When the warning indicators drop, measures can be dialed back down.

当预警级别降低，措施就可以被下调至原等级。

There was a deafening hissing and crackling, and the needle on the air pressure indicator dropped from 70 to 65 to 60 pounds in two seconds.

之后发出了震耳欲聋的嘶嘶声和噼啪声，气压计上的指针在两秒内从70降到65，降到60磅。