South West and Central Southern England Regional Weather Discussion 03/03/2018 Onwards

[karlos1983]

4 minutes ago, Man With Beard said:

Yes this "round 2" (or is it 3?) definitely trending upwards for the south coast.

Don't know about you but I've found this evening like torture trying to work out what's going on!! All week I've been thinking "wait until you see the radar" - well I can see the radar and I still don't know if it's going to happen here tonight! Mind you, west of Hampshire looks like a case of how much rather than if!

Absolutely mate, I’ve been trolling this easterly for what seems an eternity now, and now it’s delivering a snow event, which I’ve also been trolling for days ?‍♂️ The radar isn’t helping lol. Brilliant mid March fun though!! Next few years could be a good few years as well. 

Edited March 17, 2018 by karlos1983

[Man With Beard]

15 minutes ago, Mike Poole said:

I' m sorry to say that the 18z HIRLAM has backtracked a bit for everyone in the south.

Cumulative snow through to to Monday:

Still some interest for our region, but that Met Office warning for the SE todger-shaped region is looking wafer thin now!  I've just been looking at the   SE thread, (I'm right on the border) and it's not been pretty.

... while the latest ARGEPE keeps it going till Monday morning!!

[Catacol]

2 minutes ago, Mike Poole said:

Lesson learnt in 5 minutes, don't present evidence that goes against people's expectations.  Sorry. Won't do it again.  

Hehe - go on presenting! I wasnt having a dig... just dont understand the wringing of hands over perceptions of an event that has barely started. Stuff the models and the radar now - enjoy what's through the window everybody. If staring at radar and high res model runs is your cup of tea while flakes are in the air outside, then this whole snow hunt thing has become rather warped. March 18 is delivering some snow.... could be 5cm, 10cm or 15cm. Could be more... nobody will really know until tea time tomorrow and that's the fun of watching it fall.

[kent]

Watching the satellite is like trying to do a jigsaw puzzle and wondering if its all going to come together.  At the moment there are holes everywhere.

[karlos1983]

1 minute ago, kent said:

Watching the satellite is like trying to do a jigsaw puzzle and wondering if its all going to come together.  At the moment there are holes everywhere.

It’s like a jigsaw puzzle from Oxfam ?

[karlos1983]

Right, the pivot is on! I now expect to see ppn pep up as we see this event show its teeth. 

Good luck everyone ?❄️

Edited March 17, 2018 by karlos1983

[Leon1]

Just now, karlos1983 said:

Right, the pivot is on! I now expect to see ppn pep up as we see this event show its teeth. 

Good luck everyone ?❄️

only now would i think about calling it a light dusting! i hope for lots more later overnight

[Jayfromcardiff]

Surprised to see the snow settle on all surfaces here, must be the extra 30m absl at my girlfriends lol. Good luck all.

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

8 minutes ago, karlos1983 said:

It’s like a jigsaw puzzle from Oxfam ?

They've done worse than sell incomplete jigsaws. 

[Andrew_WsM]

Settling quite nicely up on the hill here, just been lamp post watching and the flakes are the biggest they've been all day.

[Ben Sainsbury]

Netweather NMM model currently has a really good grasp on current positioning and intensity of the snow over the south. 

As we head pass midnight we should already see marked increases in intensity and more so into the realms of early morning tomorrow. Hopefully it can bring the goodies to Bristol!

[offerman]

1 hour ago, fromey said:

Looks like we could be in the sweet spot!!

 I noticed another one on the radar another red patch over us snow is settling on the roads everywhere  when I left 

 I’m now on top of the hill along the track near Stourhead Gardens 

 Up on top of the downs and it really is pelting down the road or should I say the track is clear but the snow blows off of that up against the fence posts where there will be some huge drifts by the morning I reckon 

 

[Man With Beard]

12 minutes ago, karlos1983 said:

Right, the pivot is on! I now expect to see ppn pep up as we see this event show its teeth. 

Good luck everyone ?❄️

Are you going for an all nighter?

[kumquat]

Just been playing 'flash the torch' with other snow-watchers about half a mile away across the Frome valley in Frampton Cotterell. I received back some morse-coded back-garden floodlights, fricking hilarious. 

[karlos1983]

1 minute ago, Man With Beard said:

Are you going for an all nighter?

Eeeshh i want to say yes... but I’m 34 going on 74 atm ?‍♂️ Will certainly not be getting a good nights sleep, that’s a given! Which will Tut the wife off ?

[Mike Poole]

30 minutes ago, Catacol said:

Hehe - go on presenting! I wasnt having a dig... just dont understand the wringing of hands over perceptions of an event that has barely started. Stuff the models and the radar now - enjoy what's through the window everybody. If staring at radar and high res model runs is your cup of tea while flakes are in the air outside, then this whole snow hunt thing has become rather warped. March 18 is delivering some snow.... could be 5cm, 10cm or 15cm. Could be more... nobody will really know until tea time tomorrow and that's the fun of watching it fall.

Could be less than that apart from Devon and Cornwall.  Would love to be proved wrong.  I've only started to post regularly since the SSW, and it has been fun, what I joined Netweather for, but if you can't put an alternative point of view forward, what's the point?

