Related: Weather apps could in general be better, not just in terms of visualization. One thing which always annoys me is how they handle rain predictions. They give "probabilities" for rain. But what do those mean? The probability that it rains for at least one minute in the given time frame? And with at least x mm/inches of rain coming down? And isn't a low probability of short and weak rain totally different from a equally low probability of strong or long rain?
But there is a perfectly elegant alternative: Just use the expected amount of rainfall. The epected value combines both amount and probability of rainfall in one single number, without being highly arbitrary like other approaches, such as the usual reporting of plain "probabilities" with unclear interpretation.
(Of course one could add to the expected rainfall amount also the variance, to distinguish more certain predictions from more uncertain ones, though this information might often not even be that important.)
But there is a perfectly elegant alternative: Just use the expected amount of rainfall. The epected value combines both amount and probability of rainfall in one single number, without being highly arbitrary like other approaches, such as the usual reporting of plain "probabilities" with unclear interpretation.
(Of course one could add to the expected rainfall amount also the variance, to distinguish more certain predictions from more uncertain ones, though this information might often not even be that important.)