Altostratus

Seems a foolish thing to say IMHO. Given how many days away that is, no one can be certain what will happen. If this cold spell is to go into the second half of the month I do however think we need to see pressure re-building over GL. I can see the Scandi block slowly eroding away otherwise, introducing mild S’ly or SW’ly winds. The ECM is starting to come out now – will be interesting to see what it shows for the 120-144hrs time zone.

No snow here. By being out of the country I missed the best snowfall my home county of Hampshire has received in decades. Every year I waited patiently for a snow event and every year I was disappointed. The only winter in my life that I am out of the UK and the unthinkable happens! Seeing photos of the house buried comes as no consolation I can tell you. You can bet your bottom dollar that next winter will be decent too as I won't be around then either. :lol:

-5C isn't exceptional for the south coast. I remember a few years ago Bournemouth recorded -9C. That was without any snow cover too. I expect -10C would have been recorded quite widely last night in rurual areas.

A good run from the ECM. A nice settled spell of weather after the deep snow cover would help to get some very low minima. The channel low shown at 144-192hrs will undoubtdely bring milder air into the mix. It will certainly be marginal for snow in the south. It is a risk worth taking however - historically, the heaviest snowfalls have come from similar situations in the past. It is far from an ideal channel low, but if it brought snow I don't think anyone would care.

I would give anything just to teleport back to north Hampshire tonight. I guess I should consider myself lucky to have been home for the pre-Xmas dumping.

If the met office are to be believed, you have a good chance. My advice would be to keep your eye on the radar and read snow reports as they start coming in. Given the large area covered by the forum users we should be able to judge the amount quite well.

The red warning is a rare beast. There have been two occasions that I can remember this year however. One was Feb 09, the other was when the heavy thundersnow was hitting parts of the SE prior to Xmas. On both of these occasions the red warning was released during the event. The snow hasn't yet started in the highlighted red zone this time however. I live right in the METO sweet spot. Shame I'm out of the country. You wait your entire life for an event like this and the only time you are away, a huge event strikes. Law of the Sod. Take care out there guys. I want to see some good photos posted - both during and after the event.

Good luck today guys. I only wish I was there to experience it with you. I will no doubt get very jealous when the snow reports start coming in. :lol:

A good run from the GFS in the reliable time frame. I wouldn’t worry too much about what happens with the positioning of the high. The details of this will be firmed up over the next few days. Those fax charts look excellent. With the occluded front and embedded troughs circulating around the low, it looks like there is potential for a lot of snow almost countrywide.

Phenomenal ECM. I’d love to see the scenes in London if that verified. Not only does the E’ly feed keep going, there are also signs of the high retrogressing back to GL for a reload. IF that occurred, a subzero month would be quite likely. When was the last time we had one of these? Feb 86?

From the outputs I’ve seen so far this evening, it looks like an extended, very cold spell has begun. With the cold air established, there is bound to be a few surprise snowfalls – there nearly always is! The north and east are looking like the favourite spots, however, given the fact the entire country will have a deep pool of cold air in situ, coupled with a good deal of instability, snow could occur almost anywhere IMHO. All eyes to the radar over the next week or two. The synoptic setup is such that the window of opportunity for snow is much longer than we’ve become accustomed to; hence, more places should receive snow than would usually be the case. I’m sure this will go down in history as a very memorable event. Indeed I think it already has for many. Regarding the UKMO run, it isn’t entirely alone with that evolution. It looks like a another decent run to me however, with cold and snow aplenty. Looks like there could be a decent pressure rise over Scandi too. I am heading back to Cairo on the 3rd Jan. I am gutted to be leaving just as the real fun and games begin - my first winter away from the UK and it looks like it will be a decent one. Never mind, I look forward to reading everyone’s snow reports. Best of luck to everyone!

I'm surprised it is so quiet in here. That GFS run would deliver buckets of snow to the SW - classic stuff. It will invariably change between now and then but a nice trend nonetheless. In reality I can see the low being too far south to have any influence. Something to watch in the next few days anyway.

You are absolutely right. For all we know, the GFS might well have called this one right. You win some, you lose some. Based on the statistical analysis, the odds favour the ECM outcome however. It is a difficult one to call and I’m sure the professionals are debating it as much as us.