Edited March 17, 2018 by Mike Poole

[Jayfromcardiff]

4 minutes ago, karlos1983 said:

Eeeshh i want to say yes... but I’m 34 going on 74 atm ?‍♂️ Will certainly not be getting a good nights sleep, that’s a given! Which will Tut the wife off ?

I've already told the girlfriend that I'm doing an all nighter as I think we could see a decent amount.

[CheesepuffScott]

I am aiming to stay up till at least 5am. Got all me snacks.

[Wilxy]

It's going the way of the metoffice as it stands with the heavier PPN going around bristol to are south about 10 miles to are south right in line with that amber warning!

[Mapantz]

I'm supposed to be up at 6 but i'm in two minds whether to go to bed at all!

[Guest]

NO NEED TO BE SO GLOOMY - THINGS ARE BREWING NICELY! SNOW NOT SETTLING YET - WHY?

Some of you seem to be getting quite worried. Everything has been moving in the right direction during the last few hours and by around midnight some heavy continuous snow will be showing up in our region for many of us. Some of us are already seeing snow turning steadily heavier (2230 at the time of writing this bit).  I've had steady moderate snow here for the last hour and yes, it's starting to settle on the road and pavement. I'll do a general round up in an hour or so but right now I'll address the query about why the snow in some parts isn't settling on the roads and footpaths (yet). I did mention this in several of my posts yesterday and this morning and showed some charts but I'll explain it properly now. We need to focus on the ground temperatures. In the last cold spell most places down here had 1 or 2 ice days prior to any significant snow falling. The ground was frozen solid to quite a depth - perhaps to over 10 cm. All the snow settled immediately and swirled around on all surfaces. This time around we have almost as low uppers and 2 m surface temps with very low dew points and an even stronger easterly wind blowing off the land not off the Channel. The one  ingredient that is missing is that the ground temps are well above freezing. I've dug out the ground temp charts from the GFS archive runs at T+3, so barely forecasts and as close as I can find for broadly accurate values. Then I've taken tonight's 18z run and gone slightly further ahead but these are forecasts but still provide a reasonable idea of what to expect.:

      18z for Fri Mar 16th at 2100 GMT               0z for Sat Mar 17th at 0300 GMT                  6z for Sat Mar 17th at 0900 GMT              12z for Sat Mar 17th at 1500 GMT  

                       

    18z for Sat Mar 17th at 2100 GMT                  18z Sun Mar 18th at 0300 GMT                  18z Sun Mar 18th at 0900 GMT                   18z Sun Mar 18th at 2100 GMT 

                      

These charts show the ground temps down to a depth of 10 cm. You can see that most of our region had ground temps of around 7c at 2100 last night and they were still at 6c by 0300 this morning. Then the very cold air started to move in during the early morning. By 0900 the ground temps had fallen back to around 5c. By 1500 they were down to 4c. By 2100 this evening they were closer to 3c or 4c. They are predicted to fall very slowly to mostly 2c to 3c by tomorrow evening. Remember these are the average temps for the full 10 cm depth. The surface and the top 1 cm or so will be very close to zero already. While the surface is being cooled by the melting snow and the strong drying sub zero wind, the underlying warmth is still radiating upwards. Right now I would estimate that most surfaces are actually dropping just below zero - probably down to 1 cm or so. With the average down to 3c or lower, I would expect that the top 1 cm layer will be sufficiently low enough to cancel out the rising warmth from below. Any heavier snow will readily settle and even lighter snow will settle on all surfaces during Sunday. Roads and pavements retain their warmth for longer than soil. Grass is always one of the first surfaces to see snow accumulate as the blades are not affected by the warmer ground. It settled on trees and hedgerows around here from late morning. The wetness of the surface is always a red herring. It's the ground and 2 m surface temps which are critical. Even wet snow will settle if the air temp drops close to zero, initially forming a slushy surface and then accumulating. There is one saving grace from having snow settling on unfrozen ground. It forms a blanket and protects the ground from sharp frosts. Many plants are starting to come into bud and the snow may actually prevent them from being damaged or killed by the freezing conditions!   

Edited March 17, 2018 by Guest
Correct typos and check charts

[Bristawl Si]

10 minutes ago, Jayfromcardiff said:

I've already told the girlfriend that I'm doing an all nighter as I think we could see a decent amount.

Jay....has she agreed to "an all nighter" from you? She might just want to sleep

[kumquat]

7 minutes ago, tomjwlx said:

It's going the way of the metoffice as it stands with the heavier PPN going around bristol to are south about 10 miles to are south right in line with that amber warning!

Don't give up yet! I reckon we will see the streamer to the East get re-invigorated by and merge with the wrap-around of the small low/disturbance before it heads SW.

[Jayfromcardiff]

1 minute ago, Bristle boy said:

Jay....has she agreed to "an all nighter" from you? She might just want to sleep

Haha, I still think Bristol will see a decent amount by morning.

Got no bloody street lights nearby working properly so I'm having to shine the torch on my phone to see the snow.

[*Stormforce~beka*]

Look at that littler area of no snow just sit over winchester the whole time ...