Dante's Peak (1997)

Continuity mistake: When they are driving up the mountain to get to her kids, they cross a river and they get hit on the passenger side of the truck shattering the window, but later when they show them going up the mountain there is a new window there.

Harry Dalton: I've always been better at feeling out volcanoes than people and politics.

Trivia: The ‘volcanic ash' you see in this movie is actually finely shredded newspapers.

Question: I'm asking this because I don't really know a lot about volcanoes but, at the beginning of the movie, Harry was in the middle of a volcano eruption with: rain; rocks falling etc. When the volcano in Dante's Peak erupted, it was different from before, meaning that there was no rain (but ash), rivers strong enough to break a dam, burning water, dead wildlife etc. Even at the end of the movie, the volcano still had one more eruption before it finally died down. My question is, are all volcano eruptions not the same or are they just unpredictable when they explode? It just seems kind of odd that Harry was experiencing different things in nature after the volcano exploded. I hope I explained this enough; I'm just curious is all.