Last time, ReDoubt erupted for a period of five months. The mushroom-shaped plume from the pyroclastic flows shot ash 30,000 - 50,000 feet into the jet stream...over nine miles high. It coated Anchorage with a layer of ash - over 100 miles away. The ash also flamed out the engines of a KLM jet 150 miles away.
Scientists at the Alaska Volcano Observatory say they are expecting a repeat performance.
Let's just hope they're wrong, and that things just fizzle.
(photos courtesy of the Alaska Volcano Observatory)