Unalaska, AK – About a dozen flights in and out of Dutch Harbor airport have been cancelled because of ash from the Okmok volcano, which started erupting on Saturday around noon. PenAir President Danny Seybert says they've scheduled seven flights for today, Wednesday, to make up for yesterday's cancellations. He said cancellation decisions depend on cloud cover as well as ash.

"If there's a heavy cloud cover and we have to fly through lots of clouds, we're more likely to cancel the flight because you can't see the ash when it's embedded in the clouds, he said."

Seybert said to call before going to the airport and if your flight is cancelled, make sure you rebook.

Flight cancellations are partially dependant on ash advisories from the National Weather Service in Anchorage. Senior forecaster Shaun Baines says the ash advisory is continued until today at midnight.

"We try and determine, based on reports from individuals on the ground in the vicinity of the volcano, whether ash is actually falling out and reaching the surface, he said. And as long as we continue getting reports that it is, even if its very light ash, we'll continue to issue the ash fall advisories."

He says the amount of ash falling in Unalaska is of very little concern, except for its potential affects on aviation.

Scientists at the Alaska Volcano Observatory say that based on past activity at Okmok, the eruption could continue for several more weeks. The seismic activity at the site has remained steady for the last 24 hours. It is lower than the initial seismic activity on Saturday.