Backtrack

The Met Office medium range update is very encouraging for our region, looking at current modelling for Christmas/Boxing Day, there looks to be a NW'erly followed by even colder air flooding down from the North. This is encouraging. Snow falling whilst I tuck in to my Christmas dinner? Yeah go on, I'll take that. I love the Irish Sea sometimes

I kinda feel bad in a way when I ask you a question, you're so respected on here that EVERYONE hounds you for information We all do appreciate your input and someone with your knowledge on here though Ian!

White Christmas? White Boxing Day? NW buried under a blanket of snow? Watch this space.

There was a bit of everything on the 12z for everyone mate. Here's one for you from the Parallel:

The consistency is starting to form a solid trend now Steve. Fair play to you and your winter forecast so far. Everything is falling into place for a very merry Christmas for many now with many cold fans tantalizingly close to getting the only present they really wanted! Not many can argue with a chart like this to end the year: All eyes to the ECM later, this is a crucial one.

he's by far the most qualified poster here though! Nice guy too!

The latest Met Office blog highlights the risk of wintry showers in the North & East on Christmas Day. BUT - I found this very interesting: "It is important to note, however, that there’s still a chance we could see very different weather for Christmas Day. Here at the Met Office, we look at a range of computer model outcomes and a very small number of them do suggest a different picture, giving a forecast of stormy weather across the UK. Although this is currently at odds with the strongest signal from the forecast, we will closely monitor this and other possible solutions over the coming days to see if the likelihoods change" This would suggest to me, that the Met Office are actually following the ECM at this range, when the 00z generated these two charts, the first for Christmas Day, the latter for Boxing Day: Obviously the only thing at error there is the timing of the low on Boxing Day, with the Met Office stating the most likely timing would be one day earlier. I find this very interesting, obviously there are many other models which the Met Office do use, but it would seem to me that they're using the ECM? Perhaps Ian F could shed some light?

I don't think we can simply 'bin' any run just because it's not showing what we want it to show. All outputs should be taken into account, otherwise the mean output would be strictly biased.

The thing that strikes me most with the last few GFS runs, isn't the depth of the cold, a potential pattern change or a rapidly deepening North Sea low that could bring snow widely, as those things are all up in the air. What strikes me is the consistency at such a range, obviously in our world, 8 days isn't a lot of time at all, but for a model to CONSISTENTLY throw up a colder spell at such range, it makes for very interesting model watching. Not a great deal between the 06Z and the 00Z regarding upper atmospheric profiles: VS And then still, even at low-resolution, we get the same consistency (albeit with some more significant upstream changes regarding positioning, strength & energy; as one would expect) for Boxing Day and beyond, with WAA being throw into the mix, potentially leading to mid-Atlantic blocking. VS This is something, I for one, am not used to seeing. Usually beyond 7-8 days is a right mess, and whilst this is only the operational, one look at the ensemble graphs will give insight to just how much consistency there is right now between most members, and whilst outliers cannot be ruled out (as we know), I'd say the consistency is there now to have reasonably good confidence on a Northerly outbreak on, or around Christmas, with the likely scenario at this stage either later on during the day, or Boxing Day (unless you're in Northern Scotland). . The timing issue we see clearly when comparing other models, starting with the ECM which was first to pick up said cold signal, bringing a chilly Christmas day, a wet & wild Boxing Day, followed widespread cold & sub-zero temperatures on December 27th: Interesting times ahead, will it snow in time for Christmas? I'd bet on a colder spell, starting on any date from December 25th to the 28th. Will it last? That's where the fun begins.

Fantastic reply mate I'm hoping that, even if the current pattern holds out until Christmas, we can squeeze a North Westerly out of it before the change, very up and down at the minute as you know, mild, cold, mild, cold, and despite the very up and down wave of things at the minute, it's been a reasonably balanced month with the CET running just 0.2C below the average. Something has to give eventually, this being either the cold or the mild which wins out, after the warmest year on record, it only seems scientifically reasonable that we come to a stop eventually with a colder than average month, the charts at present not showing a month which is likely to come out below average (December). But as you say, I am hopeful of some kind of ridging developing in the Mid-Atlantic, holding to form a block. My favourite, and quite possibly most famous example of recent times being the below: It's only a matter of time before we get a repeat, right? One can't complain though at the current synoptics after last year's dismal performance. Promising times ahead!

Is that for the medium time-frame or the latter? For Christmas day they're great, a cold Christmas on the cards should either of those verify (which they won't). If it's the latter you're referring to, they're not so great, with the parallel at least, leading to a mild south westerly air flow by day 13. For a quick, short-lived half-hearted cold spell, I'll take it. For an actual cold spell, something that some of us haven't seen for almost two years, I would bin the GFS. The ECM COULD lead to something, but that's up in the air as of yet.

Yeah the colder uppers are being mixed out now by milder air so any showers that fall from now on will be rainy, away from higher ground.

My prayers may of been answered! Blue skies now, merging showers in about half an hour looking at the radar, lovely!

Would be great if these showers merged together some more, they're heavy in nature and contain hail & snow, but they don't last very long.

Proper hail & snow showers rattling through here! And it's not even cold!

It was indeed!

Heavy snow & hail shower just now, liverpool is being battered!

I've just seen my first flakes of the winter. Come to Liverpool for uni, walk to primark and it starts sleeting. Plenty of flakes in there, it's not as cold as runcorn here though

This region is the worst! I knew it wouldn't snow overnight, I'm not bothered about that. What's annoyed me is the fact that the colder air is now in place, the temperature is down to 2.8C, and it's raining now from a shower! Dew point too high, bloody joke. It'll snow in London before up here.

This point onwards is where it begins to get rather interesting. A lot of energy is currently being injected into the system to our south which is moving our way now, evaporative cooling should come into play, and hopefully colder air will be dragged into the system before it moves away, and slightly earlier than expected. A sickly 5.4C here though now, the milder air is certainly here, whereas Leeds is at just 1C.

Bang on 5.0C here

Looked legit to me Looked legit to me

Just popped into the South Eastern England thread, one member posted a picture of a dusting of snow this morning in the south east. Now considering we're in the north, and we haven't had a dusting yet, this has really annoyed me...

Just heavy rain here too, but this isn't the main event, that's later. My temperature is rising though, associated with the warmer uppers and mild sector. Up to 4.8C now and rising quickly. Should the temperature of continued to drop at the rate it was at 6pm, I would be excited. What's your dew point?

It's a pain but at the same time, the best snow events in the NW have always come from the Irish Sea Can't win!