Train services linking Leeds to London are subject to disruption if they're scheduled to travel to or from stations further north (e.g. Newcastle or Edinburgh). Other trains are unaffected:
http://www.nationalra...8d7d490d/details.html
I'm nearer to 60 than I am to 50 and, in all that time, I've never known central London to become completely snowbound. The volume of pedestrians and traffic usually keeps principal footpaths and roads reasonably clear of snow. Even if some buses are delayed (usually because they've experienced problems on parts of their journeys away from the city centre) they still seem to get through. Similarly, some Underground lines might have delays or cancellations on those parts of the lines which run above ground, but 'Zone 1' services always seem to keep going.
http://www.tfl.gov.uk...ime/tube/default.html
Chris