It is a complex trade off between giving too many alerts, which many be inaccurate, and fewer alerts which are highly accurate - at the cost of sometimes not sending an alert. There are settings in the settings page to adjust how the app behaves, giving you considerable control over some of the key options.
There are a number of factors that affect the accuracy of the predictions.
The generally the app is accurate to within a few minutes, and if you notice any persistent inaccuracies please let us know!
- Distance from radar - if you are more than about 150 km from the nearest radar accuracy may drop off.
- Rain type - scattered or patchy rain can be hard to predict as it frequently changes and evolves.
- Local topography - mountains and valleys can provide a challenge.
- Radar noise or blind spots - these can give false readings
- Rain Speed - slower moving rain is actually harder to predict, the faster moving the storm the more likely it is to be accurate.