Airline Loganair became the first to cancel flights in Scotland as volcanic ash headed towards Britain.
According to the latest forecasts from the Met Office a thick cloud is likely to cover much of Scotland by tomorrow morning.
At its densest the cloud is likely to exceed the top threshold set by the aviation industry for aircraft safety.
Loganair has cancelled 36 flights on Tuesday and advised customers due to travel to contact them to rearrange flights. Only inter-island routes in Orkney are unaffected.
A statement from Loganair said: "We have taken the decision to cancel all services with the exception of our inter-isles flights in Orkney. All flights due to depart between 06:00 and 13:00 hrs tomorrow have therefore been cancelled.
"You should not travel to the airport and if you are booked on a flight departing tomorrow afternoon, you should check the website for further updates before setting out for the airport.
"We are operating additional services this evening (Monday 23 May) to assist passengers due to travel tomorrow to complete their journeys in advance of the expected flight disruption."
NATS, the air traffic control organisation, confirmed that it was anticipating disruption at three small airports: Barra, Benbecula and Tiree and said the cloud could begin to cause problems as early as 6pm on Monday.
With winds blowing from the west, the cloud is expected to drift towards the North Sea by the middle of the week.
The Civil Aviation Authority said further disruption was likely unless the cloud was dispersed by the weather.
"It depends how thick the cloud is and how big it is," said a spokesman for the Civil Aviation Authority.
"If it is so big that it makes it impossible to get in or out of an airport, then flights will be cancelled. But if we are talking about small thick pockets, then it should be possible to fly around them.
"It won't be until late tonight that we have a real idea what the impact will be and passengers should contact their airlines to keep up to date."
Scotlands major airports – Glasgow, Prestwick, Aberdeen, Inverness and Edinburgh – handle about 50,000 passengers a day.
However the unsettled weather predicted over the next few days makes forecasting the passage of further volcanic ash difficult.
South westerly winds would mean that Britain would escape further disruption, but if they continue to blow from the north west another cloud could drift across at least part of the country.
"We can’t rule out disruption," said Andrew Haines, the Civil Aviation Authority's chief executive.
"But the new arrangements that have been put in place since last year’s ash cloud mean the aviation sector is better prepared and will help to reduce any disruption in the event that volcanic ash affects UK airspace.”
Last year's eruption of the Eyjafjallajökull volcano crippled aviation throughout Europe, with an estimated 100,000 flights cancelled across Europe, hitting the travel plans of around 8 million passengers.
Professor Gillian Foulger, Department of Earth Sciences at Durham University, said: “This eruption is bigger and more spectacular than the Eyjafjallajökull eruption. Its gigantic initial volcanic plume (20 km high) suggests that it may exhaust itself and cease quicker than the Eyjafjallajökull eruption, but only time will tell."
The damage caused by the latest eruption of the Grímsvötn volcano, 250 miles from the Icelandic capital, Reykjavik, is not expected to wreak the same havoc.
Not only is the ash of a different consistency and less likely to cause damage to aircraft, but aviation rules have been changed to allow airlines to continue to fly if they believe it is safe to do so.
Most leading airlines are understood to have applied to the Civil Aviation for permission to fly through ash of moderate density, following discussions with engine and aircraft manufacturers.
A BA spokesman said: "At present all our flights are operating normally. We are keeping the situation under observation."
Thomson Airways confirmed it had also put a "safety case" to the CAA to enable its operations to continue.