I am sure there will be a few red faces in the near future in the UK aviation panorama for the decission made these days (or lack of). The press need to be made aware that the UK are using a different forecast to everyone else's this is why there are no flights in the UK. It has nothing to do with scientific measurements...
What would have happenned if 24 BA planes had landed at LHR without clearance??? Well you will never find out but if they had done it the restrictions would have been lifted much faster.