Harve

Considering that I'll be spending a week of December this year at 2400m in France, temperatures 6c below average on the continent is certainly not something I'm wanting as that simply turns a very cold week into an extremely cold week. -19c anyone?

Does anybody quite like how in the GFS's 12z FI, it's Greenland being given a cold blast from the UK rather than the other way round?

Not bad considering there hasn't been a single notably chilly month, rather persistent coolness.

On the other hand, a mild spell won't need to be particularly mild for the CET to shoot right up. There's no sign of that being modelled, except for the occasional 1-2 day period, but it is very early days, and we 'can't trust FI'. So I'm wondering if my 3.2c is too low.

I have/had a similar problem with northern Derbyshire. Accent-wise it's very much in the north-west by the time you reach Buxton, climatically it's more Yorkshire / north-west, but in terms of administrative regions it's in the East Midlands. Regional TV from the North-West, East Midlands and West Midlands can all be accessed depending on which way your aerial is tuned, and apparently BBC Yorkshire can be accessed as well.

I think you know that's absolutely not true. If snow has fallen to low levels in late October and mid May before, albeit rarely, it can certainly happen in early December, it's just more likely that it will be a marginal event. Sure, if this weather system had been occurring in January or February, temperatures would perhaps be lower and the front would be less marginal, but that doesn't mean that it's too early for snow.

It would certainly be very nice for a cold December to get the 21st century average below the 1659-2011 average. edit: however, that would require a CET of 1.9c so it's reasonably unlikely!

Met office reports: Charterhall - Heavy snow Eskdalemuir - Heavy snow Spadeadam - Heavy snow Although I have just noticed that we're 40 minutes into December now, oops!

Looking at its location in Italy, well away from the Swiss/Austrian border, it's likely that it gets most of its snowfall from low pressure in the Mediterranean / southerly tracking lows rather than westerly winds and +NAO patterns, such as December 2011. These mostly benefit the northern/north-western Alps, and as such Italy tends to be rather dry for long stretches of time with only the occasional big dump. However, with GP suggesting a trough over Europe, this may be one of those occasions where Italy is one of the snowier parts of the Alps (winter 2008/2009, 2009/2010 and 2010/2011 are good examples, I think). Its altitude is certainly rather low as well, since it reaches just 2000m. So it's definitely not the place to go to bank on powder skiing, but since you're new to skiing, this really doesn't matter. As long as you're going between early January and late March there's almost definitely going to be some snow, even if it's man-made.

Bingley, West Yorkshire and Leek Thorncliffe, north Staffordshire Met Office stations are both reporting sleet at altitudes of 262m and 298m respectively.

Ignoring the substantially higher uppers, it's reasonably similar to the same date 2 years ago - a fairly benign looking chart that actually dumped 30-60cm of snow across East and South Yorkshire, northern Lincolnshire and Derbyshire in one night.

Some river levels in eastern Cornwall appear to have reached all-time highs. http://www.environment-agency.gov.uk/homeandleisure/floods/riverlevels/120543.aspx

I think this is very much altitude dependent, but it's not as if it's reserved simply for the 'highest peaks' (a phase seriously overused on this site, suggesting there's nothing between the highest peaks and the user's low-altitude location). http://www.snow-forecast.com/maps/dynamic/uk This site uses the GFS and is potentially a better indicator of likely snowfall. It seems as though County Offaly and County Laois in central Ireland are more at risk from a surprise snowfall. ...and there we have it again.

Sounds like your average November/December day in western Scotland.

I'll guess 3.2c. Possibly similar to December 2009, but starting off rather cool rather than above average. If mild becomes more plausible then I won't hesitate to raise my guess.

God, I really do miss living in Derbyshire.

Yes, I'm not quite sure what's going there. It could be the shallow low near Nova Scotia rapidly deepening and the low south of Greenland rapidly filling. It seems equally implausible that a deep low moves westwards and deepens further.

How far above average is this?! You're in the wetter south-west, but I would have thought this would be one of the drier parts and surely have an average annual rainfall of 700-1000mm or so? Is this an exceptional year or is your area far wetter than I thought?

Yup, it's a very sorry fact that getting -28c uppers across the entirety of the British-side of the Arctic (the area shown by the map) is nigh on impossible these days, nevermind by December 1st, even in the most zonal of winters with the strongest of PVs.

Did you notice later on, -10c 850hPa temperatures reach Scotland and Northern England in a slack flow? This could deliver wintry showers to eastern England and rather low minimas further north. I estimate that the UK spends 10 days with average hPa temperatures of -5/6/7c across the bulk of the country.

This is exactly what happens in the 0z run. Pressure falls over Scandinavia and northerly winds bring cold air to central/northern Europe. In the semi-reliable timeframe, the key difference I note is that the low east of Newfoundland isn't as strong (although it does strengthen) and warm air is pumped towards Iceland rather than western Greenland. The vortex is far less distorted, but due to the cool high, Britain ends up just as cool as in other runs, with mainland Europe much chillier.

Wow, I knew nature's calender runs later in the south-west, but I didn't know it was so much later. I can't remember when leaf fall began, but its end seems like a distant memory - late October perhaps?

The GFS has always had a bias towards shifting things east too rapidly/too much? So it basically shows things to always be more zonal than what actually occurs? Right.

The 12z is very similar to the 6z, especially in the high-res part of the run. There is simply no rebuilding of heights over Greenland into deep FI and the Scandinavian high is pushed away to the east at the very end. Given this happens very late, there's no 'lack of consistency' and it's not that it 'doesn't have a clue'.

Of course, I wasn't saying if they were a good or bad thing. It would perhaps be more useful if they were slightly further north, but it's better than a cold anomaly I suppose. By the way, isn't it just that they can assure pressure is high- helping the Atlantic be blocked, rather than directly contributing towards SSW's?