Even if 10cm or so of snow across a wide region is likely according to the models, it's still valid to make the argument that it might not materialise (in my opinion). You only have to look back 2 months to December, when an approaching low was forecast, right up to a few hours before i seem to remember, to bring up to 10cm of snow to fairly low levels across the Midlands (say 100-150m/~500ft). But in the end....nothing, or just a couple of cm over the highest hills.