Britain was hit by extreme weather on Sunday and it continues today, causing major problems in traffic. Transporting services are severely disrupted and it is expected to fall as much as 15 cm of snow. Many flights from the Nordics to Britain have been delayed or even cancelled and all bus fares are suspended in London.
If you are travelling to Britain or already are there, I recommend that you check with your airline regarding your flights. Also see http://www.tfl.gov.uk for London transporting information and http://www.bbc.co.uk/weather for the latest traffic updates.
Take care and good luck!