Grouse Grind and BCMC loop on a rainy day?

Hi folks,

TL;DR What conditions should I expect on the Grouse Grind (up) BCMC loop (down) tomorrow? Any tips for preparing properly?

This is going to be another rainy day hiking query post. I do a fair amount of hiking, but mostly in summer/early fall. But I have been thinking of going out of my comfort zone a bit and doing a hike in a bit of not-so-ideal weather. I usually go out for runs even if it is raining, but haven't hiked in the rain before. So, I thought I should start with one we all are the most familiar with.

I am just wondering how should I expect the conditions to be tomorrow (Sat, Oct 11) early in the morning on the trail? Would trail runners be enough with the muddy conditions, or should I wear high top boots? I see a lot of folks recommend carrying a change of clothes - I will probably carry it as well. Woods and roots are probably going to be slippery. Any other safety tips/recommendations?

Thanks