NW London does seem to do well with the snow I found that out even in previous winters when I was at uni in Herts, a small dumping in barnet, yet slush or rain back home in se ldn/nw kent!, think because your away from the thames warming influence and its more rural up there lucky people!!
Wish I could answer your question mate! I noticed its getting rather dark outside too, yet I thought the sun was supposed to be braking through?