Why does WeatherPro for iPad often show higher rainfall than the iPhone app?

WeatherPro for iPhone and WeatherPro for iPad are not identical apps. Currently the forecast summaries on WeatherPro for iPhone are split into 12 hour periods (day: 6-18 and night: 18-6 UTC) whereas the summaries on iPad are for 24 hours (18-18 UTC). Total rainfall during a full day will be higher than the rainfall during the morning or the night hence the discrepancy between the iPhone and iPad summaries.