Our main algorithm is based on real-time calculations of radar images of selected country and runs on our servers. That give us ability to predict direction and speed of surrounding precipitation for a proximately 2 hours ahead.
https://play.google.com/store/apps/details?id=org.me.weatheralarm
I would really need a feedback of users from USA, to see how accurate it is on that area.
Thank you in advance for all of your comments.