Why the score relaxes when the noise stops
Pressure drivers decay exponentially, with a time constant of about seven hours, across a three-day window. In practice a burst of alerts on Tuesday morning pushes the score up hard, and by Wednesday almost all of that push has drained away on its own.
Nobody clears it. Nobody acknowledges anything to make a number go back down. This matters more than it sounds: a score that only ever climbs turns into a wall of red that people stop reading by the second week, and one that relaxes when the noise stops still means something in month six.