Article: Supervolcano Ready To Explode? Mount St. Helens Reawakens, Continues To Rebuild Itself
It is not a "supervolcano," it is a normal, run-of-the-mill volcano. Yellowstone is a supervolcano.
On the hand, it is a live volcano. It has a magma chamber that is filling up. It is building a cone in the caldera of the old volcano.
In the short run, volcanoes are unpredictable. In the longer run, and speaking generally, they are more predictable. Mount St. Helens has had periods of dormancy and eruption. Of full and catastrophic eruption and what we are seeing right now.
It will continue to build a cone for awhile and there may be a major eruption as well. We will know it is coming, but the exact time will be unknowable.