I was pretty young when that mountain went up last time.
I seem to recall a bunch of tiny quakes happening just like mentioned.
All small 1 or 2 on the richter quakes with a few spiking to 5 or so.
Will have to look it up, but that mountain is unpredictable.
I was 9 at the time(telling my age) and I remember the "rumbling" started in January 1980 and built up to the May 18, 1980 eruption. There were some rumblings afterward for awhile.
The Mountains rumblings did start with Micro Quakes but also the mountain began bulging up to 2 feet a day.