I dont think that the UK is covered in ash !
Central London certainly is not ! the weather is sunny with light cloud or haze at high level, this might be the ash cloud or it might be natural.

No non-emergency air flights are allowed due to the risks of engine failure caused by volcanic ash/dust.
Helicopters can still fly, at relatively low level, one was used earlier today for a medical emergency.
I would expect that small fixed wing airplanes could still fly at low level, though this is prohibited.

Most unforunate for those wishing to fly, but I doubt that we will see much effect on life otherwise.
I saw hundreds of potential passengers queing at the Eurostar terminal a few hours ago.

If this carries on for long, I can forsee shortages of luxury or out of season foodstuffs as these are flown in.
I would not expect any effect on supplies of basic foods as these are either produced in the UK or imported by sea.


Although not truly an emergency, this situation must be extremly inconvienient for those wishing to fly and being held up for a day or or two.
Shows the importance of being prepared not just for major disasters, but for this sort of thing.
I wonder how many of those delayed are equiped with a change of clothes, ready cash, and a credit card , and phone numbers of friends and relatives, and coins for payphones.
I could not obtain cellphone service earlier today near St. Pancras, it normally works fine, and I suspect that the network was overloaded by the huge numbers trying to make alternative travel arrangements.