From Seattle Times:

Because of another blast of ash from Alaska's Mount Redoubt, Seattle-based Alaska Airlines has suspended flights in and out of Anchorage until Wednesday morning. The ash poses a significant risk to air travel, an airline spokeswoman said tonight.

As a safety precaution, 18 flights tonight and early Wednesday morning have been canceled. The airlines says service will be re-evaluated Wednesday.

Travelers can check the status of flights in advance online at alaskaair.com, or by calling 800-252-7522.