Operation: Reality Check - Storm Surge Markings "Operation: Reality Check" helps Duval County residents who live in a storm surge zone know their evacuation status and encourages them to have a personal and family disaster plan. The map below shows where markings have been placed showing the maximum height of storm surge at each hurricane category level.  Storm surge is the abnormal rise in water level caused by wind and pressure forces of a hurricane or tropical storm.  Levels represented here are the "maximum of maximums."