NATS have updated their advisory, and it seems to be clear skies for all UK airports from 19:00 to at least 01:00 BST 18/05/10.
Clear skies and open airports – for now..
NATS Update:
According to the latest information from the CAA and the Met Office the volcanic ash cloud clears the UK for the period 1900 (local time) until 0100 tomorrow (Tuesday) and all airports in Northern Ireland, Scotland, England and Wales will be available during this period.
There may be some restrictions to helicopter operations in the North Sea where a no-fly zone is still in force during this period.
We will update this information further as necessary.