I think the certainty of an imminent eruption of Mt St Helens was signaled by a 'growth' on the northwest slope for several days, measurements indicated it was growing about 5 feet every day.
Earthquake swarms are fairly common and not a reliable predictor. Underemployed journalists writing panic pieces shouldn't cause anybody to start nailing up 'for sale' signs.
I seem to remember that they thought the “growth” wasn’t really happening and that the devices doing the measuring were wrong. At least until they weren’t.
