Applying a flash-to-bang principle, the 30/30 rule suggests that when you see the first flash of lightning, if the accompanying thunderclap is heard at or before 30 seconds then the storm is close enough to pose a risk.

根据闪电爆炸原理，30/30法则表明，当你看到第一道闪电时，如果在30秒或之前听到伴随的雷声，那么暴风雨就足够近，足以构成危险。