I've actually climbed up mt. st. helens. It's a good hike, and even in July, there was enough snow to ski down about 4,000 feet, and maybe more. I didn't ski down it, becuase I was only 10 years old, and I hadn't even started skiing yet. You could defineatly ski down it. It might be hard to get a hiking permit to go up there though.
I doubt rain has much to do with the earthquakes. Do you think that in 20+ there hasn't been more/as much rain in that area that would 'make' the earthquakes. I haven't heard anything about previous actvity after the eruption, except building of the lava dome.
The lava dome is probobly building up, it;s onlt 600 feet tall, and tese volcanoes are composite, or stratovolanoes, where they build tehm selves up with lava and/or ash and then blow themselves up, then build up again.
They also said mt. baker was going to erupt in the 70's, but nothing happened. You really can't predict much about these volcanoes.