You'd probably still complain, and many people don't really understand percentage chance.
What does a 80% chance of rain mean to you? 80% of the region getting rain, it raining for 80% of the day, or it raining on 8 days out of 10 that they forecast an 80% chance of rain?
I can tell you that it is the latter, but I suspect that you had to read it twice to understand it. If you asked the readership of the Daily Mail this question, you would get most of them saying they don't know, and many of the rest just guessing one of the three.
And on the 2 out of 10 days that the chance says that it won't rain will still be wrong according to the media, even though the chances were correct. The media is fickle that way.
And if you remember your O Level or GCSC maths, you have to allow for short term anomalies . If you remember, when you toss a coin, over a larger number of tosses, you will get close to 50% heads and 50% tails, with some freak occurrences of it landing on it's edge. But that would not mean that you could not get 5 or even 10 heads in a row. It's unlikely, but it will happen sometimes. This is why it is never safe to bet on averages on a roulette wheel or any other game of chance.
The Met Office already do the analysis of predicted vs. actual weather. This is what they do to refine the model(s) to try to make them more accurate. But as I understand it, snow is particularly difficult to forecast, because very minor changes in the boundaries between the air layers can cause either rain, hail, sleet or snow.
The UK is caught between three major weather systems. You have the Arctic, that is cold air that attempts to push south, Europe that is fairly static, and at this time of year mostly cold, and the Atlantic which is very turbulent but quite wet and warm. As a result you have a three way battle, and I believe that it is one of the most difficult weather systems to predict in the world.
Precipitation is caused when warm moist air meets cold air in some way. The warm air moves up over the cold air, and as it gets higher and cooler, has to drop it's moisture. Depending on the temperature gradient, and the speed of air movement, and the turbulence at the air boundaries, the water droplets will coalesce and maybe freeze in different ways, leading to all of the possible outcomes.
Sometimes the forecast is easy, and sometimes it is not. Sometimes the warm air is kept south, leading to cold weather with no precipitation. Sometimes it just rolls straight off the Atlantic, leading to wet but warm weather spreading from west to east, and sometimes it diverts north, and then is carried back down south by the Arctic air, leading often to snow. And sometimes cold and warm air meet over the UK, and under these circumstances it is difficult to predict.
It is generally acknowledged that none of the current models give reliable results more than 10-14 days into the future. This means that the short term forecast will be based on modelling, and the seasonal forecast will be based on longer term cycles which can be identified by trend analysis of the of the past several years of actual weather rather than the air condition models. This makes a huge difference in the way that the forecasts should be used. You would not use the seasonal forecast to try to predict the weather for Christmas day, but you might use it to give an indication of what December in general may be like.
This is my schoolboy geography view of the weather, and no doubt somebody will pick holes in it. I do not claim to be a weather forecaster, but I believe what I've said is mostly correct.
I'm waiting for a maths or geography teacher to pull me up, so I've used the pedantic grammar alert icon!