I agree with Nick on this one. For the UK, the ECM is usually more accurate. The verification data proves this. I believe the ECM is the model with the highest resolution too. The ECM also has a large ensemble suite that has been very bullish for the past few days. The GFS ensembles have been up and down like a yo-yo. The ECM is seen by many profesional organsiations as the best model. I agree tha the GFS data cannot be discounted, but in a head-to-head contest with the ECM, the ECM is rarely wrong in these situations.

The ECM hasn’t budged and the latest GFS has shifted the low further south. I know which model I would back in this situation. I expect the GFS will slowly come around to the idea in subsequent runs. The BBC must be reasonably confident as it quite uncharacteristic of them talking about snow distribution a few days out. I remember in Feb 2001 John Kettley and everyone else, bar the UKMet and BBC, were forecasting severe cold and snow for the entire UK. The BBC were adamant that the coldest air wouldn't reach the majority of the UK. Guess who was right that time?

As I’ve mentioned before, I think the GFS data issue is being overstated. I think this started as a rumour and everyone seems to have jumped on the bandwagon. The recent poor performance is probably more due to the GFS being unable to get to grips with the large amplifications and subtle jet splits. Blocking makes modelling of the jet streams much more complex (splits, large amplifications etc). As such, there is more to model and more that can go wrong; particularly for the UK, where seemingly small adjustments have a large impact on dictating our air mass. With a run-of-the-mill zonal pattern, it is much more forgiving and the GFS seems to perform much better. Even during these periods however, it has been noted that the GFS has a history of over developing areas of low pressure. With the GFS being an American model I guess the majority of investments are focused on improving North American modelling. In theory, the top Euros should be better for here - which I recall is supported by the verification data. If the GFS turns out to be right on this one, serious questions must be asked of the other models.

Yet another GFS run fit for the bin. The programmers of the GFS need to take long hard look at why it has a tendency to be over progressive. It seems utterly incapable of dealing with subtle energy distributions. The ECM ensembles paint the picture and it is certainly not a mild one. I simply cannot see all the other models coming in line with the GFS. It simply won’t happen. I have always viewed the GFS with a sceptical eye and the rest of this week, will, hopefully, reinforce this view. I am starting to rate the GEM more highly than the GFS.

The model outputs are better than I was expecting this morning. The ECM and UKMO have both improved with the low further south. It is about time we see a run like this from the ECM, as this is a better reflection of the ensemble suite. The GFS looks wrong to me and I wouldn’t be surprised to discover it is an outlier. Regarding data issues, I think this is being blown out of proportion. I expect we are just seeing the inherent over-progressiveness of the GFS again. A good rule of thumb is to tone-down and moderate anything the GFS shows.

I agree with you. The initial channel low is too far north to deliver anything to southern areas – it looks like an all rain event here tbh. People in the south shouldn’t be expecting much from this. There is still time for a shift southwards, but this is looking unlikely IMHO. In the medium to long run, synoptically brilliant, yet failing to deliver to most southern areas. This morning’s charts have also highlighted a potential spoiler, with a ridge of high pressure building from the south. The output is excellent throughout for the north, but lacklustre for southern areas. There is still plenty of time for things to change and the general trend is certainly excellent, with blocking in all the right areas. From an IMBY perspective, I hope we don't have a similar outcome to Feb 2001, whereby the coldest air never quite made it to southern areas - It was tantalisingly close. I'm refeering to the infamous 'Kettley' cold spell for those that remember.

Very interesting day weather-wise. We've had it all today. Interestingly, the temperature has dropped to 0.6C in the last hour and the rain became sleety and almost wet snow at one point. It has stopped raining for the time being, however plenty more is on the way judging by the radar. The snow depth has probably more than halved since this morning. The surface temperatures have been cold enough to support snow all throughout the day - if only the uppers were slighly lower, this would have been an all snow event.

Currently -5.2C with a dew point of -7.8C. Last night’s low temperature was -9.2C. It will certainly be interesting when the PPN reaches here. Regardless of that, this is definitely the best cold spell in this area since the mid-nineties.

A quick temperature update before I go to bed. It is currently -8.6C here. With perfectly clear skies, I can see -10C being breached tonight.

It is snowing again here :lol: We've taken a hammering today. I haven't measured the depth but I'd guess we have about 5-6 inches.

I went for a walk about an hour ago and took some photos. The main roads already had a good covering and looked very treacherous indeed. Thankfully I’m at home today so don't have to risk the roads. Heavy snow still falling here - flakes not as big now though.

Still heavy snow. Massive flakes too. Temp is -0.2C and dew point -2.5C.