The Rockford Aviators (formerly River Hawks) played in the Frontier League through the 2015 season, after which the team left the league. Here is a video from the team’s 2014 open tryout camp, and it shows a tryout in less-than-perfect weather:
This is good to know so that you can prepare ahead of time and train in bad weather. Since you may only get one chance to audition for a pro team then you want to be ready to have a terrific workout in front of a team’s coaching staff members regardless of the conditions.
Become aware of upcoming tryouts by joining the notification service here: Independent Minor League Pro Baseball Tryouts
If you need some help increasing your 60 yard dash speed times, arm velocity, vertical leap ability, hitting power or improve your muscle mass for any professional baseball tryout (or private workout) then here are some resources to help you: Resources for improving your chances at any pro baseball tryouts