Scotland/Alba Regional Weather Discussion - 16/01/2018 Onwards

[jon_d1983]

@Snoozi where in the shire are you? I have watched the snow fly north and south of me all day and it’s still happening tonight ???

[chionomaniac]

46 minutes ago, lorenzo said:

Bang on Catch - given the strength of the warming and the sheer beauty of the split dynamics it has pretty much been a textbook transfer of the split from stratosphere to troposphere.

Here first off to frame this is the seminal Baldwin and Dunkerton Paper on NAM dynamics - NAO/AO

From this study you can see the impacts of the SSW elongated over time as the warming down wells and impacts on the troposphere( where our weather happens).

Then, to this years episode - this tweet from Amy Butler tells the story that means we had the instant tropospheric response that the perfect split of the Polar Vortex can deliver... immediate ( well 7-12 days) of an instant down welling where the easterly anomalies impact the troposphere. In this case reversing circulation and the Siberian daughter vortex immediately evident at 10hPa echoed in troposhperic forecasts.

We were at a point around 16th Feb when this could have gone tits up, but some cool wave breaking in the Atlantic severed the chances of the Siberian vortice joining forces again with the Canadian vortex, this serendipity meant the modelling continued to create a Grand Canyon, no Atlantic incursion could get thru, a brick wall if you like - picture it running from Penzance to Svalbard. This then allowed that earlier programmed Siberian vortex to shuffle round and usher in the easterly regime. Dr Butler's plot below shows the zonal wind and the Geopotential height anomaly impacting all the way down through the stratosphere to impact us locally.

Without this further wave breaking and also the subsequent cleaning out of the Canadian Vortex we would not have had a) the Scandi High and then the retrograde action to Greenland blocking. It really has been a thing of beauty.

What we saw at 10hPa back on say 08th Feb has in a text book manner down welled through the stratosphere after the SSW and manifested itself in this remarkable easterly. When the wave break to the canadian vortex getting annihalted happened i knew wwe were game on, ahead of that, on 04 Jan the MJO being in Phase 2-3 was a clue to the SSW itself taking place. The SSW then got further confirmation via the MJO entering phases 7/8 mid month breaking the Nina regime.

And that's the science from 02 Jan MJO thru, MJO recycle, through SSW , thru vortex split thru wave breaking > Easterly and historic event... Helluva amount of jigsaw pieces to get to eventually a red warning and a cold pool of -42 C at 500hPa which I saw was on statistical analysis a 1/31000 yr event.

Special times !

 

Edit - Appreciate this is a bit technical vs the F$%kloads of snow pics so if you are interested in how we got here then ping me a message and I can either point u to the threads about this or hopefully answer any questions. 

Waited for some years for an SSW and this one has delivered spectacularly - excuse my excitement - it's been a five year lag and it's an opportunity to investigate a lot of research written around the subject with of course the much improved modelling resources. Baby Steps science... @chionomaniac Ed , to save my typing again can you add to this summary- maybe confirm the precursor you saw and how it beat every agency hands down by 3 weeks

 

Not a lot to add really. First saw the possibility of a SSW end of December (through classic precursor pattern in trop) - thought it might occur late Jan, but had to wait until 11th Feb - so that forecast proved reasonable. Main thing was how the SSW developed from then. The area of the split was favourable (from Atlantic to Pacific) and by early Feb I could see that the first phase was of the SSW was the destruction of the Siberian vortex. This opened the door for any downwelling to increase the likelihood of height rises to the NE. But also by this time, significantly the second residual strat daughter over Hudson Bay was forecast to take another hit with the second warming (not technically a SSW as you can't have two over a short period). The trop strong daughter vortex extending from Greenland to Canada was curtains from this point onwards and it was only a matter of time. This meant that it could assist in the Scandi block formation through WAA into the Arctic before it too subsided. This was the last piece of the jigsaw falling into place because it allowed the Scandi block to head west and over Greenland assisting the cold Siberian winds to head westwards with it. All this was predicted by the first Sunday in Feb. Hence I remember stating that I was so excited by what the models weren't showing at that point because I suspected that it was only a matter of time until they did - even though the trop models were showing no effective response to the SSW for a while.

Not every time will we get such strat activity being very conducive and structured to an expectant trop response, but this was such one of those times, and I have waited many years for this. Happy now that pretty much most of the country has benefitted from the extreme weather that a trop response following a SSW can bring.

Edited March 1, 2018 by chionomaniac

[howham]

Much more frequent and heavier showers here tonight than any time during the day.

[Frazd103]

8 minutes ago, Mr Frost said:

Good to see you back on here mate!

