps the Strat Vortex displaced and stretched but no real signs of an increasing Wave-2 strength largely just yet. That's shown well on the image below.

Why do we want a split and major SSW instead of a displacement?

Mainly want a split rather than a displacement because split's generally increase the chance of getting a major SSW and so the zonal wind reversal reaches the Troposphere which is an important area for the evolution of our weather systems. A split rather than a displacement also usually favours a colder pattern for Europe with a displacement favouring North America with it's downwelling effects. It's also the reason that we want Wave-2 more than Wave-1 as Wave-1 displaces the Strat but often a strongly amplified Wave-2 will split the Strat and that's much better for getting a SSW in the first place and for it's efffects for Europe in terms of helping to bring us a generally colder pattern.

Why does a SSW typically bring colder weather to the mid-latitudes?

I sort of touched on it earlier, it's mainly to do with the reversal of the Stratospheric zonal winds and as Rossby waves attempt to move vertically, the reach the reversal, impart their easterly force and break up and this continues until the easterlies are in the Troposphere.

What are some SSW past events?

January 2009 SSW (thanks to Simon Lee's blogs) and the relatively quick revert to the Easterly for the UK though it didn't last for too long, it was a major SSW (I think).

February 2018 (also thanks to Simon Lee), this also occurred right after very strong polar-night jet happened as the Tropospheric Eddy-driven jet pushes up thermal wave flux and we saw the development of a strong Wave-2 split.

 

 

 

So what's coming up?

I think for the Strat it's the case of wait a while and see where we are. The best signs continue to be long-term and there's still no real signs of a SSW just a return to average, perhaps slightly above or below average. Though, the initial warming Wave which is followed by backup is now with about a week but what happens beyond that depends largely on how quickly the North American and Eurasian patterns evolve which I generalised above but there's a lot of potential difference with the actual timing, if it happens at all. That may have a fairly big effect on how things evolve. So for now, it's going to be waiting but I'm still going to be updating you on the trends with how timing is evolving, these are just my general 'musings' that my friend had to listen to me talk about this morning.".

 

So your really saying we are waiting for something out of the blue , some little outlier to come true , a local anomaly,just to confuse the whole set up ,possible yea? ,like driving down  motorway we are going one way other side going other way all good and average and flowing ,then there is a minor incident,everything slows ,in that  you change everything and then more  smaller occurrences happen , then bang we are on it, against the flow of the bigger network ? My fingers are crossed , bit like throwing a spanner in the works

ps I love your posts ,the time effort you put in is second to none ,happy new year fella:)

Edited January 4, 2023 by TN9

[Snowangel-MK]

Christmas January is over, tomorrow I officially enter real January……
No more alcohol and cake for breakfast (all the nice food is gone now so only healthy options available) the pretty lights & decorations are down (the living room feels huge…but bare) and sadly no more afternoon naps (well not the days I’m working anyway) 🥹what I really need now is some snow to cheer me up! 
 

 

[MAF]

here you go

  

right, pizza eaten, pain meds taken, time for sleep  

[Snowangel-MK]

12 minutes ago, MAF said:

here you go

  

right, pizza eaten, pain meds taken, time for sleep  

If only …. No point going to the Alps though, they are having to make their own snow for the very green & rocky looking ski slopes  

speedy recovery ‍ 

[MAF]

eye patch off this morning. limited vision but not so painful. one eye drop 4 times a day for next 3 weeks. then one drop 3 times a day for 2 weeks  

[Snowangel-MK]

Planning for the next 12 months… I’m  not sure about the weather but there is no way I’m doing dry January 🥹

No sign of a big freeze, beast from the east etc in the foreseeable despite the tabloid’s scaremongering, I was pleased to see the Met O set the records straight yesterday! 
 

 

[moogyboobles]

I think this might be the first time I've ever hung washing outside in January. 

[Reefseeker]

14 hours ago, Snowangel-MK said:

Christmas January is over, tomorrow I officially enter real January……
 

Same here, I've just taken down the decs, trees etc, although to help me through it managed to eat a couple of chocolates. I always get very sad at the end of Christmas, despite the stress it can bring, and today is no exception. Ah well, the house looks bigger now and the healthy food options are piled up in the fridge... whether they'll get eaten is another matter;)

Continuous grey and mild as usual on the weather menu today, although at least it's dry for a while. A snow fix would be wonderful, but given the outlook for the next few weeks, I'll just keep watching the Santa village webcam instead.

[MAF]

3 hours ago, moogyboobles said:

I think this might be the first time I've ever hung washing outside in January. 

i did the same! although a bit cloudy since i put it out. hooping the breeze dries it a bit more before the tumble dryer get used. 

[lassie23]

Is it safe to say that winter is over?

[Tn9]

4 minutes ago, lassie23 said:

Is it safe to say that winter is over?

I reckon we  may have a couple frosts mid  Jan ,ground not air ones  that would be pushing the boat out ..

[Bogman]

17 minutes ago, lassie23 said:

Is it safe to say that winter is over?

I would like it to be.

 

* Snow - check.

* Frost - check.

* Wind - check.

* Rain - check.

 

Warm and dry now please.

[lassie23]

18 minutes ago, Bogman said:

I would like it to be.

 

* Snow - check.

* Frost - check.

* Wind - check.

* Rain - check.

 

Warm and dry now please.

Huge energy bill -check

[alexisj9]

1 hour ago, Bogman said:

I would like it to be.

 

* Snow - check.

* Frost - check.

* Wind - check.

* Rain - check.

 

Warm and dry now please.

Was lucky down here yesterday, nice sunny day, but cloudy today. Warm and dry though.

[clark3r]

Counting down to spring now. Been very dull gloomy wet at times last 2/3 weeks. I really hope we do not get beast from the east late winter early spring, it’s pointless when sun gets stronger and quickly melts any snow. Another summer like last will do me great.

[Iceman2606]

4 January 2023 Time-Lapse

 

[Tn9]

On 03/01/2023 at 23:53, snowrye said:

Certainly a door and window rattler tonight 

Could be a burglar ,fagin used to tell us never go choring on a still night ,wait for wind ,clumsy theives get heard a mile off

[Tn9]

5 minutes ago, TN9 said:

Could be a burglar ,fagin used to tell us never go choring on a still night ,wait for wind ,clumsy theives get heard a mile off

But my favourite character is windy Miller..what a bloke ..even as kid I loved him ,1.. he had a dirty great windmill (which to this day i love ) he made his own cider and when calm he sang a song and whistled for the wind , all in all run of the mill