People tend to check in during these times:
Railfans, if present, usually hang around the large garden/planter on east side of building. They usually have one of the following... A radio frequency scanner, a camera, and/or children.
Great spot for railfanning!
STL250 cake located on north side of station
Wait for a day when the weather is nice and take time to smell the flowers!
Beware of a tall man named Dan who is a known loiterer in this location. If he starts to peddle his Hope & Change nonsense to you, run!