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I hope you all had a good Christmas? I've returned to work this morning on our early shift and it's a busy - and complex - week of weather lying ahead.

TheÌýlast days of 2009Ìýhave the potential to yield some severe, newsworthy winter weather across a broad swathe of England and Wales, including the Westcountry... at least at times.

The first looming problems will brew to our southwest this evening, as a spell of rain - heavy at times - spreads northwards to encounter increasingly cold air.Ìý And as it does, the prospect of snow starts to appear tomorrow morning, albeit we're being purposely circumspect about the exact geography of where this transition from wet stuff to wintry stuff will take place.

It'll be a close call for much of our region. QuiteÌýliterally, a distance of 10 miles north or southÌýcould make an abrupt distinction between seeing heavy rain or disruptive snow.

The image reproduced here - based on Met Office modelling - offers a reasonable guide to those areas likely to see snowfall (the contours and numbers denote precipitation totals in mm - be it rain or snow). I've highlighted the most likely focus for snowÌýwith a red boundary, but please don't take it too literally!Ìý Even without any snow, the heavy rain won't be insignificant either: as this chart suggests, some hefty rainfall totals areÌýlikely, especially on higher ground across much of the SW Peninsula.

Effectively, the M4 corridor offers a rough forecast guideline: i.e., anywhere northwards from there stands a higher chance of seeing snow into tomorrow morning, with the situation developing to give further falls throughout the rest of Tuesday (especially later)Ìýand into Wednesday.

More so than any other of our districts, I'm expecting parts of Gloucestershire to be badly hit later tomorrow, with the Cotswolds, Forest of Dean and perhaps lower levels seeing varying amounts of disruptive snow.Ìý The higher ground of the county could see accumulations over 10cm (and perhaps as much as 15-20cm) and added to this mix is the wind, blowing snow around to cause drifting and doubtless some impassable roads.

Whether areas further south - i.e., much of Somerset and Wiltshire; Bristol and Bath - see any snowfall into tomorrow is much more open to doubt.

Most of lowland Somerset (i.e., excepting the top of Exmoor and Mendips)Ìýis forecastÌýto experienceÌýheavy rain, rather than snow; however, it becomes a more 50-50 situation further north into the likes of Bristol, Bath and S. Gloucestershire.

And as last week amply demonstrated, it doesn't take very much snow to cause real problems in and around Bristol...

By Thursday, snowfall could become far more extensive across southern-central England and so if you miss the white stuff in the next 24-48hrs (as most of our region probably will), there's a high chance of catching it later in the week.Ìý By New Year's Eve, we could - I stress, could -Ìýsee some severe snowstorms developingÌýinto southern and SE England.... but that's currently subject to great uncertainty.