Did you know about the red warning in advance? I remember you saying the other day that you work in a certain sector that gives you advanced weather warnings! Rumours are still flying about in this thread that you are an Avon representative? Can you give us all a clue as to what the mystery job/sector is? 

Ha ha. Nah, mate never knew about red but knew it was going to be bad, just party to some stuff from high when it could impact the area I work with. Work in Govt, but no not Transport Minister....

[Stormeh]

I am going to be buying Rolling Stones tickets tomorrow for their gig at Murrayfield. I will probably be able to hire and a sledge and some huskies to take me to Edinburgh as the snaw will probably still be lying come June 

[101_North]

Just been out sledging again! Absolutely great stuff Showers today gave me about 8cm - measured from a cleared path. Despite the obvious compaction of yesterday's snow we have a level depth on the back grass of 28cm. Drifts are epic! Really brilliant stuff!

[Snoozi]

9 minutes ago, jon_d1983 said:

@Snoozi where in the shire are you? I have watched the snow fly north and south of me all day and it’s still happening tonight ???

am in Kemnay/Inverurie area too same as Ravelin, but a wee bit higher at 118mtrs it really is a hit or miss, but so far plenty good, and very pretty!

[jon_d1983]

2 minutes ago, Snoozi said:

am in Kemnay/Inverurie area too same as Ravelin, but a wee bit higher at 118mtrs it really is a hit or miss, but so far plenty good, and very pretty!

I think I’m too close to the coast being in Newburgh. Showers look to intensify a bit once they pass the coast. Still a decent amount of drifted snow though so can’t complain too much 

[Snoozi]

15 minutes ago, chionomaniac said:

Not a lot to add really. First saw the possibility of a SSW end of December (through classic precursor pattern in trop) - thought it might occur late Jan, but had to wait until 11th Feb - so that forecast proved reasonable. Main thing was how the SSW developed from then. The area of the split was favourable (from Atlantic to Pacific) and by early Feb I could see that the first phase was of the SSW was the destruction of the Siberian vortex. This opened the door for any downwelling to increase the likelihood of height rises to the NE. But also by this time, significantly the second residual strat daughter over Hudson Bay was forecast to take another hit with the second warming (not technically a SSW as you can't have two over a short period). The trop strong daughter vortex extending from Greenland to Canada was curtains from this point onwards and it was only a matter of time. This meant that it could assist in the Scandi block formation through WAA into the Arctic before it too subsided. This was the last piece of the jigsaw falling into place because it allowed the Scandi block to head west and over Greenland assisting the cold Siberian winds to head westwards with it. All this was predicted by the first Sunday in Feb. Hence I remember stating that I was so excited by what the models weren't showing at that point because I suspected that it was only a matter of time until they did - even though the trop models were showing no effective response to the SSW for a while.

Not every time will we get such strat activity being very conducive and structured to an expectant trop response, but this was such one of those times, and I have waited many years for this. Happy now that pretty much most of the country has benefitted from the extreme weather that a trop response following a SSW can bring.

@chionomaniac Thanks!! I remember trying to follow your SSW posts a few years ago (a lot actually) so an so glad that the circumstances have all come together to enable the dotting of the i's and crossing of t's.. Thank You so much for all your input and posts and I hope that you too are enjoying your own local weather .. have a good one   

[Bullseye]

Good day all round for most parts - caught tail end of the heavier showers through this morning and later part of afternoon. Dived into the model thread and jeez breath of fresh air like a ghost town with some continued signs for more cold next week from NE according to ECM 12z. Hoping we can catch some of the snow that is moving north from down south tomorrow although highly unlikely. Also, i see there is a big snowball event planned in Glesga this Sunday! 

Edited March 1, 2018 by Bullseye

[JoeShmoe]

Snaw back on again ...getting to silly depths now for this part of Embra !

[JamesM]

1 hour ago, Mr Frost said:

Just look at this - brings a tear to my eye! I have been 10 miles too far South of this line of constant snowfall that has been going through the North of Glasgow city centre for about 18 bloody hours now!  

Its heartbreaking! 

 

Yup, same here. Been 15 miles south of all the fun and only got a fraction of the likes of Cumbernauld where the old man is snowed in or Greenock where I didn't get to work today. 

Fields almost green here now as the snow has blown off them and drifted.

[biggreyface]

38 minutes ago, Landylou said:

Yip, wild here too! Had to give in and shut the front door....apparently not everyone in the house appreciates the snow ?

Haha 

When I was younger my parent's were always going mental at me for opening the doors in the house (close the door your letting all the heat out ) living in a house built in 1890s it actually felt like I was letting some heat in.

