I am on the EB 8, just left MSP on Monday morning. I boarded 8 in West Glacier on Sunday morning. Snow flurries were expected yesterday at the higher elevationss. I did a Red Bus Tour on Saturday and the weather was great, however, it had snowed last week and some snow remained at the peaks.
Every hiker that I talked to encounted snow or sleet in the past week.
I had not heard if they were predicting snow at the lower elevations (train tracks), but there is certainly snow at the higher elevations now.