Thor Guard Lightning Prediction System, which sounds one 15 second blast of the horn signaling suspension of all activities. A strobe light will begin flashing and remain flashing until safe conditions return. ALL PLAYERS-PARENTS MUST LEAVE PARK AND TAKE SHELTER IN PARKING LOT. YOU MAY RESUME ACTIVITIES ONLY AFTER THREE (3) 5 SECOND BLASTS OF THE HORN ARE SOUNDED AND THE STROBE LIGHT STOPS FLASHING.