Joe Levy

I think that more than 20cm of snow seems likely in Exeter now. The radar is intensifying and we have many more hours of snow still to come. I think the red warning will be very justified if the intense blob below reaches us.

Hard to say how much snow has fallen in Exeter, as it's drifted a fair bit (outside my door...), but it's something close to 10cm on the grass and pavements now I reckon! The worst/best of the snow hasn't even arrived yet, but here's the view from my kitchen about 20 minutes ago.

Accumulated snow chart from ECM at 9pm on Thursday (to be taken with a pinch of salt of course, much will probably change!). Even if it does melt after this and turn to rain, it'd undeniably be a noteworthy snow event for the SW, and it seems to stick around a lot longer further north. I honestly think it will correct south nearer the time, but this remains to be seen!

Just to inject a bit of perspective, I don't think many of us truly believed that we'd be seeing uppers like the ones shown below on tonight's ECM within 48 hours! Yes, the low pressure at the end of the week is a bit of a headache for forecasting, but actually there's bound to be a lot of excitement between now and then on account of unusually low uppers and low thicknesses, especially from Tuesday onwards. This is such a contrast to the situations we've had over the past few winters, which is probably what's putting people's nerves on edge. Let's try and enjoy this period and see what happens!

It is easy to feel downcast by the output this evening, but actually when we look back at what we saw only a week or so ago, we weren't even exactly sure whether the cold would make it to us in the first place. The arrival of that low pressure Thursday night into Friday will be a really interesting event to observe. Historically, low pressure has a tendency to correct southwards when faced with a large mass of cold air, even on the day itself. A classic example was in March 2013, which was to the detriment of many in terms of snow potential. Now the uppers are forecast to be at the same or colder than when this happened, so there is nothing to say that we won't see corrections southwards this time too. Regardless, I hope members will use this as an opportunity to observe some exciting weather developing. I'm expecting there to be a significant amount of inter-run variability over the next couple of days - the cold may well break down at the end of the week, but given how little differences can have a massive impact, I am inclined to wait before making any calls about what I think will happen! (that was the most sitting on the fence post I could have written ha!)

Not posted on here for a while, but my experience is that even if it seems as if a low pressure system is trending in a particular direction on the models, its projected track will change constantly until much nearer the time. Because tiny differences have such huge implications for us, the actual snow line will not be evident until we're within the 24 hour window. GFS 6z is not ideal for many of us in terms of snow at the end of the week, but it's at odds with the ECM and others, so no one should be concerned this far out.

I would very much like it if we did get a storm in Devon, however I'm wondering whether our window of opportunity has closed no we're moving on the other side of the cold front? Can anyone enlighten me further?

They're known as the Isles of Scilly

I've not heard anything yet on the North side of Exeter, it's still a few miles to the south west of us

By the looks of it we have storms incoming in Devon. I thought there would be no lightning but there seem to have been a few strikes near Dartmouth.

Very frustrating! It looks like the lightning has stopped barely 5-10 miles before it got to the Exe Valley! Never mind, there is a lot more activity in the channel so perhaps some of them will reach us

Confirmed: just heard thunder to the South West of Exeter

It looks like there is lightning heading towards Exeter. I wonder if anyone further South in Devon can confirm this?

Torrential rain in Exeter!

I'm in Exeter and currently it is grey and humid but nothing more haha!

Right at the very end of FI (well FI never ends really ) but this is certainly an interesting chart! Low heights digging down into Europe with a high forming over us and undercutting lows from the Atlantic! Not to be taken too seriously obviously.

Alas it all seems to be fizzling out in the London area now. Never mind, perhaps there will be a few more surprise showers! Plus, it is only December still and the few flakes I've just seen already make this winter better than last!

Sleety snow falling in Ealing!

I'm hoping it will head down towards Ealing! I've been watching it closely on the radar when I should probably have been transcribing my dissertation interview notes...

Again in FI, but this is a nice chart on the GFS(P). Both the op and the parallel are showing nice troughing digging down into Europe, however the parallel has a more favourably positioned high extending from Russia EDIT: also I never say stuff like this on here, but unless people have charts to go with their points, can we please leave out the emotionally charged posts that are made. There is no room here for gut feelings and grumblings - they go elsewhere! This is a chart based thread with lots of pretty colours on synoptic charts that I am still learning how to understand

Maybe I'm mad, but the GFS 12z op looks pretty damn good to me. Aside from what's going on in our part of the world, the NH profile does some nice things for long term cold prospects. Some good ridging in Alaska and the erosion of the PV are both rather important indeed. Plus in the short term and for the next week there's some substantial stratospheric warming going on

I wonder if someone could answer this for me - now that we know the front is slightly further north than forecasted, will this have any implications for model output with regards to the next week or so? Or even further... If anyone has any suggestions/explanations/ideas I'd appreciate it!

But then there's this which I posted early, which is probably more accurate than Twitter http://uk.weather.com/mapRoom/mapRoom

Purely observational, but this is quite fun for seeing where people are reporting snow. http://uksnowmap.com/

I've been looking at this radar but I have no idea about its accuracy http://uk.weather.com/mapRoom/mapRoom