The NCAA has a very strict lightning policy in place for all sports and it was in action at the D2 CWS. Some games were still playing there as late as 2am due to the weather delays.
I believe the standard policy is play stops when lightning is detected within 6-7 mile radius, and play does not resume until 30 minutes have passed since the last detection in that radius.
The umpires are not the decision authorities, it usually falls to a specific NCAA official that is monitoring weather events.