I'm not suprised the models are showing quite a bit of snow.

The upper level temps are easily low enough for snow provided its caused by ana fronts in a stagnant environment.

The -6C or -7C benchmark that people use for 850hpas only applies if the wind is strong and the precipitation is convective. Snow can easily fall with uppers around -3C given the right sort of conditions.

The wind speed is just as important as temperature when it comes to forecasting snow. The lower, the better. High wind speeds require colder temperatures.

ICON6Z going for a spell of snow next weekend courtesy of an occluded front.

In fact actually, I'm going to say this now. The -6C benchmark sucks.

In convective situations -6C is actually too warm for snow usually. I'd say you need to be closer to -8C. And in frontal situations (except cold fronts), -3C is closer to the norm (but it can be as high as 0C).

-6C seems like a crude average that never actually applies in any normal situation (too high for convective snow, too low for frontal snow).

If we do get some snow which sticks around due to cold nights the -6C benchmark will become even less useful as the lower atmosphere is cooled and makes further snow more likely.

We actually had a snow event at the end of the 2010 cold spell that had uppers at +1C.

Oh this is very yummy indeed. Just need a correction South and East haha

Would they? Why? There hasn't been any nearby source of seriously cold air in other Decembers recently either.

Can't really grumble with this , my only nagging thing is we will no doubt look back at December and say " A great set up but we should have done so much better "

Well yes and no. Remember last winter was one of the warmest on record for Europe. December is looking like the UK could be one of the chillest parts of Europe.(relative to its mean)

I would say the cold is starting to be build, I certainly wouldn't say " astonishing warmth "

Right over Shropshire.

What is most encouraging about this is that there is relatively little sign of the coastal/Lancashire plain rain you often seem to see on these forecasts, I'm sure Saint Snow can relate to that! If this verifies (and it's a big if of course) then given my altitude it could be very interesting indeed, perhaps not even 'marginal'.

I would take issue with the use of "only applies" with regards to -6C or -7C and while it does happen  to say "easily" at -3C is pushing it a bit. 

Gfs continues to look great with regards blocking we just need it to get abit colder. 850s are still to high for my liking.  But the longer the blocking stays the colder it will get. The question is how long will it last?

Happy with this run 

Get the two HP's to link 

-3C is definitely a better threashold for an ana front (not cold front) in a low wind environment.

Its genuinely rare to get the -6C or -7C T850 when a warm front bumps into cold air anyway, and it isn't necessary in the cold, dry and low wind environment.

This kind of thing (obviously at this range we take nothing literally) would easily produce snowfall for Devon, South Wales and the south west generally outside of Cornwall and the immediate coast.

Arguably if its snow you are looking for these charts are fantastic for rolling the dice for at least one snow event pretty much anywhere. Compare that to a less unsettled northerly or easterly; yes the airmass is colder but outside of Scotland and the coasts you may well end up with nada.

Disagree with that , there will be plenty of times -6c is just right.  Most likely in westerly flows especially in Scotland where the pressure is generally lower and therefore 850hpa layer is lower.

In a westerly with the right combination of pressure and wind speed,  -6c will be right.

In November 2016 we had a covering of snow here from this chart, doesn't look remarkable -4c 850's ,  again low pressure so the 850 layer is lower and gentle westerly winds 

https://www.wetterzentrale.de/maps/archive/2016/cfsr/CFSR_1_2016111818_1.png

The first snow event is this:

I can pretty much guarantee (even at this range) some low lying areas will see wet snow out of this. What I can't guarantee is any particular part of the UK will see snow. But somewhere at sea level will. And a decent wet slushy covering (more than dusting) type amount too probably.

Yes it is Q is correct we have had this discussion before -3 is enough in certain situations especially with any s easterly element (dryer air)

Not to mention also any slack and evaporation elements involved 

Indeed. This is so underrated.

We are trained to think in terms of beaufort 6-8 winds coming off the North sea or North atlantic and definitely for that you do need T850 to be around -8C because you get little evap cooling and the sea warming the boundary layer.

But get air stangating for any length of time and you can easily be a few more degrees more generous. Add some dry air into the equation from an oncoming warm front and you easily get to -2C or -3C. Add snow cover and weeks of low level cold and you get to about 0C.

I don't know the figures but the Midlands snow storm in December 1990 produced a lot of snow which was on very wet ground (rain to snow event) from uppers that were not that low. 

To be honest pretty much any frontal snow event (not cold front) will have high uppers. I'd wager most snow we see in any given year (outside of Scotland and the coasts) falls in conditions where T850 is warmer than -6C. 

These charts are fantastic for early December in rolling the dice for the entire UK. They are less good if you want consistent cold or snow that sticks around for any length of time. But we can't seriously complain about that in the first week of December!