Bring an umbrella. Absolutely no shade or rain cover on the upper levels. This station is ill conceived and not traveler friendly for many additional reasons.
Don't forget to ask for a transfer while boarding the bus. If you wait till you take off/ are already halfway there.. some drivers are always on their bad side and tell you it's too late.
Whoever said you cannot buy a metro day pass ($5) in the bus is wrong. You can do so long as you have a tap card so they can put value in it. They do not issue tickets.