kold weather

Also mate I'm probably 15-20 miles inland north of Portsmouth, so if I struggle with 100m+ in altitude, that probably won't mean anything good for those further E/ENE of my location. Still I'd be very dissapointed if it goes wrong for my backdoor. If it does, then surely the Downs at 200-300m will do the job! I'll get my snow fix however I can! EDIT - the further east however might also contend with slightly longer earlier morning warming which will up the temperatures modestly given the upper airflow is not all that cold.

Looking at the Met office website its pretty much a match, so the Met office site is using the UKV as well. Pivot sweetspot on the 15z UKV looks like being around the St Albans area.

Its on Net weather mate, though I've actually been cheeky and looked at the Midlands thread where someone has put up a screengrab of the 10z timeframe which looks pretty decent.

The UKV looks ok for most of the SE away from the south coast. The main thing that helps is the system coming through quicker than previously expected. Still some uncertainties about how far north it ends up. The extra 2hrs earlier than expected really prevents any morning temperature increases before the front comes through, especially further east in the region.

Interestingly the 12z ECM is the only model that has a pretty accurate representation of the location and forward speed of the front. Basically the further east it is, the further north the precip shield and pivot will be. So the 12z ECM may well be in the ballpark based on that basic analysis. On the upside, it also means a faster front = slightly less marginality for those closer to the coast. So maybe a bit less snow for the northern parts of the SE, but a wider area get snow, so I don't think we can complain overall can we.

Looking at the radar position the 12z ECM is a good match. This is good news as it probably reduces the risk for southern areas of the sleety stuff encroaching further up the coast as the time will coincide with the natural coldest part of the day anyways for a greater chunk of the region. I don't see tomorrow being a huge event, but even 3-5cms is better than what we've seen in the last 20 months.

I'm probably going to head to either Downs (depends on radar returns, etc) first thing with the dog as both are not that far away. I suspect they will do very well as is normally the case in these set-ups. Maybe North Downs just to reduce the marginality that maybe present further south which may impact the settling ratios a little on the South Downs. Maybe Blackdown Hill or somewhere like that which has solid altitude or go to Devils punchbowl which also has some decent altitude in parts.

Good news is the 12z ECM looks to have the best grip on the forward speed of the front as well at the moment. Most models are a good 2-3hrs too slow in the forward motion. Also note the N-S slant. This suggests to me any pivot is going to happen further east than some models expect at the moment which should allow more of the Midlands to enter the game as well. Just a little observation from someone in the SE for you guys up there. Its reduce marginatlity down here somewhat and gives you guys up there a better chance, so its win-win really.

So just looking at the radar, and its very early days but a couple of things I've noticed: 1: Front orientation more N-S than the models were predicting at this point, which may auger for a further east motion before it pivots, however many things can happen until then. 2: The front appears to be 2hrs ahead of most models schedule. Again on the grand scheme of things nothing too major, however the faster it comes in the more chance we have of benefiting from the colder half of the daytime for a larger area and in this set-up for those more southern locations, every little helps. Having lived near the Thames Estuary I can't tell you how big the difference between a 6-8am snowfall and a 11-1pm snowfall was for allowing snow to settle. 3: The models are just slightly pushing the snow boundary a touch further north on this suite. My location appears to be towards the southern end of the snow line at the moment, maybe draw a line from Petersfield E-W and anywhere south of that that doesn't have some height advantage may struggle looking at the models. With every bit of height you can pull that line a little further north.

The pivot appears around Surrey area from the looks of things, so yeah a shift SW compared to the other run. We are so close in now though that we are almost at radar/ground obs time. One thing that I do notice is the front appears to be a touch ahead of the timetable which is probably a good thing as the sooner it arrives the more chance of getting snow on the deck before daytime temperatures adjust upwards. Even a fractional increase probably tips some areas towards sleety snow for example and away from settling snow.

Yeah its probably going to pulse up and down as it shifts eastwards and as little lows form along the frontal boundary. Its a set-up that the models struggle with and they appear to have differing ideas as to just how strong the front is. The latest 12z ARPEGE basically totally collapses the front as it moves in and gives little snow to the region because it dries out. That is very much an outlier solution at the moment, but does show a possible worst case. Either way I wouldn't expect the front to be *that* active, perhaps 1hr of moderate snow with 1hr either side of lighter stuff that maybe maginal the further SE you go and the closer to the coast you are.

Those places will also have time on their side as well as the front comes through between 8-11am, whereas further north and east it comes through some time between 12-4pm. Which is about as bad a time as you can get as daytime heating will have lifted the temps ahead of the front a little bit, even by a small amount will tip the balance towards less snow.

Yeah I can see why the Met Office went with the wording it did, and the forecast it has on the website seems to show something similar for Kent in particular. The problem the further east you go ids the timings are not good there. It comes through at near peak daytime heating and in an already fairly marginal set-up that is enough to swing the balance from snow to rain. Thats probably why there is somewhat higher confidence in the weste of this region for snow because the timing is that bit earlier which should help the snow to fall. Going to be a wait and see type job. Sometimes these set-ups can surprise you if the front comes in stronger than expected for example and evap cooling overwhelms the marginality

I think alot depends on timing and things like that. I'd be reasonably confident west and south of London, places like Surrey, Berkshire, etc that there is going to be a 2-3hr snow spell. Things are increasingly uncertain further east and north you go, or by the coast. I suspect the Met office is cautious in its wording, especially as there is a little bit of uncertainty with just where the snow line ends up across. As i said above looking at the Met office output it does appear to be one of the most marginal out there comparing its output on the detailed forecast website (which I believe uses 3hrs UKV, though I'm certain?) to most of the models. Its in the top 10% of the most marginal, though I'm sure they are also using a suite of other models that may well be showing similar and different to the rest of the public models.

