Weather: Adding precipitation rate
Issue:
In addition to the percent chance of rain, the rate of precipitation adds to the picture of the forecast. A 100% chance of 0.05cm of rain in the next day has different implications than a 30% chance of 1.00cm of rain in the next day.
Good Examples
Wunderground
A single chart conveys temperature, probability of precipitation and rate of precipitation.
Apple Weather
Probability of precipitation is shown for both hourly and daily graphics, rate is shown for the next significant accumulation.