Seeing as its Forecast time, I thought I'd quickly pop my'n in just for fun :-)
December : Likely to start off mild, the jet stream stradding across the middle of the UK as an average position , and quite strong, with strengthy winds blowing in off the atlantic, from a series of potent LP systems feeding in and centered over NW Scotland, as the LP systems move off East, they drag in colder air, and this brings some further snow fall to the Scottish Hills and Mountains, with a wintery mix to the tops of the hills on the North of the UK, heavy rain for a time elsewhere.
A windy picture to start Dec for the vast majority of the UK, milder in the SE, about average temperatures for the Midlands, Wales, and the SW, always colder the further North one goes.
A damp and overcast start for the majority, not many exceptions to this rule, bar perhps the East Coastal fringes of the UK.
HP begins to build to the South of the UK taking up residence across the South and West , feeding in with it a more settled theme to all bar the extreme north of Scotland as we enter mid month, winds fall light, and there's plenty of brighness to be had.
Hard frosts overnight UK wide, as the winds ease.
Sotland still effected by more unstelled weather to the North, where from time to time, the feed is coming from immediate North, keeping temperatures here cool, more snow on the mountains, and a wintery mix to low levels of Sc otland, from the border south it will feel cold during the day, and especially by night, some fog and mist around early morning.
As we enter the start of the festive season I see Omega blocking becoming more persistent with HP having drifted off more to the West of the UK, allowing an ever increasing NE 'sterly feed to start effecting the NE of the Country, winds pick up, and in the extreme NE of Scotland and England temperatures drop like a stone with an increasing wind chilll factor being felt.
Plenty of lengthy spells of snow here, with some large accumulations.
Wetsern areas more under the influence of HP, so here a significantly brighter period, still cold, but dry, wind gentle winds, the border line between to two systems will see some snow, and a mixture of ''wintery precipitation".
To the south of the UK, condisions will be about average on both temperature, sunshine amounts, and drier to start with, perhaps falling more and more under the influence of LP as it drifts down from the NE.
X-Mas and into the new year.
This is where I can see a large scale change taking place, as LP moves West to be centered for a time over the UK, before HP exters itself more and it slips off East and South, in January, before this hapens the East of the UK, and the SE, have a chance of seeing some decent snow fall, and the weather direction is now more from the NE than from the West, or South.
I don't believe the feed from the East will ever make it's way as far West as Ireland, and for a time a good old battleground set up might be in effect in this area as we head into 2012, effecting the SW of the country for a time, with some snow here and in Wales on the very tops of the hills , sleety mix elsewhere.
For scotland I can see both a white x-mas and a white new years here, directly from the effects of the NE sterly.
Jan 2012 : - I think that the first few days will see some cold conditions UK wide, some laying snow still around in the SE, SC England, Eastern Parts of Wales, and N.Ireland, NE England, and Scotland.
LP gives way to HP from the West sinking southwards, and allowing the Altantic to come in.
Temperatures nationwide lift as a result, but with it comes the threat of string winds, and rain.
A gloomy month to start with for most, and a thaw of any lying snow.
Mid January I believe HP to be sitting to the South of the UK, allowing the feed to be coming more from a NW terly, mild to the South, and South West, slightly cooler to the East, but coldder in the North West, and Scotland.
Still quite windy, especialy in Scotland with some heavy rain here, falling as snow over the scottish mountains where blizzard conditions will be felt.
January ends with temperatures about everage for much of the country, however I believe HP once again finds it's way to our West, and centered closer to Iceland this time, and as we come into Feb, i blieve winter will really start to be felt.
A bitterly easterly driven front will push right across the UK brigning with it, cold daytime and exceptionally cold night time temperatures, winds a little strong , and lots of snow falling out of the sky, effecting the whole country.
HP slow to move from the NW of the UK, allowing the LP system to dump a lot of moisture over the UK, before finally sinking off south and east, or fizzling out alltogether.
I think FEB 2012 will make headlines, and will be a month to remember.
So Overal I think Dec will be cold(ish), nothing like last winter, and a lot dryer for the majortiy.
Jan will be a pretty unsettled moth with no real dominant pattern
Feb will be COLD and snowy :)
There that's my half hearted attempt...take it or leave it, but at least I had a go
Jay