"Right now, current forecasts give you a general sense of what might happen over the next day - or two or three hours from now for a large region," said Mark Hohmann, the chief executive of Ourcast.
"We're trying to zoom in on that."
The app uses the information to model the movement of the weather systems to predict where storm clouds are gathering.
"In the US there are about 150 radar stations and they provide incredibly detailed information about what's happening with moisture in the atmosphere.
But one of the challenges with that is that radar isn't an exact indication of rain on the ground," Hohmann
"We take that radar information and correlate it with actual weather stations that are on the ground."
also encourages its users to contribute reports of weather in their particular location, which goes into the algorithm used to forecast the weather.
"That refines the model even further," Hohmann
, Dark Sky forecasts the weather every 10 minutes using data from the National Weather Center
It also displays precipitation data in a visual chart.
said it's difficult to say how accurate his
app is because different types of storms lend themselves to varying levels of accuracy.