Think its as good a time as any to start this one rolling. A rather dramatic feature will move south through wednesday. Most of the precipatation at this stage looks like rain, however it will be an especially marginal situation. Evaporational cooling will really come into play here, and I think there will be some spots that see quite a bit of 'suprise snow', although at this stage I think its more speculation, where they would be.

A few tools that will be invaluable in coming days:

The high res NASA GEOS model, useful for short range forecasting out to 120: http://www.meteociel.fr/modeles/geose_cartes.php

The NAE model, invaluable for precice forecasting for a short period:

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=nae&MODELLTYP=1&VAR=modtemps&HH=66&BASE=-&WMO=u3005&ZOOM=0

The GFS skew T: Generalised version of the 850s/dew points e.c.t only limited by the accuracy of the GFS itself.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=modtemps&MODELLTYP=4&VAR=pslv&HH=48&BASE=-&WMO=u3005&ZOOM=0

Finally partial thicknesses, for a happy balance between 850s and skew charts:

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gfs&MODELLTYP=1&BASE=-&VAR=th85&HH=48&ARCHIV=0&ZOOM=0&PERIOD=&WMO=u3005

Wasn't the NAE model poor this summer when forecasting ppn?

I think snow is quite likely across much of the country this week ......

....... but it'll have turned to rain long before it reaches the ground in most places

Agreed. 

I think the peak for widespread wintry potential was back on Friday morning when the models were progging more of a shallow low feature in generally unmodified polar air. Since then the low pressure disturbance on Wednesday is now progged to be more of a developed low pressure system with a warm sector and a fairly strong SW'ly vector ahead of it and a strong NNW'ly behind it. Not conducive to lowland snow with unfavorable uppers and marginal wet bulbs at best

Northern areas, especially with altitude are still at risk and I suppose there is still the chance of some wintry showers over the higher ground of SE Britain on Thursday/Friday if the uppers become slighly more favorable. 

Sleet potential probably...

Met Office issued Warrnings for Ice..North West on Monday.. Western side for Tuesday  ...But NOT South West..

Met Office issued Warrnings for Ice..North West on Monday.. Western side for Tuesday  ...But NOT South West..

Originally Posted by: doctormog 

Not to mention up to 10cm of snow in parts of N Scotland (although probably not here!)

Originally Posted by: ARTzeman 

Yes, the north of Scotland looks like getting a pasting.  Fair to call that seasonal ooop there though

Met Office issued Warrnings for Ice..North West on Monday.. Western side for Tuesday  ...But NOT South West..

Originally Posted by: doctormog 

Not to mention up to 10cm of snow in parts of N Scotland (although probably not here!)

Originally Posted by: ARTzeman 

Looking alright for the ski resorts Doc. Possibly a good dumping.

http://expert-images.weatheronline.co.uk/daten/proficharts/en/2013/11/17/basis12/ukuk/rart/13112006_2_1712.gif

The skewT diagrams suggest very cold air in the south as we move towards wednesday. If that low pressure area, has a warm sector, that means it also has a warm front. And we know ana warm fronts are notourious for bringing snow at very generous uppers. Think the midlands and even the SE of england is at risk of seeing some wet snow for a time, before it turns to rain. Also, if the navgem is to be believed, there could be something a little more interesting on the back of that low as it stalls in the SW of the country. Rain for most, but I don't think exclusivly even on low ground.  

The very end of the BBC forecast seemed to suggest rain turning to snow then back to rain. Was hard to tell as the animation was very quickly shown in the last few seconds. Potential for a good fall of temporary snow for some?

Before that Tuesday morning could be interesting for some. Experience says my area could very well wake up with snow on the grass and cars with an inch or two above 300 metres. Buxton could be the place to be for snow on Tuesday.

Met Office issued Warrnings for Ice..North West on Monday.. Western side for Tuesday  ...But NOT South West..

Originally Posted by: Essan 

Not to mention up to 10cm of snow in parts of N Scotland (although probably not here!)

Originally Posted by: Medlock Vale Weather 

Looking alright for the ski resorts Doc. Possibly a good dumping.

Originally Posted by: doctormog 

They need it after the past few days!  

Originally Posted by: ARTzeman 

Hardly surprising in November though Andy

(The best seasons for the centres IME tend to be the ones that start just before or around Christmas). ANyway it'll be nice to (hopefully) see something wintry at lower altitudes in the coming week even if it doesn't amount to much

In the short term substantial snow will be limited to upland Northern UK over the next few days, in the form of showers on Tuesday and ppn from the organised system on Wednesday.
The low moving dowm from the Iceland region has origins in maritime modified polar air and with a defined warm sector with the triple point moving down the east coast I believe snow will be confined to leading edge in upland Scotland and North England and then perhaps exiting edge in same areas.
The parameters just don't look conducive enough for anything more than cold rain elsewhere and the most significant feature could well be the strong to gale winds associated with this low.

Later in the week a NE flow across the south may bring a few sleety episodes but as it stands uppers are not deep enough as yet to provide anything more than that.
All subject to change and if ECM is to be believed there may be something more in the pipeline longer term (and it has been quite persistant on this lately).

There is a fair chance of snow overnight Weds into Thursday as trough comes down in the cold air in the wake of the depression.  Up to 5cms on hills  in a broad band from Bath to Norwich.

See fax: http://www.meteociel.fr/modeles/ukmo2.php?ech=60&carte=2000

No doubt most people are more interested in looking 240 hours ahead and are missing the potential snow event 60 hours away

 Nice one.

Good for those in Bath or Norwich, but not so good for me, hence I am not interested at all.