Well, I am using this weather station: http://www.hillviewweather.co.uk/ so could explain why. Couldn't find one for Uxbridge so Harrow is the nearest, can't imagine there's too much difference!
Like I said, not sure of it's accuracy as I've never used the premium version before (Am I allowed to even talk about it on here?) but it shows Bedford (More to the South and West) turning into Snow. Fingers crossed for you!
Not sure how accurate RainToday Premium is but their radar shows huge blobs of snow over the Chilterns, MK, Luton and Bedford forming between 1630-1730. Also another blob of snow just South West of Guilford.
Latest forecast from the BBC has very little in the way of snow unfortunately, the further South and East you are the longer it'll last but looks to clear the region a lot earlier than predicted.
Further South East you are to the region the more you'll see, certainly think a lot of us will see something. Think NW London will see a good 30-45 minutes of snow before it clears away which is certainly better than nothing!
I work just down the road from Heathrow and I've already seen extremely angry passengers at the local Underground Station (Uxbridge) seeing that there flights have been delayed.