Will this year be a white Christmas?

It's the time of the year when weather folk mutter darkly about Bing Crosby and his infernal White Christmas anthem raising the nation's hopes of a particular type of weather on one particular day of the year! Anytime from mid November, we are asked daily about the chances of a white Christmas - even though, statistically speaking, most of the UK are more likely to see snow at Easter than Christmas.

At the risk of Grinch-ing the snowman-building stereotype - the snowy scenes that we dream of are actually far away from what is officially classed as a white Christmas; that is, one (YES, ONE!) snowflake to be observed falling in the 24 hours of 25 December at an official weather station somewhere in the UK. We're talking one teeny tiny snowman...!

Credit: PA

Actually, our last white Christmas was more recent than you may realise. Last Christmas is on record of being a white one with falling (though not lying) snow reported at 10% of Met Office weather stations.

To really get the picture postcard scenes you have to go back to 2010 - which was our last widespread white Christmas - not only was there snow on the ground at 83% of stations (the highest amount ever recorded) but snow or sleet also fell at 19% of stations.

It's not just Bing's fault to be honest. We really do have fewer white Christmases that we did 200-300 years ago. Climate change plays a part of course, as does the change of calendar in 1752 which effectively brought Christmas day back by 12 days. Bah humbug!

So what about this year? It was all looking so promising just a few weeks ago when mornings would break on a hard frost and nights were cold enough to freeze the balls off brass monkeys. Not so in the last week or so as dominating high pressure has given fog rather than frost and cloud rather than crispy winter sunshine.

Credit: PA

Changes are afoot though - though not necessarily in a way that increases our chances of looking out onto Narnia on Christmas morning. Across North America, we have seen a marked temperature contrast over recent days, and this has helped generate a powerful jet stream currently emanating out of Canada.

This then becomes the breeding ground for potent areas of low pressure which track across the Atlantic and sweep wind and rain in across the UK - the first of those is expected to move in across northwestern parts of the UK throughout tomorrow with weather warnings in force for severe gales in the extreme northwest of Scotland on Wednesday.

So unsettled and changeable conditions in the run up to the big day - wet and windy at times but with perhaps a better chance of brightness that we've seen recently.

Some uncertainty remains around the track of an area of low pressure expected to move in on Friday - and the disturbed conditions look like continuing through Christmas weekend with the chance another vigorous low pressure system heading our way. It's definitely worth staying up to date with the latest forecasts.