And to realise life has come full circle I actually used the very same phrase for my daughter the other day  .could not believe those words came out my mouth oh the shame 

[Allyw12]

58 minutes ago, edo said:

@over_the_rainbow @Allyw12 @TinyTim please tell me you got that epic 30 minute snawfest 

@edoI missed it ? typical off to have a look outside ??❄️ 

[Flotsam]

Dinging it down and just seen a flash of lightning out my kitchen window................Jeez, I love this weather

 

[frogesque]

2 minutes ago, Flotsam said:

Dinging it down and just seen a flash of lightning out my kitchen window................Jeez, I love this weather

 

We had a few epic sessions of thundersnow yesterday. Bonkers weather! Gone a bit calmer since teatime built well pleased for a Feb/March event. Total about 6.5 inches.

[SW Saltire]

Well saw most of the country today as I got to go home early ‘If you can dig yourself out’ so I did.

Went west cos thought M80 was open. Wasn’t. (Opened 10 mins afterwards) so went South East on M9 to Edinburgh and that was fine bar some snow drifts 

Fun really started thereafter as couldn’t go via Lanark or Penicuik as totally blocked roads so I went the Kilmarnock road from Broxburn (A71) and went due West until I hit Carluke and could join the M74 and went home.

Insane snow at places in Lothian. Winner was West Calder by a Glasgow mile. I’d say they have 3 feet of snow (not exaggerating). 

Quite scary when you really aren’t sure if the car is going to keep going but luckily all my fun on the quad bike making it skid from years ago paid off when the back end went a few times on a main road haha. 

Nearly died but didn’t die so all good. 

Even have some snow down here, about 4 inches here in Dumfries. Currently -3c

[Guest]

heavy showers on and off and the radar is full of it. 

[Mr Frost]

5 minutes ago, Flotsam said:

Dinging it down and just seen a flash of lightning out my kitchen window................Jeez, I love this weather

 

Looks like you are taking a pounding up there! 

See that wee blue dot just South East of Glasgow in the only dry bit aboot - that’s where I am! 

Had to look at the radar again - just one last time for comedy value!  that stuff out East will surely not miss this time!? 

 

[frogesque]

1 minute ago, SW Saltire said:

Well saw most of the country today as I got to go home early ‘If you can dig yourself out’ so I did.

Went west cos thought M80 was open. Wasn’t. (Opened 10 mins afterwards) so went South East on M9 to Edinburgh and that was fine bar some snow drifts 

Fun really started thereafter as couldn’t go via Lanark or Penicuik as totally blocked roads so I went the Kilmarnock road from Broxburn (A71) and went due West until I hit Carluke and could join the M74 and went home.

Insane snow at places in Lothian. Winner was West Calder by a Glasgow mile. I’d say they have 3 feet of snow (not exaggerating). 

Quite scary when you really aren’t sure if the car is going to keep going but luckily all my fun on the quad bike making it skid from years ago paid off when the back end went a few times on a main road haha. 

Nearly died but didn’t die so all good. 

Even have some snow down here, about 4 inches here in Dumfries. Currently -3c

Sounds hairy and that is some depth at West Calder. Glad you home safe.

[Blizzardo]

 2 snowploughs are currently stuck on the main road between Lennoxtown and Strathblane at the Lennoxtown end. They were trying to unblock the road going into my estate. The snow is blowing across the Campsies over the fields and is around 5'feet deep in places.

[Mr Frost]

10 minutes ago, Blizzardo said:

 2 snowploughs are currently stuck on the main road between Lennoxtown and Strathblane at the Lennoxtown end. They were trying to unblock the road going into my estate. The snow is blowing across the Campsies over the fields and is around 5'feet deep in places.

Blizzardo get some pictures on the go mate! Been choking to see what it’s like in that area! Have been watching snowfall going through there for hours! 

Edited March 1, 2018 by Mr Frost

[Guest]

Heaviest snaw of the week so far, unbelievable this is stunning.

[Stormeh]

Just now, Blizzardo said:

 2 snowploughs are currently stuck on the main road between Lennoxtown and Strathblane at the Lennoxtown end. They were trying to unblock the road going into my estate. The snow is blowing across the Campsies over the fields and is around 5'feet deep in places.

Thanks, I was about to ask what its like up the Campsies as I was planning on taking a wee trip up there this weekend, if the roads are cleared by then that is!

[Flotsam]

5 minutes ago, frogesque said:

We had a few epic sessions of thundersnow yesterday. Bonkers weather! Gone a bit calmer since teatime built well pleased for a Feb/March event. Total about 6.5 inches.

Thundersnow is a first for me, and I got so excited I actually squealed and started clapping my hands..............hubby came running through from the sitting room to find me standing in the dark kitchen grinning like a Cheshire cat