Interesting to look at the met office weather forecast that is on the site. Especially as they feed the 3hr model update into there (and for 6hrs range 1hr updates) Looks like the area of snow is more restricted than 90% of the models with my location E-W basically being the snow line. Go north of that and its snow, south and its sleet or even rain by the south coast. I can see why the Met Office have gone for a slightly more conservative wording for the SE on their latest update. Luckily it is one of the more 'milder' solutions I've seen over the last few hours of model watching, though its a perfectly valid thing to happen.

I think for the south coast height is going to be absolutely vital. If you are right by the coast then I think its going to be a struggle, but if your on the South Downs then your going to stand a chance. Still at least we now have near certainty that there will be a front coming through, and you need to be in it to win it as they say!

Yeah and you've not got the greatest height. My guess is it probably will snow but it may well be on the marginal side. I think much is going to depend on how strong the front actually comes in. If its a bit weak then your going to struggle. I'm going to see as I should be far enough north with enough altitude personally but if in doubt I'll head up to one of the local hills which have 2-300m elevation and almost certainly will have lying snow. Anyway in general looks like a snow event of some ind is pretty much nailed on how most of the SE, though obviously there are doubts about just how far NE the precip actually ends up in reality.

I do remember that that area got pretty low levels of snowfall, I think they ended up with maybe 1-2cms at most? Enough to tun the ground white but not much to get that excited by. I know down here in Essex we were white also but it was very modest indeed compared to vast parts of the country, I personally ended up with maybe 2-3cms I think here, and we were in a better location than some parts of EA where the bands pivot meant they got the dregs of the dying front when it came through, which you can actually see nicely on the map as it was clearing eastwards. I can't speak for the other events, December 2010 probably was centered too far south for them to get much. Feb 09 was a widespread streamer event so they may well have missed out there as well given wind direction may have set the streamers up to the north and south as they usually do. So they may well have got 3-5cms from 3 events, whilst Guildford for example probably ended up with 60-80cms from those 3 events. So to be fair can't blame them for feeling short changed!

Just worth noting that the 18z Euro4 has now also fallen in line with the rest of the models and shows the snow band across much of the south moving W-E. So very good agreement tonight, still time for it to shift BUT this time we are seeing it upgrade in terms of the location as we move closer, rather than downgrade. Snow amounts may well also be somewhat dependent on timing of the front, the models have shifted it back towards probably one of the worse times possible so any marginality may make things trickier in that regard.

It was definitely Tuesday 5th January 2010. I think my current location was literally the sweetspot back then, alas I was in Essex then and we had to make do with about 2-3cms. That event did have a few similarities in terms of evolution to what is coming up on Sunday, though the air was much colder back then. EVen just 36hrs before the event 2-5cms was the expectation. Sweetspot ended up with nearly 30cms!! Goes to show how things can shift about.

Probably Jan 2010. Was a very impressive event, I'm not sure what gave more snow as a max, that or the FEb 09 event. Either way the Feb 09-Dec 10 period was a pretty outstanding period for snow, and I'd guess could go toe to toe with any such period of the 80s, though obviously having not lived through that period, maybe others could better validate that idea!

Annoyingly I was at uni in Chichester when this event happened, I know my home got something close to a foot of snow. It was still surprisingly around in shaded places even 2 weeks later which really surprised me as the weather wasn't that cold after a few days. However we also got amazingly luck in Chichester as although the main streamer was to the north a little streamer also set-up along the south coast, i'm guessing probably the shape of the shore from brighton down to Bognor allowed some sort of lift through some frictional effect. Ended up with a quickfire 2 inches, which whilst nothing compared to back home, was alot more than I had expected and is actually a event I fondly remember for being one of the least expected snowfalls I've seen. Luckily December 10 delivered a strong event down there and I was in the sweetspot for it. Ended up with something around the 10 inch mark. The front came in far stronger and further west than expected. Indeed I'd say parts of SW Surrey was in the sweet spot for three successive winters. Big falls from the Feb 09 streamer, big fall from the Jan 10 (almost a foot in places) and then the event in early Dec 10.

I've been on and off this site for many years past 2011 depending on life situation, however I always find my way back to here! @Paul Sherman - yes South Ockendon, I do miss those days being so close to the Estuary as any decent streamer really did give a show , though any set-up that had an sort of southerly vector made things very marignal here due to the Thames. I remember multiple times here having sleety snow, whilst about 10 miles further north there'd be a decent covering. But that was the double edged sword of the Thames valley, great streams with lightning, but very marginal in other set-ups.

As for Sunday, think I will head upto the downs that are near where to I live. I'd imagine Butser may well get a decent amount settle providing the precip is far enough north. 200m+ should be enough to overcome any marginality there might be near the coast. Good news is the majority of high resolution models such as UKV and Arome are still showing snow event, its on,y the Euro4 that is too far south for pretty much all the region, but it was way too far south last time around in the end (having it basically in France when it clipped the south coast all the way to Sussex, though mainly as rain sadly away from high ground.).

On an ENE/E airflow you were pretty much upstream of my location back in the older days and we'd often share similar weather thanks to the Estuary. I in turn was an upstream person for Tom and Steve on certain airflows. I'm also a goldie oldie on this site, joined officially in early Feb 04 though I was a watcher for a week or two beforehand thanks to the snow of Jan 04.