Fog Disrupts Airports

[Ric.ror]

http://www.bbc.co.uk/news/uk-29218573

Why does this happen?
I would have thought radar would have compensated for any sight restrictions

[Sqad]

I am not an expert, but not all airports have radar controlled fog landing.

Menorca certainly doesn't and during foggy periods flights are delayed.

[Buenchico]

This has previously been answered by AB's resident airline pilot, Clanad, as being at least partly due to restrictions placed upon ground movements, rather than to those in the air. The control tower staff need to be able to see where aircraft (and the multitude of vehicles that operate around airports, such as passenger buses and fuel tankers) are positioned on the runways, taxiways and aprons, in order to avoid any possible conflicts.