Although Eyjafjallajokull continues to erupt, scientists looking at the density of the ash within the cloud believe it is transforming from an ash-producing volcano to a lava-producing one.
According to the experts, that is a positive development in terms of the potential to reopen air space more fully.
The Met Office says its latest data shows that the situation is variable and that a cloud of ash 600m deep remains floating above the UK.
Speaking from the foot of the volcano in Iceland, Sky News correspondent Robert Nisbet said: "(The Met Office) says the danger is still out there.
"They are relying on the people making these decisions to make the right ones based on the dispersal models that they have.
"The bottom line is more lava means less ash and that seems to be good news - but the situation could change at any time."
source: CNN
